Chemphyschem最新文献

Understanding Ion-Specific "Hofmeister" Effects in Enzyme Catalysis Through Using RNase A as a Paradigm Model. 以 RNase A 为范例，了解酶催化过程中的离子特异性 "霍夫迈斯特 "效应。

IF 2.3 3区化学

Chemphyschem Pub Date : 2024-11-24 DOI: 10.1002/cphc.202400820

Bahareh Taghavi Shahraki, Mazdak Khajehpour

{"title":"Understanding Ion-Specific \"Hofmeister\" Effects in Enzyme Catalysis Through Using RNase A as a Paradigm Model.","authors":"Bahareh Taghavi Shahraki, Mazdak Khajehpour","doi":"10.1002/cphc.202400820","DOIUrl":"https://doi.org/10.1002/cphc.202400820","url":null,"abstract":"Biophysical studies in the last two decades demonstrate that salts affect biomolecules in an ion-specific manner. Diverse biological processes such as protein folding, protein precipitation, protein coacervation and phase separation, and protein oligomerization, all show that this ion specificity directly relates to how individual ions interact with biomolecular surfaces. Interestingly, although ion-specific effects upon enzyme catalytic processes are well-known in the literature, a molecular level description of these effects is not yet available. This work addresses this need by investigating ion-specific effects upon the enzymatic activity and stability of RNase A. We have developed a robust framework to analyze and quantify ion-specific effects upon the RNase A catalyzed phosphate ring opening reaction of cCMP. Both the folding thermodynamics and the Michaelis-Menten kinetic parameters of this enzyme show ion-specificity. However, these effects are not necessarily directly related to each other. Ion-specific effects observed in protein folding reflects mostly how an individual ion interacts with the overall protein surface; while alternatively, ion-specific effects on enzyme activity indicate how a given ion interacts with the enzyme active site surface or alternatively, how ions interact with the substrate molecule as represented by changes in the substrate thermodynamic activity coefficient.","PeriodicalId":9819,"journal":{"name":"Chemphyschem","volume":" ","pages":"e202400820"},"PeriodicalIF":2.3,"publicationDate":"2024-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142709173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Understanding the Effects of Surface and Edge Functionalization on the Mechanical Properties of Graphene and Graphene Oxide. 了解表面和边缘功能化对石墨烯和氧化石墨烯机械特性的影响。

IF 2.3 3区化学

Chemphyschem Pub Date : 2024-11-22 DOI: 10.1002/cphc.202400919

Bharat Bhushan Sharma, Anjana Kedare, Girish Muralidharan, Ananth Govind Rajan

{"title":"Understanding the Effects of Surface and Edge Functionalization on the Mechanical Properties of Graphene and Graphene Oxide.","authors":"Bharat Bhushan Sharma, Anjana Kedare, Girish Muralidharan, Ananth Govind Rajan","doi":"10.1002/cphc.202400919","DOIUrl":"https://doi.org/10.1002/cphc.202400919","url":null,"abstract":"Graphene oxide (GO) is a widely used 2D material employed in various applications due to its tunable properties. Understanding its mechanical properties is crucial to develop polymeric nanocomposites. We employ reactive molecular dynamics simulations to understand the effects of surface and edge functionalization of carbon atoms on the mechanical strength and fracture morphology of graphene and GO. We vary the extent of functionalization of hydroxyl and epoxy groups between 0.1%-70% on the GO surface and find that the tensile strength decreases with increasing functionalization. Nevertheless, there exists an optimal level of surface functionalization of 15-20% where the tensile strength of pristine graphene is retained. Additionally, we find that functionalization alters the fracture morphology from brittle to mild ductile, which is desirable in engineering applications. We also show that the edge functionalization of finite-size graphene nanosheets transfers the failure nucleation sites from the edges to the bulk, although the tensile strength decreases due to increased buckling. Interestingly, the decrement in tensile strength due to surface functionalization is larger as compared to edge functionalization. Overall, this work highlights the possibility of customizing GO's mechanical properties through targeted surface and edge functionalization, paving the way for its controlled application in nanocomposites.","PeriodicalId":9819,"journal":{"name":"Chemphyschem","volume":" ","pages":"e202400919"},"PeriodicalIF":2.3,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142692816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

