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65e3dfe8e9ebbb4db9c7ee6b | 10.26434/chemrxiv-2024-67sfl | Encapsulation of Crystalline and Amorphous Sb2S3 within Carbon and Boron Nitride Nanotubes | The recent rediscovery of 1D and quasi-1D (q-1D) van der Waals (vdW) crystals has laid foundation to the realization of emergent electronic, optical, and quantum-confined physical phenomena in both bulk and at the nanoscale. Of these, the highly anisotropic q-1D vdW crystal structure and the visible-light optical/optoelectronic properties of antimony trisulfide (Sb2S3) have led to its widespread consideration as a promising building block for photovoltaic and non-volatile phase change devices. However, while these applications will greatly benefit from well-defined and sub-nanometer-thick q-1D structures, little has been known about feasible synthetic routes that can access single covalent chains of Sb2S3. In this work, we explore how encapsulation in single or multi-walled carbon nanotubes (SWCNTs or MWCNTs) and visible-range transparent boron nitride nanotubes (BNNTs) influences the growth and phase of Sb2S3 nanostructures. We demonstrate that nanotubes with smaller diameters had a more pronounced effect in the crystallographic growth direction and orientation of Sb2S3 nanostructures, promoting the crystallization of the guest structures along the long-axis [010]-direction. As such, we were able to reliably access well-ordered few- to single covalent chains of Sb2S3 when synthesized within defect-free SWCNTs with sub-2 nm inner diameters. Intriguingly, we found that the degree of crystalline order of Sb2S3 nanostructures was strongly influenced by the presence of defects and discontinuities along the Sb2S3-nanotube interface. We show that amorphous nanowire domains of Sb2S3 form around defect sites in larger, multi-walled nanotubes that manifest inner wall defects and discontinuities, suggesting a means to manipulate the crystallization dynamics of confined sub-10 nm-thick Sb2S3 nanostructures within nanotubes. Lastly, we show that ultrathin, predominantly amorphous, Sb2S3 encapsulated within BNNTs can impart functionality onto the host nanotube, showing a ~30-fold increase in electrical conductivity and displayed photocurrent generation compared to empty BNNTs in pressed pellets. Altogether, our results serve to solidify the understanding of how q-1D vdW pnictogen chalcogenides crystallize within confined synthetic platforms and are a step towards realizing functional materials from ensembles of encapsulated heterostructures. | Griffin Milligan; Dmitri Leo Mesoza Cordova; Ze-Fan Yao; Brian Zhi; Lyndsey Scammell; Toshihiro Aoki; Maxx Arguilla | Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-03-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65e3dfe8e9ebbb4db9c7ee6b/original/encapsulation-of-crystalline-and-amorphous-sb2s3-within-carbon-and-boron-nitride-nanotubes.pdf |
633c95752984c95bb977ea03 | 10.26434/chemrxiv-2022-88xzv | The Single Component Flavin Reductase/Flavin Dependent Halogenase AetF is a Versatile Catalyst for Selective Bromination and Iodination of Arenes and Olefins | Flavin-dependent halogenases (FDHs) natively catalyze selective halogenation of electron rich aromatic and enolate groups. Nearly all FDHs reported to date require a separate flavin reductase to supply the FADH2¬ required by these enzymes. This requirement complicates biocatalysis applications since flavin reductases are not widely available, they add to the protein waste that must be removed during product isolation, and they can lead to undesired background reactions. In this study, we establish that the single component flavin reductase/flavin dependent halogenase AetF catalyzes halogenation of a diverse set of substrates. High site selectivity was observed in many cases, and activity on relatively unactivated substrates and heterocyclic substrates was demonstrated. High enantioselectivity was observed for atroposelective halogenation and halocyclization reactions. Site-selective iodination and enantioselective cycloiodoetherification was also possible using AetF. The substrate and reaction scope of AetF, along with the fact that this enzyme requires only a commercially available glucose dehydrogenase to drive its halogenase activity, suggest that it has the potential to greatly improve the utility of biocatalytic halogenation. | Yuhua Jiang; Harrison M. Snodgrass; Yasmine S. Zubi; Caitlin V. Roof; Yanfei Guan; Dibyendu Mondal; Nicholas H. Honeycutt; Johnny W. Lee; Russell D. Lewis; Carlos Martinez; Jared C. Lewis | Biological and Medicinal Chemistry; Organic Chemistry; Catalysis; Organic Synthesis and Reactions; Bioinformatics and Computational Biology; Biocatalysis | CC BY NC ND 4.0 | CHEMRXIV | 2022-10-05 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/633c95752984c95bb977ea03/original/the-single-component-flavin-reductase-flavin-dependent-halogenase-aet-f-is-a-versatile-catalyst-for-selective-bromination-and-iodination-of-arenes-and-olefins.pdf |
651bff438bab5d20558ad4cf | 10.26434/chemrxiv-2023-rb79v-v3 | Molecular simulation approaches to study crystal nucleation from solutions: theoretical considerations and computational challenges | Nucleation is the initial step towards the formation of crystalline materials from solutions. Various factors, such as environmental conditions, composition, and external fields, can influence its outcomes and rates. Indeed, controlling this rate-determining step towards phase separation can affect the resulting material structure and properties, which are crucial for a range of scientific fields. Atomistic simulations can be exploited to gain insight into nucleation mechanisms - an aspect difficult to ascertain in experiments - and estimate nucleation rates. However, the microscopic nature of simulations affects the phase behaviour of nucleating solutions when compared to macroscale counterparts. An additional challenge is the inadequate timescales accessible to standard molecular simulations to simulate nucleation directly; this is due to the inherent rareness of nucleation events, which may be apparent in silico at even high supersaturations. In recent decades, molecular simulation methods have emerged to circumvent length- and timescale limitations. However, it is not obvious which simulation method is most suitable to study crystal nucleation from solution. This review surveys the recent advances in this field, shedding light on typical nucleation mechanisms and the appropriateness of various simulation techniques for their study. Herein, we aim to provide a deeper understanding of the complexities associated with modelling crystal nucleation from solution and identify areas for further research. Our review targets researchers across various scientific domains, including materials science, chemistry, physics and engineering, and will hopefully foster a collaborative effort to develop new strategies to comprehend and control nucleation. | Aaron Finney; Matteo Salvalaglio | Theoretical and Computational Chemistry; Physical Chemistry; Computational Chemistry and Modeling; Self-Assembly; Statistical Mechanics; Materials Chemistry | CC BY 4.0 | CHEMRXIV | 2023-10-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/651bff438bab5d20558ad4cf/original/molecular-simulation-approaches-to-study-crystal-nucleation-from-solutions-theoretical-considerations-and-computational-challenges.pdf |
6780086f81d2151a0279726b | 10.26434/chemrxiv-2025-lt941 | Disconnected Lithium Metal Damages Solid-State Electrolytes | Solid-state batteries with a lithium-metal anode are energy-storage devices that promise increased energy density and improved safety compared to liquid systems. Despite significant developments, the chemomechanical degradation of solid-state batteries represents a significant challenge to their widespread adoption. Specifically, Li-filled cracks (called 'dendrites') and electronically isolated Li inclusions ('dead' Li) are key defects resulting from coupled electrochemical-mechanical degradation during cycling. In this study, we use a symmetrical Li|LLZO|Li cell with a single-crystal electrolyte and demonstrate that an electronically isolated Li-metal inclusion exhibits bipolarity under an external electrical field, which leads to further crack expansion. We suggest that this process of 'dead' metal activation accelerates chemomechanical degradation in solid-state batteries with alkali anodes. | Diana Avadanii; Steffen Ganschow; Markus Stypa; Sonja Müller; Sabrina Lang; Dominik Kramer; Christoph Kirchlechner; Reiner Mönig | Materials Science; Energy; Ceramics; Energy Storage | CC BY NC ND 4.0 | CHEMRXIV | 2025-01-13 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6780086f81d2151a0279726b/original/disconnected-lithium-metal-damages-solid-state-electrolytes.pdf |
60c748e5bb8c1a98183dad55 | 10.26434/chemrxiv.11673711.v3 | Small Molecule-Inducible RNA-Targeting Systems for Temporal Control of RNA Regulation | <div>All aspects of mRNA lifetime and function, including its stability, translational to protein, and trafficking through the cell, are tightly regulated through coordinated post-transcriptional modifications and interactions with a multitude of effector proteins. Despite the increasing recognition of RNA regulation as a critical layer of mammalian gene expression control and its increasing excitement as a therapeutic target, tools to study and control RNA regulatory mechanisms with temporal precision in their endogenous environment are lacking. Here, we present small molecule-inducible RNA-targeting effectors based on our previously-developed CRISPR/Cas-inspired RNA targeting system (CIRTS). The CIRTS biosensor system is based on guide RNA (gRNA)-dependent RNA binding domains that interact with a target transcript using Watson-Crick-Franklin base pair interactions. Addition of a small molecule recruits an RNA effector to the target transcript, thereby eliciting a local effect on the transcript. In this work, we showcase that these CIRTS biosensors can trigger inducible RNA editing, degradation, or translation on target transcripts in a small molecule-dependent manner. We further go on to show that the new CIRTS editor can induce RNA base editing in a small molecule-dependent manner in vivo. Collectively this work provides a useful new set of tools to probe the dynamics of RNA regulatory systems and a new approach to control gene expression at the RNA level.</div> | Simone Rauch; Krysten
A. Jones; Bryan Dickinson | Bioengineering and Biotechnology; Chemical Biology | CC BY NC ND 4.0 | CHEMRXIV | 2020-02-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c748e5bb8c1a98183dad55/original/small-molecule-inducible-rna-targeting-systems-for-temporal-control-of-rna-regulation.pdf |
677390006dde43c908ddcf2d | 10.26434/chemrxiv-2025-d623q | An efficient exciton coupling scheme based on simplified time-dependent density functional theory | A very efficient and broadly applicable exciton coupling (ExC) approach based on simplified time-dependent density functional theory (sTD-DFT) is presented. Starting from this parent method, non-overlapping fragments and neglect of interfragment charge transfer excitations are assumed to arrive at the ExC procedure. This leads to an ExC Hamiltonian that pro- vides equivalent electronic absorption and circular dichroism spectra as the parent sTD-DFT method for largely separated fragments. The ExC approach easily accelerates the computa- tion of such spectra of molecular aggregates by about two orders of magnitude compared to sTD-DFT. The latter itself is already faster by about 4–5 orders of magnitude compared to regular TD-DFT. We demonstrate the performance of the approach for excitation spectra of organic molecular clusters. Given that the fragment electronic structure in the ExC-sTD- DFT approach is solved independently, computation of spectra for systems with ∼10,000 atoms can be performed within minutes of computation time. Furthermore, the role of electrostatic embedding in the independent fragments is investigated. For the purposes cov- ered in this work, the embedding can be simplified by employing a dielectric continuum, thus, greatly reducing the overall computational complexity. This approach may be used in screening photophysical properties of large molecular aggregates and soft matter materi- als. We present the derivation and implementation for the Tamm-Dancoff-approximated and the random-phase-approximation eigenvalue problems. Benchmarks compared to the parent sTD-DFT methods are shown for absorption and electronic circular dichroism spectra. | Mike Pauls; Jan Kubelka; Francesca Plückhahn; Christoph Bannwarth | Theoretical and Computational Chemistry; Computational Chemistry and Modeling; Theory - Computational | CC BY NC ND 4.0 | CHEMRXIV | 2025-01-02 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/677390006dde43c908ddcf2d/original/an-efficient-exciton-coupling-scheme-based-on-simplified-time-dependent-density-functional-theory.pdf |
60c7431bee301ca734c78f47 | 10.26434/chemrxiv.8943251.v1 | Loading Dependent Structural Model of Polymeric Micelles by Solid-State NMR | Physically loaded polymeric micelles - from bulk properties to a molecular level understanding: In this work, solid-state NMR complemented by PXRD and quantum chemical calculations is used to learn about the short range order and structural arrangement in polymeric micelles formed by amphiphilic triblock copolymers. From changes in chemical shift and line widths, we could observe that at higher loadings, not just the micellar core but also the hydrophilic corona is involved in coordination of poorly soluble guest molecules, which can explain the poorer dissolution properties. This can serve as a platform for the future, targeted modification of such polymers. <br /> | Ann-Christin Pöppler; Michael M Lübtow; Jonas Schlauersbach; Johannes Wiest; Lorenz Meinel; Robert Luxenhofer | Spectroscopy (Anal. Chem.) | CC BY NC ND 4.0 | CHEMRXIV | 1970-01-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7431bee301ca734c78f47/original/loading-dependent-structural-model-of-polymeric-micelles-by-solid-state-nmr.pdf |
60c74c2abb8c1aa07a3db391 | 10.26434/chemrxiv.12436736.v1 | Enhanced Densification and Conduction Properties of Li5+xLa3Nb2-xZrxO12 Garnet Solid-State Electrolytes Through Zn Doping on the Nb/Zr Site | <p>While garnet Li ion
conductors are attracting considerable interest as potential solid state
electrolytes for Li ion batteries, a key challenge is to improve the
conductivity, which is associated with the Li content in the structure, and to
overcome the challenges of sintering dense electrolyte membranes. In this work
we show that Zn doping on the 16a octahedral Nb site leads to substantially
improved sintering in both Li<sub>5</sub>La<sub>3</sub>Nb<sub>2</sub>O<sub>12</sub>
and Li<sub>6</sub>La<sub>3</sub>ZrNbO<sub>12</sub>. As a result of the enhanced
sintering, and the associated increase in Li content, the conductivities in
both garnet systems were significantly enhanced on Zn doping, up to 2.1 x 10<sup>-4</sup>
Scm<sup>-1</sup> at 25 <sup>o</sup>C for Li<sub>6.6</sub>La<sub>3</sub>ZrNb<sub>0.8</sub>Zn<sub>0.2</sub>O<sub>12</sub>.
This doping strategy therefore represents a promising approach to improve the
relative density and, hence, ionic conductivity of garnet solid state
electrolyte materials for possible solid-state battery applications. </p> | Bo Dong; Linhao Li; Xiao Tao; Mark P. Stockham; Chuan Li; Yongliang Li; Yulong Ding; Peter Slater | Ceramics; Solid State Chemistry; Energy Storage | CC BY NC 4.0 | CHEMRXIV | 2020-06-08 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74c2abb8c1aa07a3db391/original/enhanced-densification-and-conduction-properties-of-li5-x-la3nb2-x-zrx-o12-garnet-solid-state-electrolytes-through-zn-doping-on-the-nb-zr-site.pdf |
6232a60a5cf71917285658f8 | 10.26434/chemrxiv-2021-pzxn9-v3 | Spontaneous and Ion-Specific Formation of Inverted Bilayers at Air/Aqueous Interface | Developing better separation technologies for rare earth metals, an important aspect of a sustainable materials economy, is challenging due to their chemical similarities. Identifying molecular scale interactions that amplify the subtle differences between the rare earths can be useful in developing new separation technologies. Here, we describe ion-dependent monolayer to inverted bilayer transformation of extractant molecules at the air/aqueous interface. The inverted bilayers form with Lu3+ ions but not with Nd3+. By introducing Lu3+ ions to preformed monolayers, we extract kinetic parameters corresponding to the monolayer to inverted bilayer conversion. Temperature-dependent studies show Arrhenius behavior with an energy barrier of 40 kcal/mol. The kinetics of monolayer to inverted bilayer conversion is also affected by the character of the background anion, although anions are expected to be repelled from the interface. Our results show the outsized importance of ion-specific effects on interfacial structure and kinetics, pointing to their role in chemical separation methods. | Srikanth Nayak; Raju R Kumal; Ahmet Uysal | Physical Chemistry; Inorganic Chemistry; Lanthanides and Actinides; Interfaces; Physical and Chemical Processes | CC BY NC 4.0 | CHEMRXIV | 2022-03-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6232a60a5cf71917285658f8/original/spontaneous-and-ion-specific-formation-of-inverted-bilayers-at-air-aqueous-interface.pdf |
60c74630ee301c6e45c79476 | 10.26434/chemrxiv.11089097.v1 | On the Bonding Situation in Stannocene and Plumbocene N-Heterocyclic Carbene Complexes | A detailed experimental and computational study of a series of stannocene and plumbocene N-heterocyclic carbene complexes is presented. This unique class of group 14 Lewis acid base adducts was obtained from reactions of the corresponding metallocenes and N-heterocyclic carbenes (NHC), and were structurally characterized by single crystal X-ray diffraction. The obtained structures show a perpendicular pose of the NHC with respect to the metallocene, hence precluding the maximal interaction between the moieties. The nature of the Sn-CNHC and Pb-CNHC bonds have been investigated by applying Energy Decomposition Analysis (EDA-NOCV). For the sake of comparison, known stannocene and plumbocene Lewis base complexes have been included in the series. The attractive chemical bonding interactions are around 50% electrostatic, 30% covalent and 20% dispersion. Indeed, dispersion interactions play a determining role the bigger the substituents become. The covalent interactions derive from the donation of the carbene ligand into the empty p orbital of the metallocene. | Diego Andrada; Sergi Danés; Lisa Wirtz; Carsten Mueller; Volker Huch; Theresa Block; Rainer Pöttgen; André Schäfer | Ligands (Organomet.); Main Group Chemistry (Organomet.); Theory - Organometallic | CC BY NC ND 4.0 | CHEMRXIV | 2019-11-29 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74630ee301c6e45c79476/original/on-the-bonding-situation-in-stannocene-and-plumbocene-n-heterocyclic-carbene-complexes.pdf |
6599bdbbe9ebbb4db992eb5c | 10.26434/chemrxiv-2024-f8gtf | Unveiling the Synthesis, Spectral Characterizations, and Electrochemical Potential of Novel (E)-Furan-2-yl Acrylohydrazides: An Exploration in Molecular Design | In this study, we present the synthesis of novel derivatives of 3-furan-2-yl acrylohydrazide using a meticulous three-step reaction sequence. The synthesis ends up in the condensation of (E)-3-(furan-2-yl) acrylohydrazine (3) with diverse benzaldehyde and acetophenone derivatives. Comprehensive characterization of the synthesized compounds was achieved through 1D NMR spectroscopic analyses (1H and 13C NMR), 2D NMR spectroscopy (HSQC, NOESY), and high-resolution mass spectrometry (HRMS).
The investigation of 1H NMR data at room temperature in deuterated dimethyl sulfoxide (DMSO-d6) unveiled the existence of (E)-3-(furan-2-yl) acrylohydrazide derivatives (4a-h) in a conformational equilibrium, manifesting as a mixture of synperiplanar E (sp E) and antiperiplanar E (ap E), or synperiplanar Z (sp Z) and antiperiplanar Z (ap Z). Notably, compounds 4a and 4b predominantly adopted the sp E conformer (Ec=c sp EC=N), while compounds 4c and 4d favored the antiperiplanar conformation.
For the remaining compounds (4e-h), both conformers were nearly equimolar, with a marginal preference for the anti over the syn conformer. Interestingly, compounds 4f and 4h exhibited a prevalence of the apZ conformer (Ec=c ap ZC=N), while compound 4e featured the apE conformer (Ec=c ap EC=N).
