The Journal of Physical Chemistry A最新文献

{"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":"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,&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":"In Silico Formation of Polyphosphazene Networks Based on Phloroglucinol (Phg) and Hexachlorocyclotriphosphazene (HCCP): Structural and Mechanical Properties as a Function of the Phg:HCCP Ratio","authors":"Sylvie Neyertz,&nbsp;Méryll Barraco,&nbsp;Nieck E. Benes and David Brown*,&nbsp;","doi":"10.1021/acs.jpca.5c0027710.1021/acs.jpca.5c00277","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c00277https://doi.org/10.1021/acs.jpca.5c00277","url":null,"abstract":"<p >Twenty-four molecular models for polyphosphazene networks were created via an <i>in silico</i> polymerization of phloroglucinol Phg (C₆H₆O₃) and hexachlorocyclotriphosphazene HCCP (N₃P₃Cl₆) mixtures at different Phg:HCCP ratios. A series of monomer mixtures at Phg-to-HCCP stoichiometric ratios ranging from 1:1 to 8:1 were created using molecular dynamics (MD) simulations. Alternating phases of reactions followed by relaxation steps led to the progressive formation of percolating polyphosphazene networks. The actual ratios of Phg to HCCP rings incorporated in the network polymers remained close to those in the mixtures for initial ratios up to 2:1. Above 2:1, there was a gradual divergence toward lower values in the networks as the limits to the number of possible bonds for each monomer started to take effect. The details of the structures were found to be very complex in terms of the probability distributions of links per Phg or HCCP ring. The highest degrees of connectivity and ring packing densities were found in the networks formed from the initial mixtures having Phg-to-HCCP ratios of around 2:1. Mechanical tests were carried out in order to ascertain the resistance of the model polyphosphazene networks to compression/decompression. There again, the networks obtained from the 2:1 initial mixture were found to have the highest Young’s modulus and to display the most elasticity as they recovered their initial shape once the compression was removed. The influence of trapped excess monomers in the percolating networks was only noticeable at the highest mixture ratios. The most resistant Phg-HCCP networks are thus obtained from Phg-to-HCCP mixture ratios of around 2:1, with or without trapped excess monomers.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 13","pages":"3148–3165 3148–3165"},"PeriodicalIF":2.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143758895","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*,&nbsp; and ,&nbsp;Craig Murray*,&nbsp;","doi":"10.1021/acs.jpca.5c0071510.1021/acs.jpca.5c00715","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c00715https://doi.org/10.1021/acs.jpca.5c00715","url":null,"abstract":"<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":"129 13","pages":"3040–3051 3040–3051"},"PeriodicalIF":2.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acs.jpca.5c00715","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143758927","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":"Transferability Across Different Molecular Systems and Levels of Theory with the Data-Driven Coupled-Cluster Scheme","authors":"P. D. Varuna S. Pathirage,&nbsp;Brody Quebedeaux,&nbsp;Shahzad Akram and Konstantinos D. Vogiatzis*,&nbsp;","doi":"10.1021/acs.jpca.4c0571810.1021/acs.jpca.4c05718","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c05718https://doi.org/10.1021/acs.jpca.4c05718","url":null,"abstract":"<p >Machine learning has recently been introduced into the arsenal of tools that are available to computational chemists. In the past few years, we have seen an increase in the applicability of these tools on a plethora of applications, including the automated exploration of a large fraction of the chemical space, the reduction of repetitive computational tasks, the detection of outliers on large databases, and the acceleration of molecular