The Journal of Physical Chemistry A最新文献

{"title":"Revealing a Heavy-Atom Assisted Rotation Mechanism in the H + NH₂Cl Multi-Channel Reaction.","authors":"Yizhuo Chen, Zhao Tu, Jiaqi Li, Chuanxi Duan, Hongwei Song, Minghui Yang","doi":"10.1021/acs.jpca.5c00415","DOIUrl":"10.1021/acs.jpca.5c00415","url":null,"abstract":"<p><p>Identifying atomic-level mechanisms in elemental chemical reactions is crucial for understanding complex reaction processes. This study focuses on the typical multichannel H + NH₂Cl reaction, which plays a significant role in environmental science. High-level ab initio calculations determined seven distinct reaction pathways, leading to three product channels: H₂ + NHCl, HCl + NH₂, and Cl + NH₃. A full-dimensional, globally accurate potential energy surface was constructed by fitting 143,333 ab initio energy points, calculated at the UCCSD(T)-F12a/aug-cc-pVTZ level. The atomic-level mechanisms of the reaction along these seven pathways were identified and visualized using quasi-classical trajectory calculations. Interestingly, a novel reaction mechanism, termed \"heavy-atom assisted rotation\", was discovered. In this light-heavy-heavy reaction, the attacked heavy atom (either Cl or N) acts as a \"gangplank\", propelling the light H atom in front of the other heavy atom through rotational motion. This mechanism results in forward and sideward scattering of products at small impact parameters, which contrasts with any known direct mechanisms.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"2887-2895"},"PeriodicalIF":2.7,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612846","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, Federico Lazzari, Silvia Di Grande","doi":"10.1021/acs.jpca.5c00281","DOIUrl":"10.1021/acs.jpca.5c00281","url":null,"abstract":"<p><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":" ","pages":"2876-2886"},"PeriodicalIF":2.7,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143646546","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":"Relaxation and Photochemistry of Nitroaromatic Compounds: Intersystem Crossing through ¹ππ* to Higher ³ππ* States, and NO^• Dissociation in 9-Nitroanthracene─A Theoretical Study.","authors":"Jesús Jara-Cortés, Antonio Resendiz-Pérez, Jesús Hernández-Trujillo, Jorge Peón","doi":"10.1021/acs.jpca.4c08534","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c08534","url":null,"abstract":"<p><p>Determination of the photodegradation pathways of nitroaromatic compounds, known for their mutagenic properties and toxicity, is a relevant topic in atmospheric chemistry. In the present theoretical study, mechanisms for the photophysical relaxation and NO^• dissociation of 9-nitroanthracene (9-NA) are proposed that challenge the commonly assumed pathways based on the El-Sayed rules. The analysis of the stationary points on the potential energy surfaces obtained with multiconfigurational methods indicates that after light absorption and subsequent relaxation of the S₁ state, the system undergoes ultrafast intersystem crossing to T₂, which serves as a gate-state to the triplet manifold due to favorable energetic couplings. This occurs despite the nature of the singlet and triplet states being ¹ππ* and ³ππ*, where the receiver triplet involves NO₂ orbitals that are tilted from the polyaromatic plane, with no involvement of the ³nπ state in the process. After the singlet to triplet manifold crossing, the system evolves along two possible trajectories. One leads to the global minimum of T₁ (phosphorescent end state) and the other involves the dissociation into antryloxy and NO^• radicals. Overall, the information obtained is in agreement with steady-state and time-resolved spectroscopic data reported for 9-NA. Furthermore, it suggests that the deactivation mechanism of nitroaromatic compounds can take place between ¹ππ* and ³ππ* states, which opens a new landscape for the rationalization of the photophysics of these and other systems.