UV-visible absorption spectra for the N-acylhydrazones (4a-h) indicated absorption within the 570-635 nm range. Furthermore, cyclic voltammetry results demonstrated the capacity of the synthesized (E)-3-(furan-2-yl) acrylohydrazide derivatives (4a-h) to undergo quasi-reversible oxidation and reduction processes on a platinum electrode. These findings contribute valuable insights into the conformational dynamics and electrochemical behavior of this class of compounds, holding significance for applications in diverse scientific and technological domains.
| Coulibaly Penayori Marie-Aimée; Souleymane Coulibaly; Sieny Roger N'Dri; Ablo Evrard; Kassi Amian Brise; Sissouma Drissa; Ané Adjou | Organic Chemistry; Analytical Chemistry; Organic Synthesis and Reactions; Supramolecular Chemistry (Org.); Spectroscopy (Anal. Chem.); Materials Chemistry | CC BY 4.0 | CHEMRXIV | 2024-01-08 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6599bdbbe9ebbb4db992eb5c/original/unveiling-the-synthesis-spectral-characterizations-and-electrochemical-potential-of-novel-e-furan-2-yl-acrylohydrazides-an-exploration-in-molecular-design.pdf |
668d2d8e5101a2ffa8dd39ca | 10.26434/chemrxiv-2024-zg9v6 | Unraveling the nature of adsorbed isobutene in H-SSZ-13 with operando simulations at the top of Jacob’s ladder | Unraveling the nature of adsorbed olefins in zeolites is crucial to understand numerous zeolite-catalyzed processes. A well-grounded theoretical description critically depends on both an accurate determination of the potential energy surface (PES) and a reliable account of entropic effects at operating conditions. Herein, we propose a transfer learning approach to perform random phase approximation (RPA) quality enhanced sampling molecular dynamics simulations, thereby approaching chemical accuracy on both the determination and exploration of the PES. The proposed methodology is used to investigate isobutene adsorption in H-SSZ-13 as prototypical system to estimate the relative stability of physisorbed olefins, carbenium ions and surface alkoxide species (SAS) in Brønsted-acidic zeolites. We show that the tert-butyl carbenium ion formation is highly endothermic and no entropic stabilization is observed compared to the physisorbed complex within H-SSZ-13. Hence, its predicted concentration and lifetime are negligible, making a direct experimental observation unlikely. Yet, it remains a shallow minimum on the free energy surface over the whole considered temperature range (273-873 K), being therefore a short-lived reaction intermediate rather than a transition state species. | Massimo Bocus; Sander Vandenhaute; Veronique Van Speybroeck | Theoretical and Computational Chemistry; Physical Chemistry; Catalysis; Computational Chemistry and Modeling; Machine Learning; Heterogeneous Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 2024-07-10 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/668d2d8e5101a2ffa8dd39ca/original/unraveling-the-nature-of-adsorbed-isobutene-in-h-ssz-13-with-operando-simulations-at-the-top-of-jacob-s-ladder.pdf |
60c73e18567dfe52d8ec378f | 10.26434/chemrxiv.6668189.v1 | Reactive Nanopattern in a Triple Structured Bio-Inspired Honeycomb Film as a Clickable Platform | A hierarchically structured platform was obtained from spontaneous self-assembly of a poly(styrene)-<i>b</i>-poly(vinylbenzylchloride) (PS-<i>b</i>-PVBC) block copolymer (BCP) during breath figure (BF) templating. The BF process using a water/ethanol atmosphere gave a unique double porosity in which hexagonally arranged micron-sized pores were encircled by a secondary population of smaller, nano-sized pores. A third level of structuration was simultaneously introduced between the pores by directed BCP self-assembly to form out-of-the-plane nano-cylinders, offering very rapid bottom-up access to a film with unprecedented triple structure which could be used as a reactive platform for introducing further surface functionality. The surface nano-domains of VBC were exploited as reactive nano-patterns for site-specific chemical functionalization by firstly substituting the exposed chlorine moiety with azide, then “clicking” an alkyne by copper (I) catalyzed azide-alkyne Huisgen cycloaddition (CuAAC). Successful chemical modification was verified by NMR spectroscopy, FTIR spectroscopy, and XPS, with retention of the micro- and nanostructuration confirmed by SEM and AFM respectively. Protonation of the cyclotriazole surface groups triggered a switch in macroscopic behavior from a Cassie-Baxter state to a Wenzel state, highlighting the possibility of producing responsive surfaces with hierarchical structure. | Pierre Marcasuzaa; Samuel Pearson; Karell Bosson; Laurence Pessoni; Jean-Charles Dupin; Laurent Billon | Nanostructured Materials - Materials; Organic Polymers; Polymer morphology; Polymer scaffolds | CC BY NC ND 4.0 | CHEMRXIV | 2018-06-25 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73e18567dfe52d8ec378f/original/reactive-nanopattern-in-a-triple-structured-bio-inspired-honeycomb-film-as-a-clickable-platform.pdf |
60c74a0c4c89191399ad3167 | 10.26434/chemrxiv.12142578.v1 | Smart Chemiluminescence Probes and Dual-Amplification of Signal for Detection of Amyloid Beta Species in Alzheimer’s Disease Model | <div>Fluorescence and chemiluminescence imaging are the most widely applied optical emissive imaging</div><div>methods in biomedical research. “Smart” (turn-on) fluorescence imaging has been routinely used for in</div><div>vitro, cellular, and in vivo imaging; however, smart chemiluminescence imaging has been rarely explored.</div><div>In this report, we designed chemiluminescence probe ADLumin-1 and validated that ADLumin-1 was a</div><div>smart chemiluminescence probe for amyloid beta (Ab) species, evidenced by a 216-fold amplification of</div><div>chemiluminescence intensity upon mixing with Abs in vitro. In vivo two photon imaging indicated that</div><div>ADLumin-1 could efficiently cross blood-brain- barrier (BBB) and provided excellent contrast both for Ab</div><div>plaques and cerebral amyloid angiopathy (CAA). In vivo whole brain imaging showed that the</div><div>chemiluminescence signal of ADLumin-1 from 5-month-old transgenic AD (5xFAD) mice was 1.80-fold</div><div>higher than that from the age-matched wild-type mice. Moreover, we demonstrated that it was feasible to</div><div>further dually-amplify signal via chemiluminescence resonance energy transfer (DAS-CRET) using two</div><div>non-conjugated smart probes (ADLumin-1 and CRANAD-3) in solutions, brain homogenates, and in vivo</div><div>whole brain imaging. Our results showed that DAS-CRET could provide a 2.25-fold margin between 5-</div><div>month-old 5xFAD mice and wild type mice. To our knowledge, this is the first report that a</div><div>chemiluminescence probe could be used for detecting Ab species both in vitro and in vivo. Although</div><div>ADLumin-1 was designed for Abs, we believe that our strategy could be potentially extended to a wide</div><div>range of targets, including other aggregating-prone proteins. Notably, our results suggested that the</div><div>strategies for turning-on fluorescence could be used for amplifying chemiluminescence, and we believe that</div><div>our studies could inspire considerably more research on chemiluminescence imaging</div> | Jing Yang; Wei Yin; Richard Van; Keyi Yin; Peng Wang; Chao Zheng; Biyue Zhu; Kathleen Ran; Can Zhang; Yihan Shao; Chongzhao Ran | Imaging | CC BY NC ND 4.0 | CHEMRXIV | 2020-04-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74a0c4c89191399ad3167/original/smart-chemiluminescence-probes-and-dual-amplification-of-signal-for-detection-of-amyloid-beta-species-in-alzheimer-s-disease-model.pdf |
63cebb911a1ead723eb4e979 | 10.26434/chemrxiv-2023-g9bkz-v2 | Iron Oxide Fe3O4 Nanoparticles for Electromagnetic Shielding | Magnetic iron oxide nanoparticles (Fe3O4) can be dispersed in a supporting material so that the composite can better respond to electromagnetic fields, absorbing a part of their energy. In the discussion here proposed, therefore, we will consider the role of these nanoparticles in the applications for electromagnetic interference (EMI) shielding. Inserted in intrinsically conducting polymers (ICPs) for instance, the nanoparticles are increasing EMI shielding effectiveness of polymer, producing light weight "absorption-type" shields, which are specifically relevant for absorbing microwaves. Composite materials, based on Fe3O4 nanoparticles with polypyrrole or polyaniline, will be considered in detail. Other materials, such as the recent biochar-based composites, will be discussed too. | Amelia Carolina Sparavigna | Materials Science; Composites | CC BY NC ND 4.0 | CHEMRXIV | 2023-01-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63cebb911a1ead723eb4e979/original/iron-oxide-fe3o4-nanoparticles-for-electromagnetic-shielding.pdf |
60c74f9f702a9b115618bbf2 | 10.26434/chemrxiv.12636704.v2 | RASPD+: Fast Protein-Ligand Binding Free Energy Prediction Using Simplified Physicochemical Features | The virtual screening of large numbers of compounds against target protein binding sites has become an integral component of drug discovery workflows. This screening is often done by computationally docking ligands into a protein binding site of interest, but this has the drawback that a large number of poses must be evaluated to obtain accurate estimates of protein-ligand binding affinity. We here introduce a fast prefiltering method for ligand prioritization that is based on a set of machine learning models and uses simple pose-invariant physicochemical descriptors of the ligands and the protein binding pocket. Our method, Rapid Screening with Physicochemical Descriptors + machine learning (RASPD+), is trained on PDBbind data and achieves a regression performance better than for the original RASPD method and comparable to traditional scoring functions on a range of different test sets without the need for generating ligand poses. Additionally, we use RASPD+ to identify molecular features important for binding affinity and assess the ability of RASPD+ to enrich active molecules from decoys. | Stefan Holderbach; Lukas Adam; Bhyravabhotla Jayaram; Rebecca Wade; Goutam Mukherjee | Machine Learning; Chemoinformatics - Computational Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2020-09-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74f9f702a9b115618bbf2/original/raspd-fast-protein-ligand-binding-free-energy-prediction-using-simplified-physicochemical-features.pdf |
60c73cc99abda254a7f8b5de | 10.26434/chemrxiv.14754525.v1 | Pseudocyclic Bis-N-Heterocycle-Stabilized Iodanes – Synthesis, Characterization and Applications | In this manuscript we describe novel bicationic iodonium salts which are stabilized by covalently connected <i>N</i>-heterocycles (Bis-<i>N</i>-Heterocycle-stabilized Iodanes BNHIs). We provide structural data, their synthesis as well as their application in benchmark oxidative transformations. | Andreas Boelke; Soleicha Sadat; Enno Lork; Boris Nachtsheim | Organic Synthesis and Reactions; Homogeneous Catalysis; Organocatalysis; Redox Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 2021-06-10 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73cc99abda254a7f8b5de/original/pseudocyclic-bis-n-heterocycle-stabilized-iodanes-synthesis-characterization-and-applications.pdf |
60c74d4abb8c1a79ad3db58f | 10.26434/chemrxiv.12609536.v1 | Nanospray Desorption Electrospray Ionization (nano-DESI) Mass Spectrometry Imaging of Drift Time-Separated Ions | Simultaneous spatial localization and structural characterization of
molecules in complex biological samples currently represents an analytical
challenge for mass spectrometry imaging (MSI) techniques. In this study, we
describe a novel experimental platform, which substantially expands the
capabilities and enhances the depth of chemical information obtained in high
spatial resolution MSI experiments performed using nanospray desorption
electrospray ionization (nano-DESI). Specifically, we designed and constructed
a portable nano-DESI MSI platform and coupled it with a drift tube ion mobility
spectrometer-mass spectrometer (IM-MS). Separation of biomolecules observed in
MSI experiments based on their drift times provides unique molecular
descriptors necessary for their identification by comparison with databases. Furthermore,
it enables isomer-specific imaging, which is particularly important for
unraveling the complexity of biological systems. Imaging of day 4 pregnant
mouse uterine sections using the newly developed nano-DESI-IM-MSI system demonstrates
rapid isobaric and isomeric separation
and reduced chemical noise in MSI experiments. A direct comparison of the
performance of the new nano-DESI-MSI platform operated in the MS mode with the
more established nano-DESI-Orbitrap platform indicates a comparable performance
of these two systems. A spatial resolution of better than ~16 µm and similar molecular
coverage was obtained using both platforms.
The structural information provided by the ion mobility separation
expands the molecular specificity of high-resolution MSI necessary for the
detailed understanding of biological systems. | Daisy Unsihuay; ruichuan yin; Daniela Mesa Sanchez; Yingju Li; Xiaofei Sun; Sudhansu Dey; Julia Laskin | Analytical Chemistry - General; Analytical Apparatus; Mass Spectrometry | CC BY NC ND 4.0 | CHEMRXIV | 2020-07-06 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74d4abb8c1a79ad3db58f/original/nanospray-desorption-electrospray-ionization-nano-desi-mass-spectrometry-imaging-of-drift-time-separated-ions.pdf |
60c73e58702a9b1414189d55 | 10.26434/chemrxiv.6948875.v1 | A 3D Network of Graphene/Silicon/Graphene Sandwich Sheets as Anode for Li-Ion Battery | <p>A freestanding 3D network strucutre
of graphene/Si/graphene designed & fabricated.</p>
<p>Coloumbic efficiency of the
first de-/liathiation cycle over 80%.</p>
<p>Stable
areal capacities up to 0.62 mAh cm<sup>-2</sup> were achieved.</p><p>Anodes maitained interconnected, superlight, flexible
structures after 1000 cycles.</p> | Zhijun Feng; Ang Fu; Lun Chen; Chenhui Huang; Fei Pei; Yanling He; Fang Xiaoliang; Qu Baihua; Chen Xinyi; Alan Man Ching Ng; Jingqin Cui | Composites; Energy Storage | CC BY NC ND 4.0 | CHEMRXIV | 1970-01-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73e58702a9b1414189d55/original/a-3d-network-of-graphene-silicon-graphene-sandwich-sheets-as-anode-for-li-ion-battery.pdf |
60c7509cbdbb89473ea39f55 | 10.26434/chemrxiv.13060268.v1 | Chiral Primary Amine/Ketone Cooperative Catalysis for Asymmetric α-Hydroxylation with Hydrogen Peroxide | <p>Carbonyl and amine are yin and yang in organocatalysis
that mutually activate and transform each other. As intrinsically reacting
partners, carbonyl and amine tend to condensate, depleting their individual
activity when employed as catalysts. Though widely established as prominent
catalytic strategies, aminocatalysis and carbonyl catalysis seems not coexist
well and a cooperative amine/carbonyl dual catalysis remains virtually unknown.
Here we report a cooperative primary amine and ketone dual catalysis in the
asymmetric <i>α</i>-hydroxylation with H<sub>2</sub>O<sub>2</sub>. Besides
participating in the typical enamine catalytic cycle, the chiral primary amine
catalyst was found to work cooperatively with a ketone catalyst to activate H<sub>2</sub>O<sub>2</sub>
<i>via</i> an oxaziridine intermediate
derived from<i> in-situ</i> generated ketimine intermediate. The resulted
enamine-oxaziridine coupling then facilitated highly-controlled hydroxylation
of <i>β</i>-ketocarbonyls that are not possible with other catalytic methods. The
dual catalytic approach allows for highly enantioselective <i>α</i>-hydroxylation
of a broad range of <i>β</i>-ketocarbonyls. Particularly, late-stage
hydroxylation for peptidyl amide or chiral esters can also be achieved with
high stereoselectivity. With its operational simplicity and mild conditions, this
cooperative amine/ketone catalysis provides a new strategy in catalytic
activation of H<sub>2</sub>O<sub>2</sub> and expands the domain of typical
amine and carbonyl catalysis to include those challenging transformations.</p> | Mao Cai; Kaini Xu; Yuze Li; zongxiu nie; Long Zhang; Sanzhong Luo | Organic Compounds and Functional Groups; Physical Organic Chemistry; Stereochemistry; Homogeneous Catalysis; Organocatalysis | CC BY NC ND 4.0 | CHEMRXIV | 2020-10-07 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7509cbdbb89473ea39f55/original/chiral-primary-amine-ketone-cooperative-catalysis-for-asymmetric-hydroxylation-with-hydrogen-peroxide.pdf |
615e344cf718df61bbd60b70 | 10.26434/chemrxiv-2021-wd9sd | Coumarin-bisureas as potent fluorescent transmembrane anion transporters | A series of fluorescent coumarin bis-ureas have been synthesised and their anion transport properties studied. The compounds function as highly potent HCl co-transport agents in lipid bilayer membranes. | Mohamed Fares; Xin Wu; Daniel A. McNaughton; Alexander M. Gilchrist; William Lewis; Paul A. Keller; Alain Arias-Betancur; Ricardo Pérez-Tomás; Philip Alan Gale | Organic Chemistry; Supramolecular Chemistry (Org.) | CC BY NC 4.0 | CHEMRXIV | 2021-10-07 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/615e344cf718df61bbd60b70/original/coumarin-bisureas-as-potent-fluorescent-transmembrane-anion-transporters.pdf |
6448347c83fa35f8f63e2d64 | 10.26434/chemrxiv-2023-dlbcj | Nonlocal functionals inspired by the strongly interacting limit of DFT: exact constraints and implementation | Capturing strong correlation effects remains a key challenge for the development of improved exchange-correlation (XC) functionals in density functional theory. The recently proposed multiple radii functional (MRF) [J. Phys. Chem. Lett. 2017, 8, 2799; J. Chem. Theory Comput. 2019, 15, 3580] was designed to capture strong corre- lation effects seamlessly, as its mathematical structure draws from that of the exact XC functional in the limit of infinite correlations. The MRF functional provides a frame- work for building approximations along the density-fixed adiabatic connection, delivers accurate XC energy densities in the standard DFT gauge (same as that of the exact exchange energy density), and is free of one-electron self-interaction errors. To facilitate the development of XC functionals based on the MRF, we examine the behavior of the MRF functional when applied to uniform and scaled densities and consider how it can be made exact for the uniform electron gas. These theoretical insights are then used to build improved forms for the fluctuation function, an object that defines XC energy densities within the MRF framework. We also show how the MRF fluctuation function for physical correlation can be easily readjusted to accurately capture the XC functional in the limit of infinite correlations, demonstrating the versatility of MRF for building approximations for different correlation regimes. We describe the implementation of MRF using densities expanded on Gaussian basis sets, which improves the efficiency of previous grid-based MRF implementations. Finally, we present prospects for using the resulting MRF features for machine learning of XC approximations. | Stefan Vuckovic; Hilke Bahmann | Theoretical and Computational Chemistry; Theory - Computational | CC BY 4.0 | CHEMRXIV | 2023-04-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6448347c83fa35f8f63e2d64/original/nonlocal-functionals-inspired-by-the-strongly-interacting-limit-of-dft-exact-constraints-and-implementation.pdf |
6362cd72aca198e32eefe05b | 10.26434/chemrxiv-2022-77kjh | Direct air capture and conversion of carbon dioxide into cyclic carbonates with basic ionic liquids | Achieving net zero greenhouse gas emissions (ghg) is a top priority to limit the impacts of global warming. Carbon dioxide is the most abundant ghg and its direct air capture (DAC) is a very attractive strategy to reduce its concentration in the atmosphere. However, the existing capturing processes are technologically challenging due to the costs of the processes and the low concentration of CO2. The efficient valorisation of the CO2 captured could help overcoming many technoeconomic limitations. Sorbants capable to concentrate CO2 from the atmosphere require strong interactions (e.g. carbamate synthesis), which increase the cost of regeneration of the sorbants and introduce thermodynamic barriers to efficiently transform the CO2 into added value products. Here we present a novel methodology for direct air capture and conversion (DACC) able to efficiently convert CO2 from air into cyclic carbonates using epoxides or halohydrins as substrates. The new approach employs commercially available basic ionic liquids (ILs), it works without the need of sophisticated and expensive co-catalysts or sorbants and under mild reaction conditions. The CO2 from atmospheric air was efficiently captured by IL solution (0.98 molCO2/molIL) and subsequently completely converted (> 99%) to cyclic carbonate. A mechanism of conversion was evaluated and proposed, which helped to identify relevant reaction intermediates based on halohydrins, which could be sourced from biomass derivatives. A 100% selectivity towards the desired cyclic carbonates was obtained employing this methodology. Finally, the catalyst was reactivated employing an ion exchange column, and reused for at least 3 cycles. | Marcileia Zanatta; Eduardo García-Verdugo; Victor Sans | Catalysis; Homogeneous Catalysis; Organocatalysis | CC BY NC ND 4.0 | CHEMRXIV | 2022-11-03 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6362cd72aca198e32eefe05b/original/direct-air-capture-and-conversion-of-carbon-dioxide-into-cyclic-carbonates-with-basic-ionic-liquids.pdf |
