The Journal of Physical Chemistry A最新文献

{"title":"Correction to \"Thermochemistry of Species in Gas-Phase Thermal Oxidation of C₂ to C₈ Perfluorinated Carboxylic Acids\".","authors":"Hrishikesh Ram, Thomas P Sadej, C Claire Murphy, Tim J Mallo, Phillip R Westmoreland","doi":"10.1021/acs.jpca.5c01422","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c01422","url":null,"abstract":"","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143661777","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":"Reaction between Hydrogen Peroxide and Ozone: Possibility of the Formation of H2O5","authors":"Bhabesh Baro,&nbsp;Himanshu Borah,&nbsp;Shankupar Rynjah and Biplab Sarkar*,&nbsp;","doi":"10.1021/acs.jpca.4c0670710.1021/acs.jpca.4c06707","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c06707https://doi.org/10.1021/acs.jpca.4c06707","url":null,"abstract":"<p >Gas-phase reaction of ozone and hydrogen peroxide to form water and singlet oxygen, a reactive oxygen species, has been investigated employing density functional theory and ab initio coupled cluster, CCSD(T) methods. The calculated H₂O₂ loss (4.01 × 10^–7 s^–1 at 296 K) has excellent agreement with the experimental observations considering the ozone concentration in the stratosphere and upper troposphere of the order of 10¹³ molecules cm^–3. Notably, a new pathway leading to the formation of H₂O₅ has been observed, which has not been reported in the existing literature until now.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 12","pages":"2829–2834 2829–2834"},"PeriodicalIF":2.7,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703813","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":"Spontaneous Deprotonation of HO2• at Air–Water Interface","authors":"Philips Kumar Rai,&nbsp;Amit Kumar and Pradeep Kumar*,&nbsp;","doi":"10.1021/acs.jpca.4c0819410.1021/acs.jpca.4c08194","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c08194https://doi.org/10.1021/acs.jpca.4c08194","url":null,"abstract":"<p >HO₂^• is a crucial radical in atmospheric chemistry, with applications ranging from HO₂^•/OH^• interconversion to controlling the budget of various trace gases in the atmosphere. It is known that one of the potential sinks for HO₂^• is clouds and aerosols, though the mechanism is not clear to date. In the present study, using Born–Oppenheimer molecular dynamics simulations, we have demonstrated that the dissociation of HO₂^• on the surface of a water droplet, as well as in the bulk phase, is a spontaneous process. In addition, we have computed the Gibbs free energy for the deprotonation of HO₂^• on both the surface and in the bulk, which suggests that deprotonation of HO₂^• on the surface occurs faster compared to the same in the bulk.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 12","pages":"2912–2921 2912–2921"},"PeriodicalIF":2.7,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703758","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":"Accurate Structures and Spectroscopic Parameters of CN-Substituted Polycyclic Hydrocarbons at DFT Cost","authors":"Vincenzo Barone*,&nbsp;Federico Lazzari and Silvia Di Grande,&nbsp;","doi":"10.1021/acs.jpca.5c0028110.1021/acs.jpca.5c00281","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c00281https://doi.org/10.1021/acs.jpca.5c00281","url":null,"abstract":"<p >The structures, isomerization energies, and rotational and vibrational spectra of prototypical CN-substituted polycyclic hydrocarbons in the gas phase have been analyzed using a general computational strategy based on Pisa composite schemes (PCS) and second-order vibrational perturbation theory (VPT2). The