The Journal of Physical Chemistry A最新文献

{"title":"Triplet J-Driven DNP─A Proposal to Increase the Sensitivity of Solution-State NMR without Microwave","authors":"Maria Grazia Concilio*,&nbsp;Yiwen Wang,&nbsp;Linjun Wang and Xueqian Kong*,&nbsp;","doi":"10.1021/acs.jpca.5c0207910.1021/acs.jpca.5c02079","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c02079https://doi.org/10.1021/acs.jpca.5c02079","url":null,"abstract":"<p >Dynamic nuclear polarization (DNP) is an important method to enhance the limited sensitivity of nuclear magnetic resonance (NMR). Using the existing mechanisms such as Overhauser DNP (ODNP) is still difficult to achieve significant enhancement of NMR signals in solutions at a high magnetic field. The recently proposed J-driven DNP (JDNP) condition (when the exchange interaction <i>J</i>_ex of two electron spins matches the electron or the nuclear Larmor frequency ω_E and ω_N) may enable signal enhancement in solution as it requires only dipolar interaction between the biradical polarization agent and the analyte. However, likewise ODNP, the current JDNP strategy still requires the saturation of the electron polarization with high microwave power which has poor penetration and is associated with heating effects in most liquids. The replacement of high-power microwave irradiation is possible if the temporal electron polarization imbalance is created by an electron electromagnetic (EM) irradiation at different wavelengths such as the visible light. Here, we propose a triplet-JDNP mechanism which first exploits the light-induced singlet fission process (i.e., a singlet exciton is converted into two triplet excitons). As the JDNP condition <i>J</i>_ex ≈ ± ω_E is fulfilled, a triplet-to-triplet cross-relaxation process will occur with different rates and consequently lead to the creation of hyperpolarization on the coupled nuclear spin states. This communication discusses the theory behind the triplet-JDNP proposal, as well as the polarizing agents and conditions that will enable the new approach to enhance NMR’s sensitivity without the need of microwave irradiation.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 17","pages":"3886–3897 3886–3897"},"PeriodicalIF":2.7,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890374","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":"Adsorption of Silver Clusters on Naphthalene: Theoretical Insights into Structural, Energetic, Electronic, and Infrared Properties","authors":"Rahma Dahmani,&nbsp;Camille Alauzet,&nbsp;Gabriella Di Genova,&nbsp;Fernand Spiegelman and Aude Simon*,&nbsp;","doi":"10.1021/acs.jpca.5c0043610.1021/acs.jpca.5c00436","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c00436https://doi.org/10.1021/acs.jpca.5c00436","url":null,"abstract":"<p >In the present study, we carry out a comprehensive investigation of the structural, bonding, and infrared spectral properties of the low-energy complexes of silver clusters Ag_<i>n</i> (<i>n</i> = 1–8) adsorbed on naphthalene C₁₀H₈ (Nap). The structural properties are obtained through a systematic multimethod global optimization scheme. The potential energy surfaces of the complexes are first explored at the density functional-based tight binding level of theory via extensive Monte Carlo parallel tempering simulations complemented by gradient-driven quenching, thus providing prescreened samples of low-energy structural conformations. The most stable isomers are then reoptimized at the density functional theory level using a functional that includes dispersion, namely B3LYP-D3BJ. The properties of the global minima are analyzed at the latter level. Unsurprisingly, the structures of Ag_<i>n</i> adsorbates within the most stable complexes are close to those of the bare clusters. Regarding 2D Ag_<i>n</i> structures (<i>n</i> = 2–6), those with Ag_<i>n</i> perpendicular to the Nap plane are found to be the most stable for <i>n</i> = 2–4, while parallel conformations are preferred for <i>n</i> = 5 and 6. The significant role of dispersion interactions in the stability of these complexes is shown. The study of the influence of Ag_<i>n</i> adsorption on the evolution of the HOMO–LUMO band gaps and vertical ionization potentials (VIPs) shows that the odd–even alternation of the adsorbate cluster electronic properties is maintained and that the VIP decreases with size. Finally, the influence of the adsorption