671dfabe98c8527d9e84595b | 10.26434/chemrxiv-2024-vxf63-v2 | Neutral and Dicationic [5]helicene-embedded Cycloparaphenylene Nanohoops with Möbius Topology and Local/In-Plane Aromaticity | The relationship between Möbius topology and aromaticity is still elusive to date, which is, to a large extent, due to the related synthetic challenges and, further, the scarcity in both the quantity and the diversity of the constructed Möbius systems. In this work, we report the synthesis of [4n]Möbius conjugated all-carbon nanohoops ([5]H-[7,8]CPPs) by utilizing a [5]helicene unit as a hidden writhe and a masked aromatic unit to overcome the strain inherited from Möbius topology. X-ray analyses reveal that [5]H-[7,8]CPPs contain a [5]helicene moiety and an oligoparaphenylene unit, and display a Möbius topology. Photophysical investigations demonstrated that [5]H-[7,8]CPPs exhibited moderately high fluorescence quantum yields, which are significantly higher than those of pristine [5]helicene and [7,8]CPPs. Chiroptical studies revealed that [5]H-[7,8]CPPs displayed an obvious Cotton effect in circular dichroism and bright circularly polarized luminescence, indicating that the chirality of [5]helicene was efficiently transferred to the overall carbon nanohoops. Importantly, theoretical investigations reveal that, though possessing a Möbius topology and a 4n π-electron array in the neutral state, such all-carbon nanohoops fundamentally exhibit local Hückel aromaticity, while their dications, with a 4n+2 π-electron in the conjugation circuits, show Hückel in-plane global aromaticity, deviating from the Heilbronner prediction. The results may help us to better understand the complicated relationship between Möbius topology and aromaticity. | Huiji Yang; Shengzhu Guo; Weijie Guo; Lin Liu; Xiaoyu Liu; Jing He; Yanqing Fan; Zhe Lian; Xiaonan Li; Shu Huang; Xuebo Chen; Ying Wang; Hua Jiang | Organic Chemistry; Supramolecular Chemistry (Org.) | CC BY NC ND 4.0 | CHEMRXIV | 2024-10-29 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/671dfabe98c8527d9e84595b/original/neutral-and-dicationic-5-helicene-embedded-cycloparaphenylene-nanohoops-with-mobius-topology-and-local-in-plane-aromaticity.pdf |
60c73d0d702a9b6abc189ad7 | 10.26434/chemrxiv.5349151.v1 | Predicting the Mechanical Properties of Zeolite Frameworks by Machine Learning | We show here that machine learning is a powerful new tool for predicting the elastic
response of zeolites. We built our machine learning approach relying on geometric features
only, which are related to local geometry, structure and porosity of a zeolite, to
predict bulk and shear moduli of zeolites with an accuracy exceeding that of force field
approaches. The development of this model has illustrated clear correlations between
characteristic features of a zeolite and elastic moduli providing exceptional insight into
the mechanics of zeolitic frameworks. Finally, we employ this methodology to predict
the elastic response of 590 448 hypothetical zeolites, and the results of this massive
database provide clear evidence to stability trends in porous materials. | Jack D. Evans; François-Xavier Coudert | Computational Chemistry and Modeling | CC BY 4.0 | CHEMRXIV | 2017-09-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73d0d702a9b6abc189ad7/original/predicting-the-mechanical-properties-of-zeolite-frameworks-by-machine-learning.pdf |
63fecf1e897b18336f4e51a6 | 10.26434/chemrxiv-2023-g0j05 | Honeycomb reactor: a promising device for streamlining aerobic oxidation under continuous flow conditions | We report on the high potential of a honeycomb reactor for use in aerobic oxidation under continuous flow conditions. The honeycomb reactor is made of porous material with narrow channels separated by porous walls allowing for high density accumulation in the reactor. This structure raised the mixing efficiency of a gas-liquid reaction system, and it effectively accelerated aerobic oxidation of benzyl alcohols to benzaldehydes under continuous flow conditions. This reactor is a promising device for streamlining aerobic oxidation with high process safety because it is a closed system. | Masahiro Hosoya; Yusuke Saito; Yousuke Horiuchi | Organic Chemistry; Catalysis; Chemical Engineering and Industrial Chemistry; Organic Synthesis and Reactions; Pharmaceutical Industry; Homogeneous Catalysis | CC BY 4.0 | CHEMRXIV | 2023-03-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63fecf1e897b18336f4e51a6/original/honeycomb-reactor-a-promising-device-for-streamlining-aerobic-oxidation-under-continuous-flow-conditions.pdf |
66a3c89801103d79c5c42bee | 10.26434/chemrxiv-2024-k8g8t | Comprehensive Characterization and Sustained, On-Demand Delivery of Corneal Epithelial Extracellular Vesicles for Healing Corneal Epithelium | Extracellular vesicles (EVs) derived from corneal epithelial cells have shown great promise in promoting corneal wound healing and stromal regeneration but face challenges with rapid clearance from the eye. This study addresses this challenge by developing a sustained release platform using a biocompatible collagen-based hydrogel. We successfully isolated, purified, and characterized corneal epithelial EVs, assessed their efficacy in corneal epithelial healing in vitro, and demonstrated their sustained delivery over ten days followed by an on-demand release through enzymatic degradation of the hydrogel. To develop a microscale understanding of the EV-diffusion inside the hydrogel matrix, we probed the hydrogel network with several model compounds and nanoparticles by using advanced confocal microscopy analyses followed by fitting our results to established diffusion models. Our findings suggest this innovative approach offers a safe and effective strategy to promote corneal wound healing. This technology has the potential to revolutionize corneal injury treatment and improve patient outcomes. | Jenny Rosenquist Lybecker; Ann Van de Ven; Ken Braesch-Andersen; David Juriga; Norein Norein; Per Hansson; Ayan Samanta | Materials Science; Nanoscience; Biocompatible Materials; Biodegradable Materials; Controlled-Release Systems; Materials Chemistry | CC BY 4.0 | CHEMRXIV | 2024-07-29 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66a3c89801103d79c5c42bee/original/comprehensive-characterization-and-sustained-on-demand-delivery-of-corneal-epithelial-extracellular-vesicles-for-healing-corneal-epithelium.pdf |
6608e3c466c138172950e040 | 10.26434/chemrxiv-2024-1jwr7 | Investigation of the Free-Base Zr-Porphyrin MOFs as Humidity Sensors for an Indoor Setting | Maintaining optimal relative humidity is paramount for human comfort. Therefore, the utilization of quartz crystal microbalance (QCM) as a humidity sensor platform holds significant promise due to its cost-effectiveness and high sensitivity. This study explores the efficacy of three free-base Zr porphyrin metal-organic frameworks (MOFs) - namely MOF-525, MOF-545, and NU-902 - as sensitive materials for QCM-based humidity sensors. Our extended experimental findings reveal that these materials exhibit notable sensitivity, particularly within relative humidity ranges of 40% to 100%. However, we observe potential irreversible adsorption sites within the MOF-545 framework, hindering its ability to revert to its initial state after prolonged exposure. In light of this observation, we conduct periodic cycling experiments at relative humidity levels of 40-70% to evaluate the measurement repeatability and feasibility of these sensors for indoor applications. Interestingly, the periodic cycling study demonstrates that MOF-545 shows promising repeatability, positioning it as a strong contender for indoor humidity sensing. In contrast, MOF-525 may necessitate extended desorption time, and NU-902 displays diminished sensitivity at low relative humidity levels. Nevertheless, a preliminary treatment of the MOF-545 QCM sensor may be necessary to address irreversible adsorption sites and uphold measurement repeatability, as only reversible adsorption sites are currently accessible. This study underscores the potential of MOF-based QCM sensors for effective humidity monitoring in indoor environments, thus facilitating improved comfort and environmental control. | Nicholaus Prasetya; Salih Okur | Materials Science; Organometallic Chemistry; Chemical Engineering and Industrial Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-04-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6608e3c466c138172950e040/original/investigation-of-the-free-base-zr-porphyrin-mo-fs-as-humidity-sensors-for-an-indoor-setting.pdf |
60c74cc4337d6c18f0e27cc6 | 10.26434/chemrxiv.12526190.v1 | Material Property Targets for Emerging Nanomaterials to Enable Point-of-Use and Point-of-Entry Water Treatment Systems | The scarcity of potable water is an imminent threat to at least half the world's population. Engineered nanomaterials (ENMs) have the potential to treat water from polluted sources to mitigate the scarcity of potable water. However, the performance demands on these materials in practical applications has not been studied in detail. This is but one of the challenges that hinder the widespread implementation of ENMs for water treatment. The emerging fit-for-purpose paradigm which encourages water treatment at the point-of-use (POU) or point-of-entry (POE) could lower the barrier for the use of ENMs in water technology by incorporating smaller, decentralized ENM-based treatment systems. This work develops a bottom-up and top-down modeling framework to facilitate the design of nanoporous membrane-based sorbents, a promising class of ENMs, for POU and POE water treatment applications. Langmuir isotherm and membrane structure-property calculations provide the multiscale link between molecular properties, including affinity, saturation capacity, and pore size, device design decisions, including membrane area and thickness, and system design decisions, including sorbent mass and number of parallel modules. The framework predicts that for lead contaminants, existing materials are near molecular and systems limitations; improvements in the properties of adsorptive materials to treat lead will yield few benefits for POU and POE treatment systems. Moreover, the framework provides dimensionless formulas that apply to all adsorptive systems that exhibit (near) equilibrium behavior as an easy-to-use tool for the broader membrane science and environmental engineering communities to assess the feasibility of emerging materials to meet process demands. A case study regarding materials for arsenic removal demonstrates how to apply the modeling framework to calculate material properties targets and predict system performance for an arbitrary single-solute adsorption process. Finally, these dimensionless models are used to identify three distinct regions of relative performance between batch and semi-continuous processes. These results give caution to applying scale-up heuristics outside their valid region, which can lead to under- or over-design during bottom-up studies. The presented modeling framework is a crucial step to fully optimize engineered nanomaterials across material, device, and system scales. | Elvis Eugene; William Phillip; Alexander Dowling | Environmental Science; Nanostructured Materials - Nanoscience; Water Purification | CC BY NC ND 4.0 | CHEMRXIV | 2020-06-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74cc4337d6c18f0e27cc6/original/material-property-targets-for-emerging-nanomaterials-to-enable-point-of-use-and-point-of-entry-water-treatment-systems.pdf |
67989d4e6dde43c908b0913c | 10.26434/chemrxiv-2025-cwkdk | Approaching Hypothetical RbTl in Experiment and Theory – X-Ray Structure Determination of Cs1-xRbxTl (x=0.18, 0.42) and a Solid Solution K1-xRbxTl (x≤0.69) | Although the binary alkali metal thallides ATl with A= Li, Na, K, and Cs have been reported in literature, binary RbTl at ambient pressure is still missing. Experiments according to a 1:1 ratio of Rb:Tl, either according to Zintl’s procedure in low temperature experiments in liquid ammonia or classical solid state synthesis at high temperature, did not result in the desired product. Therefore, several ternary compositions with a mixture of K/Rb and Cs/Rb have been prepared. For K/Rb mixtures a solid solution in the KTl structure type up to a proportion of 69% rubidium could be obtained. Site occupancy preferences for rubidium on the alkali metal sites in the KTl type are obtained in experiment and supported by theory. In contrast to Rb/K mixtures being realizable in the KTl structure type, Rb/Cs mixtures did not allow for the isolation of materials according to the CsTl structure type. Instead, two new monoclinic compounds could be isolated (Cs0.82Rb0.18Tl: C2/c, a=14.4136(4) Å, b=11.1678(3) Å, c=40.8013(11) Å, β=96.353(2) °, V=6527.4(3) ų; Cs0.58Rb0.42Tl: C2/c, a=14.2610(3) Å, b=11.1116(2) Å, c=27.5589(7) Å, β=104.056(2) °, V=4236.30(17) ų). Detailed DFT calculations on both, binary and mixed cation systems were performed and support the experimental results. | Vanessa F. Schwinghammer; Saleem A. Khan; Susanne M. Tiefenthaler; Tomáš Kovářík; Jan Minar; Stefanie Gärtner | Theoretical and Computational Chemistry; Inorganic Chemistry; Solid State Chemistry; Theory - Inorganic; Crystallography – Inorganic | CC BY 4.0 | CHEMRXIV | 2025-01-30 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67989d4e6dde43c908b0913c/original/approaching-hypothetical-rb-tl-in-experiment-and-theory-x-ray-structure-determination-of-cs1-x-rbx-tl-x-0-18-0-42-and-a-solid-solution-k1-x-rbx-tl-x-0-69.pdf |
668ff141c9c6a5c07afab2c5 | 10.26434/chemrxiv-2023-7c75d-v2 | Quantitative photoacoustic spectral transformations in theranostic Solid Lipid Nanoparticles labelled with increasing concentrations of a Photoacoustic NIR BODIPY | Solid lipid nanoparticles (SLNs) have shown great capabilities for drug delivery and are therefore attractive theranostic candidates when labelled with an imaging contrast agent. This work aims to create the first SLNs labelled for photoacoustic (PA) imaging by encapsulating a specially designed and near-infrared absorbing BODIPY dye (BY-aniline-Palm) into SLNs of dexamethasone palmitate. A one-pot formulation protocol enabled us to replace the prodrug by the BY-aniline-Palm label in various proportions up to 100%. Increasing the dye content exhibited complex but gradual transformations of the SLNs in terms of optical absorption and PA spectra, and the formation of aggregates at high concentration. A comprehensive and quantitative PA spectrometric study revealed a photoacoustic generation efficiency (PGE) that is spectrally varying and notably greater than 1. A joined spectral decomposition of the absorption and PA spectra into a sum of three Gaussian functions displayed a per-band evolution of the PGE when the concentration of BY-aniline-Palm varied and showed an interplay between the bands with a constant spectrum area. Finally, a novel quantitative PA spectroscopic approach, involving measurements at three different ambient temperatures, demonstrated that the remarkable PGE values arise from a significant thermo-elastic expansion of the SLN during the PA signal generation independently of the absorption band. This study highlights that labeled SLNs are promising agents for PA imaging and also unveils complex transformations that can occur in such nanosystems with a dye prone to aggregation. | Clément Linger; Giulia Maccini; Gilles Clavier; Rachel Méallet; Nicolas Tsapis; Jérôme Gateau | Biological and Medicinal Chemistry; Nanoscience; Bioengineering and Biotechnology; Drug Discovery and Drug Delivery Systems | CC BY NC ND 4.0 | CHEMRXIV | 2024-07-12 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/668ff141c9c6a5c07afab2c5/original/quantitative-photoacoustic-spectral-transformations-in-theranostic-solid-lipid-nanoparticles-labelled-with-increasing-concentrations-of-a-photoacoustic-nir-bodipy.pdf |
625ea44fd048ed5db94940a3 | 10.26434/chemrxiv-2022-rsg01 | Preprints in chemistry: a research team’s journey | The benefits of publishing research papers first in preprint form are substantial and long-lasting also in chemistry. Recounting the outcomes of our team’s nearly six-year journey through preprint publishing, we show evidence of how preprinting research findings and new ideas substantially benefits both early career and senior researchers in the chemical sciences. | Rosaria Ciriminna; Mario Pagliaro | Chemical Education; Chemical Education - General | CC BY NC 4.0 | CHEMRXIV | 2022-04-21 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/625ea44fd048ed5db94940a3/original/preprints-in-chemistry-a-research-team-s-journey.pdf |
631cb94fbe03b27bd2f10d4d | 10.26434/chemrxiv-2022-g1fb2 | Improving the Colloidal Stability of PEGylated BaTiO3 Nanoparticles with
Surfactants | Barium titanate, BaTiO3, nanoparticles (NPs) have been widely used as a ferroelectric/piezoelectric/pyroelectric material in the electronic-optical ceramic industry. However, the stability of BaTiO3 NP suspension are a matter of concern for their advanced applications in wet-ceramic manufacturing, imaging, and electrorheological fluids. In this study, we investigated the effect of three different surfactants (sodium dodecylbenzenesulfonate (anionic), cetyltrimethylammonium bromide (cationic), and sorbitan monooleate (non-ionic)) on the stability of PEGylated BaTiO3 nanoparticles in two solvents (water and ethylene glycol) by means of dynamic light scattering, ζ potential, UV-visible spectroscopy, scanning electron microscopy, and visual observation. Our findings indicate that the anionic surfactant acted as the best stabilizer for BaTiO3 nanofluids, while the cationic surfactant was the least favourable stabilizer in both water and ethylene glycol, due to the balance between attraction and repulsive forces. The results of this research provide a simple and effective approach to control and improve the colloidal stability of BaTiO3 nanoparticles. | Maryam Taheri; Sepideh Maaref; Apostolos Kantzas; Steven Bryant; Simon Trudel | Physical Chemistry; Nanoscience; Interfaces; Physical and Chemical Properties; Surface; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2022-09-12 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/631cb94fbe03b27bd2f10d4d/original/improving-the-colloidal-stability-of-pe-gylated-ba-ti-o3-nanoparticles-with-surfactants.pdf |
61dd009bf51b226cc2117ca5 | 10.26434/chemrxiv-2021-xr8tf-v2 | Improving machine learning performance on small chemical reaction data with unsupervised contrastive pretraining | Machine learning (ML) methods have great potential to transform chemical discovery by accelerating the exploration of chemical space and drawing scientific insights from data. However, modern chemical reaction ML models, such as those based on graph neural networks (GNNs), must be trained on a large amount of labelled data in order to avoid overfitting the data and thus possessing low accuracy and transferability. In this work, we propose a strategy to leverage unlabelled data to learn accurate ML models for small labelled chemical reaction data. We focus on an old and prominent problem—classifying reactions into distinct families—and build a GNN model for this task. We first pretrain the model on unlabelled reaction data using unsupervised contrastive learning and then fine-tune it on a small number of labelled reactions. The contrastive pretraining learns by making the representations of two augmented versions of a reaction similar to each other but distinct from other reactions. We propose chemically consistent reaction augmentation methods that protect the reaction center and find they are the key for the model to extract relevant information from unlabelled data to aid the reaction classification task. The transfer learned model outperforms a supervised model trained from scratch by a large margin. Further, it consistently performs better than models based on traditional rule-driven reaction fingerprints, which have long been the default choice for small datasets. In addition to reaction classification, the effectiveness of the strategy is tested on regression datasets; the learned GNN-based reaction fingerprints can also be used to navigate the chemical reaction space, which we demonstrate by querying for similar reactions. The strategy can be readily applied to other predictive reaction problems to uncover the power of unlabelled data for learning better models with a limited supply of labels. | Mingjian Wen; Samuel M. Blau; Xiaowei Xie; Shyam Dwaraknath; Kristin A. Persson | Theoretical and Computational Chemistry; Physical Chemistry; Computational Chemistry and Modeling; Machine Learning; Chemoinformatics - Computational Chemistry; Materials Chemistry | CC BY NC 4.0 | CHEMRXIV | 2022-01-11 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/61dd009bf51b226cc2117ca5/original/improving-machine-learning-performance-on-small-chemical-reaction-data-with-unsupervised-contrastive-pretraining.pdf |
64b8e251b605c6803b0c5229 | 10.26434/chemrxiv-2023-t63jq | Vibrio vulnificus marine pathogen detection with thin-film impedance biosensors | Vibrio vulnificus (Vv) is a marine pathogen that can cause rapid death by septicemia (vibriosis) in humans and several fish species. This pathogen is considered a biomarker of climate change, as both its presence and vibriosis incidence in coastal environments are increasing because of global warming. Currently, gold-standard methods for Vv detection are all PCR-based, requiring expensive equipment and skilled personnel, which hinders their use on a global scale. The aim of this work was to design and test a more affordable method that could be used worldwide for both vibriosis diagnosis and pathogen monitoring in water. To this end, we functionalized thin film microelectrodes with thiolated single-stranded DNA sequences complementary to the species-specific genetic marker, the gene vvha, and monitored the impedance changes upon hybridization. We tested the biosensor specificity with synthetic and natural DNA samples (from cultures of Vv and V. cholerae, a closely related species) and determined the detectable concentration range. The results obtained showed that this biosensor was specific for Vv, achieving detection down to 1 pM DNA, which corresponds approximately to 3x102 bacteria/mL. Consequently, this biosensor could be used on a global scale for vibriosis diagnostics, health risk studies and climate change monitoring, with potential application for in situ detection. | Arnau Pérez Roig; Bergoi Ibarlucea; Carmen Amaro; Gianaurelio Cuniberti | Analytical Chemistry | CC BY NC 4.0 | CHEMRXIV | 2023-07-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64b8e251b605c6803b0c5229/original/vibrio-vulnificus-marine-pathogen-detection-with-thin-film-impedance-biosensors.pdf |
