The Journal of Physical Chemistry A最新文献

{"title":"Factors Influencing Poor Ice Nucleation by Model Fatty Acid Monolayers","authors":"Lian Pharoah,&nbsp;Allan K. Bertram,&nbsp;G. N. Patey","doi":"10.1021/acs.jpca.6c03014","DOIUrl":"https://doi.org/10.1021/acs.jpca.6c03014","url":null,"abstract":"<p>Organic ice-nucleating substances(INSs) are relevant to atmospheric,biological, and industrial systems. Fatty acid and fatty alcohol monolayershave been used as model surfaces to investigate ice nucleation byorganic materials. Laboratory studies show that fatty acid monolayersare inefficient ice nucleators, whereas fatty alcohol monolayers withsimilar alkyl-chain lengths can nucleate ice at temperatures up toapproximately 20 °C warmer. Here, we use molecular dynamics simulationsto investigate the molecular origin of this difference for a modelfatty acid monolayer. Our results show that a major factor inhibitingice nucleation by fatty acid monolayers is the presence of partiallycharged carbonyl oxygen atoms. The electrostatic interactions of theseatoms with interfacial water molecules is consistent with strong carbonyl-waterhydrogen bonding, and disrupts the formation of ordered, ice-likebilayers that are critical for nucleation on fatty alcohol monolayers.This conclusion is supported by simulations in which removing thepartial charges on the carbonyl oxygen atoms restores ice nucleation.In contrast, differences in lattice mismatch and headgroup structureplay a lesser role. These findings provide molecular-level insightinto how interfacial functional groups control the ice nucleatingability of organic surfaces.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"130 40","pages":"7978–7987"},"PeriodicalIF":3.0,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149130667","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":"Electron Correlation in Chemical Bonding: From Dispersion to Covalent Stabilization in Prototype Diatomic Systems","authors":"Guo-Qiang Hai,&nbsp;Ladir Cândido,&nbsp;Braulio Gabriel Alencar Brito","doi":"10.1021/acs.jpca.6c02311","DOIUrl":"https://doi.org/10.1021/acs.jpca.6c02311","url":null,"abstract":"<p>The interplay betweenelectron correlation and chemical bondingremains a central issue in quantum chemistry. While covalent bondsarise from electron sharing and long-range interactions from weakcorrelation, the quantitative connection between these regimes isnot fully understood. In this work, we combine ab initio Quantum MonteCarlo (QMC) and Hartree–Fock (HF) calculations to examine howcorrelation contributes to bonding in the prototypical diatomic systemsH₂, LiH, and Li₂. By mapping correlation energiesand reaction forces along the full dissociation coordinate, we showthat correlation gives rise to the asymptotic long-range dispersionattraction between separated neutral fragments, while also modifyingthe interaction at shorter bond distances. Near equilibrium, HF interactionsdominate in H₂ and LiH, although correlation contributessignificantly to the binding energy, reaching about 41% in LiH. InH₂, the correlation contribution to the interatomic forcebecomes repulsive near equilibrium, giving a force-level interpretationof the well-known shift of the correlated equilibrium bond lengthrelative to the HF result. In contrast, in Li₂, correlationaccounts for nearly 80% of the binding energy, indicating that stabilizationcan arise primarily from correlation when HF attraction is weak. Theseresults provide a quantitative and physically transparent characterizationof how electron correlation contributes across different bonding regimesin representative diatomic systems. The present analysis offers aconsistent interpretation of the evolution from long-range dispersionto short-range covalent stabilization within computationally reliableprototype molecules.