simulations. An attractive application of machine learning in molecular electronic structure theory is the “recycling” of molecular wave functions for faster and more accurate completion of complex quantum chemical calculations. Along these lines, we have developed hybrid quantum chemical/machine learning workflows that utilize information from low-level wave functions for the accurate prediction of higher-level wave functions. The <i>data-driven coupled-cluster</i> (DDCC) family of methods is discussed in this article together with the importance of the inclusion of physical properties in such hybrid workflows. After a short introduction to the philosophy and the capabilities of DDCC, we present our recent progress in extending its applicability to larger and more complex molecular structures and data sets. A significant advantage offered by DDCC is its transferability, with respect to different molecular systems and different excitation levels. As we show here, predicted wave functions at the coupled-cluster singles and doubles level of theory can be used for the accurate prediction of the perturbative triples of the CCSD(T) scheme. We conclude with some personal considerations with respect to future directions related to the development of the next generation of such hybrid quantum chemical/machine learning models.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 13","pages":"2988–2997 2988–2997"},"PeriodicalIF":2.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143758928","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":"Decentralized Metal–Metal Bonding in the AuNi(CO)4– Anion Described Equally Well with Dative Bonding as with Electron-Sharing Bonding","authors":"Zhiling Liu*,&nbsp;Yonghong Yan,&nbsp;Yufeng Yang,&nbsp;Xiaoyue Yao,&nbsp;Jingmei Jiao,&nbsp;Fuqiang Zhang,&nbsp;Jianfeng Jia and Ya Li*,&nbsp;","doi":"10.1021/acs.jpca.4c0814910.1021/acs.jpca.4c08149","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c08149https://doi.org/10.1021/acs.jpca.4c08149","url":null,"abstract":"<p >The heterodinuclear AuNi(CO)₄^– complex is scrutinized in the gas phase by using mass-selected anionic photoelectron velocity-map imaging spectroscopy in conjunction with theoretical computations. The ground state of AuNi(CO)₄^– is characterized to have an Au–Ni bonded structure, consisting of an AuCO fragment attached to the Ni center of the Ni(CO)₃ fragment. Comprehensive quantum chemical studies reveal that the AuNi(CO)₄^– complex at equilibrium structure features a decentralized bonding scenario, where the exotic metal–metal σ bonding may be equally well described with dative bonding as with electron-sharing bonding between two fragments.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 13","pages":"2998–3006 2998–3006"},"PeriodicalIF":2.7,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143758832","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":"Periodic Trends of Ions Bound in Molecular Cages: M^<i>n</i>+-[2.2.2]-Benzocryptand Complexes in the Gas Phase.","authors":"Chin Lee, Kendrew Au, Casey D Foley, Cole D Allen, Susan B Rempe, Pengyu Ren, Edwin L Sibert, Timothy S Zwier","doi":"10.1021/acs.jpca.5c00314","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c00314","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Cryptands are three-dimensional molecular cages that selectively bind cations in their interiors, discriminating between atomic cations based on their size and charge state. We report a detailed study of the IR and UV spectroscopy and structures of M&lt;sup&gt;&lt;i&gt;n&lt;/i&gt;+&lt;/sup&gt;-[2.2.2]-benzocryptand (BzCrypt) complexes with M&lt;sup&gt;&lt;i&gt;n&lt;/i&gt;+&lt;/sup&gt; = Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Rb&lt;sup&gt;+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;, and Ba&lt;sup&gt;2+&lt;/sup&gt; under cryo-cooled conditions in the gas phase, to discern periodic trends in the absence of thermal, solvent, or packing effects. This work builds off an initial report that