60c758669abda21c56f8e8d5 | 10.26434/chemrxiv.14547396.v1 | Nitrogen-Substitution in the Flapping Wings of Cyclooctatetraene-Fused Molecules | New synthetic protocols to the nitrogen-embedded flapping molecules have been developed. Gram-scale synthesis of a key precursor, tetraamine of dibenzo[<i>a</i>,<i>e</i>]cyclooctatetraene has been established for designing flapping quinoxaline and flapping phenazineimide. The impact of the nitrogen substitution on the photophysical properties and the viscosity-probing function has been investigated in comparison with the reported flapping anthraceneimide. | Kensuke Suga; Takuya Yamakado; Shohei Saito | Organic Synthesis and Reactions; Photochemistry (Org.); Physical Organic Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2021-05-07 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c758669abda21c56f8e8d5/original/nitrogen-substitution-in-the-flapping-wings-of-cyclooctatetraene-fused-molecules.pdf |
63a885c7dadddc16ca9adc6f | 10.26434/chemrxiv-2022-vr9n1 | Inserted Hydrogen Promotes Oxidation Catalysis of Mixed Ru0.3Ti0.7O2 as Exemplified with Propane Combustion and the HCl Oxidation Reaction | The solid solution of a reducible oxide with a (non or) less reducible oxide may open the way to incorporate substantial amounts of hydrogen by the simple exposure to H2 at elevated temperatures, as exemplified by the mixture of RuO2 and TiO2. We are able to incorporate 17.6 mol% hydrogen into the mixed oxide Ru0.3Ti0.7O2 by H2 exposure at 250 °C, while this is not possible for pure RuO2 and rutile TiO2 that is either reduced to metallic Ru or does not allow for hydrogen absorption, respectively. Hydrogenated Ru0.3Ti0.7O2 may be utilized in hydrogenation catalysis. In this study, however, we demonstrate that hydrogen-incorporated Ru0.3Ti0.7O2 improves substantially the catalytic performance in oxidation reactions such as the propane combustion and HCl oxidation reaction. Hydrogen induced lattice strain in Ru0.3Ti0.7O2 accompanied with altered electronic properties is likely to be the reason for the observed enhanced catalytic activity. Hydrogen treatment can be performed in the reactor, thus providing an additional parameter to fine-tune in situ the catalytic performance of a mixed oxide catalyst. | Wei Wang; Phillip Timmer; Alexander Spriewald-Luciano; Yu Wang; Tim Weber; Lorena Glatthaar; Yun Guo; Bernd Smarsly; Herbert Over | Catalysis; Heterogeneous Catalysis; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2022-12-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63a885c7dadddc16ca9adc6f/original/inserted-hydrogen-promotes-oxidation-catalysis-of-mixed-ru0-3ti0-7o2-as-exemplified-with-propane-combustion-and-the-h-cl-oxidation-reaction.pdf |
64ccd98adfabaf06ffb0760a | 10.26434/chemrxiv-2023-cxlm1-v3 | 109Ag NMR Chemical Shift as a Descriptor for Brønsted Acidity from Molecules to Materials | Molecular-level understanding of the acid/base properties of heterogeneous catalysts requires the development of selective spectroscopic probes to establish structure-activity relationships. In this work we show that substituting the surface protons in oxide supports by isolobal N-heterocyclic carbene (NHC) Ag cations and measuring their 109Ag nuclear magnetic resonance (NMR) signatures enables to probe the speciation and to evaluate the corresponding Brønsted acidity of the substituted OH surface sites. Specifically, a series of silver N-heterocyclic carbene (NHC) Ag(I) complexes of general formula [(NHC)AgX] are synthesized and characterized, showing that the 109Ag NMR chemical shift of the series correlates with the Brønsted acidity of the conjugate acid of X- (i.e., HX), thus establishing an acidity scale based on 109Ag NMR chemical shift. The methodology is then used to evaluate the Brønsted acidity of the OH sites of representative oxide materials using Dynamic Nuclear Polarization (DNP-)enhanced solid-state NMR spectroscopy. | Colin Hansen; Scott R. Docherty; Weicheng Cao; Alexander V. Yakimov; Christophe Copéret | Inorganic Chemistry; Catalysis; Organometallic Chemistry; Organometallic Compounds; Spectroscopy (Inorg.); Heterogeneous Catalysis | CC BY NC 4.0 | CHEMRXIV | 2023-08-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64ccd98adfabaf06ffb0760a/original/109ag-nmr-chemical-shift-as-a-descriptor-for-br-nsted-acidity-from-molecules-to-materials.pdf |
60c7566b469df4f62af452e4 | 10.26434/chemrxiv.14245712.v1 | On the Activation of PhICl2 with Pyridine | <div>It has been previously proposed that pyridines can activate PhICl2 by displacing a chloride and forming the [PhI(Pyr)(Cl)]+ cation as a reactive intermediate. Here we show that pyridine does not displace chloride, but rather forms a weak complex with the iodine via halogen bonding along the C-I bond axis. This interaction is investigated by NMR, structural, charge density and theoretical investigations, which all indicate the pyridine does not activate PhICl2 as proposed.</div><div><br /></div> | Tiffany Poynder; Analia Orue; Tania _; Lachlan Sharp-Bucknall; Matthew Flynn; David
J. D. Wilson; Kasun Athukoroala; Jack K. Clegg; Jason Dutton | Coordination Chemistry (Inorg.); Kinetics and Mechanism - Inorganic Reactions; Crystallography – Inorganic | CC BY NC ND 4.0 | CHEMRXIV | 2021-03-19 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7566b469df4f62af452e4/original/on-the-activation-of-ph-i-cl2-with-pyridine.pdf |
67d1839e81d2151a021e0b79 | 10.26434/chemrxiv-2025-9n9k7-v2 | Unveiling Chemomechanical Degradation in Aqueous Batteries with Online Acoustic Emission Sensing | Online acoustic emission (AE) sensing is a promising nondestructive technique for battery health monitoring. Herein, we report on the ability of AE sensing to differentiate among different chemomechanical degradation events in a TiS2-based model aqueous chemistry. Short and high-frequency AE signals primarily stem from fracture-related degradation of TiS2, such as layer delamination, exfoliation, and cracking. Longer and lower-frequency signals originate from gas bubbles bursting when the cell is cycled outside the water stability window. The two processes demonstrate distinct AE features, allowing them to be semi-quantitatively distinguished from both time and frequency domains. Complementary physicochemical characterizations have been conducted to correlate with the AE observation, including online electrochemical mass spectrometry, operando synchrotron X-ray diffraction, and ex situ scanning electron microscopy. Our work indicates that online AE sensing holds the promise to identify complex chemomechanical degradation processes in rechargeable batteries. | Inti Espinoza Ramos; Ziyin Guo; Rebecca Clulow; Boyang Su; Qi Zhao; Frederik Holm Gjørup; Annika Ahlberg Tidblad; Leiting Zhang | Materials Science; Analytical Chemistry; Energy; Analytical Apparatus; Energy Storage | CC BY NC ND 4.0 | CHEMRXIV | 2025-03-13 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67d1839e81d2151a021e0b79/original/unveiling-chemomechanical-degradation-in-aqueous-batteries-with-online-acoustic-emission-sensing.pdf |
6667047712188379d8c610a6 | 10.26434/chemrxiv-2024-b186s | TADF mechanism in a carbene-copper emitter: Insights from the nuclear ensemble simulations | We use the nuclear ensemble approach to study the mechanism of thermally activated delayed fluorescence (TADF) in a carbene-copper-amide (CMA1) emitter. The results obtained for the emitter in the gas phase are consistent with previously published surface hopping non-adiabatic dynamics simulations for the same system. CMA1 has two excited-state conformations with distinct excited state dynamics. For both conformations, the intersystem crossing (ISC) from the S1 state occurs via higher-lying triplets, but the reverse ISC (rISC) can occur exclusively in the perpendicular orientation of the ligands, directly between the T1 and S1 states. Non-adiabatic mixing with higher triplet states is not required for efficient rISC, but T1 changes diabatic character significantly along the vibrational modes. Furthermore, we find that the inclusion of the solvent effects has a significant impact on the TADF mechanism, enabling rISC in both conformations. The calculated rate constants and lifetimes are within an order of magnitude of the experimental values. | Laure de Thieulloy; Leonardo Evaristo de Sousa; Piotr de Silva | Theoretical and Computational Chemistry; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-06-11 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6667047712188379d8c610a6/original/tadf-mechanism-in-a-carbene-copper-emitter-insights-from-the-nuclear-ensemble-simulations.pdf |
60c750f2bdbb897a3da39fb0 | 10.26434/chemrxiv.13102307.v1 | Catalytic Asymmetric Reductive Alkylation of Enamines to Chiral Aliphatic Amines | <p>Herein, we report a mild and
general nickel-catalysed asymmetric reductive alkylation to effectively
convert enamines—a class of important yet underexploited feedstock
chemicals—into drug-like α-branched chiral amines and derivatives. This
reaction involves the regio- and stereoselective hydrometallation of an
enamine to generate a catalytic amount of enantioenriched alkylnickel
intermediate, followed by C–C bond formation via alkyl electrophiles.</p> | Jia-Wang Wang; Yan Li; Wan Nie; Zhe Chang; Zi-An Yu; Yi-Fan Zhao; Xi Lu; Yao Fu | Homogeneous Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 2020-10-16 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c750f2bdbb897a3da39fb0/original/catalytic-asymmetric-reductive-alkylation-of-enamines-to-chiral-aliphatic-amines.pdf |
6332e752ea6a224bd4ffcf78 | 10.26434/chemrxiv-2022-q747m | Hierarchical organization of structurally colored cholesteric phases of cellulose via 3-d printing | Structural color—a widespread phenomenon observed throughout nature is caused by light interference from ordered phases of matter. While state-of-the-art nanofabrication techniques can produce structural organization in small areas, we still lack a cost-effective, and scalable techniques to generate tunable color at sub-micron length scales. In this work, we produced structurally colored hydroxypropyl cellulose filaments with a suppressed angular color response by 3-d printing. Our systematic study of the morphology of the filaments reveals the key stages in the induction of a two-degree hierarchical order through 3-d printing. The first degree of order originates from the changing of the cholesteric pitch at a few hundred nm scale via chemical modification and tuning of the solid content of the lyotropic phase. Upon 3-d printing, the secondary hierarchical order of periodic wrinkling was introduced through the Helfrich-Hurault deformation of the shear-aligned cholesteric phases. Our work reveals the mechanism of the wrinkling behavior evidenced by detailed morphological characterization using SEM. In single layered filaments, we identified four morphological zones with varying order of wrinkles. Through this work, we demonstrate the possibility of modifying the wrinkling behavior and thus the angle dependence of the color response by changing the printing conditions. | Tadeusz Balcerowski; Burak Ozbek; Ozge Akbulut; Ahu Gümrah DUMANLI | Physical Chemistry; Materials Science; Liquid Crystals; Optical Materials; Self-Assembly; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2022-09-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6332e752ea6a224bd4ffcf78/original/hierarchical-organization-of-structurally-colored-cholesteric-phases-of-cellulose-via-3-d-printing.pdf |
66d1ea93a4e53c4876266f0a | 10.26434/chemrxiv-2024-gk1ws-v2 | Constrained Nuclear-Electronic Orbital QM/MM Approach for Simulating Complex Systems with Quantum Nuclear Delocalization Effects Incorporated | The hybrid quantum mechanics/molecular mechanics (QM/MM) approach, which combines the accuracy of quantum mechanical (QM) methods with the efficiency of molecular mechanics (MM) methods, is widely used in the study of complex systems. However, past QM/MM implementations often neglect or face challenges in addressing nuclear quantum effects, despite their crucial role in many key chemical and biological processes. Recently, our group developed the constrained nuclear-electronic orbital (CNEO) theory, a cost-efficient approach that accurately addresses nuclear quantum effects, especially quantum nuclear delocalization effects. In this work, we integrate CNEO with the QM/MM approach through the electrostatic embedding scheme and apply the resulting CNEO QM/MM to two hydrogen-bonded complexes. We find that both solvation effects and nuclear quantum effects significantly impact hydrogen bond structures and dynamics. Notably, in the glutamic acid - glutamate complex, which mimics a common low barrier hydrogen bond in biological systems, CNEO QM/MM accurately predicts nearly equal proton sharing between the two residues. With an accurate description of both quantum nuclear delocalization effects and environmental effects, CNEO QM/MM is a promising new approach for simulating complex chemical and biological systems. | Xianyuan Zhao; Zehua Chen; Yang Yang | Theoretical and Computational Chemistry; Physical Chemistry | CC BY 4.0 | CHEMRXIV | 2024-09-02 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66d1ea93a4e53c4876266f0a/original/constrained-nuclear-electronic-orbital-qm-mm-approach-for-simulating-complex-systems-with-quantum-nuclear-delocalization-effects-incorporated.pdf |
60c73d0e4c891913bdad1b5e | 10.26434/chemrxiv.5401951.v1 | Anharmonic Origin of Giant Thermal Displacements in the Metal-Organic Framework UiO-67 | Molecular dynamics simulations investigating the torsion of the BPDC linker in UiO-67 and IRMOF-10. | Katrine Svane; Jessica Bristow; Aron Walsh | Hybrid Organic-Inorganic Materials | CC BY 4.0 | CHEMRXIV | 2017-09-15 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73d0e4c891913bdad1b5e/original/anharmonic-origin-of-giant-thermal-displacements-in-the-metal-organic-framework-ui-o-67.pdf |
66755ac9c9c6a5c07a061d0b | 10.26434/chemrxiv-2024-rf0jn | Ni-Catalyzed Enantioselective Three-Component Reductive Alkylacylation of Enamides | Chiral alpha-amino ketones have found extensive applications as functional molecules. A nickel-catalyzed, enantioselective, and fully intermolecular three-component 1,2-alkylacylation of N-acyl enamides has been realized with tertiary alkyl bromides and carboxylic acid-derived electrophiles as the coupling reagents. This reductive coupling strategy is operationally simple, exhibiting broad substrate scope and excellent functional group tolerance using readily available starting materials and allowing rapid access to structurally complex α-amino ketone derivatives in high enantioselectivity. A suitable chiral biimidazoline ligand together with additional chelation of the amide carbonyl group in a Ni alkyl intermediate facilitates the enantioselective control by suppressing the background reaction, accounting for the excellent enantioselectivity. Mechanistic studies indicated intermediacy of radical species. | Jichao Xiao; Tingting Jia; Shuang Chen; Mengxiao Pan; Xingwei Li | Organic Chemistry; Catalysis; Organic Synthesis and Reactions; Stereochemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-06-21 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66755ac9c9c6a5c07a061d0b/original/ni-catalyzed-enantioselective-three-component-reductive-alkylacylation-of-enamides.pdf |
60c7555e337d6c2955e28bf6 | 10.26434/chemrxiv.14095649.v1 | Experimental and Computational Evidence of non-MEP Pathways in the Fragmentation and Rearrangement of Bicyclo[3.3.1] heptane Diazonium Ions | The non-minimum energy pathways on the fragmentation of bicyclic diazoniumions and subsequent carbocationic rearrangements has been studied by a combination of computational chemistry (MD simulations, IRC, stationary point analysis) and experiments (TR-IR and UV from ps to µs, NMR kinetics).<div><br /></div> | Bastian Wulff; Patrick Sakrausky; Katrin Adamczyk; Nils Huse; Julia Rehbein | Physical Organic Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2021-02-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7555e337d6c2955e28bf6/original/experimental-and-computational-evidence-of-non-mep-pathways-in-the-fragmentation-and-rearrangement-of-bicyclo-3-3-1-heptane-diazonium-ions.pdf |
6785104a81d2151a02ebdc93 | 10.26434/chemrxiv-2025-1vrmv | Bicyclic Sulfonium Pincer Ligand with a Thiatriptycenium Backbone - Synthesis and Applications in π-Acid Catalysis | A bicyclic PSP-pincer ligand featuring a sulfonium cation at the bridgehead position of its rigid triptycene-like scaffold was synthesized and metallated with a bis-cationic Pt(II) center. The resulting tris-cationic Pt(II) complex exhibits excellent photostability and improved catalytic performance compared to its analogue with the previously reported sulfonium pincer ligand. | Mohammad Zafar; Donia Shamali; Nitsan Barel; David Danovich; Yuri Tulchinsky | Organic Chemistry; Inorganic Chemistry; Catalysis; Ligands (Inorg.); Main Group Chemistry (Inorg.); Homogeneous Catalysis | CC BY 4.0 | CHEMRXIV | 2025-01-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6785104a81d2151a02ebdc93/original/bicyclic-sulfonium-pincer-ligand-with-a-thiatriptycenium-backbone-synthesis-and-applications-in-acid-catalysis.pdf |
626c81581033887f68ffcc46 | 10.26434/chemrxiv-2022-xhr1q | Structure and Dynamics of Adsorbed Dopamine on Solvated Carbon Nanotubes and in a CNT Groove | Advanced carbon microelectrodes are being developed for the in vivo detection of neurotransmitters, such as dopamine (DA), including many carbon nanotube (CNT) based electrodes. Our prior simulations of DA and dopamine-o-quinone (DOQ) on pristine, flat graphene showed rapid surface diffusion for all adsorbed species, but it is not known how CNT surfaces affect dopamine adsorption and surface diffusivity. In this work, we use molecular dynamics simulations to investigate the adsorbed structures and surface diffusion dynamics of DA and DOQ on CNTs of varying curvature and helicity. In addition, we study DA dynamics in a groove between two aligned CNTs to model the spatial constraints at the junctions within CNT assemblies. We find that the adsorbate diffusion on a solvated CNT surface depends upon curvature. However, this effect cannot be attributed to changes in the surface energy roughness because the lateral distributions of the molecular adsorbates are similar across curvatures, diffusivities on zigzag and armchair CNTs are indistinguishable, and the curvature dependence disappears in the absence of solvent. Instead, adsorbate diffusivities correlate with the vertical placement of the adsorbate's moieties, its tilt angle, its orientation along the CNT axis, and the number of waters in its first hydration shell -- all of which will influence its effective hydrodynamic radius. Finally, DA diffuses into and remains in the groove between a pair of aligned and solvated CNTs, enhancing diffusivity along the CNT axis. These first studies of surface diffusion on a CNT electrode surface are important for understanding the changes in diffusion dynamics of dopamine on nanostructured carbon electrode surfaces. | Qizhang Jia; B. Jill Venton; Kateri H. DuBay | Theoretical and Computational Chemistry; Computational Chemistry and Modeling | CC BY NC ND 4.0 | CHEMRXIV | 2022-05-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/626c81581033887f68ffcc46/original/structure-and-dynamics-of-adsorbed-dopamine-on-solvated-carbon-nanotubes-and-in-a-cnt-groove.pdf |
64abb7e4ba3e99daefd2b89f | 10.26434/chemrxiv-2023-szfgf | Calcium L-Malate and D-Tartarate Frameworks as Adjuvants for the Sustainable Delivery of Fungicide | Agrichemical adjuvants that combine a highly selective, efficient, and active mode of operation are critically needed to realize a more sustainable approach to their usage. Herein, we report the synthesis and full characterization of two new metal-organic frameworks (MOFs), termed UPMOF-1 and UPMOF-2, that were constructed from eco-friendly Ca2+ ions and naturally-occurring, low molecular weight plant acids, L-malic and D-tartaric acid, respectively. Upon structural elucidation of both MOFs, a widely-used fungicide, hexaconazole (Hex), was loaded on the structures reaching binding affinities of -5.0 and -3.5 kcal mol-1 and loading capacities of 63 and 62% for Hex@UPMOF-1 and Hex@UPMOF-2, respectively, as a result of the formation of stable host-guest interactions. Given the MOFs’ framework chemistry and predisposition to disassembly in relevant agricultural conditions, the sustained release kinetics were determined to show near quantitative release (98 and 95% for Hex@UPMOF-1 and Hex@UPMOF-2, respectively) after >500 h – a release profile drastical-ly different than the control (>80% release in 24 h), from which the high efficiency of these new systems was established. To confirm their high selectivity and activity, in vitro and in vivo studies were performed to illustrate the abilities of Hex@UPMOF-1 and Hex@UPMOF-2 to combat the known, aggressive pathogen Ganoderma boninense (G. boninense) that causes basal stem rot disease in oil palm. Accordingly, at an extremely low concentration of 0.05 μg mL-1, both Hex@UPMOF-1 and Hex@UPMOF-2 were demonstrated to completely inhibit (100%) G. boninense growth and during a 26-week in vivo nursery trial, the progression of basal stem rot infection was not only completely halted upon treatment with Hex@UPMOF-1 and Hex@UPMOF-2, but seedling growth accelerated given the additional nutrients supplied via the disassembly of the MOFs. This study represents a significant step forward in designing adjuvants to support the environ-mentally responsible use of agrichemical crop protection. | Nurul Farhana Ahmad Aljafree; Mohamad Firdaus Ahmad ; Umar Abd Aziz; Mostafa Yousefzadeh Borzehandani; Adila Mohamad Jaafar; Norhayu Asib; Ha Lac Nguyen; Mohamed Ibrahim Mohamed Tahir; Muhammad Alif Mohammad Latif; Kyle Cordova; Mohd Basyaruddin Abdul Rahman | Inorganic Chemistry; Agriculture and Food Chemistry; Food; Solid State Chemistry; Materials Chemistry; Crystallography – Inorganic | CC BY NC ND 4.0 | CHEMRXIV | 2023-07-11 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64abb7e4ba3e99daefd2b89f/original/calcium-l-malate-and-d-tartarate-frameworks-as-adjuvants-for-the-sustainable-delivery-of-fungicide.pdf |