final results obtained in this way show, in most cases, relative average deviations with respect to experimental rotational constants close to 0.1%, corresponding to errors of around 1 mÅ and 0.1° for bond lengths and valence angles, respectively. At the same time, fundamental IR absorption bands are reproduced with average deviations below 10 cm^–1 without any scaling factor. In addition to the intrinsic interest of the studied molecules, this work confirms that spectroscopic studies of large systems can be supported by unsupervised computational tools that couple accuracy with reasonable cost.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 12","pages":"2876–2886 2876–2886"},"PeriodicalIF":2.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703872","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":"Comprehensive DFTB Parametrization and Its Utilization as a Preoptimizer for Investigating Au-Nanostructures + H2O Systems","authors":"Paria Fallahi,&nbsp; and ,&nbsp;Hossein Farrokhpour*,&nbsp;","doi":"10.1021/acs.jpca.4c0792310.1021/acs.jpca.4c07923","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c07923https://doi.org/10.1021/acs.jpca.4c07923","url":null,"abstract":"<p >A novel parameterization of a self-consistent charge density functional-based tight-binding scheme (SCC-DFTB) to characterize gold (Au)-water hybrid systems by developing new pair parameters for (Au, O, H-X where X = Au, O, H) using the DFTB module of Material Studio 2020 is introduced. To characterize Au-water systems within the DFTB framework, the derived parameters are systematically compared with DFT-DMOL3 and DFTB-AuOrg (existing library of DFTB) data for Au_n clusters (<i>n</i> = 2, 4, 8, 25, and 34), Au_n mono layer surfaces (<i>n</i> = 7, 19, 25, 37, and 49), Au₅₀ bilayer surface, and Au nanostructures-H₂O complexes. The geometrical, energetic, and electronic characteristics derived from the newly parametrized library (DFTB-AuOH) for the Au clusters align well with both the DFT-DMOL3 and the DFTB-AuOrg results, demonstrating that the stability of the Au clusters is accurately represented by the existing parameters. The structural outcomes derived from the DFTB-AuOH for Au surfaces indicate its substantial capability to optimize extensive gold surfaces in comparison to the DFT-DMOL3 approach, in which, in this case, the DFTB-AuOrg approach identified bent surfaces as the optimized configurations. Furthermore, the structural and energetic achievements determined from the DFTB-AuOH for Au nanostructure complexes with water molecule(s) reveal low-energy configurations and optimized structures with minimal variation when compared to DFT-DMOL3. The linear correlation equations of <i>Y</i> = (−0.044) <i>X</i> – 10.198 and <i>Y</i> = (−0.05) <i>X</i> – 10.538 are applied to the adsorption and interaction energy, respectively, to scale these DFTB-AuOH energies to their corresponding DFT-DMOL3 energies and to investigate all these energies in relation to the gold surface size, thereby confirming these accomplishments and demonstrating their compatibility significantly. The activation energy of water dissociation on Au surfaces is compared through all three approaches, and it also demonstrates significant compatibility as well. Lastly, the study of the molecular dynamics simulations reveals significant variations in the expected dynamic behavior among the DFTB-AuOH, DFT-DMOL3, and DFTB-AuOrg techniques. DFTB-AuOH consistently exhibits variations that more closely align with DFT-DMOL3, albeit of lesser magnitude, in contrast to DFTB-AuOrg, which predicts significantly smaller fluctuations overall.