of Ag_<i>n</i> on the infrared properties of Nap is analyzed: small shifts are observed as well as the appearance of new bands due to symmetry reduction. The essential novelty consists of relative intensity changes reflecting charge transfer (though not dominant) from Nap to Ag_<i>n</i>. Our study globally shows that Nap–Ag_<i>n</i> interactions lead to a modulation of the electronic and vibrational properties of Ag_<i>n</i> and Nap. This could be of interest for structural diagnosis and reactivity. Perspectives concerning the use of the present structural search methodology for more complex hybrid metal–organic systems in various application fields are suggested.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 17","pages":"3829–3843 3829–3843"},"PeriodicalIF":2.7,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890302","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":"Relativistic Effects in Ligand Field Theory (II): Optical and Magnetic Properties of d1 Atoms in Cubic and Tetragonal Symmetries","authors":"Jhon Fredy Pérez-Torres*,&nbsp;","doi":"10.1021/acs.jpca.5c0105210.1021/acs.jpca.5c01052","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c01052https://doi.org/10.1021/acs.jpca.5c01052","url":null,"abstract":"<p >The relativistic motion of an electron in the <i>n</i>d atomic subshell subjected to an electrostatic ligand field and a magnetic field is studied. The ligand and magnetic fields are treated as perturbations on equal footing, employing the atomic Dirac spinors <i>n</i>d_3/2 and <i>n</i>d_5/2 as basic vectors according to relativistic ligand field theory. The parametrized ligand field allows for the description of <i></i><math><msubsup><mrow><mi>C</mi></mrow><mrow><mrow><mn>4</mn></mrow><mrow><mi>v</mi></mrow></mrow><mrow><mo>′</mo></mrow></msubsup></math>, <i></i><math><msubsup><mrow><mi>D</mi></mrow><mrow><mrow><mn>4</mn></mrow><mrow><mi>h</mi></mrow></mrow><mrow><mo>′</mo></mrow></msubsup></math>, <i></i><math><msubsup><mrow><mi>O</mi></mrow><mrow><mi>h</mi></mrow><mrow><mo>′</mo></mrow></msubsup></math>, and <i></i><math><msubsup><mrow><mi>T</mi></mrow><mrow><mi>d</mi></mrow><mrow><mo>′</mo></mrow></msubsup></math> symmetries as particular cases. The wave functions of the ground state manifold Γ_<i>i</i>(²D_3/2) are employed to calculate the Zeeman coefficients and consequently the Curie constant according to Van Vleck’s theory of paramagnetism. The theoretical framework is illustrated in Rb₂TaCl₆, ReF₆, Ba₂NaOsO₆, VO(R-acac)₂, and Cs[MoOCl₄] d¹-systems. It is indicated how correlating the optical transition energies with the magnetic susceptibility enables experimental determination of the theory’s parameters: the relativistic ratio <i>p</i>/<i>q</i>, the spin–orbit coupling constant ξ_<i>n</i>d, and the ligand field strengths <i>Dq</i>, <i>Ds,</i> and <i>Dt</i>. Then, from the deduced parameters, the X-band signals of the electron paramagnetic resonance spectrum are predicted. A strong dependency of the magnetic properties upon the relativistic ratio <i>p</i>/<i>q</i> is observed. Energies of the well-separated (ca. 330 cm^–1) optical transitions Γ₆(²D_3/2) ← Γ₇(²D_3/2) and Γ₇(²D_5/2) ← Γ₇(²D_3/2) for Cs[MoOCl₄] are predicted. Our results suggest that the reported spin–orbit coupling constant ξ_5d for ReF₆ might have been overestimated by more than 1000 cm^–1, offering valuable insights into the accuracy of previous experimental and theoretical studies.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 17","pages":"3844–3856 3844–3856"},"PeriodicalIF":2.7,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890423","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":"Chlorocyclohexane Valence and Rydberg Electronic Excitations","authors":"E. Bandeira,&nbsp;S. Kumar,&nbsp;A. S. Barbosa,&nbsp;N. C. Jones,&nbsp;S. V. Hoffmann,&nbsp;M. H. F. Bettega* and P. Limão-Vieira*,&nbsp;","doi":"10.1021/acs.jpca.5c0112210.1021/acs.jpca.5c01122","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c01122https://doi.org/10.1021/acs.jpca.5c01122","url":null,"abstract":"<p >Here we present new cross-section values of chlorocyclohexane (C₆H₁₁Cl) from vacuum ultraviolet (VUV) photoabsorption measurements in the photon energy range of 5.0–10.8 eV (115–248 nm). Theoretical calculations using time-dependent density functional theory (TD-DFT) have been performed to aid in the interpretation of the photoabsorption