65c3662be9ebbb4db9d7a430 | 10.26434/chemrxiv-2024-75qm5 | Volasertib: Stable Complexes with Albumin and Encapsulation into Alginate/Montmorillonite Bionanocomposites | In the present work, we study different physicochemical properties related to LADME processes of volasertib, a Polo-like kinase 1 inhibitor in advanced clinical trials. Firstly, the protonation equilibria, the extent of ionization at the physiological pH and pKa values of this drug are studied combining spectroscopic techniques and computational calculations. Secondly, the binding process of volasertib to the human serum albumin (HSA) protein is analyzed by fluorescence spectroscopy. We report a high affinity to HSA and their pharmacokinetic implications are discussed accordingly. Additionally, volasertib is encapsulated in an alginate/montmorillonite bionanocomposite as a proof of concept for an oral delivery nanocarrier. The physical properties of that nanocomposite as well as volasertib delivery kinetics are analyzed. | Jesús Fernández-Sainz; Diego Herrera-Ochoa; Pedro J. Pacheco-Liñán; Margarita Darder; José Albaladejo; Iván Bravo; Andrés Garzón Ruiz | Physical Chemistry; Biological and Medicinal Chemistry; Biophysics; Drug Discovery and Drug Delivery Systems; Spectroscopy (Physical Chem.) | CC BY NC ND 4.0 | CHEMRXIV | 2024-02-08 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65c3662be9ebbb4db9d7a430/original/volasertib-stable-complexes-with-albumin-and-encapsulation-into-alginate-montmorillonite-bionanocomposites.pdf |
63e9f0e69da0bc6b33d7f6cf | 10.26434/chemrxiv-2023-nkhr1 | Multiple Helicenes Defected by Heteroatoms and Heptagons with Narrow Emissions and Superior Photoluminescence Quantum Yields | The incorporation of heteroatoms and/or heptagons as the defects into helicenes expands the variety of chiroptical materials with novel properties. However, it is still challenging to construct novel boron-doped heptagon-containing helicenes with high photoluminescence quantum yields (PLQYs) and narrow full-width-at-half-maximum (FWHM) values. We report an efficient and scalable synthesis of a quadruple helicene 4Cz-NBN with two nitrogen-boron-nitrogen (NBN) units and a double helicene 4Cz-NBN-P1 bearing two NBN-doped heptagons, the latter could be formed via a two-fold Scholl reaction of the former. The helicenes 4Cz-NBN and 4Cz-NBN-P1 exhibit excellent PLQYs up to 99% and 65% with narrow FWHM of 24 nm and 22 nm, respectively. The emission wavelengths are tunable via stepwise titration experiments of 4Cz-NBN-P1 toward fluoride, enabling distinguished circularly polarized luminescence (CPL) from green, orange (4Cz-NBN-P1-F1) to yellow (trans/cis-4Cz-NBN-P1-F2) with near-unity PLQYs and broader circular dichroism (CD) ranges. The five structures of the aforementioned four helicenes were confirmed by single crystal X-ray diffraction analysis. This work provides a novel design strategy for construction non-benzenoid multiple helicenes exhibiting narrow emissions with superior PLQYs. | Dehui Tan; Jiaqi Dong; Qingliang Feng; Suning Wang; Deng-Tao Yang | Physical Chemistry; Organic Chemistry; Photochemistry (Physical Chem.); Structure; Materials Chemistry; Crystallography – Organic | CC BY NC 4.0 | CHEMRXIV | 2023-02-15 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63e9f0e69da0bc6b33d7f6cf/original/multiple-helicenes-defected-by-heteroatoms-and-heptagons-with-narrow-emissions-and-superior-photoluminescence-quantum-yields.pdf |
60c74ea4f96a00957a287b1a | 10.26434/chemrxiv.12781232.v1 | Quantum Machine Learning for Drug Discovery | <p>The growing public and private datasets focused on small molecules screened against biological targets or whole organisms <sup>1</sup> provides a wealth of drug discovery relevant data. Increasingly this is used to create machine learning models which can be used for enabling target-based design <sup>2-4</sup>, predict on- or off-target effects and create scoring functions <sup>5,6</sup>. This is matched by the availability of machine learning algorithms such as Support Vector Machines (SVM) and Deep Neural Networks (DNN) that are computationally expensive to perform on very large datasets and thousands of molecular descriptors. Quantum computer (QC) algorithms have been proposed to offer an approach to accelerate quantum machine learning over classical computer (CC) algorithms, however with significant limitations. In the case of cheminformatics, one of the challenges to overcome is the need for compression of large numbers of molecular descriptors for use on QC. Here we show how to achieve compression with datasets using hundreds of molecules (SARS-CoV-2) to hundreds of thousands (whole cell screening datasets for plague and <i>M. tuberculosis</i>) with SVM and data re-uploading classifier (a DNN equivalent algorithm) on a QC benchmarked against CC and hybrid approaches. This illustrates a quantum advantage for drug discovery to build upon in future.</p> | Kushal Batra; Kimberley M. Zorn; Daniel H. Foil; Eni Minerali; Victor O. Gawriljuk; Thomas R. Lane; sean ekins | Machine Learning; Artificial Intelligence; Quantum Computing; Chemoinformatics - Computational Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2020-08-10 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74ea4f96a00957a287b1a/original/quantum-machine-learning-for-drug-discovery.pdf |
6381ef660949e11b8456d21a | 10.26434/chemrxiv-2022-3xrg0 | Multi-objective optimization of thermoplastic CF/PEKK drilling through a hybrid method integrating NSGA-II and TOPSIS: an approach towards sustainable manufacturing | Carbon-fibre-reinforced-polyetherketonketone (CF/PEKK) has attracted increasing interest in the aviation industry due to its self-healing/recycling properties. However, its machining performance is not well understood and there is a lack of optimization study for minimizing its hole damage and improving the production efficiency. Here, we report the first multi-objective optimization study for CF/PEKK drilling. A hybrid optimization algorithm integrating NSGA-II and TOPSIS is deployed to obtain the Pareto solutions and rank the multiple solutions based on closeness to ideal solutions. To highlight the impact of different matrix properties on the optimization outcome, comparative study with conventional thermoset CF/epoxy was carried out for the first time. Experimental validation shows the proposed method can achieve 91.5-95.7% prediction accuracy and the Pareto solutions effectively controlled the delamination and thermal damage within permissible tolerance. The vastly different optimal drilling parameters identified for CF/PEKK and CF/epoxy is attributed to the thermoplastic nature of CF/PEKK with unique thermal/mechanical interaction characteristics. | Jia Ge; Wenchang Zhang; Ming Luo; Giuseppe Catalanotti; Brian. G Falzon; Colm Higgins; Dinghua Zhang; Yan Jin; Dan Sun | Materials Science; Polymer Science; Composites | CC BY 4.0 | CHEMRXIV | 2022-11-29 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6381ef660949e11b8456d21a/original/multi-objective-optimization-of-thermoplastic-cf-pekk-drilling-through-a-hybrid-method-integrating-nsga-ii-and-topsis-an-approach-towards-sustainable-manufacturing.pdf |
65d41b129138d231617e67b2 | 10.26434/chemrxiv-2023-wwhbn-v2 | Evidence for Dearomatizing Spirocyclization and Dynamic Effects in the Nitrogen Deletion of Tetrahydroisoquinolines | Selectivity in organic chemistry is generally presumed to arise from energy differences between competing selectivity-determining transition states. However, in cases where static DFT fails to reproduce experimental product distributions, dynamic effects can be examined to understand the behavior of more complex reaction systems. Previously, we reported a method for nitrogen deletion of secondary amines which relies of the formation of isodiazene intermediates that subsequently extrude dinitrogen with concomitant C-C bond formation via a caged diradical. Herein, a detailed mechanistic analysis of the nitrogen deletion of 1-aryl-tetrahydroisoquinolines is presented, suggesting that in this system the previously determined diradical mechanism undergoes dynamically controlled partitioning to both the normal 1,5-coupling product and an unexpected spirocyclic dearomatized intermediate, which converges to the expected indane by an unusually facile 1,3-sigmatropic rearrangement. This mechanism is not reproduced by static DFT but is supported by quasi-classical molecular dynamics calculations and unifies several unusual observations in this system, including partial chirality transfer, non-statistical isotopic scrambling at the ethylene bridge, the isolation of spirocyclic dearomatized species in a related heterocyclic series, and the observation that introduction of an 8-substituent dramatically improves enantiospecificity. | Jeanne Masson-Makdissi; Remy Lalisse; Mingbin Yuan; Balu Dherange; Osvaldo Gutierrez; Mark Levin | Theoretical and Computational Chemistry; Organic Chemistry; Organic Synthesis and Reactions; Physical Organic Chemistry; Computational Chemistry and Modeling | CC BY NC ND 4.0 | CHEMRXIV | 2024-02-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65d41b129138d231617e67b2/original/evidence-for-dearomatizing-spirocyclization-and-dynamic-effects-in-the-nitrogen-deletion-of-tetrahydroisoquinolines.pdf |
673e646b7be152b1d0fc7d91 | 10.26434/chemrxiv-2024-dhs71 | The Effect of Viologen Counterions on the Topologies of La(III)–Tetraoxolene Coordination Frameworks | Lanthanoid containing coordination polymers have attracted significant attention due to their potential application in photoluminescence, high-density information storage, and chemical sensing. Controlling the connectivity of the frameworks is a crucial goal, as both the physical and chemical properties of these compounds are closely related to their network topologies. Two viologen cations have been investigated for their structure directing effects in the synthesis of La(III)–tetraoxolene frameworks containing F, Cl and Br substituents. The framework topologies obtained demonstrate the potential for viologen cations to influence the structure of the La–tetraoxolene coordination polymers through non-covalent interactions. | Yuying Feng; Martin van Koeverden; Carol Hua | Inorganic Chemistry; Coordination Chemistry (Inorg.); Lanthanides and Actinides; Supramolecular Chemistry (Inorg.) | CC BY NC ND 4.0 | CHEMRXIV | 2024-11-22 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/673e646b7be152b1d0fc7d91/original/the-effect-of-viologen-counterions-on-the-topologies-of-la-iii-tetraoxolene-coordination-frameworks.pdf |
62501027505f630a116f0df6 | 10.26434/chemrxiv-2022-xwn74 | Error quantification of phase transition quantities from cluster weighting calculations | The following article has been submitted to The Journal of Chemical Physics. After it is published, it will be found at https://aip.scitation.org/journal/jcp .
In this work, we investigate how uncertainties in experimental input data influence the results of quantum cluster equilibrium calculations.
In particular, we focus on the calculation of vaporization enthalpies and entropies of seven organic liquids, compare two computational approaches for their calculation and investigate how these properties are affected by changes in the experimental input data.
It is observed that the vaporization enthalpies and entropies show a smooth dependence on changes in the reference density and boiling point.
The reference density is found to have only a small influence of the vaporization thermodynamics, whereas the boiling point has a large influence on the vaporization enthalpy but only a small influence on the vaporization entropy.
Furthermore we employed the Gauss--Hermite estimator in order to quantify the error in the thermodynamic functions that stems from uncertainties in the experimental reference data at the example of the vaporization enthalpy of (R)-butan-2-ol.
We quantify the error as 30.95 J/mol.
Additionally we compare the convergence behaviour and computational effort of the Gauss--Hermite estimator with the Monte Carlo approach and show the superiority of the former.
By this, we present how uncertainty quantification can be applied to examples from theoretical chemistry. | Jan Blasius; Paul Zaby; Jürgen Dölz; Barbara Kirchner | Theoretical and Computational Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2022-04-08 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/62501027505f630a116f0df6/original/error-quantification-of-phase-transition-quantities-from-cluster-weighting-calculations.pdf |
66c4a4c020ac769e5f2a57dd | 10.26434/chemrxiv-2024-sctzb-v2 | Monomer-Recyclable Polyesters From Ring-Opening Polymeri-zation of a CO2/Butadiene-derived Tri-Substituted Six-Membered Lactone | The selective ring-opening homo-polymerization of CO2/butadiene-derived lactone monomers has emerged as an appealing approach for synthesizing chemically recyclable polyesters from CO2. Previous research has only concentrated on di-substituted six-membered lactones. In this study, a newly designed tri-substituted six-membered CO2/butadiene-derived lac-tone monomer, 3,3,6-triethyltetrahydro-2H-pyran-2-one (Et-HL), was polymerized successfully through selective ring-opening polymerization (ROP) using NaOMe, tBu-P4/BnOH, or tBu-P4. The tBu-P4/BnOH affords linear-poly(Et-HL) with typical living polymerization behaviors, while a maximum number-average molecular weight (Mn) of 1050 kg mol-1 and a dispersity (Đ) of 1.52 was achieved for cyclic-poly(Et-HL) using only tBu-P4. Similar thermal properties were found between poly(Et-HL) and polyHL derived from Et-HL’s di-substituted precursor, 3,6-diethyltetrahydro-2H-pyran-2-one (HL). The ceiling temperature (Tc) was calculated to be 265 K (-8℃) at [Et-HL]0 = 1.0 mol L-1 in THF for poly(Et-HL), which is only slightly lower than HL (Tc = -6℃, [HL]0 = 1.0 mol L-1). Catalytic methods were developed for monomer recycling of both linear- and cyclic-poly(Et-HL). Direct observation of key intermediates by Nuclear Magnetic Resonance (NMR) reveals the mechanistic differences between Et-HL and HL. tBu-P4 efficiently promotes the deprotonation of the α-hydrogen adjacent to the carbonyl in HL, presumably yielding an enolate as the nucleophile responsible for the initial ring opening in the for-mation of cyclic-polyHL. However, Et-HL's additional substituent prohibits this process, instead favoring direct attack on the ester bond of the monomer by tBu-P4 in the initial ring opening to afford cyclic-poly(Et-HL). A tail-to-head strain-releasing mechanism was proposed to rationalize the selective formation of cyclic polymers for both HL and Et-HL using only tBu-P4. In the case of linear polymers, HL and Et-HL share a similar mechanism involving initiator anion attacking the monomer ester bond. The topological shift from cyclic to linear for poly(Et-HL) is more sensitive to initiator: tBu-P4 ratio (1:1 vs polyHL's 10:1), reflecting the impact of the additional substituent in Et-HL. This work represents the first example for the ROP of six-membered lactones bearing more than 2 substituents, simultaneously offering fundamental understand-ing for the Thorpe-Ingold effect on the ROP of CO2/butadiene-derived six-membered lactones for the first time. | Jialin Xu; Yuxuan Niu; Bo-lin Lin | Polymer Science; Polymerization (Polymers) | CC BY NC ND 4.0 | CHEMRXIV | 2024-08-21 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66c4a4c020ac769e5f2a57dd/original/monomer-recyclable-polyesters-from-ring-opening-polymeri-zation-of-a-co2-butadiene-derived-tri-substituted-six-membered-lactone.pdf |
620d30df2168672e2d78b8f9 | 10.26434/chemrxiv-2022-lmgpq | N-Aminopyridinium Reagents as Traceless Activating Groups in the Synthesis of N-Aryl Aziridines | N-functionalized aziridines, which are both useful intermediates and are present in important synthetic targets, can be envisioned as arising from the direct addition of nitrenes (i.e., NR fragments) to olefinic substrates. The exceptional reactivity of most nitrenes, in particular with respect to unimolecular decomposition reactions, prevents general application of nitrene-transfer chemistry to the synthesis of N-functionalized aziridines. Here we describe a strategy for the synthesis of N-aryl aziridines based on 1) olefin aziridination with N-aminopyridinium reagents to afford N-pyridinium aziridines followed by 2) Ni-catalyzed C–N cross-coupling of the N-pyridinium aziridines with aryl boronic acids. The N-pyridinium aziridine intermediates also participate in ring-opening chemistry with a variety of nucleophiles to afford 1,2-aminofunctionalization products. Preliminary mechanistic investigations indicate aziridine cross-coupling proceeds via a noncanonical mechanism involving initial aziridine opening promoted by the bromide counterion of the Ni catalyst, C–N cross-coupling, and finally aziridine reclosure. Together, these results provide new opportunities to achieve selective incorporation of generic aryl nitrene equivalents in organic molecules. | Hao Tan; Samya Samanta; Asim Maity; David Powers | Organic Chemistry; Catalysis; Organic Compounds and Functional Groups; Organic Synthesis and Reactions | CC BY NC 4.0 | CHEMRXIV | 2022-02-17 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/620d30df2168672e2d78b8f9/original/n-aminopyridinium-reagents-as-traceless-activating-groups-in-the-synthesis-of-n-aryl-aziridines.pdf |
67ac78a081d2151a021fc300 | 10.26434/chemrxiv-2025-0zqll | Precision in peak parameter estimation for Gaussian and Lorentzian profiles: Guidelines for instrument optimization | The analysis of signal data plays a fundamental role across diverse scientific fields, where the high-precision estimation of peak parameters such as intensity, position, bandwidth, and area is essential for advancing scientific progress. However, understanding how these parameters are influenced by profile shape and instrumentation remains a key challenge, as these factors fundamentally determine the precision and efficiency of analytical measurements. To address this, we derive analytical solutions for the precision of Lorentzian profile peak parameters under Poisson noise constraints using the Cramér–Rao inequality and Fisher information. By comparing these precision limits with those of Gaussian profiles, we identify the peak characteristics that strongly influence parameter precision. Our results demonstrate that the profile slope and tail intensity are critical factors for estimating peak position and position differences, with Gaussian profiles exhibiting higher precision under identical conditions. Conversely, the weaker intensity–bandwidth correlation in Gaussian profiles contributes to their superior precision in intensity and bandwidth estimation. Additionally, Lorentzian profiles show a √3-fold improvement in area ratio precision over intensity ratio precision, surpassing the corresponding improvement in Gaussian profiles. This distinction arises from the larger area and stronger intensity–bandwidth correlation inherent in Lorentzian profiles. These findings highlight the significant impact of profile shape on peak parameter precision, providing essential guidance for decision-making in instrument design and analytical conditions. By integrating these analytical solutions with insights from analytical chemistry, we establish a theoretical framework linking peak parameter precision with instrument performance. This framework enables quantitative evaluation of the effects of equipment and experimental design improvements on measurement precision. As a practical application, we numerically demonstrate how enhanced instrument conditions improve the precision of isotope ratio measurements of CO2 using Raman spectroscopy. Our findings provide practical guidelines for instrument optimization and budget planning, ultimately supporting high-precision analytical applications. | Yuuki Hagiwara; Tatsu Kuwatani | Analytical Chemistry; Analytical Chemistry - General | CC BY NC ND 4.0 | CHEMRXIV | 2025-02-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67ac78a081d2151a021fc300/original/precision-in-peak-parameter-estimation-for-gaussian-and-lorentzian-profiles-guidelines-for-instrument-optimization.pdf |
60c7c737469df43596f45a9c | 10.26434/chemrxiv.7322183.v1 | Ab initio derived force fields for Zeolitic Imidazolate Frameworks: MOF-FF for ZIFs | <div>
<div>
<div>
<p>In this paper we parameterized in a consistent way a new force field for a range of
different zeolitic imidazolate framework systems (ZIF-8, ZIF-8(H), ZIF-8(Br) and ZIF-
8(Cl)), extending the MOF-FF parameterization methodology in two aspects. First,
we implemented the possibility to use periodic reference data in order to prevent the
difficulty of generating representative finite clusters. Second, a more efficient global
optimizer based on the covariance matrix adaptation evolutionary strategy (CMA-ES)
was employed during the parameterization process. We confirmed that CMA-ES, as
a state-of-the-art black box optimizer for problems on continuous variables, is more
suitable for force field optimization than the previous genetic algorithm. The obtained
force field was then fully validated with respect to static and dynamic properties. Much
effort was spent to ensure that the FF is able to describe the crucial linker swing effect
in a large number of ZIF-8 derivatives. For this reason we compared our force field to ab initio molecular dynamic simulations and found an accuracy comparable to those
obtained by different exchange–correlation functionals.