What is the exchange-repulsion energy? Insight by partitioning into physically meaningful contributions. 什么是交换-反推能量？通过将其划分为有物理意义的贡献来了解。

IF 2.3 3区化学

Chemphyschem Pub Date : 2024-11-21 DOI: 10.1002/cphc.202400887

Johannes Henrichsmeyer, Michael Thelen, Reinhold F Fink

{"title":"What is the exchange-repulsion energy? Insight by partitioning into physically meaningful contributions.","authors":"Johannes Henrichsmeyer, Michael Thelen, Reinhold F Fink","doi":"10.1002/cphc.202400887","DOIUrl":"https://doi.org/10.1002/cphc.202400887","url":null,"abstract":"It is shown that the exchange repulsion energy, Exr, can be rationalized by partitioning the respective energy expression for two systems with Hartree-Fock orbitals into physically meaningful contributions. A division of Exr into a positive kinetic and a negative potential part is possible, but these contributions correlate only poorly with the actual exchange repulsion energy. A more meaningful partitioning is derived, where all kinetic energy contributions are collected in a term that vanishes for exact Hartree-Fock orbitals due to their stationarity conditions. The remaining terms can be distinguished into an exchange integral contribution as well as contributions to the repulsion energy with two, three and four orbital indices. The forms, relationships and absolute sizes of these terms suggest an intuitive partitioning of the exchange repulsion energy into Molecular Orbital Pair Contributions to the Exchange repulsion energy (MOPCE). Insight into the analytic form and quantitative size of these contributions is provided by considering the 3Σ+u (1σg1σu) state of the H2 molecule, the water dimer, as well as an argon atom interacting with Cl2 and N2.","PeriodicalId":9819,"journal":{"name":"Chemphyschem","volume":" ","pages":"e202400887"},"PeriodicalIF":2.3,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142686119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Stable π Radical BDPA: Adsorption on Cu(100) and Survival of Spin. 稳定的 π Radical BDPA：在 Cu(100) 上的吸附和自旋存活。

IF 2.3 3区化学

Chemphyschem Pub Date : 2024-11-21 DOI: 10.1002/cphc.202400852

Jacob Dickinson Teeter, Daniel P Miller, Stefan Müllegger

引用次数: 0

Absorption and Excited-State Coherences of Cryogenically Cold Retinal Protonated Schiff Base in Vacuo. 低温视网膜质子化席夫碱在真空中的吸收和激发态相干。

IF 2.3 3区化学

Chemphyschem Pub Date : 2024-11-21 DOI: 10.1002/cphc.202400878

Lars Henrik Andersen, Nikolaj Klinkby, Anne Pilgaard Rasmussen, Anders G S Lauridsen

引用次数: 0

Unraveling the stereoisomer configurations of 1,1'-bis(tert-butylphosphino)ferrocene in the gas phase. 揭示 1,1'-双（叔丁基膦）二茂铁在气相中的立体异构体构型。