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 12","pages":"2835–2853 2835–2853"},"PeriodicalIF":2.7,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703834","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":"Highly Symmetrical Palladium Cluster Complexes with Either Anticuboctahedral or Cuboctahedral Pd₁₃ Core: Theoretical Insight into Factors Determining Symmetrical Structure.","authors":"Yu Tian, Bo Zhu, Tetsuro Murahashi, Shigeyoshi Sakaki","doi":"10.1021/acs.jpca.4c07401","DOIUrl":"10.1021/acs.jpca.4c07401","url":null,"abstract":"&lt;p&gt;&lt;p&gt;One of the important open questions is what factor(s) determines the symmetry of the structure of the metal nanocluster complex. [Pd&lt;sub&gt;13&lt;/sub&gt;(μ-Cl)&lt;sub&gt;3&lt;/sub&gt;(μ&lt;sub&gt;4&lt;/sub&gt;-C&lt;sub&gt;16&lt;/sub&gt;H&lt;sub&gt;16&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt; (&lt;b&gt;Anti-μ&lt;/b&gt;&lt;sub&gt;&lt;b&gt;4&lt;/b&gt;&lt;/sub&gt;; C&lt;sub&gt;16&lt;/sub&gt;H&lt;sub&gt;16&lt;/sub&gt; = [2.2]paracyclophane) has an anticuboctahedral Pd&lt;sub&gt;13&lt;/sub&gt; core unlike [Pd&lt;sub&gt;13&lt;/sub&gt;(μ&lt;sub&gt;4&lt;/sub&gt;-C&lt;sub&gt;7&lt;/sub&gt;H&lt;sub&gt;7&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/sup&gt; with cuboctahedral Pd&lt;sub&gt;13&lt;/sub&gt; core. DFT calculations show that &lt;b&gt;Anti-μ&lt;/b&gt;&lt;sub&gt;&lt;b&gt;4&lt;/b&gt;&lt;/sub&gt; is more stable than isomers, [Pd&lt;sub&gt;13&lt;/sub&gt;(μ-Cl)&lt;sub&gt;3&lt;/sub&gt;(μ&lt;sub&gt;3&lt;/sub&gt;-C&lt;sub&gt;16&lt;/sub&gt;H&lt;sub&gt;16&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;(μ&lt;sub&gt;4&lt;/sub&gt;-C&lt;sub&gt;16&lt;/sub&gt;H&lt;sub&gt;16&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt; and [Pd&lt;sub&gt;13&lt;/sub&gt;(μ-Cl)&lt;sub&gt;3&lt;/sub&gt;(μ&lt;sub&gt;2&lt;/sub&gt;-C&lt;sub&gt;16&lt;/sub&gt;H&lt;sub&gt;16&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;(μ&lt;sub&gt;4&lt;/sub&gt;-C&lt;sub&gt;16&lt;/sub&gt;H&lt;sub&gt;16&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt; with cuboctahedral Pd&lt;sub&gt;13&lt;/sub&gt; core (&lt;b&gt;Cubo-μ&lt;/b&gt;&lt;sub&gt;&lt;b&gt;3&lt;/b&gt;&lt;/sub&gt;&lt;b&gt;,μ&lt;/b&gt;&lt;sub&gt;&lt;b&gt;4&lt;/b&gt;&lt;/sub&gt; and &lt;b&gt;Cubo-μ&lt;/b&gt;&lt;sub&gt;&lt;b&gt;2&lt;/b&gt;&lt;/sub&gt;&lt;b&gt;,μ&lt;/b&gt;&lt;sub&gt;&lt;b&gt;4&lt;/b&gt;&lt;/sub&gt;, respectively) and [Pd&lt;sub&gt;13&lt;/sub&gt;(μ-Cl)&lt;sub&gt;3&lt;/sub&gt;(μ&lt;sub&gt;3&lt;/sub&gt;-C&lt;sub&gt;16&lt;/sub&gt;H&lt;sub&gt;16&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt; with distorted icosahedral Pd&lt;sub&gt;13&lt;/sub&gt; core (&lt;b&gt;dis-Ih-μ&lt;/b&gt;&lt;sub&gt;&lt;b&gt;3&lt;/b&gt;&lt;/sub&gt;). Not the stabilities of [Pd&lt;sub&gt;13&lt;/sub&gt;(μ-Cl)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt; core and (C&lt;sub&gt;16&lt;/sub&gt;H&lt;sub&gt;16&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt; ligand-shell but rather the interaction energy (&lt;i&gt;E&lt;/i&gt;&lt;sub&gt;int&lt;/sub&gt;) between [Pd&lt;sub&gt;13&lt;/sub&gt;(μ-Cl)&lt;sub&gt;3&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt; and (C&lt;sub&gt;16&lt;/sub&gt;H&lt;sub&gt;16&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt; ligand-shell determines stabilities of these complexes. μ&lt;sub&gt;4&lt;/sub&gt;-C&lt;sub&gt;16&lt;/sub&gt;H&lt;sub&gt;16&lt;/sub&gt; coordination bond is stronger than μ&lt;sub&gt;2&lt;/sub&gt;- and μ&lt;sub&gt;3&lt;/sub&gt;-coordination bonds, leading to a larger &lt;i&gt;E&lt;/i&gt;&lt;sub&gt;int&lt;/sub&gt; value in &lt;b&gt;Anti-μ&lt;/b&gt;&lt;sub&gt;&lt;b&gt;4&lt;/b&gt;&lt;/sub&gt; than in isomers bearing