</p></div></div></div><div><div><div>
</div>
</div>
</div> | Johannes P. Dürholt; Guillaume Fraux; François-Xavier Coudert; Rochus Schmid | Computational Chemistry and Modeling; Theory - Computational | CC BY NC ND 4.0 | CHEMRXIV | 2018-11-12 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7c737469df43596f45a9c/original/ab-initio-derived-force-fields-for-zeolitic-imidazolate-frameworks-mof-ff-for-zi-fs.pdf |
63586a3855a0818fd6c5396d | 10.26434/chemrxiv-2022-kmbsn | Exploring 129Xe NMR parameters for structural investigation of biomolecules: relativistic, solvent, and thermal Effects | In recent years, the study of new probes has aroused great interest in the scientific community around the world. Therefore, in the present work, we present a potential candidate for a new spectroscopic probe, the Xe(CO)3(NNO) conjugated to 2-(4’-Aminophenyl) Benzothiazole complex, XeABT. For this proposal, chemical shift calculations at the DFT level were performed, thus, a factorial design was carried out in order to choose the best computational method. The best combination was the base function ZORA-def2-TZVP, with the functional PBE0 and considering the relativistic effects with the ZORA implementation. Our findings reveal that the 129Xe chemical shifts is affected by thermal and solvent effects and considering an enzymatic environment a significant decrease in δ(129Xe) values are observed, suggesting with the XeABT complex it may be a promising spectroscopic probe. | Mateus A. Gonçalves; Gustavo A. Andolpho; Elaine F. F. da Cunha; Teodorico C. Ramalho | Theoretical and Computational Chemistry; Biological and Medicinal Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2022-10-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63586a3855a0818fd6c5396d/original/exploring-129xe-nmr-parameters-for-structural-investigation-of-biomolecules-relativistic-solvent-and-thermal-effects.pdf |
642fe20d0784a63aeeb00251 | 10.26434/chemrxiv-2023-mvsxn | Coupled cluster finite temperature simulations of periodic materials via machine learning | Density functional theory is the workhorse of materials simulations. Unfortunately, the quality of results often varies depending on the specific choice of the exchange-correlation functional, and this significantly limits the predictive power of this approach. Coupled cluster theory, including single, double and perturbative triple particle-hole excitation operators, is widely considered as the `gold standard` of quantum chemistry as it can achieve chemical accuracy for non-strongly correlated applications. Because of the high computational cost, the application of coupled cluster theory in materials simulations is rare, and this is particularly true if finite-temperature properties are of interest for which molecular dynamics simulations have to be performed. By combining recent progress in machine learning models with low data requirements for energy surfaces and in the implementation of coupled cluster theory for periodic materials, we show that chemically accurate simulations of materials are practical and could soon become significantly widespread. As an example of this numerical approach, we consider the calculation of the enthalpy of adsorption of CO2 in a porous material. | Basile Herzog; Alejandro Gallo; Felix Hummel; Michael Badawi; Tomáš Bučko; Sébastien Lebègue; Andreas Grüneis; Dario Rocca | Theoretical and Computational Chemistry; Computational Chemistry and Modeling; Machine Learning | CC BY NC ND 4.0 | CHEMRXIV | 2023-04-10 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/642fe20d0784a63aeeb00251/original/coupled-cluster-finite-temperature-simulations-of-periodic-materials-via-machine-learning.pdf |
62680ac61033886c40fb3ed5 | 10.26434/chemrxiv-2022-cwdm2 | Synthesis and styrene copolymerization of novel hydroxy, methyl and methoxy ring-trisubstituted phenylcyanoacrylates | Novel hydroxy, methyl and methoxy ring-trisubstituted 2-methoxyethyl phenylcyanoacrylates, RPhCH=C(CN)CO2CH2CH2OCH3 (where R is 2,3-dimethyl-4-methoxy, 2,5-dimethyl-4-methoxy, 2,4-dimethoxy-6-methyl, 3,5-dimethoxy-4-hydroxy,
4-hydoxy-3,5-dimethyl, 2,3,4-trimethoxy, 2,4,5-trimethoxy, 2,4,6-trimethoxy, 3,4,5-trimethoxy) were prepared and copolymerized with styrene. The acrylates were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-trisubstituted benzaldehydes and 2-methoxyethyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C NMR. All the acrylates were copolymerized with styrene in solution with radical initiation (ABCN) at 70C. The compositions of the copolymers were calculated from nitrogen analysis.
| Mariah A. Byk; Althia J. Coyoc; Mariah S. Flowers; Werhawet Gebremeskel; Bogdan Gontar; Jose Gonzalez Jr; Patrick J. Hartrich; Anna C. Howell; Sara M. Rocus; William S. Schjerven; Gregory B Kharas | Organic Chemistry; Polymer Science | CC BY 4.0 | CHEMRXIV | 2022-04-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/62680ac61033886c40fb3ed5/original/synthesis-and-styrene-copolymerization-of-novel-hydroxy-methyl-and-methoxy-ring-trisubstituted-phenylcyanoacrylates.pdf |
6320b9de3940c2c95efdfe4a | 10.26434/chemrxiv-2022-99slz | Regioselective, efficient and scalable syntheses of 1,2-thiaselenanes | We develop the first regioselective syntheses of 1,2-thiaselenane-4-amine (TSA4) and 1,2-thiaselenane-5-amine (TSA5): redox-active motifs with high value in chemical biology, that until now were hindered by tedious synthesis. We leverage an aziridine intermediate and a kinetically controlled S-acylation for regioselective chalcogen installations. We optimise short, fast sequences with just one or two chromatographic steps that cheaply deliver these motifs on scale for high-throughput inhibitor screening, and provide a robust methodology for assembling other selenenylsulfides. | Lukas Zeisel; Martin S. Maier; Oliver Thorn-Seshold | Biological and Medicinal Chemistry; Organic Chemistry; Organic Compounds and Functional Groups; Organic Synthesis and Reactions; Chemical Biology | CC BY NC 4.0 | CHEMRXIV | 2022-09-14 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6320b9de3940c2c95efdfe4a/original/regioselective-efficient-and-scalable-syntheses-of-1-2-thiaselenanes.pdf |
65d512b7e9ebbb4db9d06893 | 10.26434/chemrxiv-2024-tzplt | Rapid and complete prediction of Madder natural dyes’ color and properties through computational method | Experimental chemists traditionally hold experimentation in high regard, but computational chemistry has the potential to revolutionize this perspective. Our work exemplifies this shift, employing computational methods such as Density Functional Theory (DFT), Time-Dependent Density Functional Theory (TD-DFT), and Quantum Mechanic/Molecular Mechanic (QM/MM) to delve into the realm of photodegradation of color. Focused on Madder dye, a natural and historical pigment renowned for its diverse color properties, we tackle challenges that traditional experimentation struggled to address. The historical difficulty in deciphering the spectroscopic properties of Madder's colorants due to extraction challenges, impurities, and high costs is overcome through computational spectroscopy techniques. By marrying computational insights with experimental data, we predict UV-Vis, color, and NMR spectra, considering factors like pH, solvent effects, and conformers. The study underscores the impact of solute-solvent interactions on reproducing experimental measurements, laying the foundation for a comprehensive database to understand color properties in cultural heritage. These initial findings pave the way for future exploration of complex systems like Madder lake. This transformative shift empowers researchers and scientists to conquer crucial challenges in comprehending the properties of ancient colors for cultural heritage preservation, advancing the development of durable bio-sourced colors, and discovering new color applications. | Linh TRAN; Romain BERRAUD-PACHE; Maguy JABER | Theoretical and Computational Chemistry; Physical Chemistry; Materials Science; Dyes and Chromophores | CC BY NC ND 4.0 | CHEMRXIV | 2024-02-21 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65d512b7e9ebbb4db9d06893/original/rapid-and-complete-prediction-of-madder-natural-dyes-color-and-properties-through-computational-method.pdf |
60c74a784c891914e3ad3224 | 10.26434/chemrxiv.12212942.v1 | Improved Thermoelectric Performance in N-Type Half-Heusler NbCoSn by Heavy-Element Pt Doping | Half-Heusler compounds with a valence electron count of 18, including ZrNiSn, ZrCoSb, and NbFeSb, are good thermoelec-tric materials owing to favourable electronic structures. Previous computational studies had predicted a high electrical power factor in another half-Heusler compound NbCoSn, but it has not been extensively investigated experimentally. Herein, the synthesis, structural characterization, and thermoelectric properties of the heavy-element Pt-doped NbCoSn compounds are reported. Pt is found to be an effective dopant enabling the optimization of electrical power factor, simul-taneously leading to a strong point defect scattering of phonons, and thereby suppressing the lattice thermal conductivity. Annealing significantly improves the carrier mobility, which is ascribed to the decreased grain boundary scattering. As a result, a maximum power factor of ~3.4 mWm-1K-2 is obtained at 600 K. In conjunction with the reduced lattice thermal conductivity, a maximum figure of merit zT of ~0.6 is achieved at 773 K for the post-annealed NbCo0.95Pt0.05Sn, an increase of 100% compared to the undoped NbCoSn. This work highlights the important roles of the doping element and micro-structure on the thermoelectric properties of half-Heusler compounds<br /><p></p> | Federico Serrano Sanchez; Ting Luo; Junjie Yu; Wenjie Xie; Gudrun Auffermann; Anke Weidenkaff; Tiejun Zhu; Xinbing Zhao; José A. Alonso; Baptiste Gault; Claudia Felser; Chenguang Fu | Alloys; Piezoelectricity and Thermoelectricity | CC BY NC ND 4.0 | CHEMRXIV | 2020-04-29 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74a784c891914e3ad3224/original/improved-thermoelectric-performance-in-n-type-half-heusler-nb-co-sn-by-heavy-element-pt-doping.pdf |
648c70714f8b1884b7638f6f | 10.26434/chemrxiv-2023-zn3sb | Encapsulation in Charged Droplets Generates Distorted Host-Guest Complexes | The ability of various hydrogen-bonded resorcinarene-based capsules to bind alkylbisDABCOnium (DnD) guests of different lengths was investigated in solution and in the gas phase. While no host-guest interactions were detected in solution, encapsulation could be achieved in the charged droplets formed during electrospray ionisation (ESI), under conditions violating electroneutrality. This included guests which are far too long in their most stable conformation to fit inside the cavity of the capsules. A combination of three mass spectrometric techniques, collision-induced dissociation, hydrogen/deuterium exchange, and ion-mobility mass spectrometry together with computational modelling allow us to determine the binding mode of the DnD guests inside the cavity of the capsules. Significant distortions of the guest cation into horseshoe like arrangements are required to optimise cation-π interactions with the host. With longer guest, the capsules also adopt distorted geometries with partially open hydrogen-bonding seams. Such quasi “spring-loaded” capsules can form in the charged droplets during the ESI process as there is no competition between guest encapsulation and ion pair formation with the counterions that preclude encapsulation in solution. The encapsulation complexes are sufficiently stable in the gas phase – even when strained – because non-covalent interactions significantly strengthen in the absence of solvent. | Daniel Stares; Agnieszka Szumna; Christoph Schalley | Organic Chemistry; Analytical Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-06-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/648c70714f8b1884b7638f6f/original/encapsulation-in-charged-droplets-generates-distorted-host-guest-complexes.pdf |
656c7e4a5bc9fcb5c9f23f1c | 10.26434/chemrxiv-2023-4qzh8 | Visible-Light-Induced Exciton Dynamics and Trans-to-Cis Isomerization in Azobenzene Aggregates: Insights from Surface Hopping / Semiempirical Configuration Interaction Molecular Dynamics Simulations | Assemblies of photochromic molecules feature exciton states, which govern photochemical and photophysical processes in multichromophoric systems. Understanding photoinduced dynamics of the assemblies requires nonadiabatic treatment involving multiple exciton states and numerous nuclear degrees of freedom, thus posing a challenge for simulations. In this work, we address this challenge for aggregates of azobenzene, a prototypical molecular switch, performing on-the-fly surface hopping calculations combined with semiempirical configuration interaction electronic structure and augmented with transition density matrix analysis to characterize exciton evolution. Specifically, we consider excitation of azobenzene tetramers in the nπ* absorption band (located in the visible (blue) part of the electromagnetic spectrum) thus extending our recent work on dynamics after ππ* excitation (corresponding to the ultraviolet region) [Titov, J. Phys. Chem. C 2023, 127, 13678–13688]. We find that the nπ* excitons, which are initially strongly localized by ground state conformational disorder, undergo further (very strong) localization during short-time photodynamics. This excited-state localization process is extremely ultrafast, occuring within first 10 fs of photodynamics. We observe virtually no exciton transfer of the localized excitons in the nπ* manifold. However, the transfer may occur via secondary pathways involving ππ* states or the ground state. Moreover, we find that nπ* quantum yields of the trans-to-cis isomerization are reduced in the aggregated state. | Evgenii Titov | Theoretical and Computational Chemistry; Physical Chemistry; Nanoscience; Computational Chemistry and Modeling; Theory - Computational; Photochemistry (Physical Chem.) | CC BY 4.0 | CHEMRXIV | 2023-12-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/656c7e4a5bc9fcb5c9f23f1c/original/visible-light-induced-exciton-dynamics-and-trans-to-cis-isomerization-in-azobenzene-aggregates-insights-from-surface-hopping-semiempirical-configuration-interaction-molecular-dynamics-simulations.pdf |
64e4e239dd1a73847f4ef50b | 10.26434/chemrxiv-2023-cfnrh | Non-threaded isomers of sungsanpin and ulleungdin lasso peptides inhibit H1299 cancer cell migration | Lasso peptides are a structurally distinct class of biologically active natural products, defined by their short
sequences with impressively interlocked tertiary structures.
Their characteristic peptide [1]rotaxane motif confers marked proteolytic and thermal resiliency, and reports on their diverse biological functions have been credited to their exceptional sequence variability. Because of these unique properties, taken together with improved technologies for their biosynthetic production, lasso peptides are emerging as a designable scaffold for peptide-based therapeutic discovery and development. Although the defined structure of lasso peptides is recognized for its remarkable properties, the role of the motif for imparting bioactivity is less understood. For example, sungsanpin and ulleungdin are natural lasso peptides that similarly exhibit encouraging cell migration inhibitory activities in A549 lung carcinoma epithelial cells despite sharing only one-third sequence homology. We hypothesized that the shape of the lasso motif is beneficial for the preorganization of the conserved residues, which might be partially retained in variants lacking the threaded structure. Herein, we describe solid-phase peptide synthesis strategies to prepare acyclic, head-to-sidechain (branched), and head-to-tail (macrocyclic) cyclic variants based on the sungsanpin (Sun) and ulleungdin (Uln) sequences. Proliferation assays and timelapse cell motility imaging studies were used to evaluate the cell inhibitory properties of natural Sun compared alongside the synthetic Sun and Uln isomers. These studies demonstrate that the lasso motif is not a required feature to slow cancer cell migration, and more generally show that these non-threaded isomers can retain similar activity to the natural lasso peptide despite the differences in their overall structures. | Lori Digal; Shiela Samson; Mark Stevens; Abhijit Ghorai; Hyungyu Kim; Marcus Mifflin; Keith Carney; David Williamson; Soohyun Um; Gabe Nagy; Dong-Chan Oh; Michelle Mendoza; Andrew Roberts | Biological and Medicinal Chemistry; Organic Chemistry; Chemical Biology | CC BY NC ND 4.0 | CHEMRXIV | 2023-08-23 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64e4e239dd1a73847f4ef50b/original/non-threaded-isomers-of-sungsanpin-and-ulleungdin-lasso-peptides-inhibit-h1299-cancer-cell-migration.pdf |
65781a5b7acf130c320bc67a | 10.26434/chemrxiv-2023-71td6-v2 | Solar-Powered Molecular Crystal micro-Motor Based on an Anthracene-Thiazolidinedione Photoisomerization Reaction | We reported the synthesis and characterization of a new type of photoisomerizable molecule (Z)-5-(anthracen-9-ylmethylene)-3-butylthiazolidine-2,4-dione (C4-ATD), whose Z/E isomerization induces large geometry changes but only slight changes in its absorption profile. Acicular micro-molecular crystals made from C4-ATD were fabricated using the seeded growth method from aqueous surfactants. Large aspect ratio microwires exhibit robust and autonomous photomechanical oscillations under a variety of conditions, including normal solar irradiation. Preliminary experiments on other alkyl chain derivatives that contain the ATD motif suggest that oscillatory motion is a general characteristic of this family of molecular crystals. The combination of photochrome design and crystal engineering enables the concept of molecular machines fueled by light to be extended to molecular crystals, whose directional work can easily overcome Brownian noise in room-temperature liquids. | Kevin Lam; Imadul Islam; Veronica Carta; Mohammed N. Almtiri; Ibrahim Bushnak; RABIH O AL-KAYSI; Christopher J. Bardeen | Organic Chemistry; Photochemistry (Org.); Materials Chemistry; Crystallography – Organic | CC BY NC ND 4.0 | CHEMRXIV | 2023-12-12 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65781a5b7acf130c320bc67a/original/solar-powered-molecular-crystal-micro-motor-based-on-an-anthracene-thiazolidinedione-photoisomerization-reaction.pdf |
64e88b8579853bbd7866084c | 10.26434/chemrxiv-2023-kkk48-v2 | Impact of Hydrogen Concentration for CO2 reduction on PdHx | Pd hydride has shown better electrochemical CO2 reduction reaction (CO2RR) performance compared to metal Pd implying that H in the PdHx surface plays a vital role in affecting the performance. Using density functional theory (DFT) calculations in combination with active learning cluster expansion and Monte Carlo simulated annealing we identify 12 stable PdHx (111) configurations on the DFT convex hull and investigate the binding energies of intermediates in the CO2RR and the competing hydrogen evolution reaction. Through analysis of intermediate binding energies and a microkinetic model, we identify the atomic structures of the PdHx phase most likely to produce syngas. The high activity of the PdH0.6 surface can be attributed to the fact that H segregation in the PdHx (111) surface breaks the linear relation between COOH* and CO* adsorbates.Pd hydride has shown better electrochemical CO2 reduction reaction (CO2RR) performance compared to metal Pd implying that H in the PdHx surface plays a vital role in affecting the performance. Using density functional theory (DFT) calculations in combination with active learning cluster expansion and Monte Carlo simulated annealing we identify 12 stable PdHx (111) configurations on the DFT convex hull and investigate the binding energies of intermediates in the CO2RR and the competing hydrogen evolution reaction. Through analysis of intermediate binding energies and a microkinetic model, we identify the atomic structures of the PdHx phase most likely to produce syngas. The high activity of the PdH0.6 surface can be attributed to the fact that H segregation in the PdHx (111) surface breaks the linear relation between COOH* and CO* adsorbates. | Changzhi Ai; Jinhyun Chang; Alexander Tygesen; Tejs Vegge; Heine Anton Hansen | Physical Chemistry; Catalysis; Electrocatalysis; Electrochemistry - Mechanisms, Theory & Study; Surface; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2023-08-25 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64e88b8579853bbd7866084c/original/impact-of-hydrogen-concentration-for-co2-reduction-on-pd-hx.pdf |
625881d3ebac3a5bd9d522da | 10.26434/chemrxiv-2022-dzpcg | Mechanical Bond Enhanced Lithium Halide Ion-Pair Binding by Halogen Bonding Heteroditopic Rotaxanes | A family of novel halogen bonding (XB) and hydrogen bonding (HB) heteroditopic [2]rotaxane host systems constructed by active metal template (AMT) methodology, were studied for their ability to cooperatively recognise lithium halide (LiX) ion-pairs. 1H NMR ion-pair titration experiments in CD3CN:CDCl3 solvent mixtures revealed a notable “switch-on“ of halide anion binding in the presence of a co-bound lithium cation, with rotaxane hosts demonstrating selectivity for LiBr over LiI. The strength of halide binding was shown to greatly increase with increasing number of halogen bond donors integrated into the interlocked cavity, where an all-XB rotaxane was found to be the most potent host for LiBr. DFT calculations corroborated these findings, determining the mode of LiX ion-pair binding. Notably, ion-pair binding was not observed with the corresponding XB/HB macrocycles alone, highlighting the cooperative heteroditopic rotaxane axle-macrocycle component mechanical bond effect as an efficient strategy for ion-pair recognition in general. | Vihanga Munasinghe; Jessica Pancholi; Dilhan Manawadu; Zongyao Zhang; Paul Beer | Theoretical and Computational Chemistry; Inorganic Chemistry; Organometallic Chemistry; Bonding; Main Group Chemistry (Inorg.); Coordination Chemistry (Organomet.) | CC BY NC ND 4.0 | CHEMRXIV | 2022-04-18 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/625881d3ebac3a5bd9d522da/original/mechanical-bond-enhanced-lithium-halide-ion-pair-binding-by-halogen-bonding-heteroditopic-rotaxanes.pdf |