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"130 40","pages":"7875–7886"},"PeriodicalIF":3.0,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149130671","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":"Estimating the Thermochemical Energies of MECP","authors":"Chaofan Li,&nbsp;Wenli Zou","doi":"10.1021/acs.jpca.6c04725","DOIUrl":"https://doi.org/10.1021/acs.jpca.6c04725","url":null,"abstract":"<p>In spin-forbidden reactions, the minimum energy crossingpoint(MECP) is a key structure besides stationary points. When the MECPcorresponds to a new transition state, however, the reaction barrierand thermochemical energies derived from vibrational frequencies cannotbe strictly defined. This study assesses the accuracy of several approximationsfor estimating the thermochemical energies of MECP from Hessian matrices,including the projected effective Hessian method reported in the literature,as well as additional approaches proposed here. Among them, a simplemethod, MSHg, based on a two-state spin-mixing model, exhibits thehighest accuracy when spin–orbit coupling is not strong, roughlyfor elements up to xenon. Nevertheless, for spin-forbidden reactionsinvolving 5d or heavier atoms, the MECP structure may deviate significantlyfrom the genuine transition state, and consequently, none of theseapproximations can achieve thermochemical energy errors within 1.0kcal/mol at standard temperature and pressure; in practice, the errorsmay reach 2.0–3.0 kcal/mol or higher, highlighting the inherentlimitations of MECP calculations.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"130 40","pages":"8055–8064"},"PeriodicalIF":3.0,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149124823","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":"Multicenter Bonding in Wilkinson’s Catalyst: A Theoretical Study from a Distorted Monomer to a Localized Dimer","authors":"Aleksandr Zaichenko,&nbsp;Holger F. Bettinger,&nbsp;Ivana Fleischer,&nbsp;Doreen Mollenhauer","doi":"10.1021/acs.jpca.6c04219","DOIUrl":"https://doi.org/10.1021/acs.jpca.6c04219","url":null,"abstract":"<p>In this work, we present a computational study of Wilkinson’scatalyst, [Rh(PPh₃)₃Cl], focusing on the connectionbetween geometric structure, electronic structure, and thermodynamicsin its monomeric and dimeric forms, as well as the coordination ofhydrogen atoms. Scalar-relativistic DFT with modern meta-GGA-basedfunctionals, coupled-cluster benchmarks, and bonding analyses (NBO/NRT)show that steric effects and noncovalent interactions control deviationsfrom ideal square-planar geometry in the metastable monomeric structureas well as affect dissociation and dimerization energetics, whereaselectronic factors dominate the dimer structure and enthalpy. Themonomer is characterized by intrinsically delocalized multicenterbonding, best described as two crossed three-center, four-electron(3c–4e) interactions spanning Rh, while entropy-controlleddimerization induces a qualitatively different and more localizedbonding regime. In both species, Rh acts as an electron acceptor indonor-acceptor Rh–ligand interactions and remains consistentwith a 16-electron configuration. Thermodynamic results support theexperimentally observed tendency toward dimerization in solution,highlighting the importance of multicenter bonding, entropic factors,and steric control for interpreting the structure and reactivity ofWilkinson’s catalyst.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"130 40","pages":"7915–7927"},"PeriodicalIF":3.0,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149124914","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":"A DFT Study on the General [3 + n] (n = 2–6) Cycloaddition Reaction Mechanism of Bicyclo[1.1.0]butanyl Ketones in Borane Catalysis","authors":"Mingwei Bai,&nbsp;Huai Sun,&nbsp;Rui Ma,&nbsp;Litao Song,&nbsp;Liying Zhang,&nbsp;Xue Li,&nbsp;Yu Jia","doi":"10.1021/acs.jpca.6c03436","DOIUrl":"https://doi.org/10.1021/acs.jpca.6c03436","url":null,"abstract":"<p>Bicyclo[1.1.0]butane (BCB) is a bridged-ring compoundfeaturingthe smallest ring yet the highest ring strain, which can promote cyclizationreactions. However, why is “strain release” not sufficientto directly construct eight- or nine-membered bridged-ring products,whereas this can be achieved in organoborane catalysis? Herein, wesuggest that the combination of strain release and participation ofa Lewis acid organoborane catalyst would lead to the occurrence ofcycloaddition reactions. Density functional theory (DFT) calculationshave been performed to study the possible α,γ-[3 + n]and γ,α-[3 + n] cycloaddition pathways and the