μ&lt;sub&gt;2&lt;/sub&gt;- or μ&lt;sub&gt;3&lt;/sub&gt;-coordination bond. An icosahedral Pd&lt;sub&gt;13&lt;/sub&gt; core is not favorable for these Pd&lt;sub&gt;13&lt;/sub&gt; complexes because of the absence of a Pd&lt;sub&gt;4&lt;/sub&gt; plane. [Pd&lt;sub&gt;13&lt;/sub&gt;(μ-Cl)&lt;sub&gt;3&lt;/sub&gt;(μ&lt;sub&gt;4&lt;/sub&gt;-C&lt;sub&gt;16&lt;/sub&gt;H&lt;sub&gt;16&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt; with cuboctahedral Pd&lt;sub&gt;13&lt;/sub&gt; (&lt;b&gt;Cubo-μ&lt;/b&gt;&lt;sub&gt;&lt;b&gt;4&lt;/b&gt;&lt;/sub&gt;) is not stable despite the presence of six Pd&lt;sub&gt;4&lt;/sub&gt; planes, because its three Pd&lt;sub&gt;4&lt;/sub&gt; planes with μ-Cl ligand cannot form μ&lt;sub&gt;4&lt;/sub&gt;-C&lt;sub&gt;16&lt;/sub&gt;H&lt;sub&gt;16&lt;/sub&gt; coordination bond due to steric repulsion of C&lt;sub&gt;16&lt;/sub&gt;H&lt;sub&gt;16&lt;/sub&gt; with the μ-Cl ligand. In contrast, &lt;b&gt;Anti-μ&lt;/b&gt;&lt;sub&gt;&lt;b&gt;4&lt;/b&gt;&lt;/sub&gt; is stable because it has six Pd&lt;sub&gt;4&lt;/sub&gt; planes with no Cl ligand to form strong μ&lt;sub&gt;4&lt;/sub&gt;-C&lt;sub&gt;16&lt;/sub&gt;H&lt;sub&gt;16&lt;/sub&gt; coordination bonds without steric repulsion. Also, discussion is presented on the difference in symmetry between [Pd&lt;sub&gt;13&lt;/sub&gt;(μ-Cl)&lt;sub&gt;3&lt;/sub&gt;(μ&lt;sub&gt;4&lt;/sub&gt;-C&lt;sub&gt;16&lt;/sub&gt;H&lt;sub&gt;16&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;+&lt;/sup&gt; and [Pd&lt;sub&gt;13&lt;/sub&gt;(μ&lt;sub&gt;4&lt;/sub&gt;-C&lt;sub&gt;7&lt;/sub&gt;H&lt;sub&gt;7&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;]&lt;sup&gt;2+&lt;/s","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"2510-2520"},"PeriodicalIF":2.7,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143514057","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":"Evaluating Ground State Energies of Chemical Systems with Low-Depth Quantum Circuits and High Accuracy.","authors":"Shuo Sun, Chandan Kumar, Kevin Shen, Elvira Shishenina, Christian B Mendl","doi":"10.1021/acs.jpca.4c07045","DOIUrl":"10.1021/acs.jpca.4c07045","url":null,"abstract":"<p><p>Quantum computers have the potential to efficiently solve the electronic structure problem but are currently limited by noise and shallow circuits. We present an enhanced Variational Quantum Eigensolver (VQE) ansatz based on the Qubit Coupled Cluster (QCC) approach that requires optimization of only <i>n</i> parameters, where <i>n</i> is the number of Pauli string generators, rather than the typical <i>n</i> + 2<i>m</i> parameters, where <i>m</i> is the number of qubits. We evaluate the ground state energies and molecular dissociation curves of strongly correlated molecules, namely O₃ and Li₄, using active spaces of varying sizes in conjunction with our enhanced QCC ansatz, Unitary Coupled Cluster Single-Double (UCCSD) ansatz, and the classical Coupled Cluster Singles and Doubles (CCSD) method. Compared to UCCSD, our approach significantly reduces the number of parameters while maintaining high accuracy. Numerical simulations demonstrate the effectiveness of our approach, and experiments on superconducting and trapped-ion quantum computers showcase its practicality on real hardware. By eliminating the need for symmetry-restoring gates and reducing the number of parameters, our enhanced QCC ansatz enables accurate quantum chemistry calculations on near-term quantum devices for strongly correlated systems.