The Journal of Physical Chemistry A最新文献

{"title":"","authors":"Paul Saxe*, Jessica Nash*, Mohammad Mostafanejad*, Eliseo Marin-Rimoldi*, Hasnain Hafiz*, Louis G. Hector Jr* and T. Daniel Crawford*, ","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 30","pages":"XXX-XXX XXX-XXX"},"PeriodicalIF":2.8,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acs.jpca.5c03164","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144737818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"","authors":"","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 30","pages":"XXX-XXX XXX-XXX"},"PeriodicalIF":2.8,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/jxv129i030_1966076","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144737822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"","authors":"Sarai Dery Folkestad*, Kristine Lauvstad Kruken and Henrik Koch, ","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 30","pages":"XXX-XXX XXX-XXX"},"PeriodicalIF":2.8,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acs.jpca.5c01190","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144737846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"","authors":"Yao Guo, Menglong Gao, Linghao Zhu, Zunwei Zhu, Jianxin Li, Miaomiao Li, Changwei Lai*, Haixiang Song* and Qing Shen*, ","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 30","pages":"XXX-XXX XXX-XXX"},"PeriodicalIF":2.8,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acs.jpca.5c01900","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144737815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"","authors":"Yiqing Wang, Hu Zhou*, He Wang, Yuan Li, Zheyan Tu, Lixun Song, Gang Wu, Yali Du, Zebin Li, Qiang Wu, Xin Zhang, Zewen Zong, Dong Feng, Yu Liu, Jianglei Luan, Lei Song, Kaiwen Chang, Yudi Cong, Zhengqi Liu, Guangyi Wang*, Yongtao Zhao, Hongfei Zhang and Ximeng Chen*, ","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 30","pages":"XXX-XXX XXX-XXX"},"PeriodicalIF":2.8,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acs.jpca.5c03433","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144737816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In Silico Estimation of Solvent Polarizabilities and Dipolarities","authors":"Marcos Caroli Rezende*,&nbsp;Nicolás Rozas-Castro and Rodrigo Ormazábal-Toledo,&nbsp;","doi":"10.1021/acs.jpca.5c03648","DOIUrl":"10.1021/acs.jpca.5c03648","url":null,"abstract":"<p >The solvatochromic behavior of β-carotene and of two analogous cationic polymethine dyes with distinct chain-lengths (PD 2501 and PD 1659) was investigated theoretically by means of TD-DFT calculations of their solvatochromic transition energies in ten solvents, at three levels of theory, with linear-response (LR-CPCM) and corrected linear-response (cLR- and cLR²-CPCM) approaches. The calculated transition energies of β-carotene and of PD 2501 showed good correlations (<i>r</i>² &gt; 0.96) with the values of the medium polarizability (<i>SP</i>). Calculated transition energies of PD 1659 showed equally good correlations (<i>r</i>² &gt; 0.93) with the values of the solvent dipolarity (<i>SdP</i>), without contamination by the medium polarizabilities. The obtained linear relationships with the <i>SP</i> and <i>SdP</i> scales thus offer an in silico alternative for estimating medium polarizabilities and dipolarities of new solvents or solvent mixtures in cases where the varieties of probes employed for their determination are not available or show solubility problems.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 32","pages":"7365–7375"},"PeriodicalIF":2.8,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144751879","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}

{"title":"Machine Learning-Driven Deconvolution of Mixed X-ray Absorption Spectra","authors":"Kexin Wang,&nbsp;Haishan Yu*,&nbsp;Xiangwei Lu and Kai Chen*,&nbsp;","doi":"10.1021/acs.jpca.5c02158","DOIUrl":"10.1021/acs.jpca.5c02158","url":null,"abstract":"<p >X-ray absorption spectroscopy (XAS) plays a crucial role in determining the oxidation states, local atomic structures, and electronic configurations of materials. However, the interpretation of complex spectra with multiple ion sites and varying local chemical environments can be labor-intensive and requires specialized expertise, presenting challenges for researchers. To address these issues, this study employs machine learning (ML) techniques to analyze mixed XAS data, with a particular focus on the cobalt (Co) element. We constructed a simulated data set of L-edge spectra, incorporating various combinations and energy shifts produced from multiplet calculations. Through a systematic evaluation of dimensionality reduction and ML methodologies, we identified a combination that achieved both high accuracy and efficiency in classification tasks. Our approach involved isolating individual components from the mixed spectra and implementing an automatic fitting algorithm to extract critical parameters, such as component proportions and Gaussian broadening. The fitting results closely aligned with the input spectra, thereby validating our methodology. This innovative process facilitates the determination of valence states, local crystal field parameters, and composition ratios, significantly enhancing the efficiency of spectral analysis.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 32","pages":"7535–7548"},"PeriodicalIF":2.8,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144751880","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}

{"title":"Experimental and Kinetic Study on OH* and CH* Chemiluminescence of Methane Oxidation at High Temperature behind Reflected Shock Waves","authors":"Minjie Yang,&nbsp;Dongxian Li,&nbsp;Xu Li,&nbsp;Meng Xu and Changhua Zhang*,&nbsp;","doi":"10.1021/acs.jpca.5c03877","DOIUrl":"10.1021/acs.jpca.5c03877","url":null,"abstract":"<p >Chemiluminescence, as an effective diagnostic method, is often used to study the flame structure, heat release, and equivalence ratio, which are significantly important for describing the complex combustion process. In this work, the time histories of chemiluminescence emission from OH*(A²Σ⁺) and CH*(A²Δ) in reacting methane/oxygen/argon mixtures have been simultaneously measured behind reflected shock waves. Experiments were conducted at pressures around 1.0 and 2.0 atm, equivalence ratios of 0.5 and 1.0, a fuel concentration of 0.2%, and temperatures ranging from approximately 1725 to 2743 K. Based on the measured OH* chemiluminescence time histories, the rate constant of reaction CH + O₂ ⇒ OH* + CO was determined to be 9.24 × 10¹⁵ × <i>T</i>^–0.4 exp(−4150 cal·mol^–1/<i>RT</i>) cm³ mol^–1 s^–1. A methane combustion mechanism involving the OH* and CH* reaction kinetics was constructed. The reliability of the constructed kinetic mechanism was verified by using the experimental kinetic data of OH* and CH* chemiluminescence, including the time histories and relative peak intensities.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 32","pages":"7517–7526"},"PeriodicalIF":2.8,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144751799","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}