originof chemoselectivity for achiral borane BR₃ catalyzed [3+ n] (n = 5, 6) cycloaddition reactions of BCB ketones. The computationalresults unmasked that the γ,α-[3 + n] cycloaddition pathwayis more energetically favorable, and the BCB-ring-opening processis the chemoselectivity-determining step. The frontier molecular orbital(FMO) and distortion/interaction analyses indicate that the participationof BR₃ catalysts can indeed diminish the cycloadditionenergy barrier by narrowing the energy gap to advance the reaction,and the distortion of the BCB-part moiety is one of the most importantchemoselectivity-controlling factors. Moreover, electrophilic vector <span><span></span><math><mover><mrow><msup><mrow><mi>F</mi></mrow><mrow><mo>+</mo></mrow></msup><mspace></mspace></mrow><mrow><mo>→</mo></mrow></mover></math></span>analysis can be utilized to predict theorigin of reaction chemoselectivity. Therefore, this work would bevaluable not only for designing synthetic routes to multiple small-,medium-, or even large-bridged ring skeletons in organoborane catalysisbut also for expanding the applications of a novel Projection of OrbitalCoefficient Vector (POCV) analysis method in the organocatalytic field.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"130 40","pages":"7896–7906"},"PeriodicalIF":3.0,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149124876","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":"Void Effects on Thermal Decomposition of 3,4-Bis(3-nitrofurazan-4-yl)furoxan: A Deep Potential Molecular Dynamics Study","authors":"Jun Jiang,&nbsp;Xiaofeng Yuan,&nbsp;Jingwei Meng,&nbsp;Shanqing Li,&nbsp;Zhaowen Liu,&nbsp;Junyi Wang,&nbsp;Xue-Hai Ju","doi":"10.1021/acs.jpca.6c04410","DOIUrl":"https://doi.org/10.1021/acs.jpca.6c04410","url":null,"abstract":"<p>Voiddefect represents unavoidable microscopic defect in energeticmaterials, yet its influence on thermal decomposition remains poorlyunderstood at the atomic level. In this paper, deep potential moleculardynamics (DPMD) simulations were employed to investigate the influenceof void defects as internal interfaces on the thermal decompositionof 3,4-bis(3-nitrofurazan-4-yl)furoxan (DNTF). The results show thatthe thermal decomposition of DNTF consists of two exothermic stages.Void defects accelerate the initial decrease in potential energy,whereas the lower density associated with voids delays the seconddecrease. Voids promote the breaking of C–N and C–Cbonds, thereby accelerating DNTF decomposition. In addition, voidsenhance the mobility of surrounding atoms, with the double-void configuration(S3) exhibiting stronger promoting effect than the single large void(S1). Voids also induce more pronounced temperature fluctuations inthe surrounding region, particularly in S1. Void defects do not alterthe decomposition pathway of DNTF, and the ring-opening reaction ofthe furoxan remains the earliest decomposition pathway. The activationenergy of S1 is 98.1 kJ/mol through DPMD, which is lower than thatof the perfect crystal. Under multiple computational methods (FWO,KAS and AIC), the comparison results between Small S1 and Small S2also demonstrate that the presence of voids consistently yields loweractivation energy values. The experimental activation energy is 121.4kJ/mol using the Kissinger method. The decomposition products consistof CO₂, NO, NO₂ and N₂O, which areconsistent with past experiments.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"130 40","pages":"8027–8035"},"PeriodicalIF":3.0,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149130640","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":"Kinetic Mechanism Development and Pollutant Chemistry in NH3/H2/CH4 Combustion","authors":"Sunkyu Shin,&nbsp;Yu-Chi Kao,&nbsp;Timo T. Pekkanen,&nbsp;Yujie Qian,&nbsp;Yi-Pei Li,&nbsp;William H. Green","doi":"10.1021/acs.jpca.6c04337","DOIUrl":"https://doi.org/10.1021/acs.jpca.6c04337","url":null,"abstract":"<p>Ammonia (NH₃) is a promising carbon-free fuel,but becauseit is difficult to combust, blending ammonia with co-fuels such asH₂ and CH₄ is one approach to improve combustibility.However, the underlying chemical interactions, particularly coupledcarbon–nitrogen (C–N) pathways, become increasinglycomplex