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"2379-2386"},"PeriodicalIF":2.7,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11912482/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143602999","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":"Ab Initio Molecular Dynamics Simulation Study on the Thermal Decomposition Mechanism of Two F-Containing Compounds: 3,3,7,7-Tetrakis(difluoramino)-octahydro-1,5-dinitro-1,5-diazocine (HNFX) and 1,3,5-Trinitro-2,2-bis(trifluoromethyl)-1,3,5-triazinane (TNBFT).","authors":"Kai Zhong, Chaoyang Zhang","doi":"10.1021/acs.jpca.5c00215","DOIUrl":"10.1021/acs.jpca.5c00215","url":null,"abstract":"<p><p>F-containing explosives with additional F atoms compared to traditional CHON ones should contain a more complex decomposition mechanism. Nevertheless, understanding the mechanism and effect of F-containing groups on stability remains limited. This study investigates the thermal decomposition mechanisms of two typical F-containing compounds, 3,3,7,7-tetrakis(difluoramino)-octahydro-1,5-dinitro-1,5-diazocine (HNFX) and 1,3,5-trinitro-2,2-bis(trifluoromethyl)-1,3,5-triazinane (TNBFT), using ground-state ab initio molecular dynamics simulations and compares them with RDX. The results show that HNFX decomposes from the partition of -NF₂ to form NF₃ and HF at 1500 K and above 2000 K, respectively, while TNBFT undergoes the concerted H transfer and HONO elimination at 1500 K and the N-NO₂ bond cleavage at relatively high temperatures. Additionally, HF and fluorocarbons, as the primary fluorinated products, lower the yields of H₂O and CO₂ compared to RDX, but they can act as oxidizers in combustion with Al particles. Moreover, it is found that F-containing groups significantly weaken the bonds nearby and the total molecular stability. Based on our bond strength analysis and simulation results, the reported experimental confirmation of the thermal stability of HNFX may be questionable. This insight is expected to deepen the thermal decomposition mechanisms of F-containing explosives and guide the design of high-performance composites thereof.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"2537-2547"},"PeriodicalIF":2.7,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143514052","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":"Key Kinetic Interactions between NO_<i>X</i> and Unsaturated Hydrocarbons: H Atom Abstraction from C₃-C₇ Alkynes, Dienes, and Trienes by NO₂.","authors":"Zhengyan Guo, Hongqing Wu, Ruoyue Tang, Xinrui Ren, Ting Zhang, Mingrui Wang, Guojie Liang, Hengjie Guo, Song Cheng","doi":"10.1021/acs.jpca.4c07335","DOIUrl":"10.1021/acs.jpca.4c07335","url":null,"abstract":"<p><p>An adequate understanding of the NO_<i>x</i> interacting chemistry is a prerequisite for a smoother transition to carbon-lean and carbon-free fuels such as ammonia and hydrogen. In this regard, this study presents a comprehensive study on the H atom abstraction by NO₂ from C₃ to C₇ alkynes, dienes, and trienes forming 3 HNO₂ isomers (i.e., TRANS_HONO, HNO₂, and CIS_HONO), encompassing 8 hydrocarbons and 24 reactions. Through a combination of high-level quantum chemistry computation, electronic structures, single-point energies, C-H bond dissociation energies, and 1-D hindered rotor potentials of the reactants, transition state (TS), complexes, and products involved in each reaction are determined at DLPNO-CCSD(T)/cc-pVDZ//M06-2<i>X</i>/6-311++g(d,p), from which potential energy surfaces and energy barriers for each reaction are determined. Following this, the rate coefficients for all studied reactions, over a temperature range from 298 to 2000 K, are computed based on TS theory using the Master Equation System Solver program by considering unsymmetric tunneling corrections. Comprehensive analysis of branching ratios