IF 2.3 3区化学

Chemphyschem Pub Date : 2024-11-20 DOI: 10.1002/cphc.202400881

Wenhao Sun, Denis Kargin, Zsolt Kelemen, Rudolf Pietschnig, Melanie Schnell

{"title":"Unraveling the stereoisomer configurations of 1,1'-bis(tert-butylphosphino)ferrocene in the gas phase.","authors":"Wenhao Sun, Denis Kargin, Zsolt Kelemen, Rudolf Pietschnig, Melanie Schnell","doi":"10.1002/cphc.202400881","DOIUrl":"https://doi.org/10.1002/cphc.202400881","url":null,"abstract":"The molecular structure of a ferrocene derivative with adjacent centers of chirality, 1,1'-bis(tert - butylphosphino)ferrocene, has been examined in the gas phase using broadband microwave spectroscopy under the isolated and cold conditions of a supersonic jet. The diastereomers of 1,1'-bis(tert-butylphosphino)ferrocene can adopt homo- and hetero-chiral configurations, owing to the P-chiral substituents on the cyclopentadienyl rings. Moreover, the internal ring rotation of each diastereomer gives rise to four conformers with eclipsed ring arrangements, where the two tert-butylphosphino groups were separated by dihedral angles of approximately 72◦, 144◦, 216◦, and 288◦ with respect to the two ring centers. The interconversion barriers between the conformations are below 2 kJ/mol, whereas the pyramidal inversion of the tert-butylphosphino groups is hindered by more than 140 kJ/mol, calculated at the B3LYP-D3(BJ)/def2-QZVP level of theory. In the experimental microwave spectrum, we unambiguously identified the two global-minimum diastereomers with 72◦ conformations. The absence of other conformers can be attributed to the relaxation dynamics in the supersonic jet, which transfers the high-energy conformers to the respective global-minimum geometries. Additionally, we discovered that London dispersion inter- actions between the two tert-butylphosphino groups play a crucial role in stabilizing the structures of this ferrocene complex.","PeriodicalId":9819,"journal":{"name":"Chemphyschem","volume":" ","pages":"e202400881"},"PeriodicalIF":2.3,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142680832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Perturbational and variational energy decomposition analysis on hydrogen bonds of coordinated glycine with water molecule. 配位甘氨酸与水分子氢键的扰动和变异能量分解分析。

IF 2.3 3区化学

Chemphyschem Pub Date : 2024-11-20 DOI: 10.1002/cphc.202400948

Snežana D Zarić, Sonja S Zrilić, Dragan B Ninković, Mihajlo Etinski

{"title":"Perturbational and variational energy decomposition analysis on hydrogen bonds of coordinated glycine with water molecule.","authors":"Snežana D Zarić, Sonja S Zrilić, Dragan B Ninković, Mihajlo Etinski","doi":"10.1002/cphc.202400948","DOIUrl":"https://doi.org/10.1002/cphc.202400948","url":null,"abstract":"Three types of hydrogen bonds of coordinated glycine and water had been investigated: NH/O of α-amino group, O1/HO involving oxygen coordinated to the metal ion (O1), and O2/HO involving α-carbonyl oxygen (O2). Various glycine complexes were investigated: octahedral cobalt(III) and nickel(II), square pyramidal copper(II), and square planar copper(II), palladium(II), and platinum(II) complexes. Nature of these three hydrogen bond types was analysed using symmetry-adapted perturbation theory (SAPT) and variational energy decomposition analysis (EDA) method (TPSS-D3/def2-TZVPP). The results of the EDA decomposition are in good agreement with the reliable SAPT2+3/def2-TZVPP and its total interaction values with CCSD(T)/CBS energies. Electrostatic interaction is generally the dominant attractive energy term in most of the interactions, followed by orbital relaxation, and lastly dispersion as the weakest. We compared EDA results of various complexes to determine the effects of complex charge, metal oxidation, coordination, and atomic number on the energy decomposition terms. The complex charge influences the values of decomposition terms the most, followed by metal oxidation and coordination number, while atomic number effects them the least. All complex and metal changes have a more significant effect on the results of NH/O and O1/HO then O2/HO interactions, due to its location further away from the metal ion.","PeriodicalId":9819,"journal":{"name":"Chemphyschem","volume":" ","pages":"e202400948"},"PeriodicalIF":2.3,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142674724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

17O NMR spectroscopy reveals CO2 speciation and dynamics in hydroxide-based carbon capture materials. 17O NMR 光谱揭示了基于氢氧化物的碳捕获材料中的 CO2 分类和动力学。

IF 2.3 3区化学

Chemphyschem Pub Date : 2024-11-20 DOI: 10.1002/cphc.202400941

Benjamin Rhodes, Lars Schaaf, Mary Zick, Suzi Pugh, Jordon Hilliard, Shivani Sharma, Casey Wade, Phillip Milner, Gábor Csányi, Alexander Forse