spectrum. The information from these calculations has allowed the assignment of the excited states in valence, mixed valence-Rydberg, and Rydberg transitions. The fine features in the photoabsorption bands have been assigned to (C–H₂)₄ symmetric stretching (and C–H stretching), <i></i><math><msubsup><mrow><mi>v</mi></mrow><mrow><mn>7</mn></mrow><mrow><mo>′</mo></mrow></msubsup><mrow><mo>(</mo><msup><mrow><mi>a</mi></mrow><mrow><mo>′</mo></mrow></msup><mo>)</mo></mrow></math>, (C–H₂)₄ wagging, <i></i><math><msubsup><mrow><mi>v</mi></mrow><mrow><mn>11</mn></mrow><mrow><mo>′</mo></mrow></msubsup><mrow><mo>(</mo><msup><mrow><mi>a</mi></mrow><mrow><mo>′</mo></mrow></msup><mo>)</mo></mrow></math> and ring puckering/C–Cl stretching <i></i><math><msubsup><mrow><mi>v</mi></mrow><mrow><mn>23</mn></mrow><mrow><mo>′</mo></mrow></msubsup><mrow><mo>(</mo><msup><mrow><mi>a</mi></mrow><mrow><mo>′</mo></mrow></msup><mo>)</mo></mrow></math> modes. From the absolute cross-section values, photolysis lifetimes in the Earth’s atmosphere have been estimated, showing that solar photolysis may only be considered a relevant sink at altitudes above 20 km. Additional calculations at the TD-DFT level of theory have been performed to obtain potential energy curves for the lowest-lying electronic states, highlighting the role of predissociative character.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 17","pages":"3857–3866 3857–3866"},"PeriodicalIF":2.7,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890336","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":"Precise Determination of Excited State Rotational Constants and Black-Body Thermometry in Coulomb Crystals of Ca+ and CaH+","authors":"Swapnil Patel,&nbsp; and ,&nbsp;Kenneth R. Brown*,&nbsp;","doi":"10.1021/acs.jpca.5c0022910.1021/acs.jpca.5c00229","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c00229https://doi.org/10.1021/acs.jpca.5c00229","url":null,"abstract":"<p >We present high-resolution rovibronic spectroscopy of calcium monohydride molecular ions (CaH⁺) cotrapped in a Coulomb crystal with calcium ions (⁴⁰Ca⁺), focusing on rotational transitions in the <i></i><math><mo>|</mo><msup><mi>X</mi><mn>1</mn></msup><msup><mi>Σ</mi><mo>+</mo></msup></math>, <i>ν</i>″ = 0⟩ → |<i>A</i>¹Σ⁺, <i>ν</i>′ = 2⟩ manifold. By resolving individual P and R branch transitions with record precision and using Fortrat analysis, we extract key spectroscopic constants for the excited state |<i>A</i>¹Σ⁺, <i>ν</i>′ = 2⟩, specifically, the band origin, the rotational constant, and the centrifugal correction. Additionally, we demonstrate the application of high-resolution rotational spectroscopy of CaH⁺ presented here as an in situ probe of the local environmental temperature. We correlate the relative amplitudes of the observed transitions to the underlying thermalized ground-state rotational population distribution and extract the blackbody radiation (BBR) temperature.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 16","pages":"3624–3629 3624–3629"},"PeriodicalIF":2.7,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143863214","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":"Deciphering Photochemical Reactivity of Maleimides by Ultrafast Spectroscopy: How Minor Pathways Have Major Implications in Photochemical Reactions","authors":"Dipti Garg,&nbsp;Alexander N. Tarnovsky* and Jayaraman Sivaguru*,&nbsp;","doi":"10.1021/acs.jpca.5c0186010.1021/acs.jpca.5c01860","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c01860https://doi.org/10.1021/acs.jpca.5c01860","url":null,"abstract":"<p >Excited-state relaxation dynamics of hydroxy substituted <i>N</i>-phenyl maleimide are investigated following 355 nm excitation by ultrafast femtosecond transient absorption spectroscopy with dispersed, broadband probing. The dynamics of hydroxy <i>N</i>-phenyl maleimide is compared to that of <i>N</i>-phenyl maleimide lacking the hydroxy group using the same technique after 350 nm excitation. We found that the hydroxy-substituted maleimide and the maleimide lacking the hydroxyl substituent feature very short excited-state lifetimes due to radiationless vibronic deactivation which is the major relaxation pathway in both the maleimide chromophores. In addition, the hydroxy-substituted maleimide, which was previously shown not to undergo the photocycloaddition reaction with alkenes upon direct irradiation consitions displays a very minor pathway with spectral and kinetic signatures consistent with an excited-state proton transfer reaction. Removal of the -OH group in the maleimide lacking the hydroxyl substituent opens an intersystem crossing channel, which explains the photocycloaddition under direct irradiation in this class of maleimides lacking hydroxyl substituents.