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

Analytical Solution for the Sensitivity Coefficients of Ignition Delay Times.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2025-04-01 DOI: 10.1021/acs.jpca.4c05256

Jingqi Hu, Chung K Law, Wenkai Liang

{"title":"Analytical Solution for the Sensitivity Coefficients of Ignition Delay Times.","authors":"Jingqi Hu, Chung K Law, Wenkai Liang","doi":"10.1021/acs.jpca.4c05256","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c05256","url":null,"abstract":"In this study, a theoretical analysis of the sensitivity coefficients of ignition delay times is performed by using eigenvalue analysis. Using H2/O2 and CH4/H2/O2 kinetic systems as examples, it is demonstrated that the analytical solutions achieve accurate predictions of the sensitivity coefficients of the ignition delay time as compared with the computational solutions. Furthermore, the temperature dependence of the sensitivity coefficients can also be predicted by the theory. For the H2/O2 system, the sensitivity coefficients of the key elementary reactions can be predicted with high accuracy at wide ranges of temperature, pressure, and equivalence ratio. For the CH4/H2/O2 system, due to the complexity of the kinetic interactions, while the sensitivity of some reactions with relatively low values can be less accurate, the key reactions with high sensitivity can all be accurately predicted. The comparison of theory with various sizes shows that high-dimensional analysis can achieve closer prediction with the same computational cost. The potential to calculate sensitivity coefficients based on the eigenvalue is noteworthy and encouraging.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143762570","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

Extending Tensor Network Methods Beyond Pairwise Interactions in Adsorption Systems.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2025-04-01 DOI: 10.1021/acs.jpca.4c08371

Anastasiia V Karpova, Sergey S Akimenko, Anastasiia I Uliankina, Alexander V Myshlyavtsev

引用次数: 0

Vibrational Analysis Based on Cavity-Enhanced Raman Spectroscopy: Cyclohexane.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2025-03-31 DOI: 10.1021/acs.jpca.4c07709

Qing-Ying Yang, Qin Yang, Yi-Fan Song, An-Wen Liu, Jin Wang, Yan Tan, Yu R Sun, Shui-Ming Hu

引用次数: 0

Identification of the Elusive Methyl-Loss Channel in the Crossed Molecular Beam Study of Gas-Phase Reaction of Dicarbon Molecules (C₂; X¹Σ_g⁺/a³Π_u) with 2-Methyl-1,3-butadiene (C₅H₈; X¹A').

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2025-03-28 DOI: 10.1021/acs.jpca.5c00639

Iakov A Medvedkov, Zhenghai Yang, Shane J Goettl, Ralf I Kaiser

{"title":"Identification of the Elusive Methyl-Loss Channel in the Crossed Molecular Beam Study of Gas-Phase Reaction of Dicarbon Molecules (C2; X1Σg+/a3Πu) with 2-Methyl-1,3-butadiene (C5H8; X1A').","authors":"Iakov A Medvedkov, Zhenghai Yang, Shane J Goettl, Ralf I Kaiser","doi":"10.1021/acs.jpca.5c00639","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c00639","url":null,"abstract":"The crossed molecular beam technique was utilized to explore the reaction of dicarbon C2 (X1Σg+/a3Πu) with 2-methyl-1,3-butadiene (isoprene, CH2C(CH3)CHCH2; X1A') at a collision energy of 28 ± 1 kJ mol-1 using a supersonic dicarbon beam generated via photolysis (248 nm) of helium-seeded tetrachloroethylene (C2Cl4). Experimental data combined with previous ab initio calculations provide evidence of the detection of the hitherto elusive methyl elimination channels leading to acyclic resonantly stabilized hexatetraenyl radicals: 1,2,4,5-hexatetraen-3-yl (CH2CC•CHCCH2) and/or 1,3,4,5-hexatetraen-3-yl (CH2CHC•CCCH2). These pathways are exclusive to the singlet potential energy surface, with the reaction initiated by the barrierless addition of a dicarbon to one of the carbon-carbon double bonds in the diene. In combustion systems, both hexatetraenyl radicals can isomerize to the phenyl radical (C6H5) through a hydrogen atom-assisted isomerization─the crucial reaction intermediate and molecular mass growth species step toward the formation of polycyclic aromatic hydrocarbons and soot.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143735563","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

Teacups, a Python Package for the Simulation of Time-Resolved EPR Spectra of Spin-Polarized Multi-Spin Systems.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2025-03-28 DOI: 10.1021/acs.jpca.5c01512