{"title":"17O NMR spectroscopy reveals CO2 speciation and dynamics in hydroxide-based carbon capture materials.","authors":"Benjamin Rhodes, Lars Schaaf, Mary Zick, Suzi Pugh, Jordon Hilliard, Shivani Sharma, Casey Wade, Phillip Milner, Gábor Csányi, Alexander Forse","doi":"10.1002/cphc.202400941","DOIUrl":"https://doi.org/10.1002/cphc.202400941","url":null,"abstract":"Carbon dioxide capture technologies are set to play a vital role in mitigating the current climate crisis. Solid-state 17O NMR spectroscopy can provide key mechanistic insights that are crucial to effective sorbent development. In this work, we present the fundamental aspects and complexities for the study of hydroxide-based CO2 capture systems by 17O NMR. We perform static density functional theory (DFT) NMR calculations to assign peaks for general hydroxide CO2 capture products, finding that 17O NMR can readily distinguish bicarbonate, carbonate and water species. However, in application to CO2 binding in two test case hydroxide-functionalised metal-organic frameworks (MOFs): MFU-4l and KHCO3-cyclodextrin-MOF, we find that a dynamic treatment is necessary to obtain agreement between computational and experimental spectra. We therefore introduce a workflow that leverages machine-learning forcefields to capture dynamics across multiple chemical exchange regimes, providing a significant improvement on static DFT predictions. In MFU-4l, we parameterise a two-component dynamic motion of the bicarbonate motif involving a rapid carbonyl seesaw motion and intermediate hydroxyl proton hopping. For KHCO3-CD-MOF, we combined experimental and modelling approaches to propose a new mixed carbonate-bicarbonate binding mechanism and thus, we open new avenues for the study and modelling of hydroxide-based CO2 capture materials by 17O NMR.","PeriodicalId":9819,"journal":{"name":"Chemphyschem","volume":" ","pages":"e202400941"},"PeriodicalIF":2.3,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142674718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Commercial silica materials functionalized with a versatile organocatalyst for the catalysis of acylation reactions in liquid media. 用一种多功能有机催化剂功能化的商用二氧化硅材料，用于催化液体介质中的酰化反应。

IF 2.3 3区化学

Chemphyschem Pub Date : 2024-11-19 DOI: 10.1002/cphc.202400936

Raoul D Brand, Mareike Maass, Anatoliy G Grebenyuk, Alexander A Golub, Bernd M Smarsly

{"title":"Commercial silica materials functionalized with a versatile organocatalyst for the catalysis of acylation reactions in liquid media.","authors":"Raoul D Brand, Mareike Maass, Anatoliy G Grebenyuk, Alexander A Golub, Bernd M Smarsly","doi":"10.1002/cphc.202400936","DOIUrl":"https://doi.org/10.1002/cphc.202400936","url":null,"abstract":"Silica materials represent a promising material for the application in heterogeneous organocatalysis due to their readily modifiable surface and chemical inertness. To achieve high catalyst loadings, usually, porous carriers with high surface areas are used, such as special silica monoliths or spherical particles for backed bed reactors. Yet, their synthesis is elaborate, and thus less complex and cheaper alternatives are of interest, especially considering scaling up. In this work, two commercial silica materials functionalized with the organocatalyst 4-(dimethylamino)pyridine (DMAP) were used in catalytic acylation reactions: a mesoporous silica gel (Siliabond®-DMAP) and non-porous silica nanoparticles (Ludox®). Both were successfully used in the acylation of phenylethanol, but the latter required significantly longer reaction times, presumably due to mass-transfer limitations as a consequence of substantial agglomeration that limits the accessible amount of catalyst. Furthermore, it was shown that the influence of the linker molecule is negligible, since both reaction yields and the activation energy remain largely similar. As main result the commercial material Siliabond-DMAP, despite the non-uniform particles, exhibited significant yield in a flow setup, thus demonstrating the potential as support material for application in heterogeneous organocatalysis.","PeriodicalId":9819,"journal":{"name":"Chemphyschem","volume":" ","pages":"e202400936"},"PeriodicalIF":2.3,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142674722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cover Feature: Exploration of Optimization Strategies for Locking Sulfur in 2D Layered/Polymer-Enveloped Cathode Composite for High Power Li-S Batteries (ChemPhysChem 22/2024) 封面专题：用于大功率锂离子电池的二维层状/聚合物开发型阴极复合材料中锁硫的优化策略探索（ChemPhysChem 22/2024）

IF 2.3 3区化学

Chemphyschem Pub Date : 2024-11-19 DOI: 10.1002/cphc.202482202

M. Johnsi, V. J. Asha Shalini, M. Azhagulakshmi, B. Kavin Kumar, N. Balasubramanian

引用次数: 0