The Journal of Physical Chemistry A最新文献_第2页

Toward Gaussian Process Regression Modeling of a Urea Force Field 尿素力场的高斯过程回归建模

IF 2.781 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-09-20 DOI: 10.1021/acs.jpca.4c04117

Tomasz Bukowy, Matthew L. Brown, Paul L. A. Popelier

{"title":"Toward Gaussian Process Regression Modeling of a Urea Force Field","authors":"Tomasz Bukowy, Matthew L. Brown, Paul L. A. Popelier","doi":"10.1021/acs.jpca.4c04117","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c04117","url":null,"abstract":"FFLUX is a next-generation, machine-learnt force field built on three cornerstones: quantum chemical topology, Gaussian process regression, and (high-rank) multipolar electrostatics. It is capable of performing molecular dynamics with near-quantum accuracy at a lower computational cost than standard ab initio molecular dynamics. Previous work with FFLUX was concerned with water and formamide. In this study, we go one step further and challenge FFLUX to model urea, a larger and more flexible system. In result, we have trained urea models at the B3LYP/aug-cc-pVTZ level of theory, with a mean absolute error of 0.4 kJ mol–1 and a maximum prediction error below 7.0 kJ mol–1. To test their performance in molecular dynamics simulations, two sets of FFLUX geometry optimizations were carried out: 5 dimers corresponding to energy minima and 75 random dimers. The 5 dimers were recovered with a root-mean-square deviation below 0.1 Å with respect to their ab initio references. Out of the 75 random dimers, 68% converged to the qualitatively same dimer as those obtained at the ab initio level. Furthermore, we have ranked the 5 FFLUX-optimized dimers in the order of their relative FFLUX single-point energies and compared them with the ab initio method. The energy ranking fully agreed but for one crossover between two successive minima. Finally, we have demonstrated the importance of geometry-dependent (i.e., flexible) multipole moments, showing that the lack of multipole moment flexibility can lead to average errors in the total intermolecular electrostatic energy of more than 2 orders of magnitude.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.781,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Non-Radiative Deactivation in Isolated Quinoline. 孤立喹啉中的非辐射失活。

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-09-20 DOI: 10.1021/acs.jpca.4c04208

Floriane Sturm, Christoph Herok, Ingo Fischer

引用次数: 0

Comparative Study of n-C5 Bond Dissociation Energies and H-Atom Abstraction via H for Alkane, Alcohol, Methyl Ether, Nitroso, Nitro, Nitrite, and Nitrate 烷烃、酒精、甲醚、亚硝基、硝基、亚硝酸盐和硝酸盐的 n-C5 键解离能和通过 H 原子萃取 H 的比较研究

IF 2.781 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-09-20 DOI: 10.1021/acs.jpca.4c05309

Malte Döntgen, K. Alexander Heufer

{"title":"Comparative Study of n-C5 Bond Dissociation Energies and H-Atom Abstraction via H for Alkane, Alcohol, Methyl Ether, Nitroso, Nitro, Nitrite, and Nitrate","authors":"Malte Döntgen, K. Alexander Heufer","doi":"10.1021/acs.jpca.4c05309","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c05309","url":null,"abstract":"Energetic materials have a wide range of applications, for many of which new materials are constantly developed. For understanding how energetic materials are chemically converted, it is essential to systematically understand how relevant functional groups affect the stability and properties of such materials. Here, the impact of nitroso, nitro, nitrite, and nitrate functional groups on a pentyl moiety is studied theoretically, focusing on bond dissociation energies and H atom abstraction via Ḣ. The nitroso group is found to imply the strongest effects, while the nitro group appears to exert a stabilizing effect on the pentyl moiety. Importantly, the nitrogenated functional groups generally stabilize the pentyl moiety, in contrast to alcohol and methyl ether functional groups. Therefore, it is concluded that using analogies to the chemistries of the latter two functional groups for chemical kinetic modeling of nitrogenated functional groups is not adequate. Based on the presented bond dissociation energies and rate coefficients, it is to be expected that unimolecular bond fissions at the nitrogenated functional groups will dominate over a wide temperature range. Building on the provided data, future detailed chemical kinetic modeling efforts for nitroso, nitro, nitrite, and nitrate compounds can be aided or initiated.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.781,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Exploring the Efficiency of C343 Coumarin Dye-Sensitized Solar Cells Using Substituents. 利用取代基探索 C343 香豆素染料敏化太阳能电池的效率。