as fuel composition expands. Existing kinetic mechanisms aretypically constructed by manually merging NH₃ and hydrocarbonsubmechanisms, often with limited systematic treatment of C–Ncross chemistry and frequently involving empirical tuning of kineticparameters. In this work, a comprehensive kinetic mechanism for NH₃/H₂/CH₄ combustion is developed usingthe Reaction Mechanism Generator without any empirical parameter tuning.The mechanism builds upon a previously validated NH₃/H₂ model and a recent, high-quality hydrocarbon mechanism. C–Nchemistry is obtained from the literature when available and automaticallyconstructed with Reaction Mechanism Generator when not. For selectimportant reactions, we calculated kinetic parameters in this work.The developed mechanism is validated against laminar burning velocities,ignition delay times, and flow reactor and jet-stirred reactor measurements,showing good agreement over a wide range of conditions. Using thevalidated model, pollutant formation and consumption pathways forNO_<em>x</em>, N₂O, HCN, and CO are systematicallyinvestigated across the ternary composition space.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"130 40","pages":"8011–8026"},"PeriodicalIF":3.0,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149124924","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":"Ab Initio Chemical Kinetics of Radical–Radical Reaction of CH3O with NO2","authors":"Manlin Wang,&nbsp;Yikai Li,&nbsp;Peng Zhang","doi":"10.1021/acs.jpca.6c03945","DOIUrl":"https://doi.org/10.1021/acs.jpca.6c03945","url":null,"abstract":"<p>This work theoretically investigated the ab initio chemicalkineticsof the radical–radical reaction between the methoxy (CH₃O) and nitrogen dioxide (NO₂), which representsa key C–N interaction in ammonia/hydrocarbon cocombustion.The stationary-point energies were determined at the CCSD(T)/CBS//M06–2X/def2-TZVPPlevel of theory. For the barrierless reaction pathways, potentialenergy scans were performed using the multireference CASPT2(14e,9o)method to account for the evolving multireference character alongthe reaction coordinate. The kinetic calculations were focused onthe barrierless path leading to the CH₃ONO₂ formation.The temperature- and pressure-dependent rate constants and productbranching of the path were determined by using the RRKM/Master Equationanalysis combined with the conventional transition state theory (CTST)and the variable reaction coordinate transition state theory (VRC-TST).Another path leading to the CH₃OONO formation was identified,and it is found to involve an inner transition state likely causedby the internal conformational change of NO₂.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"130 40","pages":"7907–7914"},"PeriodicalIF":3.0,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149124950","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":"Multi-Field Relaxation Dynamics of Parahydrogen-Hyperpolarized Propane Gas MRI Contrast Agent.","authors":"Clementinah Oladun, Nuwandi M Ariyasingha, Anna Samoilenko, Md Raduanul H Chowdhury, Zhongjie Shi, Kehuan Luo, Sidhartha Tan, Oleg G Salnikov, Dudari B Burueva, Alba Xhupi, Majd Suleiman, Jerome McCreadie, Larisa M Kovtunova, Igor V Koptyug, Juri G Gelovani, Panayiotis Nikolaou, Jessica Ettedgui, Rolf E Swenson, Kazutoshi Yamamoto, Norikazu Koyasu, Murali C Krishna, Joseph W Plummer, Adrienne E Campbell-Washburn, Michael J Barlow, Boyd M Goodson, Eduard Y Chekmenev","doi":"10.1021/acs.jpca.6c05094","DOIUrl":"https://doi.org/10.1021/acs.jpca.6c05094","url":null,"abstract":"<p><p>Hyperpolarized gas-phase MRI is an emerging diagnostic modality, with the clinical utility of hyperpolarized Xe-129 gas for functional lung imaging recently supported by FDA regulatory approval. However, the requirement for dedicated multi-nuclear hardware and complex, centralized production logistics remains a significant translational hurdle. Here, we investigate the longitudinal relaxation dynamics of hyperpolarized propane gas─a promising, proton-frequency alternative produced via heterogeneous parahydrogen-induced polarization (HET-PHIP)─across a wide range of magnetic field strengths: 0.35 T, 0.55 T, 3 T, and 7 T MRI scanners. In the imaging