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143727008","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":"Pentagonal Star-like Three-Layered Aromatic Sandwich Structure of the [Li₁₀Be₂B₅]^+/0/- Cluster.","authors":"Lijuan Yan, Jun Liu, Yuanzheng Luo, Jean-François Halet","doi":"10.1021/acs.jpca.4c07750","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c07750","url":null,"abstract":"<p><p>Boron-based sandwich structures have garnered significant interest in recent years. However, species containing pentagonal boron rings are particularly rare. Herein, we theoretically predict an energetically low-lying three-layered sandwich structure of Li₁₀Be₂B₅^- (of <i>D</i>_5h symmetry). The central layer features a pentagonal planar B₅ ring staggeringly intercalated between two Be-centered pentagonal Li₅Be rings. Bonding analysis reveals that the entire cluster demonstrates σ/π aromaticity. Specifically, the inner B₅ layer contributes 6π/10σ-electron aromaticity, while each of the top and bottom layers contributes 2σ-electron aromaticity, leading to high symmetry in both the geometry and bonding patterns. Such a sandwich structure can also exist as the most stable conformation in both neutral and cationic states despite one of the delocalized σ bonds associated with the two outer Li₅Be layers being absent. Additionally, this aromaticity is clearly supported by a negative NICS_zz value and local diatropic contributions from the B₅ fragment. Our discovery enriches the sandwich family and provides a possible class of cluster units to form nanostructures.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143726991","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":"Interaction of Small Nitriles Occurring in the Atmosphere of Titan with Metal Ions of Meteoric Origin","authors":"Hypatia Meraviglia,&nbsp;Jacie Jordan,&nbsp;Camille Foscue,&nbsp;Briawna Stigall,&nbsp;Chance Persons,&nbsp;William S. Taylor* and Makenzie Provorse Long*,&nbsp;","doi":"10.1021/acs.jpca.4c0863810.1021/acs.jpca.4c08638","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c08638https://doi.org/10.1021/acs.jpca.4c08638","url":null,"abstract":"<p >Meteoric material injected into the atmosphere of Titan, Saturn’s moon, can react with nitriles and other organic compounds that constitute Titan’s atmosphere. However, specific chemical outcomes have not been fully explored. To understand the fates of meteoric metal ions in the Titan environment, reactions of Mg⁺ and Al⁺ with CH₃CN (acetonitrile) and C₂H₅CN (propionitrile) were carried out using a drift cell ion reactor at room temperatures (300 K) and reduced temperatures (∼193 K) and modeled using density functional theory and coupled-cluster theory. Analysis of reactant ion electronic state distributions via electronic state chromatography revealed that Mg⁺ was produced in our instrument exclusively in its ground (²S) state, whereas Al⁺ was produced in both its ¹S ground state and ³P first excited state. Mg⁺(²S) and Al⁺(¹S) produce association products exclusively with both CH₃CN and C₂H₅CN. Primary association reactions with C₂H₅CN occurred with higher reaction efficiencies than those with CH₃CN. Mg⁺(²S) sequentially associates up to four nitrile ligands, and Al⁺(¹S) associates up to three, each via the nitrile nitrogen. Computed binding energies are strongest for the first ligand and diminish with subsequent nitriles. Mg⁺(²S) exhibits a stronger preference for binding nitriles than Al⁺(¹S) because its unpaired electron delocalizes to the nitrile ligands through back-bonding, whereas the lone pair on Al⁺(¹S) remains localized on the metal center. Al⁺(³P) exhibited evidence of bimolecular product formation with both nitriles. Computational modeling of Al⁺(³P) with CH₃CN suggests that the major product, AlCH₃⁺, is kinetically favored over the more energetically stable product, Al⁺(HCN).</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 13","pages":"3098–3112 3098–3112"},"PeriodicalIF":2.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acs.jpca.4c08638","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143758792","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":"Interaction of Small Nitriles Occurring in the Atmosphere of Titan with Metal Ions of Meteoric Origin.","authors":"Hypatia Meraviglia, Jacie Jordan, Camille Foscue, Briawna Stigall, Chance Persons, William S Taylor, Makenzie Provorse Long","doi":"10.1021/acs.jpca.4c08638","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c08638","url":null,"abstract":"<p><p>Meteoric material injected into the atmosphere of Titan, Saturn's moon, can react with nitriles and other organic compounds that