Theresia Quintes, Stefan Weber, Sabine Richert

{"title":"Teacups, a Python Package for the Simulation of Time-Resolved EPR Spectra of Spin-Polarized Multi-Spin Systems.","authors":"Theresia Quintes, Stefan Weber, Sabine Richert","doi":"10.1021/acs.jpca.5c01512","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c01512","url":null,"abstract":"Spin-polarized magnetic systems, generated by the interaction of photoactive molecules with light, play a key role in a wide range of scientific applications. Representative examples are OLEDs, organic photovoltaics, and singlet fission. Further, they are important intermediates in certain biological processes including photosynthesis and, possibly, avian magnetoreception. Transient continuous-wave electron paramagnetic resonance (trEPR) spectroscopy is a powerful tool to reveal the temporal evolution of nonequilibrium spin states, which contains valuable information on any photoinduced dynamic processes occurring in these systems. For the analysis of the recorded trEPR data, simulations are essential. While the simulation of static trEPR spectra is supported well by tools like EasySpin, the simulation of time-resolved trEPR data is less developed. Here, we introduce teacups, a new freely available and well-documented Python-based routine for the simulation of the temporal evolution of trEPR spectra. The internal dynamics of different spin-polarized systems can be analyzed, thereby enhancing our mechanistic understanding. In this manuscript, we explain the theoretical background and provide a description of the features and setup of teacups. Further, a step-by-step example for data analysis is provided.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143727019","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

Comprehensive Insights into Exciplex Behavior in Nonpolar Media: Revisiting Weller's Framework with Molecular Conformation.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2025-03-28 DOI: 10.1021/acs.jpca.5c01445

Suhyun Park, Ena Yun, Jong-Won Song, Hohjai Lee

{"title":"Comprehensive Insights into Exciplex Behavior in Nonpolar Media: Revisiting Weller's Framework with Molecular Conformation.","authors":"Suhyun Park, Ena Yun, Jong-Won Song, Hohjai Lee","doi":"10.1021/acs.jpca.5c01445","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c01445","url":null,"abstract":"Exciplexes are pivotal in organic light-emitting diodes and photovoltaics. However, their formation and emission in nonpolar solvents remain unclear. Revisiting Weller's works on photoinduced electron transfer (PET) rates and exciplex emission based on electrochemical redox potentials, we investigate exciplex behavior in cyclohexane using anthracene (Ant) as an acceptor and N,N-dimethylaniline (DMA) derivatives as donors. Employing steady-state and time-resolved spectroscopy, electrochemistry, and density functional theory (DFT) calculations, we demonstrate that electrochemical redox potentials alone inadequately explain the exciplex behavior in nonpolar environments. Our DFT analysis reveals that the C-N rotational angle of the dimethylamine group of a donor influences the highest occupied molecular orbital (HOMO) energy levels, affecting quenching processes. Furthermore, time-dependent DFT simulations accurately reproduce experimental exciplex emission spectra, linking emission intensity to donor contribution in the exciplex HOMO. These findings deepen the understanding of exciplex behavior in nonpolar media and provide insights for designing and interpreting exciplex-based optoelectronic materials.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143727097","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

Spin-Free Exact Two-Component Linear Response Coupled Cluster Theory for the Estimation of Frequency-Dependent Second-Order Properties.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2025-03-28 DOI: 10.1021/acs.jpca.4c03584

Sudipta Chakraborty, Tamoghna Mukhopadhyay, Achintya Kumar Dutta

引用次数: 0

Quantum Chemical Study on the Evolution of Sulfur Functional Groups during Char Burnout.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2025-03-27 DOI: 10.1021/acs.jpca.4c07973

Bastian Schnieder, Rochus Schmid, Christof Hättig

{"title":"Quantum Chemical Study on the Evolution of Sulfur Functional Groups during Char Burnout.","authors":"Bastian Schnieder, Rochus Schmid, Christof Hättig","doi":"10.1021/acs.jpca.4c07973","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c07973","url":null,"abstract":"The oxy-fuel combustion of biochar connected with carbon capture, storage, and utilization technologies is an environmentally beneficial alternative for the replacement of fossil fuels. Biochar itself consists of porously stacked layers of hydrocarbons containing several heteroatoms, such as oxygen, nitrogen, and sulfur. At present, only limited information on the combustion mechanisms for oxygen and nitrogen functionalities is available in the literature; specific information on the combustion mechanisms of sulfur-containing groups (SFGs) is lacking. In this study, we present electronic structure calculations to uncover the mechanisms of the initial oxidation reactions of SFGs. Furthermore, it is examined if the reaction mechanisms remain similar or change with increasing system size. For this purpose, we apply an automatized workflow combining reactive molecular dynamics simulations with static electronic structure calculations at different levels of theory. The results show that terminal groups such as thiols, sulfonic acids, thioketones, and S,S-dioxides follow similar reaction pathways. These SFGs are all gradually oxidized before they eventually are eliminated as SOx(Hy) species from the carbon framework. Embedded thiophenes follow somewhat different reaction pathways that lead to the elimination of HOS· radicals or carbonyl sulfide (COS), depending on the system size. For the found oxidation channels, we report reaction and activation energies and rate constants that can be used to improve comprehensive kinetic models for the combustion of sulfur-containing biochar as a biomass-based renewable energy source.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143727003","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