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-09-19 Epub Date: 2024-09-05 DOI: 10.1021/acs.jpca.4c03300

T O Daniel, L Rhyman, P Ramasami

引用次数: 0

Temperature-Dependent Kinetics of the Reactions of the Criegee Intermediate CH₂OO with Aliphatic Aldehydes. Criegee 中间体 CH2OO 与脂肪族醛的反应随温度变化的动力学。

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-09-19 Epub Date: 2024-09-04 DOI: 10.1021/acs.jpca.4c04990

Jonas J Enders, Zachary A Cornwell, Aaron W Harrison, Craig Murray

{"title":"Temperature-Dependent Kinetics of the Reactions of the Criegee Intermediate CH2OO with Aliphatic Aldehydes.","authors":"Jonas J Enders, Zachary A Cornwell, Aaron W Harrison, Craig Murray","doi":"10.1021/acs.jpca.4c04990","DOIUrl":"10.1021/acs.jpca.4c04990","url":null,"abstract":"Criegee intermediates, formed by alkene ozonolysis in the troposphere, can react with volatile organic compounds (VOCs). The temperature-dependent kinetics of the reactions between the Criegee intermediate CH2OO and three aliphatic aldehydes, RCHO where R = H, CH3, and C2H5 (formaldehyde, acetaldehyde, and propionaldehyde, respectively), have been studied using a laser flash-photolysis transient absorption spectroscopy technique. The experimental measurements are supported by ab initio calculations at various composite levels of theory that characterize stationary points on the reaction potential and free energy surfaces. As with other reactions of CH2OO with organic carbonyls, the mechanisms involve 1,3-dipolar cycloaddition at the C=O group, over submerged barriers, leading to the formation of 1,2,4-trioxolane secondary ozonides. The bimolecular rate constants of all three reactions decrease with increasing temperature over the range 275-335 K and are characterized by equations of Arrhenius form: k(T) = (7.1 ± 1.5) × 10-14exp((1160 ± 60)/T), (8.9 ± 1.7) × 10-15exp((1530 ± 60)/T), and (5.3 ± 1.3) × 10-14exp((1210 ± 70)/T) cm3 s-1 for HCHO, CH3CHO, and C2H5CHO, respectively. Based on estimated concentrations of CH2OO, the reactions with aldehydes are unlikely to play a significant role in the atmosphere.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142131209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

The Role of Spin-Orbit Coupling in the Linear Absorption Spectrum and Intersystem Crossing Rate Coefficients of Ruthenium Polypyridyl Dyes. 自旋轨道耦合在多吡啶钌染料线性吸收光谱和系统间交叉速率系数中的作用。

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-09-19 Epub Date: 2024-09-04 DOI: 10.1021/acs.jpca.4c04122

Justin J Talbot, Thomas P Cheshire, Stephen J Cotton, Frances A Houle, Martin Head-Gordon