constitute Titan's atmosphere. However, specific chemical outcomes have not been fully explored. To understand the fates of meteoric metal ions in the Titan environment, reactions of Mg⁺ and Al⁺ with CH₃CN (acetonitrile) and C₂H₅CN (propionitrile) were carried out using a drift cell ion reactor at room temperatures (300 K) and reduced temperatures (∼193 K) and modeled using density functional theory and coupled-cluster theory. Analysis of reactant ion electronic state distributions via electronic state chromatography revealed that Mg⁺ was produced in our instrument exclusively in its ground (²S) state, whereas Al⁺ was produced in both its ¹S ground state and ³P first excited state. Mg⁺(²S) and Al⁺(¹S) produce association products exclusively with both CH₃CN and C₂H₅CN. Primary association reactions with C₂H₅CN occurred with higher reaction efficiencies than those with CH₃CN. Mg⁺(²S) sequentially associates up to four nitrile ligands, and Al⁺(¹S) associates up to three, each via the nitrile nitrogen. Computed binding energies are strongest for the first ligand and diminish with subsequent nitriles. Mg⁺(²S) exhibits a stronger preference for binding nitriles than Al⁺(¹S) because its unpaired electron delocalizes to the nitrile ligands through back-bonding, whereas the lone pair on Al⁺(¹S) remains localized on the metal center. Al⁺(³P) exhibited evidence of bimolecular product formation with both nitriles. Computational modeling of Al⁺(³P) with CH₃CN suggests that the major product, AlCH₃⁺, is kinetically favored over the more energetically stable product, Al⁺(HCN).</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143707782","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":"Confinement-Induced Stability Evolution of Na Clusters in Closed Pores of Hard Carbon: A DFT and AIMD Study.","authors":"Hongtao Yu, Zonglin Yi, Wanru Jia, Weiyan Hou, Lijing Xie, Zhenbing Wang, Jingpeng Chen, Fangyuan Su, Dong Jiang, Cheng-Meng Chen","doi":"10.1021/acs.jpca.5c00209","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c00209","url":null,"abstract":"<p><p>Hard carbon (HC) is considered as the most promising anode material for sodium-ion batteries due to its disordered structure, high sodium storage capacity, and low cost. However, within the domain of low-voltage plateaus, the thermodynamic stability and kinetic evolution of Na clusters confined within microporous structures have remained inadequately characterized. In this work, the nucleation mechanisms as well as the thermodynamic stability of Na clusters are thoroughly investigated by density functional theory (DFT) and ab initio molecular dynamics (AIMD) methods based on a well-built disordered HC structure model. A new method to construct the HC model is applied by applying strain to achieve contraction of the carbon skeleton through DFT calculations to obtain the curved HC model. On the basis of the HC model, we calculated the confinement effect of the closed pore on the cluster by DFT calculations. We find that the bent carbon layer leads to an elevated electrostatic potential, which makes it easy to attract clusters, as well as a change in the configuration of the clusters, thus affecting the electron distribution within the clusters, leading to different cohesive energies and affecting the reversibility of the clusters. During the evolution of cluster dynamics, Na⁺ tends to form clusters in larger closed pores while it tends to fill the pore walls in smaller closed pores. This work provides theoretical guidance for improving the plateau capacity and initial Coulombic efficiency of sodium-ion batteries.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143727098","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":"Isotope Effect on the Few-Femtosecond Relaxation Dynamics of the Ethylene Cation.","authors":"Matteo Lucchini, Manuel Cardosa-Gutierrez, Mario Murari, Fabio Frassetto, Luca Poletto, Mauro Nisoli, Francoise Remacle","doi":"10.1021/acs.jpca.5c01020","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c01020","url":null,"abstract":"<p><p>Few-femtosecond extreme-ultraviolet (EUV) pulses with tunable energy are employed to initiate the Jahn-Teller structural rearrangement in the ethylene cation. We report on a combined experimental and theoretical investigation of an unusual isotope