67124819cec5d6c142820790 | 10.26434/chemrxiv-2024-njm9t | Statistical Interaction Analyses on AgamOBP1 - DEET/Icaridin Complex | We performed a series of fragment molecular orbital (FMO) calculations on the droplet models of the complex formed between the mosquito (Anopheles gambiae) odorant binding protein (AgamOBP1) and two typical repellents (DEET and Icaridin). The interaction energies with the amino acid residues at the binding sites were then statistically evaluated and the differences between these two ligands were revealed. | Kazuki Akisawa; Yurina Sakuma; Akiko Tsukamoto; Hideo Doi; Koji Okuwaki; Yoshinori Hirano; Eiji Yamamoto; Kenji Yasuoka; Yuji Mochizuki | Theoretical and Computational Chemistry; Biological and Medicinal Chemistry; Drug Discovery and Drug Delivery Systems; Computational Chemistry and Modeling | CC BY NC ND 4.0 | CHEMRXIV | 2024-10-21 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/67124819cec5d6c142820790/original/statistical-interaction-analyses-on-agam-obp1-deet-icaridin-complex.pdf |
6704530012ff75c3a1c36ad8 | 10.26434/chemrxiv-2024-78tt8-v2 | DC24: A New Density Coherence Functional for Multiconfiguration Density-Coherence Functional Theory | In this study, we explored several alternative functional forms to construct more accurate and more physical density coherence functionals for multiconfiguration density-coherence functional theory. Each functional is parameterized against the same database as used in our previous work. The best density coherence functional, which is called DC24, has a more physical interpretation, and – as a side benefit – it also has a mean unsigned error of 1.73 kcal/mol, which is a 9% improvement as compared to the previous functional. The article also contains a new definition of the unpaired electron density, which may be useful in other contexts as well. | Dayou Zhang; Yinan Shu; Donald G. Truhlar | Theoretical and Computational Chemistry; Computational Chemistry and Modeling; Theory - Computational | CC BY 4.0 | CHEMRXIV | 2024-10-08 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6704530012ff75c3a1c36ad8/original/dc24-a-new-density-coherence-functional-for-multiconfiguration-density-coherence-functional-theory.pdf |
61b3e0b125f39a3ea7d5b294 | 10.26434/chemrxiv-2021-0brbt | Waste apple pomace conversion to acrylic acid: Economic and environmental assessment | The global demand for acrylic acid (AA) is increasing due to its wide range of applications. Due to this growing demand, alternative AA production strategies must be explored to avoid the exacerbation of prevailing climate and global warming issues since current AA production strategies involve AA production using fossil resources. Investigations on alternative strategies for AA production therefore constitute an important research interest. The present study therefore assesses waste apple pomace (WAP) as a feedstock for the sustainable AA produc-tion. To undertake this assessment, process models, based on two production pathways were designed, modelled and simulated in ASPEN plus® software. The two competing production pathways investigated include a process incorporating WAP conversion to lactic acid (LA), prior to LA dehydration to generate AA (denoted as the FD pathway) and another process involving WAP conversion to propylene, prior to propylene oxidation to generate AA (denoted as the TFO pathway). Economic and environmental performances of the FD and TFO pathways were assessed via the minimum selling price (MSP) and potential environmental impacts per h (PEI/h) metrics. The study was able to show that the FD pathway presented an improved economic performance (MSP of AA: US $1.17 per kg) performance compared to the economic performance (MSP of AA: US $1.56 per kg) of the TFO pathway. Crucially, the TFO process was shown to present an improved environmental performance (2.07 kPEI/h) compared to the environmental performance of the FD process (8.72 kPEI/h). These observations sug-gests that the selection of the preferred AA production will require a trade-off between the performance measures, and the integration of a multi-criteria decision assessment in future work. | Oseweuba Okoro; Lei Nie; Houman Alimoradi; Amin Shavandi | Chemical Engineering and Industrial Chemistry; Natural Resource Recovery | CC BY NC 4.0 | CHEMRXIV | 2021-12-13 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/61b3e0b125f39a3ea7d5b294/original/waste-apple-pomace-conversion-to-acrylic-acid-economic-and-environmental-assessment.pdf |
60c74b60842e655c2ddb313c | 10.26434/chemrxiv.12317546.v1 | Bond Valence Sum: A Powerful Tool for Determination of Oxidation States of Metal Ions in Coordination Compounds | Transition metal ions in coordination compounds can
adopt different oxidation states. The Bond Valence Sum (BVS) model, based
solely on structural information, relates the bond lengths around a metal center
to its oxidation state. This model can provide details on the oxidation states
of the metal ions and serves as an additional support for the accuracy of crystal
structure determination. Herein, we introduce the fundamental concept of the BVS
method and summarize the empirical BVS parameters for selective metal ions that
have more than one oxidation state. Applications of the method to mononuclear
and polynuclear complexes will be discussed. | Tu Nguyen | Coordination Chemistry (Inorg.) | CC BY NC ND 4.0 | CHEMRXIV | 2020-05-19 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c74b60842e655c2ddb313c/original/bond-valence-sum-a-powerful-tool-for-determination-of-oxidation-states-of-metal-ions-in-coordination-compounds.pdf |
65188056a69febde9efe46b6 | 10.26434/chemrxiv-2023-c6qp1-v3 | A Simple Electron-Density Based Force Field Model for High-Energy Interactions between Atoms and Molecules | In high-energy molecular dynamics or Monte-Carlo simulations, standard force fields that are optimised for simulations at ambient temperature are inadequate. This is largely because their repulsive part has been regarded as not very significant even well below zero interaction energy. It is therefore not obvious which force fields to resort to for simulating hot gases or plasmas. A Force Field model which uses the electronic densities of non-interacting atoms or molecules within the pair approximation is introduced. We start by deriving a naïve model that neglects any exchange and correlation effects between the electronic clouds and then correct this model by adding a term calibrated from ab initio calculations using CCSD(T)/cc-pVTZ level of theory. The resulting expression can be regarded as a simple exchange-correlation functional. We compare the results for the repulsive part of the potential energy hyper-surfaces with force fields commonly used on some dimers of small molecules. | José Romero; Paulo Limão-Vieira; Kersti Hermansson; Michael Probst | Theoretical and Computational Chemistry; Physical Chemistry; Computational Chemistry and Modeling; Quantum Mechanics | CC BY 4.0 | CHEMRXIV | 2023-10-03 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/65188056a69febde9efe46b6/original/a-simple-electron-density-based-force-field-model-for-high-energy-interactions-between-atoms-and-molecules.pdf |
60c7573f4c89196bfbad499e | 10.26434/chemrxiv.14345639.v2 | Requirements of Orbital Phase Continuity Revisited: A FMO Approach | <div>
<p>Cyclic orbital interaction, in which a
series of orbitals interact with each other so as to make a monocyclic system,
affords stabilization if the requirements of orbital phase continuity are
satisfied. Initially, these requirements were derived from the consideration of
a three-body system. Here I propose that these requirements can be easily derived by
considering FMO theory. </p>
</div> | Yuji Naruse | Theory - Computational; Physical and Chemical Properties | CC BY NC ND 4.0 | CHEMRXIV | 2021-04-02 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7573f4c89196bfbad499e/original/requirements-of-orbital-phase-continuity-revisited-a-fmo-approach.pdf |
63475ea4bb6d8b1a0f568827 | 10.26434/chemrxiv-2022-dlthj | “Magic” sinter-resistant cluster sizes of Ptn supported on Alumina | Subnano cluster catalysts, while highly promising due to unique activity, selectivity, and atom-efficiency, are limited in wider applications, as they are prone to deactivation via sintering. Even size-selection, which was previously shown to reduce sintering of nanoparticles, cannot reduce the sintering of highly fluxional subnano clusters, due to their inherent isomeric diversity. Here, we use a combination of theory and experiment to show that Pt clusters on Al2O3 exhibit size-dependent sintering resistance. We furthermore show that Pt4/Al2O3 and Pt7/Al2O3 are “magic” sinter-resistant cluster sizes. Their stability is attributed to the greater degree of bulk-like crystallinity of the dominant isomers. In addition, we identify different spatial signatures characteristic of the sintering of clusters with differing sintering stabilities. | Patricia Poths; Zixiang Hong; Guangjing Li; Scott L. Anderson; Anastassia N. Alexandrova | Theoretical and Computational Chemistry; Physical Chemistry; Catalysis; Computational Chemistry and Modeling; Clusters; Interfaces | CC BY 4.0 | CHEMRXIV | 2022-10-13 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/63475ea4bb6d8b1a0f568827/original/magic-sinter-resistant-cluster-sizes-of-ptn-supported-on-alumina.pdf |
60c73e3e842e65807cdb18b0 | 10.26434/chemrxiv.6726437.v1 | Dramatic Improvement of Stability by In-Situ Linker Cyclization of a Metal-Organic Framework | We employ a two-step
strategy for accessing crystalline porous covalent networks of highly
conjugated π-electron systems. For this, we first assembled a crystalline
metal-organic framework (MOF) precursor based on Zr(IV) ions and a linear
dicarboxyl linker molecule featuring backfolded, highly unsaturated alkyne
backbones; massive thermocyclization of the organic linkers was then triggered
to install highly conjugated, fused-aromatic bridges throughout the MOF
scaffold while preserving the crystalline order. The formation of cyclized carbon
links not only greatly strengthen the precursor coordination scaffold, but more
importantly, enhance electroactivity and charge transport throughout the
polycyclic aromatic grid. | Yun-Long Hou; Mu-Qing Li; Shengxian Cheng; Yingxue Diao; Filipe Vilela; Yonghe He; Jun He; Zhengtao Xu | Hybrid Organic-Inorganic Materials; Main Group Chemistry (Organomet.); Reaction (Organomet.); Clusters | CC BY NC ND 4.0 | CHEMRXIV | 1970-01-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c73e3e842e65807cdb18b0/original/dramatic-improvement-of-stability-by-in-situ-linker-cyclization-of-a-metal-organic-framework.pdf |
60c758049abda2e025f8e825 | 10.26434/chemrxiv.14488821.v1 | Data for Molecular Dynamics Simulations of Escherichia Coli Cytochrome Bd Oxidase with the Amber Force Field | <div>
<div>
<div>
<div>
<p>Cytochrome <i>bd</i>-type quinol oxidase is an important metalloenzyme that allows many
bacteria to survive in low oxygen conditions. Since bd oxidase is found in many
prokaryotes but not in eukaryotes, it has emerged as a promising bacterial drug target.
Examples of organisms containing bd oxidases include the <i>Mycobacterium
tuberculosis (Mtb)</i> bacterium that causes tuberculosis (TB) in humans, the <i>Vibrio
cholerae</i> bacterium that causes cholera, the <i>Pseudomonas aeruginosa</i> bacterium
that contributes to antibiotic resistance and sepsis, and the <i>Campylobacter jejuni</i>
bacterium that causes food poisoning. <i>Escherichia coli (E. coli)</i> is another organism
exhibiting the cytochrome <i>bd</i> oxidase. Since it has the highest sequence identity to
<i>Mtb</i> (36 %) and we are ultimately interested in finding drug targets for TB, we have
built parameters for the <i>E. coli bd </i>oxidase (Protein Data Bank ID number: 6RKO) that
are compatible with the all-atom Amber ff14SB force field for molecular dynamics (MD)
simulations. Specifically, we built parameters for the three heme cofactors present in all
species of bacterial cytochrome <i>bd</i>-type oxidases (heme b<sub>558</sub>, heme b<sub>595</sub>, and
heme d) along with their axial ligands. This data report includes the parameter files that
can be used with Amber's LEaP program to generate input files for MD simulations
using the Amber software package. We also provide the PDB data files of the initial
model both by itself and solvated with TIP3P water molecules and counterions.
</p>
</div>
</div>
</div>
</div> | Surl-Hee Ahn; Christian Seitz; Vinicius Cruzeiro; James McCammon; Andreas Goetz | Biophysics; Drug Discovery and Drug Delivery Systems; Computational Chemistry and Modeling | CC BY NC ND 4.0 | CHEMRXIV | 2021-04-28 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c758049abda2e025f8e825/original/data-for-molecular-dynamics-simulations-of-escherichia-coli-cytochrome-bd-oxidase-with-the-amber-force-field.pdf |
64181b0daad2a62ca10c08ec | 10.26434/chemrxiv-2023-669wc | Ruthenium-catalysed C‒H amidation for the late-stage synthesis of PROTACs | PROteolysis TArgeting Chimeras (PROTACs) are a powerful modality in drug discovery, offering the potential to address outstanding medical challenges. However, the synthetic feasibility of PROTACs, and the empiric and complex nature of their structure-activity relationships continue to present formidable limitations. As such, modular and reliable approaches to streamline the synthesis of these compounds are highly desirable. Here, we describe a robust ruthenium-catalysed late-stage C‒H amidation strategy, to provide modular access to both fully elaborated PROTACs and drug conjugates. Using readily available dioxazolone reagents, a broad range of inherently present functional groups can guide the C–H amidation on complex bioactive molecules. High selectivity and functional group tolerance enable the late-stage installation of linkers bearing orthogonal functional handles for downstream elaboration. Finally, the single-step synthesis of PROTAC and biotin conjugates is demonstrated, showcasing the potential of this methodology to provide efficient and sustainable access to advanced therapeutics and chemical biology tools. | Daniele Antermite; Stig D. Friis; Johan R. Johansson; Okky D. Putra; Lutz Ackermann; Magnus J. Johansson | Biological and Medicinal Chemistry; Organic Chemistry; Catalysis; Organic Synthesis and Reactions; Drug Discovery and Drug Delivery Systems; Homogeneous Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 2023-03-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64181b0daad2a62ca10c08ec/original/ruthenium-catalysed-c-h-amidation-for-the-late-stage-synthesis-of-prota-cs.pdf |
615b42f90ad1ff19078a2c65 | 10.26434/chemrxiv-2021-hstgf-v3 | Elevating Density Functional Theory to Chemical Accuracy for Water Simulations through a Density-Corrected Many-Body Formalism | Density functional theory (DFT) has been extensively used to model the properties of water. Albeit maintaining a good balance between accuracy and efficiency, no density functional has so far achieved the degree of accuracy necessary to correctly predict the properties of water across the entire phase diagram. Here, we present density-corrected SCAN (DC-SCAN) calculations for water which, minimizing density-driven errors, elevate the accuracy of the SCAN functional to that of “gold standard” coupled-cluster theory. Building upon the accuracy of DC-SCAN within a many-body formalism, we introduce a data-driven many-body potential energy function, MB-SCAN(DC), that quantitatively reproduces coupled cluster reference values for interaction, binding, and individual many-body energies of water clusters. Importantly, molecular dynamics simulations carried out with MB-SCAN(DC) also reproduce the properties of liquid water, which thus demonstrates that MB-SCAN(DC) is effectively the first DFT-based model that correctly describes water from the gas to the liquid phase. | Saswata Dasgupta; Eleftherios Lambros; John Perdew; Francesco Paesani | Theoretical and Computational Chemistry; Physical Chemistry; Theory - Computational; Machine Learning; Quantum Mechanics; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2021-10-05 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/615b42f90ad1ff19078a2c65/original/elevating-density-functional-theory-to-chemical-accuracy-for-water-simulations-through-a-density-corrected-many-body-formalism.pdf |
60c75218702a9b054418c07b | 10.26434/chemrxiv.12185427.v3 | Ground-State Destabilization by Active-Site Hydrophobicity Controls the Selectivity of a Cofactor- Free Decarboxylase | <div>
<div>
<p>
</p><div>
<div>
<div>
<p>Bacterial arylmalonate decarboxylase (AMDase) and evolved variants have become a valuable
tool with which to access both enantiomers of a broad range of chiral arylaliphatic acids with high
optical purity. Yet, the molecular principles responsible for the substrate scope, activity and
selectivity of this enzyme are only poorly understood to this day, greatly hampering the
predictability and design of improved enzyme variants for specific applications. In this work,
empirical valence bond and metadynamics simulations were performed on wild-type AMDase and
variants thereof, to obtain a better understanding of the underlying molecular processes
determining reaction outcome. Our results clearly reproduce the experimentally observed substrate
scope, and support a mechanism driven by ground-state destabilization of the carboxylate group
being cleaved by the enzyme. In addition, our results indicate that, in the case of the non-converted
or poorly-converted substrates studied in this work, increased solvent exposure of the active site
upon binding of these substrates can disturb the vulnerable network of interactions responsible for
facilitating the AMDase-catalyzed cleavage of CO2. Finally, our results indicate a switch from
preferential cleavage of the pro-(R) to the pro-(S) carboxylate group in the CLG-IPL variant of
AMDase for all substrates studied. This appears to be due to the emergence of a new hydrophobic
pocket generated by the insertion of the six amino acid substitutions, into which the pro-(S)
carboxylate binds. Our results allow insight into the tight interaction network determining
AMDase selectivity, which in turn provides guidance for the identification of target residues for
future enzyme engineering. </p>
</div>
</div>
</div>
</div>
</div> | Michal Biler; Rory Crean; Anna K. Schweiger; Robert Kourist; Shina Caroline Lynn Kamerlin | Computational Chemistry and Modeling | CC BY NC ND 4.0 | CHEMRXIV | 2020-11-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c75218702a9b054418c07b/original/ground-state-destabilization-by-active-site-hydrophobicity-controls-the-selectivity-of-a-cofactor-free-decarboxylase.pdf |
62133f817a054addd614f4b5 | 10.26434/chemrxiv-2022-j85br | Polymer selection impacts the pharmaceutical profile of site specifically conjugated Interferon-α2a | Conjugation of poly(ethylene glycol) (PEG) to biologics is a successful strategy to favorably impact the pharmacokinetics and efficacy of the resulting bioconjugate. We compare bioconjugates synthesized by strain-promoted azide-alkyne cycloaddition (SPAAC) using PEG and linear polyglycerol (LPG) of about 20 kDa or 40 kDa, respectively, with an azido functionalized human Interferon-α2a (IFN-α2a) mutant. Site specific PEGylation and LPGylation resulted in IFN-α2a bioconjugates with improved in vitro potency as compared to commercial Pegasys. LPGylated bioconjugates had faster disposition kinetics despite comparable hydrodynamic radii to their PEGylated analogues. Overall exposure of the PEGylated IFN-α2a with a 40 kDa polymer exceeded Pegasys which, in return, was comparable to the 40 kDa LPGylated conjugates. The study points to an expanded polymer design space by means of which the selected polymer class may result in different distribution of the studied bioconjugates. | Niklas Hauptstein; Paria Pouyan; Kevin Wittwer; Gizem Cinar; Oliver Scherf-Clavel; Martina Raschig; Kai Licha; Tessa Lühmann; Ivo Nischang; Ulrich S. Schubert; Christian Pfaller; Rainer Haag; Lorenz Meinel | Biological and Medicinal Chemistry; Polymer Science; Bioengineering and Biotechnology | CC BY NC 4.0 | CHEMRXIV | 2022-02-22 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/62133f817a054addd614f4b5/original/polymer-selection-impacts-the-pharmaceutical-profile-of-site-specifically-conjugated-interferon-2a.pdf |
611c1b431adf937711f91854 | 10.26434/chemrxiv-2021-g8vm4 | In Silico Discovery of Multistep Chemistry Initiated by a Conical Intersection: The Challenging Case of Donor Acceptor Stenhouse Adducts | Detailed mechanistic understanding of multistep chemical reactions triggered by internal conversion via a conical intersection is a challenging task that emphasizes limitations in theoretical and experimental techniques. Hypothesis-driven methodologies (e.g. characterization of critical points and biased molecular dynamics) are commonly employed to explore chemical space and simulate reaction events. In this contribution, we present a discovery-based, hypothesis-free computational approach based on first principles molecular dynamics to discover and refine the switching mechanism of Donor-Acceptor Stenhouse Adducts (DASAs). Using state-of-the-art graphical processing units-enabled electronic structure calculations we performed in total ~2ns of adiabatic and non-adiabatic ab initio molecular dynamics discovering a) critical intermediates that are involved in the open-to-closed transformation, b) several competing pathways which lower the overall switching yield, and c) key elements for future design strategies. Our dynamics describe the natural evolution of both the nuclear and electronic degrees of freedom that govern the interconversion between DASA ground state intermediates exposing significant elements for the future design strategies of molecular switches. | David M. Sanchez; Umberto Raucci; Todd J. Martínez | Theoretical and Computational Chemistry; Computational Chemistry and Modeling; Theory - Computational | CC BY NC ND 4.0 | CHEMRXIV | 2021-08-19 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/611c1b431adf937711f91854/original/in-silico-discovery-of-multistep-chemistry-initiated-by-a-conical-intersection-the-challenging-case-of-donor-acceptor-stenhouse-adducts.pdf |