{"title":"The Role of Spin-Orbit Coupling in the Linear Absorption Spectrum and Intersystem Crossing Rate Coefficients of Ruthenium Polypyridyl Dyes.","authors":"Justin J Talbot, Thomas P Cheshire, Stephen J Cotton, Frances A Houle, Martin Head-Gordon","doi":"10.1021/acs.jpca.4c04122","DOIUrl":"10.1021/acs.jpca.4c04122","url":null,"abstract":"The successful use of molecular dyes for solar energy conversion requires efficient charge injection, which in turn requires the formation of states with sufficiently long lifetimes (e.g., triplets). The molecular structure elements that confer this property can be found empirically, however computational predictions using ab initio electronic structure methods are invaluable to identify structure-property relations for dye sensitizers. The primary challenge for simulations to elucidate the electronic and nuclear origins of these properties is a spin-orbit interaction which drives transitions between electronic states. In this work, we present a computational analysis of the spin-orbit corrected linear absorption cross sections and intersystem crossing rate coefficients for a derivative set of phosphonated tris(2,2'-bipyridine)ruthenium(2+) dye molecules. After sampling the ground state vibrational distributions, the predicted linear absorption cross sections indicate that the mixture between singlet and triplet states plays a crucial role in defining the line shape of the metal-to-ligand charge transfer bands in these derivatives. Additionally, an analysis of the intersystem crossing rate coefficients suggests that transitions from the singlet into the triplet manifolds are ultrafast with rate coefficients on the order of 1013 s-1 for each dye molecule.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142131210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

IR and UV Spectroscopy of Gas-Phase Monohydrated Protonated Guanine 气相一水质子化鸟嘌呤的红外和紫外光谱分析

IF 2.781 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-09-19 DOI: 10.1021/acs.jpca.4c04976

J. Dezalay, G. Grégoire, M. Broquier, S. Soorkia

引用次数: 0

Dynamics of HCN, HNC, and HNCO Formation in the 193 nm Photodissociation of Formamide. 甲酰胺在 193 纳米波长光解过程中形成 HCN、HNC 和 HNCO 的动力学。

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-09-19 Epub Date: 2024-09-03 DOI: 10.1021/acs.jpca.4c02232

Kacee L Caster, Nathan A Seifert, Branko Ruscic, Ahren W Jasper, Kirill Prozument

{"title":"Dynamics of HCN, HNC, and HNCO Formation in the 193 nm Photodissociation of Formamide.","authors":"Kacee L Caster, Nathan A Seifert, Branko Ruscic, Ahren W Jasper, Kirill Prozument","doi":"10.1021/acs.jpca.4c02232","DOIUrl":"10.1021/acs.jpca.4c02232","url":null,"abstract":"Formamide (NH2CHO) is the simplest molecule containing a peptide linkage [-NH-C(═O)-], and it plays an essential role in the study of prebiotic chemistry. Exposure to UV irradiation allows formamide to decompose and act as a prebiotic feedstock in the formation of nucleobases and other necessary starting materials. The photodissociation mechanism of gaseous formamide at 193 nm is studied using (a) chirped-pulse Fourier transform millimeter-wave spectroscopy in the 260-290 GHz spectral region in a room-temperature flow-tube reactor at 1 μbar pressure, (b) a combination of electronic structure theory, transition state theory, and quasiclassical trajectories, and (c) the Active Thermochemical Tables. The HCN and HNC photoproducts of hydrogenated (NH2CHO) and deuterated (NH2CDO and ND2CHO) formamide precursors are examined to gain insight into the photodissociation mechanism. The theoretical investigation has characterized the main pathway leading to each of the HCN/HNC isomers from the precursor isotopologues. The theoretical branching ratio [HNC]/[HCN] = 2.1 for nascent photofragments agrees with the experiment. The effect of the postphotolysis HNC ↔ HCN isomerization on the [HNC]/[HCN] ratio is predicted. We report the experimental branching ratio [HNCO]: ([HNC] + [HCN]) = 12 ± 3 and propose that most of HNCO originates from dissociation on the S1 electronic state of formamide.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142118372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Removal of Moxifloxacin from Aqueous Solutions Using GO/Cr-MOFs. 使用 GO/Cr-MOFs 去除水溶液中的莫西沙星。

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-09-19 Epub Date: 2024-09-04 DOI: 10.1021/acs.jpca.4c03714