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 17","pages":"3876–3885 3876–3885"},"PeriodicalIF":2.7,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890330","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":"Unified Framework for Molecular Response Functions of Different Electronic-Structure Models","authors":"Bin Gao*,&nbsp; and ,&nbsp;Magnus Ringholm,&nbsp;","doi":"10.1021/acs.jpca.4c0778910.1021/acs.jpca.4c07789","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c07789https://doi.org/10.1021/acs.jpca.4c07789","url":null,"abstract":"<p >A unified framework─SymResponse─has been developed as a versatile tool to aid the implementation of response theory for different electronic-structure models. The framework manipulates the quasi-energy formulation of response theory at a symbolic level by building on top of other well-developed symbolic libraries. Response functions can therefore be nicely represented by “symbolic expressions,” which can be further evaluated numerically by users by developing their own evaluation routines with the assistance of SymResponse. The design of SymResponse makes it extensible to different electronic-structure models with only a moderate further amount of development effort. Response theory at Hartree–Fock, density functional theory, and coupled-cluster levels has been implemented in the present work as a demonstration, where elimination rules [<contrib-group><span>Kristensen, K.</span></contrib-group> <cite><i>J. Chem. Phys.</i></cite> <span>2008</span>, <em>129</em>, <elocation-id>214103</elocation-id>] can also be applied to offer the possibility to reduce the size of computational tasks.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 16","pages":"3709–3721 3709–3721"},"PeriodicalIF":2.7,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acs.jpca.4c07789","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143863215","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":"Stability of sp3 Carbons in Hydrogenated Graphene Quantum Dots and Their Electronic and Optical Properties Studied Using Density Functional Theory","authors":"Nasiru Aminu Rano,&nbsp; and ,&nbsp;Natalia Martsinovich*,&nbsp;","doi":"10.1021/acs.jpca.4c0782510.1021/acs.jpca.4c07825","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c07825https://doi.org/10.1021/acs.jpca.4c07825","url":null,"abstract":"<p >Graphene quantum dots (GQDs) are zero-dimensional nanomaterials composed of sp²-hybridized carbon atoms, which are widely researched because of their tunable optical properties. GQDs contain defects, such as sp³-hybridized carbon atoms, which may be introduced during synthesis and can affect these materials’ properties. In this study, we use hydrogenated polycyclic aromatic hydrocarbons as models for GQDs containing sp³-hybridized carbon atoms. We analyze the effect of sp³ carbons on the stabilities and electronic and optical properties of GQDs using density functional theory (DFT) and time-dependent DFT calculations. We find that sp³ carbons can form stable arrangements as dimers or continuous chains along the edges of GQDs. Our results reveal that the presence of sp³ carbons can tune the HOMO–LUMO gap, dependent on the position of sp³ carbons within the GQD. Calculated optical absorption spectra show a reduction in intensity and a blue shift of the main absorption peak for most of the investigated sp³-containing structures; additionally, the presence of sp³ carbons can extend the optical absorption of these structures into the red and infrared regions of the solar spectrum (600 to 900 nm), depending on the concentration and arrangement of sp³ carbons. These results provide insight into structural factors responsible for the variation of the electronic and optical properties of GQD nanomaterials and suggest that controlling the amount of residual sp³ carbon atoms introduced during synthesis can be used to tailor the properties of GQDs.