compared the gas phase structures of K&lt;sup&gt;+&lt;/sup&gt;-BzCrypt and Ba&lt;sup&gt;2+&lt;/sup&gt;-BzCrypt (Foley et al., &lt;i&gt;J. Phys. Chem. A&lt;/i&gt; &lt;b&gt;2023&lt;/b&gt;, &lt;i&gt;127&lt;/i&gt;, 6227), where the ions are of the right size to fit inside the cage optimally. The electronic origins of the UV spectra shift by more than 1000 cm&lt;sup&gt;-1&lt;/sup&gt; with ion size and charge, with strong electronic origins and modest low frequency Franck-Condon activity arising from the confined motion of the ion in response to electronic excitation of the aromatic chromophore. In the infrared, the embedded ion produces significant shifts and anharmonic couplings in the alkyl CH stretch infrared spectrum (2800-3000 cm&lt;sup&gt;-1&lt;/sup&gt;) that reflect the way in which the cryptand cage changes its shape to maximize its binding with ions of different size and charge. We employ an anharmonic local mode model of the manifold of CH stretch transitions to assign the experimentally observed structures. All six ions are bound inside the cage primarily by the six O atoms in the three diether bridges, with secondary binding to the two tertiary amines. Mid-IR spectra in the 1000-1700 cm&lt;sup&gt;-1&lt;/sup&gt; region are dominated by transitions that carry significant C-O stretch character. We develop a local mode model of the CO stretch vibrations whose frequencies are shown to vary significantly with the M&lt;sup&gt;&lt;i&gt;n&lt;/i&gt;+&lt;/sup&gt; charge state but respond only weakly to the conformation of the cage as long as primary binding is to all six O atoms. Based on a complete search of the conformational potential energy surface, we track the calculated relative energies of a set of 16 low-energy conformations as a function of the imbedded cation. The assigned structures are either the calculated global minima for that M&lt;sup&gt;&lt;i&gt;n&lt;/i&gt;+&lt;/sup&gt;-BzCrypt complex or its closest competitor. When cations that are smaller than optimal are bound inside the cryptand cage (Na&lt;sup&gt;+&lt;/sup&gt;, Ca&lt;sup&gt;2+&lt;/sup&gt;, Sr&lt;sup&gt;2+&lt;/sup&gt;), the 'end-to-end' N···N distance is shortened significantly from its optimal value (6.06 in K&lt;sup&gt;+&lt;/sup&gt;-BzCrypt and 5.96 Å in Ba&lt;sup&gt;2+&lt;/sup&gt;-BzCrypt) by twisting the phenyl ring from its parallel optimal configuration to nearly perpendicular to the N···N axis, reducing the N···N distance to 5.24, 5.31, and 5.47 Å in the observed Ca&lt;sup&gt;2+&lt;/sup&gt;-, Na&lt;sup&gt;+&lt;/sup&gt;-, and Sr&lt;sup&gt;2+&lt;/sup&gt;-BzCrypt complexes. Finally, Rb&lt;sup&gt;+&lt;/sup&gt; ","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143699112","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":"Bromine Monoxide Radical Reaction with Propyl-Peroxy and Isopropyl-Peroxy Radicals: Thermokinetic Insights from Cavity Ring-Down Spectroscopy","authors":"Prasanna Kumar Bej,&nbsp; and ,&nbsp;Balla Rajakumar*,&nbsp;","doi":"10.1021/acs.jpca.4c0724110.1021/acs.jpca.4c07241","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c07241https://doi.org/10.1021/acs.jpca.4c07241","url":null,"abstract":"&lt;p &gt;The experimental rate coefficients for the reaction of bromine monoxide (BrO) with propyl peroxy (PrO&lt;sub&gt;2&lt;/sub&gt;) and isopropyl peroxy (&lt;i&gt;i&lt;/i&gt;-PrO&lt;sub&gt;2&lt;/sub&gt;) radicals were determined using cavity ring-down spectroscopy in the temperature ranges of 263–338 and 253–383 K, respectively. The rate coefficient for the BrO + PrO&lt;sub&gt;2&lt;/sub&gt; was measured to be (1.43 ± 0.14) × 10&lt;sup&gt;–12&lt;/sup&gt; cm&lt;sup&gt;3&lt;/sup&gt; molecule&lt;sup&gt;–1&lt;/sup&gt; s&lt;sup&gt;–1&lt;/sup&gt; and for the BrO + &lt;i&gt;i&lt;/i&gt;-PrO&lt;sub&gt;2&lt;/sub&gt; as (0.76 ± 0.01) × 10&lt;sup&gt;–12&lt;/sup&gt; cm&lt;sup&gt;3&lt;/sup&gt; molecule&lt;sup&gt;–1&lt;/sup&gt; s&lt;sup&gt;–1&lt;/sup&gt; at 298 K and 95 Torr. The temperature has an inverse effect on the rate coefficients in the studied range, given by &lt;i&gt;&lt;/i&gt;&lt;math&gt;&lt;msubsup&gt;&lt;mrow&gt;&lt;mi&gt;k&lt;/mi&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mrow&gt;&lt;mi&gt;B&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;mi&gt;O&lt;/mi&gt;&lt;/mrow&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;P&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;mi&gt;O&lt;/mi&gt;&lt;/mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;263&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;338&lt;/mn&gt;&lt;mi&gt;K&lt;/mi&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/math&gt; = &lt;i&gt;&lt;/i&gt;&lt;math&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mn&gt;2.55&lt;/mn&gt;&lt;mo&gt;±&lt;/mo&gt;&lt;mn&gt;0.92&lt;/mn&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/math&gt; × &lt;i&gt;&lt;/i&gt;&lt;math&gt;&lt;msup&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;14&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mi&gt;exp&lt;/mi&gt;&lt;mrow&gt;&lt;mo&gt;[&lt;/mo&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mn&gt;1228.6&lt;/mn&gt;&lt;mo&gt;±&lt;/mo&gt;&lt;mn&gt;244.0&lt;/mn&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mo&gt;]&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt; cm&lt;sup&gt;3&lt;/sup&gt; molecule&lt;sup&gt;–1&lt;/sup&gt; s&lt;sup&gt;–1&lt;/sup&gt; and &lt;i&gt;&lt;/i&gt;&lt;math&gt;&lt;msubsup&gt;&lt;mrow&gt;&lt;mi&gt;k&lt;/mi&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mrow&gt;&lt;mi&gt;B&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;mi&gt;O&lt;/mi&gt;&lt;/mrow&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;mo&gt;‐&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;P&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;mi&gt;O&lt;/mi&gt;&lt;/mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;253&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;383&lt;/mn&gt;&lt;mi&gt;K&lt;/mi&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/math&gt; = &lt;i&gt;&lt;/i&gt;&lt;math&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mn&gt;1.58&lt;/mn&gt;&lt;mo&gt;±&lt;/mo&gt;&lt;mn&gt;0.48&lt;/mn&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/math&gt; × &lt;i&gt;&lt;/i&gt;&lt;math&gt;&lt;msup&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;14&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mi&gt;exp&lt;/mi&gt;&lt;mrow&gt;&lt;mo&gt;[&lt;/mo&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mn&gt;1093.7&lt;/mn&gt;&lt;mo&gt;±&lt;/mo&gt;&lt;mn&gt;147.0&lt;/mn&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mo&gt;]&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt; cm&lt;sup&gt;3&lt;/sup&gt; molecule&lt;sup&gt;–1&lt;/sup&gt; s&lt;sup&gt;–1&lt;/sup&gt;. The rate coefficient was negligibly affected by the pressure variation from 95 to 220 Torr. The multireference theoretical calculations using the CASPT2-F12/AVDZ//M062-X/AVDZ level of theory for the H-abstraction reaction channel were used to determine the electronic energies of all species involved in the reactions. The reaction rate coefficient was calculated by using canonical variational transition (CVT) state theory with small curvature tunneling corrections, yielding results that are in close agreement with the experimentally measured values. At 298 K, the calculated rate coefficient for BrO + PrO&lt;sub&gt;2&lt;/sub&gt; was 1.49 × 10&lt;sup&gt;–12&lt;/sup&gt; cm&lt;sup&gt;3&lt;/sup&gt; molecule&lt;sup&gt;–1&lt;/sup&gt; s&lt;sup&gt;–1&lt;/sup&gt;, while for the BrO + &lt;i&gt;i&lt;/i&gt;-PrO&lt;sub&gt;2&lt;/sub&gt;, it was calculated to be 0.83 × 10&lt;sup&gt;–12&lt;/sup&gt; cm&lt;sup&gt;3&lt;/sup&gt; molecule&lt;sup&gt;–1&lt;/sup&gt; s&lt;sup&gt;–1&lt;/sup&gt;, which is close to the experimental result within the error limit. The rate coefficient for the recombination reaction of the radicals BrO + ","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 13","pages":"3071–3084 3071–3084"},"PeriodicalIF":2.7,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143758775","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}