elucidates the diversity and similarities between different species, different HNO₂ isomers, and different abstraction sites. Incorporating the calculated rate parameters into a recent chemistry model reveals the significant influences of this type of reaction on model performance, where the updated model is consistently more reactive for all the alkynes, dienes, and trienes studied in predicting autoignition characteristics. Sensitivity and flux analyses are further conducted, through which the importance of H atom abstractions by NO₂ is highlighted. With the updated rate parameters, the branching ratios in fuel consumption clearly shift toward H atom abstractions by NO₂ while away from H atom abstractions by ȮH. The obtained results emphasize the need for adequately representing these kinetics in new alkyne, diene, and triene chemistry models to be developed by using the rate parameters determined in this study, and call for future efforts to experimentally investigate NO₂ blending effects on alkynes, dienes, and trienes.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"2584-2597"},"PeriodicalIF":2.7,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142918694","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":"Parametrization of Linear Vibronic Coupling Models for Degenerate Electronic States.","authors":"Dilara Farkhutdinova, Severin Polonius, Paul Karrer, Sebastian Mai, Leticia González","doi":"10.1021/acs.jpca.4c07472","DOIUrl":"10.1021/acs.jpca.4c07472","url":null,"abstract":"<p><p>Linear vibronic coupling (LVC) models have proven to be effective in describing coupled excited-state potential energy surfaces of rigid molecules. However, obtaining the LVC parameters in molecules with many degrees of freedom and a large number of, possibly (near-)degenerate, electronic states can be challenging. In this paper, we discuss how the linear intra- and interstate couplings can be computed correctly using a numerical differentiation scheme, requiring a phase correction and sufficient numerical precision in the involved electronic structure calculations. The numerical scheme is applied to three test systems with symmetry-induced state degeneracies: SO₃, [PtBr₆]^2-, and [Ru(bpy)₃]²⁺. The first two systems are employed to validate the performance of the parametrization scheme. LVC potentials for SO₃ are shown to reproduce the trigonal symmetry of the potential energy surfaces. The integration of the LVC potentials for [PtBr₆]^2- with the surface-hopping trajectory method illustrates how spurious parameters lead to erroneous trajectory behavior. In the transition metal complex [Ru(bpy)₃]²⁺, extensive nonadiabatic simulations using LVC potentials are compared to those conducted with direct on-the-fly potentials. The simulations with LVC potentials demonstrate excellent agreement with the on-the-fly results while incurring costs that are 5 orders of magnitude lower. Further, the simulations evidence that intersystem crossing in [Ru(bpy)₃]²⁺ occurs at a slightly slower rate than luminescence decay, underscoring the importance of simulating the actual experimental observable when comparing computed time constants with experimental time constants. Lastly, the initial nuclear response to excitation involves a rapid, short-lived, and small elongation of the Ru-N bonds, with no charge localization occurring on a sub-ps time scale.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"2655-2666"},"PeriodicalIF":2.7,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11912485/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143555360","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}