60c741a7bb8c1a2dc63d9fbb | 10.26434/chemrxiv.8081174.v1 | Formic Acid Mediated Direct Z-Selective Reductive Coupling of Dienes and Aldehydes | We demonstrate that formic acid mediates the Rh-catalyzed, Z-selective coupling of dienes and aldehydes. The process is distinguished by broad tolerance towards reducible or electrophilic groups. Kinetic analysis suggests that generation of the catalytically active Rh-intermediate by ligand dissociation is the rate determining step. The rapid generation and trapping of Rh-allyl intermediates is key to preventing chain-walking isomerization events that plague related protocols. Insights gained through this study may have wider implications in selective metal-catalyzed hydrofunctionalization reactions.<br /> | Christopher Cooze; Raphael Dada; Rylan Lundgren | Organic Synthesis and Reactions; Homogeneous Catalysis | CC BY NC ND 4.0 | CHEMRXIV | 1970-01-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c741a7bb8c1a2dc63d9fbb/original/formic-acid-mediated-direct-z-selective-reductive-coupling-of-dienes-and-aldehydes.pdf |
64fb0789b6ab98a41c139327 | 10.26434/chemrxiv-2023-l4g1v | Phospha-cyanines in their Ideal Polymethine State: Synthesis and Structure-Properties Relationships | We report the synthesis and full characterization of a family of phosphorus containing polymethine cyanines (phospha-cyanines). The compounds are easily prepared in two steps starting from readily available phosphanes. The impact of the P-substituents and the counterions on the structural and optical properties is investigated through a joint experimental/theoretical approach. Based on the study of the single crystal X-ray diffraction structures, all phospha-cyanines present a bond length alternation (BLA) close to zero, independently of the substituent and the counterions, which indicates an ideal polymethine state. All these compounds display the typical cyanine-like UV-vis absorption with an intense and sharp transition with a vibronic shoulder. TD-DFT calculations allowed to fully rationalize the optical properties (absorption/emission wavelengths, luminescence quantum yields). Interestingly, due to the tetrahedral shape of the P-atom, the optical properties are independent of the counterion, which is in marked contrast with N-analogs, which enables predictive engineering of the phospha-cyanines regardless of the medium in which they are used. | Alexandre Chemin; Iryna Knysh; Denis Ari; marie cordier; Thierry Roisnel; Boris Le Guennic; Muriel Hissler; Denis Jacquemin; Pierre-Antoine Bouit | Physical Chemistry | CC BY 4.0 | CHEMRXIV | 2023-09-11 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/64fb0789b6ab98a41c139327/original/phospha-cyanines-in-their-ideal-polymethine-state-synthesis-and-structure-properties-relationships.pdf |
60c756a54c89190edfad489c | 10.26434/chemrxiv.14292158.v1 | Aggregation-Induced Emission: A Challenge for Computational Chemistry. the Example of TPA-BMO. | A multi-scale and multi-environment computational approach is proposed to study of the modulation of the emission behavior of the triphenylamine (Z)-4-benzylidene-2-methyloxazol-5(4H)-one (TPA-BMO) molecule [Tang <i>et al</i>., J. Phys. Chem. C,<b>119</b>, 21875 (2015)]. Going from (TD-)DFT calculations to classical Molecular Dynamics simulations through the hybrid ONIOM QM/QM’ approach and the <i> </i><i>in situ</i> chemical polymerization methodology, we have rationalized distinct photophysical phenomena: (1) in low-polar solvents, a polarity-dependent solvatochromic effect as well as a modulation of the emission quantum yield, attributed to possible photophysical energy dissipation caused by low-frequency vibrational modes, (2) in the aggregate, a subtle competition between an excitonic coupling and a restriction of the intramolecular vibrations leading to an Aggregation-Induced Emission behavior, and (3) in the polymer matrix, an antagonist effect between the loss of global flexibility and the presence of vibrational modes similar to those observed in solution, explaining a similar emissive behavior within the polymer.<p></p> | Laure de Thieulloy; Laura Le Bras; Benoît Zumer; Claire Lemarchand; Nicolas Pineau; Carlo Adamo; Aurélie Perrier | Theory - Computational; Spectroscopy (Physical Chem.) | CC BY NC ND 4.0 | CHEMRXIV | 2021-03-25 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c756a54c89190edfad489c/original/aggregation-induced-emission-a-challenge-for-computational-chemistry-the-example-of-tpa-bmo.pdf |
66acdff05101a2ffa8ecda50 | 10.26434/chemrxiv-2024-vr3jp-v2 | Ni-doped Cu oxide catalysts for ORR: suppressing H2O2 formation by engineering chemical strain | Ni-doped copper oxide (Cu[Ni]Ox/Au) has demonstrated considerable promise towards efficient
oxygen reduction reaction (ORR) under alkaline conditions. The Cu-rich samples like
Cu0.8Ni0.2Ox/Au show better activity and selectivity than benchmarks such as Pt and Au, exhibiting
H2O2 yields < 5% throughout a large potential range. The electrode's performance did not degrade
even under 3000 potential cycles under ORR conditions. In-situ Raman spectroscopy indicated a
Cu-O-Ni type framework where Ni doping into CuOx results in coordinatively unsaturated Ni
centers within the Cu-O-Ni framework. These centers are active towards easier cleavage of O-O
bonds resulting in an overall preference for the 4e pathway for O2 reduction to H2O. | Sekhar Biswal; chinmoy ranjan | Physical Chemistry; Catalysis; Analytical Chemistry; Electrocatalysis | CC BY NC ND 4.0 | CHEMRXIV | 2024-08-05 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66acdff05101a2ffa8ecda50/original/ni-doped-cu-oxide-catalysts-for-orr-suppressing-h2o2-formation-by-engineering-chemical-strain.pdf |
62b52b19e84dd1dcff011015 | 10.26434/chemrxiv-2022-7rzq7 | Cation-Controlled Olefin Isomerization Catalysis with Palladium Pincer Complexes | A series of palladium(II) pincer complexes with dif-ferent substituents on the amine donor has been prepared and studied in olefin isomerization cataly-sis. Installing a macrocycle into the pincer ligand enables cation-switchable positional olefin isomer-ization: no reaction is observed with the catalyst alone, while in the presence of Li+ salts isomeriza-tion proceeds cleanly. Mechanistic studies implicate a key role of highly electrophilic Pd centers with accessible olefin binding sites in catalysis. | Alexandra Farquhar; Kristen Gardner; Sebastian Acosta-Calle ; Andrew Camp ; Chun-Hsing Chen; Alexander Miller | Inorganic Chemistry; Organometallic Chemistry; Organometallic Compounds; Catalysis; Ligand Design | CC BY NC ND 4.0 | CHEMRXIV | 2022-06-27 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/62b52b19e84dd1dcff011015/original/cation-controlled-olefin-isomerization-catalysis-with-palladium-pincer-complexes.pdf |
62d8007e581987674d48b516 | 10.26434/chemrxiv-2022-1j3np-v2 | Highly Efficient Green & Red Narrowband Emissive Organic Light-Emitting Diodes Employing Multi-Resonant Thermally Activated Delayed Fluorescence Emitters | Herein, we demonstrate how judicious selection of donor decorating a central multi-resonant thermally activated delayed fluorescence (MR-TADF) core based on quinolino[3,2,1-de]acridine-5,9-dione (DiKTa) can lead to very high-performance organic light-emitting diodes (OLEDs). Decorating the DiKTa core with triphenylamine (TPA) and diphenylamine (DPA) in 3TPA-DiKTa and 3DPA-DiKTa resulted in compounds showing bright, narrowband green/red emission in doped films, respectively. The OLEDs based on these emitters showed excellent performance with record-high maximum external quantum efficiencies (EQEmax) for this family of emitters, with a EQEmax of 30.8% for the device with 3TPA-DiKTa (EL = 551 nm) and 16.7% for the device with 3DPA-DiKTa (EL = 613 nm). The outstanding device performance with 3TPA-DikTa was attributed to preferential horizontal orientation of the transition dipole moment, with anisotropy factor (a) of 0.189. These results demonstrate that the careful selection of the substituents in MR-TADF emitter can tune the color of OLEDs and significantly enhance device performance. | Sen Wu; Abhishek Kumar Gupta; Kou Yoshida; Junyi Gong; David Hall; David Cordes; Alexandra Slawin; Ifor Samuel; Eli Zysman-Colman | Physical Chemistry; Organic Chemistry; Organic Compounds and Functional Groups; Optics; Spectroscopy (Physical Chem.); Materials Chemistry | CC BY 4.0 | CHEMRXIV | 2022-07-20 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/62d8007e581987674d48b516/original/highly-efficient-green-red-narrowband-emissive-organic-light-emitting-diodes-employing-multi-resonant-thermally-activated-delayed-fluorescence-emitters.pdf |
60c7505ff96a00f7be287e08 | 10.26434/chemrxiv.13033718.v1 | Synthesis and Characterization of a New Monometallic Manganese Layered Double Hydroxide with Unique Redox Properties | Iron and cobalt monometallic Layered Double Hydroxide (LDH), combining divalent and trivalent cations of the same chemical element, are commonly used respectively for nitrate reduction and oxygen evolution reaction. This article reports the first synthesis of a LDH using only manganese<br />as metallic ion. X-Ray diffractograms, infrared and Raman spectra show that the structure obtained through the oxidation of a basic Mn<sup>II</sup> salt with persulfate is comparable to the structure of Fe-LDH also known as Green Rust. XPS shows that in this solid coexist Mn<sup>II</sup> and Mn<sup>III</sup> states. Thermodynamic considerations predict that this solid can reduce nitrate into gaseous nitrogen without further reduction<br />into ammonium or ammonia unlike what is observed for Fe-LDH. | Damien Cornu; Romain Coustel; Aurélien Renard; Pierrick Durand; Cédric Carteret; Christian Ruby | Minerals; Crystallography – Inorganic | CC BY NC ND 4.0 | CHEMRXIV | 2020-10-01 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c7505ff96a00f7be287e08/original/synthesis-and-characterization-of-a-new-monometallic-manganese-layered-double-hydroxide-with-unique-redox-properties.pdf |
60c753919abda26d22f8dfdc | 10.26434/chemrxiv.13514377.v1 | Toughening Hydrogels Through Force-triggered Chemical Reactions that Lengthen Polymer Strands | <p>The utility and lifetime of materials made from polymer networks, including hydrogels, depend on their capacity to stretch and resist tearing. In gels and elastomers, those mechanical properties are often limited by the covalent chemical structure of the polymer strands between cross-links, which is typically fixed during the material synthesis. Here, we report polymer networks in which the constituent strands lengthen through force-coupled reactions that are triggered as the strands reach their nominal breaking point. Reactive strand extensions of up to 40% lead to hydrogels that stretch 40-50% further than, and exhibit tear energies twice that of, networks made from analogous control strands. The enhancements are synergistic with those provided by double network architectures, and complement other existing toughening strategies. </p> | Zi Wang; Xu Jun Zheng; Tetsu Ouchi; Tatiana Kouznetsova; Haley Beech; Sarah Av-Ron; Brandon Bowser; Shu Wang; Jeremiah Johnson; Julia Kalow; Bradley Olsen; Jian Ping Gong; Michael Rubinstein; Stephen Craig | Elastic Materials; Polyelectrolytes - Materials; Hydrogels; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2021-01-04 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c753919abda26d22f8dfdc/original/toughening-hydrogels-through-force-triggered-chemical-reactions-that-lengthen-polymer-strands.pdf |
60c75790337d6c2333e2904f | 10.26434/chemrxiv.14423522.v1 | Preparative-Scale Synthesis of Nonacene | <p>During the last
years we have witnessed progressive evolution of preparation of acenes with
length up to dodecacene by on-surface synthesis in UHV or generation of acenes
up to decacene in solid matrices at low temperatures. While these protocols
with very specific conditions produce the acenes in amount of few molecules,
the strategies leading to the acenes in large quantities dawdle behind. Only
recently and after 70 years of synthetic attempts, heptacene has been prepared
in bulk phase. However, the preparative scale synthesis of higher homologues
still remains a formidable challenge. Here we report the preparation and
characterisation of nonacene and show its excellent thermal and in-time stability.
</p> | Andrej Jancarik; Jan Holec; Yuuya Nagata; Michal Šámal; Andre Gourdon | Organic Compounds and Functional Groups; Organic Synthesis and Reactions | CC BY NC ND 4.0 | CHEMRXIV | 2021-04-16 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c75790337d6c2333e2904f/original/preparative-scale-synthesis-of-nonacene.pdf |
635b8cc12e0c63f41f3fc54b | 10.26434/chemrxiv-2022-jslsp | Exploring the effects of wetting and free fatty acid deposition on an atomistic hair fiber surface model incorporating Keratin Associated Protein 5-1 | The complex development of cosmetic and medical formulations relies on an ever-growing accuracy of predictive models of hair surfaces. Hitherto, modeling efforts have focused on the description of 18-methyl eicosanoic acid (18-MEA), the primary fatty acid covalently attached to the hair surface, without explicit modeling of the protein layer. Herein, the molecular details of the outermost surface of the human hair fiber surface, also called the F-layer, were studied using molecular dynamics (MD) simulations. The F-layer is composed primarily of Keratin associated proteins KAP5 and KAP10, which are decorated with 18-MEA on the outer surface of a hair fiber. In our molecular model, we incorporated KAP5-1, and evaluated the surface properties of 18-MEA through MD simulations, resulting in 18-MEA surface density, layer thickness, and tilt angles in agreement with previous experimental and computational studies. Subsequent models with reduced 18-MEA surface density were also generated to mimic damaged hair surfaces. Response to wetting of virgin and damaged hair showed rearrangement of 18-MEA on the surface, allowing for water penetration into the protein layer. To demonstrate a potential use case for these atomistic models, we deposited naturally occurring fatty acids and measured 18-MEA’s response in both dry and wet conditions. As fatty acids are often incorporated in shampoo formulations, this work demonstrates the ability to model adsorption of ingredients on hair surfaces. This study illustrates for the first time, the complex behavior of a realistic F-layer at the molecular level and opens the possibility of studying adsorption behavior of larger, more complex molecules and formulations. | Jeffrey Sanders; Benjamin J Coscia; Alexandr Fonari; Mayank Misra; Paulo G Mileo; David J Giesen; Andrea R Browning; Mathew D Halls | Theoretical and Computational Chemistry; Physical Chemistry; Biological and Medicinal Chemistry; Biophysics; Computational Chemistry and Modeling; Surface | CC BY 4.0 | CHEMRXIV | 2022-11-09 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/635b8cc12e0c63f41f3fc54b/original/exploring-the-effects-of-wetting-and-free-fatty-acid-deposition-on-an-atomistic-hair-fiber-surface-model-incorporating-keratin-associated-protein-5-1.pdf |
66a218e65101a2ffa8fc3d52 | 10.26434/chemrxiv-2024-4xbg8-v2 | Advanced Control in Truncated Silver Nanoplate Synthesis: Tunable Size, Thickness, and Plasmonic Properties | We present a seed-mediated approach for producing silver nanoplates with customizable size and thickness, offering high yield and precise optical properties. Leveraging ethylenediaminetetraacetic acid (EDTA) in the seed-mediated synthesis, we employ small single-crystal silver seeds as a foundation. The interaction between Ag+ and EDTA at different pHs dynamically controls silver complexation/reduction kinetics during seed overgrowth, yielding truncated nanoplates with superior optical responses. The pH adjustment within the range of 8 to 10.5 enables manipulation of nanoplate growth, resulting in a flexible optical response spanning 519 to 1006 nm associated with morphological changes (size and thickness). Additionally, nanoplate overgrowth extends plasmon resonance up to ca. 2000 nm. Notably, the incorporation of Adenosine 5’-monophosphate (AMP) enhances nanoplate stability and more important, enables precise thickness adjustment, independent of growth kinetics. Our method offers a systematic approach to tailor nanoplate morphology and optical properties with unprecedented precision. | Adrián Fernández-Lodeiro; Carlos Fernández-Lodeiro; Silvia Nuti; Ignacio Pérez-Juste; Isabel Pastoriza-Santos; Jorge Pérez-Juste; Enrique Carbo-Argibay; José Luís Capelo; Carlos Lodeiro; Javier Fernández-Lodeiro | Nanoscience; Nanostructured Materials - Nanoscience; Plasmonic and Photonic Structures and Devices; Materials Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-07-25 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66a218e65101a2ffa8fc3d52/original/advanced-control-in-truncated-silver-nanoplate-synthesis-tunable-size-thickness-and-plasmonic-properties.pdf |
66285bb1418a5379b089ab2d | 10.26434/chemrxiv-2023-h3c60-v5 | Revisiting textbook azide-clock reactions: A “propeller-crawling” mechanism explains differences in rates | An ongoing challenge to chemists is the analysis of pathways and kinetics for chemical reactions in solution–including transient structures between the reactants and products that are difficult to resolve using laboratory experiments. Here, we enabled direct molecular dynamics simulations of a textbook series of chemical reactions on the hundreds of ns to µs timescale using the weighted ensemble (WE) path sampling strategy with hybrid quantum mechanical/molecular mechanical (QM/MM) models. We focused on azide-clock reactions involving addition of azide anion to each of three long-lived trityl cations in an acetonitrile-water solvent mixture. Results reveal a two-step mechanism: (1) diffusional collision of reactants to form an ion-pair intermediate, (2) “activation”, or rearrangement of the intermediate to the product. Our simulations not only yield reaction rates that are within error of experiment, but also rates for individual steps, indicating the activation step as rate-limiting for all three cations. Further, the trend in reaction rates is due to dynamical effects, i.e. differing extents of the azide anion “crawling” along the cation’s phenyl-ring “propellers” during the activation step. Our study demonstrates the power of analyzing pathways and kinetics to gain insights on reaction mechanisms, underscoring the value of including WE and other related path sampling strategies in the modern toolbox for chemists. | Anthony Bogetti; Matthew Zwier; Lillian Chong | Theoretical and Computational Chemistry | CC BY NC ND 4.0 | CHEMRXIV | 2024-04-24 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/66285bb1418a5379b089ab2d/original/revisiting-textbook-azide-clock-reactions-a-propeller-crawling-mechanism-explains-differences-in-rates.pdf |
6411fd162bfb3dc251d2ada1 | 10.26434/chemrxiv-2023-08gpl | Excimer Energies | A multistate energy decomposition analysis (MS-EDA) method is introduced for excimers using density functional theory. Although EDA has been widely applied to intermolecular interactions in the ground-state, few methods are currently available for excited state complexes. Here, the total energy of an excimer state is separated into exciton excitation energy ΔE_Ex (|Ψ_X•Ψ_Y >^*), resulting from the state interaction between locally excited monomer states |Ψ_X^*•Ψ_Y> and |Ψ_X•Ψ_Y^*>, a super-exchange resonance energy ΔE_SE, originating from the mutual charge transfer between two monomers |Ψ_X^+•Ψ_Y^-> and |Ψ_X^-•Ψ_Y^+>, and an orbital-and-configuration delocalization term ΔE_OCD due to the expansion of configuration space and block-localized orbitals to the fully delocalized dimer system. Although there is no net charge transfer in symmetric excimer cases, the resonance of charge-transfer states is critical to stabilizing the excimer. The monomer localized excited and charge-transfer states are variationally optimized, forming a minimal active space for nonorthogonal state interaction (NOSI) calculations in multistate density functional theory to yield the intermediate states for energy analysis. The present MS-EDA method focuses on properties unique to excited states, providing insights into exciton coupling, super-exchange and delocalization energies. MS-EDA is illustrated on the acetone and pentacene excimer systems; three configurations of the latter case are examined, including the optimized excimer, a stacked configuration of two pentacene molecules and the fishbone orientation. It is found that excited-state energy splitting is strongly dependent on the relative energies of the monomer excited states and the phase-matching of the monomer wave functions. | Ruoqi Zhao; Christian Hettich; Jun Zhang; Meiyi Liu; Jiali Gao | Theoretical and Computational Chemistry; Theory - Computational | CC BY 4.0 | CHEMRXIV | 2023-03-16 | https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/6411fd162bfb3dc251d2ada1/original/excimer-energies.pdf |
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