{"title":"Semi-Classical Transition State Theory (SCTST) Rate Coefficients for the Reaction of H and H2O2: A High-Level Theoretical Study","authors":"Thanh Lam Nguyen*,&nbsp;Mahshid Manouchehri,&nbsp;Jozef Peeters* and John F. Stanton*,&nbsp;","doi":"10.1021/acs.jpca.5c04239","DOIUrl":"10.1021/acs.jpca.5c04239","url":null,"abstract":"<p >The bimolecular reaction of hydrogen atom (H) and hydrogen peroxide (H₂O₂), which plays an important role in combustion of H₂-fuel, has been characterized using a combination of a high-accuracy coupled-cluster-based composite method for constructing the potential energy surface and W. H. Miller’s semiclassical transition state theory (SCTST) for determining the reaction rate coefficients from first principles. Two distinct reaction mechanisms have been characterized, pathway R1 for a direct H-abstraction mechanism yielding H₂ + HO₂ and pathway R2 for a nucleophilic substitution (S_N2) mechanism leading to OH + H₂O. Pathway R1 is found to be most important at temperatures below 200 K due to quantum tunneling effects while pathway R2 having a lower barrier dominates at higher temperatures and in combustion conditions (<i>ca</i>. 90%). For the temperature range of 200 – 2000 K, the calculated rate coefficients of the two channels can be represented by the expressions <i>k</i>₁ (<i>T</i>) = 8.5 × 10^–26 × <i>T</i>^4.316 × exp (195/<i>T</i>) cm³ s^–1 and <i>k</i>₂ (<i>T</i>) = 2.0 × 10^–18 × <i>T</i>^2.40 × exp (−1221/<i>T</i>) cm³ s^–1, respectively. The reliability of these theoretical rate coefficients is supported by the close agreement of the calculated total rate coefficient <i>k</i>₁(<i>T</i>) + <i>k</i>₂(<i>T</i>), within 30%, with the available, directly measured experimental <i>k</i>_tot data, lending confidence to our kinetic predictions for use at combustion temperatures where experimental data are lacking.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 32","pages":"7527–7534"},"PeriodicalIF":2.8,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144751881","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}

{"title":"Changes in Protonation State of Atmospherically Relevant α-Hydroxyacids at the Air–Water Interface Measured by Surface Tension and IR-RAS","authors":"Burgess E. Rugeley,&nbsp;Katherine R. Holt,&nbsp;Erica B. Peterson,&nbsp;Selma Moulai-Khatir,&nbsp;Claire F. N. Koltun and Rebecca J. Rapf*,&nbsp;","doi":"10.1021/acs.jpca.5c02825","DOIUrl":"10.1021/acs.jpca.5c02825","url":null,"abstract":"<p >Characterization of the acid–base behavior and surface protonation state of atmospherically relevant organic acids is of key importance in our understanding of interfacial reactivity, as well as our ability to accurately model aerosol impact on climate. Here we investigate the protonation state of two medium-chain α-hydroxyacids, 2-hydroxyhexanoic acid (HHA) and 2-hydroxyoctanoic acid (HOA), at the air–water interface and in the bulk. The ratio of surface-deprotonated to surface-protonated species at varying pH was examined using surface tension titrations, finding an effective surface-p<i>K</i>_a of 4.5 ± 0.2 for HHA and 5.41 ± 0.05 for HOA, both of which are significantly higher than their bulk p<i>K</i>_a values of 3.9 ± 0.1 and 4.0 ± 0.1, respectively, which were determined <i>via</i> potentiometric titration. However, the effective surface-p<i>K</i>_a obtained from surface tension measurements also contains contributions from adsorption and desorption processes, which means that it does not directly probe differences in the dissociation equilibrium at the interface. We show that infrared reflection–absorption spectroscopy (IR-RAS) can be used to directly probe the surface dissociation of α-hydroxyacids <i>in situ</i> for the first time, demonstrating the utility of IR-RAS as a technique for these types of studies. By correcting for the relative surface activity of the anion and acid species, the surface-p<i>K</i>_a obtained using IR-RAS is a better measure of the actual shift in dissociation equilibrium at the interface. Through comparison to the bulk spectra obtained using attenuated total reflectance (ATR) spectroscopy, we confirmed that the protonated form of the α-hydroxyacids is favored at the water surface. However, we find that the difference between the surface-p<i>K</i>_a and bulk pK_a obtained spectroscopically is 0.2 ± 0.1 for HHA and 0.4 ± 0.2 for HOA. This suggests that the relative shift in the dissociation constant at the interface is modest, and that adsorption processes play an important role in the speciation at the interface and must be explicitly considered in these studies. Overall, we confirm the importance of fundamental lab studies to examine the speciation at air–water interfaces as a function of solution condition, as bulk pH alone is not sufficient to predict the distribution of species present at the interface.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 31","pages":"7170–7182"},"PeriodicalIF":2.8,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144726045","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}