effect on the low-energy competing H/D-loss and H₂/D₂-loss channels observed in the ultrafast dynamics induced by an EUV-pump pulse and probed by an infrared (IR) pulse. The relative production yields of C₂D₄⁺, C₂D₃⁺, and C₂D₂⁺ exhibit pronounced oscillations with a period of ∼50 fs as a function of the pump-probe delay, while the oscillatory patterns are less pronounced for C₂H₄⁺. By using surface hopping to model the nonadiabatic dynamics in the four lowest electronic states of the cation, we show that the enhanced oscillations in deuterated fragment yields arise from a synergy between the isotope effects on the wave packet relaxation through the network of conical intersections and on the vibrational frequencies of the cation.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143707784","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":"Isotope Effect on the Few-Femtosecond Relaxation Dynamics of the Ethylene Cation","authors":"Matteo Lucchini,&nbsp;Manuel Cardosa-Gutierrez,&nbsp;Mario Murari,&nbsp;Fabio Frassetto,&nbsp;Luca Poletto,&nbsp;Mauro Nisoli and Francoise Remacle*,&nbsp;","doi":"10.1021/acs.jpca.5c0102010.1021/acs.jpca.5c01020","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c01020https://doi.org/10.1021/acs.jpca.5c01020","url":null,"abstract":"<p >Few-femtosecond extreme-ultraviolet (EUV) pulses with tunable energy are employed to initiate the Jahn–Teller structural rearrangement in the ethylene cation. We report on a combined experimental and theoretical investigation of an unusual isotope effect on the low-energy competing H/D-loss and H₂/D₂-loss channels observed in the ultrafast dynamics induced by an EUV-pump pulse and probed by an infrared (IR) pulse. The relative production yields of C₂D₄⁺, C₂D₃⁺, and C₂D₂⁺ exhibit pronounced oscillations with a period of ∼50 fs as a function of the pump–probe delay, while the oscillatory patterns are less pronounced for C₂H₄⁺. By using surface hopping to model the nonadiabatic dynamics in the four lowest electronic states of the cation, we show that the enhanced oscillations in deuterated fragment yields arise from a synergy between the isotope effects on the wave packet relaxation through the network of conical intersections and on the vibrational frequencies of the cation.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 13","pages":"3063–3070 3063–3070"},"PeriodicalIF":2.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143758837","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":"Primary and Secondary Dissociation Pathways in the UV Photochemistry of α-Dicarbonyls.","authors":"Johanna E Rinaman, Craig Murray","doi":"10.1021/acs.jpca.5c00715","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c00715","url":null,"abstract":"<p><p>Photolysis of the α-dicarbonyls biacetyl (BiAc, CH₃COCOCH₃) and acetylpropionyl (AcPr, CH₃COCOC₂H₅) following UV excitation to the S₂ state at 280 nm was studied using velocity-map ion imaging. Single-photon VUV ionization at 118 nm was used to detect alkyl and acyl radical photoproducts. Photolysis of BiAc at 280 nm yields the expected Norrish Type I photofragments CH₃ and CH₃CO in a 1.0:1.3 ratio. The CH₃CO speed distribution is bimodal; the fast component is assigned to formation of a CH₃CO fragment pair on the T₁ surface while the slow component most likely results from prompt secondary dissociation of energized CH₃COCO radicals initially produced in conjunction with CH₃, tentatively assigned to dissociation on T₂. AcPr photolysis at 280 nm produces CH₃, CH₃CO and additionally C₂H₅ and C₂H₅CO radicals, with a total alkyl to acyl ratio of 1.0:0.7. Both types of acyl radicals have bimodal speed distributions, which are momentum-matched only for the fast tails. By analogy with BiAc, the fast component is attributed to formation of the CH₃CO + C₂H₅CO pair on the T₁ surface. The slower components are attributed to secondary dissociation of the corresponding energized RCOCO radicals formed in conjunction with the detected alkyl radicals. The results highlight the role that characterization of the detailed partitioning of the available energy can play in identifying mechanisms and quantifying branching between competitive pathways.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143707785","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}