studies, gradient-echo MRI pulse sequence variants with small flip angle excitation radio-frequency pulses were utilized to record a series of scans to monitor the effective decay of the hyperpolarized state of propane gas in spherical plastic phantoms and excised rabbit lungs. We demonstrate that the effective lifetime (characterized by the constant of a mono-exponential signal decay Td) of hyperpolarized propane is strongly field-dependent, exhibiting a marked decrease from 1.51 ± 0.04 s (0.35 T) to 0.59 ± 0.02 s (0.55 T) to 0.54 ± 0.02 s (3 T) to 0.23 ± 0.01 s (7 T) in phantom studies using an RF flip angle of 5°. This trend is attributed to the presence of partially retained long-lived spin states at the low field of 0.35 T, which are quenched at higher field strengths as the spin system transitions from the strong-coupling to the weak-coupling regime. Moreover, the unfavorable spin-rotation dominated relaxation results in a further decrease of Td at higher magnetic fields, especially evident at 7 T. Furthermore, we assess the relaxation behavior in excised rabbit lungs at 0.35 T, reporting a Td value of 0.68 ± 0.12 s. This accelerated relaxation of hyperpolarized propane in the lung compared to phantom models is likely driven by susceptibility-induced dephasing and increased surface-to-volume interactions within the alveolar architecture. The results using hyperpolarized propane were also compared with imaging studies using hyperpolarized Xe-129 gas in the excised rabbit lungs at 0.35 T, yielding an effective 129Xe T1 of 11 ± 2 s. These results provide a fundamental biophysical characterization of hyperpolarized propane and underscore its potential as a highly accessible contrast agent for regional pulmonary function mapping.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149163550","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":"DFT Study on the Origin of 1,2-Regioselectivity in Cu2O-Catalyzed Addition of Acetonitrile to Cinnamaldehyde","authors":"Ye-Chuan Duan,&nbsp;Lu-Jia Zhong,&nbsp;Bin Chen,&nbsp;Da-Gang Zhou","doi":"10.1021/acs.jpca.6c04564","DOIUrl":"https://doi.org/10.1021/acs.jpca.6c04564","url":null,"abstract":"<p>The synthesis of unsaturated β-hydroxynitrilesis of significantimportance in pharmaceutical and materials chemistry. However, traditionaltransition-metal-catalyzed reactions of α,β-unsaturatedcarbonyls often suffer from poor regioselectivity, favoring the thermodynamicallycontrolled 1,4-addition over the desired 1,2-addition. To elucidatethe origin of the high 1,2-regioselectivity observed experimentallyin the Cu₂O/<em>t</em>-BuOK catalytic system, comprehensivedensity functional theory (DFT) calculations were performed usingthe M06-L-D3 functional with the ma-def2-TZVP basis set in the SMDsolvation model. The computational results reveal that the reactionproceeds via a multistep mechanism involving ligand coordination,C–H activation, and nucleophilic addition. The Hard–SoftAcid–Base (HSAB) theory and Dewar–Chatt–Duncanson(DCD) model confirm that the soft Cu(I) centers preferentially coordinatewith the soft C═C double bond of the aldehyde rather than thehard carbonyl oxygen. This coordination mode effectively polarizesthe substrate, enhancing the electrophilicity of the carbonyl carbonand suppressing the competing 1,4-addition pathway. Among the identifiedpathways, the route via compound 11 is the most energetically favorable.The proton transfer assisted by <em>t</em>-BuO^– exhibits an energy barrier of 16.5 kcal/mol, leading to the formationof a nucleophilic cyanide anion. Subsequently, the energy barrierof 1,2-addition is 5.8 kcal/mol lower than that of 1,4-addition, apreference attributed to stronger noncovalent interactions (NCIs)and shorter bond-forming distances in the transition state. This studyprovides deep mechanistic insights into the copper-catalyzed cyanomethylationof α,β-unsaturated aldehydes, highlighting the criticalrole of metal-substrate coordination geometry in controlling regioselectivity.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"130 40","pages":"7942–7952"},"PeriodicalIF":3.0,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149124929","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}