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 17","pages":"3790–3806 3790–3806"},"PeriodicalIF":2.7,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acs.jpca.4c07825","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890323","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":"Evaluation of Thermodynamic Averages in a Phase Space with Overlapping Subdomains","authors":"Longyuan Zhang,&nbsp; and ,&nbsp;J. R. Schmidt*,&nbsp;","doi":"10.1021/acs.jpca.4c0754110.1021/acs.jpca.4c07541","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c07541https://doi.org/10.1021/acs.jpca.4c07541","url":null,"abstract":"<p >We demonstrate a simple methodology for accurately and efficiently evaluating the ensemble average of thermodynamic observables across a phase space divided into arbitrary, potentially overlapping, subdomains defined, for example, via corresponding collective variables or descriptors. By dividing the phase space in this manner, the challenging task of sampling the complete phase space is rigorously transformed into relatively easier sampling over subdomains, each of which can be sampled independently and without regard to their mutual overlap. Accurate thermal averages of observables over the complete phase space are then obtained by sampling over these subdomains and properly reweighting them based on their degree of mutual overlap at each point in phase space. To demonstrate the efficacy of our approach, we examine applications to simple Lennard-Jones clusters and subsequently to ion clusters in aqueous solution, where the various cluster connectivities and morphologies provide a natural division of phase space. More generally, we anticipate that our approach holds promise for a wide range of applications, from nucleation free energy surfaces to the thermodynamics of protein conformational changes, providing a natural complement to traditional enhanced sampling methods.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 17","pages":"3940–3948 3940–3948"},"PeriodicalIF":2.7,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890331","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":"Unveiling the Atmospheric Oxidation of Hexafluoroisobutylene, (CF3)2C═CH2, with Cl Atom, NO3 Radical, and O3 Molecule","authors":"Rabu Ranjan Changmai,&nbsp;Samsung Raja Daimari and Manabendra Sarma*,&nbsp;","doi":"10.1021/acs.jpca.4c0835110.1021/acs.jpca.4c08351","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c08351https://doi.org/10.1021/acs.jpca.4c08351","url":null,"abstract":"<p >The CFC alternative, 3,3,3-trifluoro-2(trifluoromethyl)-1-propene, (CF₃)₂C═CH₂ (HFIB), plays a pivotal role across various industrial sectors owing to its unique chemical properties, versatility, and diverse applications as a refrigerant, propellant, aerosol, etc. However, its extensive presence in industrial processes raises concerns about its environmental impact. In this study, atmospheric oxidation of HFIB by reaction with Cl, NO₃, and O₃ is investigated theoretically to unravel the reaction mechanism, thermodynamics, and kinetics. This study employs quantum chemical methods to explore the various reaction pathways via potential energy surface diagrams. The addition reactions are the dominating reactions of HFIB with atmospheric oxidants. The thermodynamics and kinetics were analyzed, revealing exothermic addition and endothermic abstraction reactions. The rate coefficients (<i>k</i>_o,Cl, <i>k</i>_o,NO₃, and <i>k</i>_o,O₃) computed using the M06–2X/6–311++G(d,p) level of theory are 0.71 × 10^–11, 1.75 × 10^–18, and 9.05 × 10^–20 cm³ molecule^–1 s^–1, respectively, which align closely with the experimental rate. The atmospheric implication studies suggested that the reaction with major atmospheric oxidants, ^·OH and Cl, primarily influences the lifetime of the species. The calculated cumulative lifetime is 11.70 days, while the radiative efficiency is 0.0265 W m^–2 ppb^–1. The global warming potential values for the 20-, 100-, and 500-year time horizons also compare well with the experimental findings. Furthermore, the subsequent loss processes of the product radicals were investigated in the atmosphere. Thus, this study provides a crucial aspect in assessing the environmental impact of CFC alternatives.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 17","pages":"3906–3920 3906–3920"},"PeriodicalIF":2.7,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890390","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}