Fuhua Wei, Xiang Yu, Qinhui Ren, Hongliang Chen, Yutao Zhang, Zhao Liang

{"title":"Removal of Moxifloxacin from Aqueous Solutions Using GO/Cr-MOFs.","authors":"Fuhua Wei, Xiang Yu, Qinhui Ren, Hongliang Chen, Yutao Zhang, Zhao Liang","doi":"10.1021/acs.jpca.4c03714","DOIUrl":"10.1021/acs.jpca.4c03714","url":null,"abstract":"The composite material, consisting of graphene oxide (GO) and chromium metal-organic frameworks (Cr-MOFs), was successfully synthesized by using a solvothermal method. The organic ligand employed was 2,5-dihydroxyterephthalic acid, while chromium acetate served as the source of the metal. The resulting material underwent characterization through Fourier transform infrared, scanning electron microscopy, and X-ray diffraction techniques. Subsequently, the adsorption capacity of the composite material toward moxifloxacin was evaluated. The results indicated a gradual increase in the moxifloxacin removal rate from GO/Cr-MOFs over time until reaching an equilibrium with a maximum removal rate of 90.4%. Additionally, it was observed that higher temperatures led to a decrease in the adsorption capacity. By incorporating 30 mg of GO/Cr-MOFs into a solution containing 40 ppm of moxifloxacin, the adsorption capacity could be maximized at 222.25 mg/g. Experimental data on MOF adsorption of moxifloxacin were analyzed using pseudo-first-order kinetics (PFO), pseudo-second-order kinetics (PSO), and Langmuir, Freundlich, and Temkin isotherm models for theoretical research purposes. Results showed that the PSO model exhibited a better correlation than the PFO model did. Furthermore, experimental data demonstrated good agreement with the Freundlich isothermal model, suggesting its effectiveness in accurately describing the adsorption process. Henceforth, it can be concluded that chemisorption plays a significant role in removing moxifloxacin by GO/Cr-MOFs. The van't Hoff equation analysis revealed an exothermic and spontaneous nature of moxifloxacin adsorption onto GO/Cr-MOFs. Compared to other materials, the GO/Cr-MOF composite exhibited high potential for applications such as drug removal or related fields.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142124221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Gas Hydrate Dynamics with Parameter-Free Clathrate Phase Description: Validation for Hydrate Formation and Dissociation. 气体水合物动力学与无参数凝块相描述：验证水合物的形成和解离。

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-09-19 Epub Date: 2024-09-04 DOI: 10.1021/acs.jpca.4c03130

Shubhangi Sharma, Harshal J Dongre, Amiya K Jana

{"title":"Gas Hydrate Dynamics with Parameter-Free Clathrate Phase Description: Validation for Hydrate Formation and Dissociation.","authors":"Shubhangi Sharma, Harshal J Dongre, Amiya K Jana","doi":"10.1021/acs.jpca.4c03130","DOIUrl":"10.1021/acs.jpca.4c03130","url":null,"abstract":"One of the major challenges involved in clathrate hydrate science that has remained for more than six decades lies in highly parametric clathrate phase estimation. In this contribution, a recently developed parameter-free hydrate phase statistical equilibrium model is employed for the first time to formulate the formation and dissociation dynamics of clathrates and predict their experimental observation at diverse geological conditions. This rigorous thermokinetic model takes into account various practical issues, notably hydrate formation in nanometer-sized pores (confirmed through seismic survey studies), irregularity in porous particle shape and pore size, renewal of the particle surface over which hydrate majorly forms and decays, and nth-order phase transformation. The model parameters are identified by formulating the genetic algorithm-based optimization strategy. Finally, this multicomponent hydrate model is tested by predicting the formation and decomposition data having pure water as well as saltwater with and without porous media. The proposed formulation secures a promising performance with a lower absolute average relative deviation for a wide variety of data sets over the latest hydrate models.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142131207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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