Neutral Cyclic Nitreones: Electronic Structure Analysis Reveals an Unorthodox Perspective of Several Zwitterionic Heterocyclic Species.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2025-03-27 Epub Date: 2025-03-10 DOI: 10.1021/acs.jpca.4c08235

Astha Gupta, Pooja Saulanki, Prasad V Bharatam

{"title":"Neutral Cyclic Nitreones: Electronic Structure Analysis Reveals an Unorthodox Perspective of Several Zwitterionic Heterocyclic Species.","authors":"Astha Gupta, Pooja Saulanki, Prasad V Bharatam","doi":"10.1021/acs.jpca.4c08235","DOIUrl":"10.1021/acs.jpca.4c08235","url":null,"abstract":"Nitreones are compounds with the general formula L → N+ ← L'. These compounds exhibit medicinal properties and have found applications in phase transfer catalysis. A few nitreones are cyclic; protonated cycloguanil (an antimalarial agent) is the most prominent example. Recently, a few more cyclic compounds were experimentally reported, in which the central N+ was shown to exhibit nitreone character. This led to attention being paid to the chemistry of neutral cyclic nitreones. A thorough literature search led to two sets of cyclic nitreones: C → N ← C type and P → N ← P type. In this work, we report quantum chemical analysis in exploring the electronic structure of neutral cyclic nitreones. Molecular orbital analysis, electron density analysis, charge, electron localization function (ELF), complexation energy values, and Tolman electronic parameter (TEP) all indicate that the studied compounds do carry nitrogen in the N(I) oxidation state and the two lone pairs are at the central nitrogen; thus, they qualify to be considered as cyclic nitreones.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"2854-2865"},"PeriodicalIF":2.7,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143595873","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

Theoretical Investigation on the Reaction Kinetics of OH with Furfural.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2025-03-27 Epub Date: 2025-03-13 DOI: 10.1021/acs.jpca.4c06221

Qiongxuan Zhu, Lili Xing, Zhiyuan Ma, Liuchao Lian, Jing Zhu, Haojie Li, Mengjie Liu, Xuetao Wang

{"title":"Theoretical Investigation on the Reaction Kinetics of OH with Furfural.","authors":"Qiongxuan Zhu, Lili Xing, Zhiyuan Ma, Liuchao Lian, Jing Zhu, Haojie Li, Mengjie Liu, Xuetao Wang","doi":"10.1021/acs.jpca.4c06221","DOIUrl":"10.1021/acs.jpca.4c06221","url":null,"abstract":"Furfural is a typical representative molecule of furan compounds and an important intermediate species in the oxidation of furan derivatives. The rate constant of furfural with OH is calculated for the first time using a high-level quantum chemistry method combined with the Rice-Ramsperger-Kassel-Marcus theory/master equation method. The M06-2X/jun-cc-pVTZ method was used to construct the potential energy surface of the reaction path. The preliminary reactions can occur through three different pathways: H-abstraction from the furan ring, H-abstraction from the side chain, and a preliminary OH-addition. The pathways via the OH-addition mechanism of the furfural + OH system were superior to H-abstraction in the temperature range of 298-400 K. When the temperature exceeds 400 K, the H-abstraction will be faster. Moreover, with the increase of pressure, the competition of the pathway via the OH-addition mechanism in the low-temperature region will gradually weaken. Under low-temperature conditions, INT1 and INT4 are the main intermediate species. The formation of bimolecular products, the 2-furanol (P7) + aldehyde group and the (3E)-4-hydroxybuta-1,3-diene-1-one (P8) + aldehyde group at C(2) and C(5) sites, are the main reaction pathways via the OH-addition mechanism. The formation of (2-furanyl)(oxy) methyl (P4) + H2O (i.e., R4) always dominates for the four H-abstraction reactions. For the initial H-abstraction reaction, there is no pressure dependence, but for the preliminary OH-addition reaction, there is a significant positive pressure dependence. This work not only provides the necessary rate constants for modeling development but also provides theoretical guidance for the practical application of furan-based fuel.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"2932-2945"},"PeriodicalIF":2.7,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622891","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