The Journal of Physical Chemistry A最新文献

{"title":"Using Topology to Predict Electrides in the Solid State.","authors":"Stefano Racioppi, Eva Zurek","doi":"10.1021/acs.jpca.5c05317","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c05317","url":null,"abstract":"<p><p>Electrides are characterized by electron density highly localized in interstitial sites, which do not coincide with direct interatomic contacts. The rigorous quantum mechanical definition of electrides is based upon topological criteria derived from the electron density, and in particular the presence of non-nuclear attractors (NNAs). We employ these topological criteria in combination with crystal structure prediction methods (the XtalOpt evolutionary algorithm), to accelerate the discovery of crystalline electrides at ambient and nonambient pressures. The localization and quantification of NNAs is used as the primary discriminator for the electride character of a solid within a multiobjective evolutionary structure search. We demonstrate the reliability of this approach through a comprehensive crystal structure prediction study of Ca₅Pb₃ at 20 GPa, a system previously theorized to exhibit electride character under compression. Our strategy could predict, and sort on-the-fly, several unknown low-enthalpy phases that possess NNAs in interstitial loci, such as the newly discovered <i>P</i>4/<i>mmm</i> structure. These results demonstrate how evolutionary algorithms, guided by rigorous topological descriptors, can be relied upon to effectively survey complex phases to find new electride candidates.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145311983","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":"Occurrence and Impact of Electric-Field-Induced Discontinuities in Correlation Energies from Localized Pair-Natural-Orbital Methods.","authors":"Jose P Madriaga, T Daniel Crawford","doi":"10.1021/acs.jpca.5c05210","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c05210","url":null,"abstract":"<p><p>We report an investigation of discontinuities in the correlation energy produced by external static electric fields within the local pair-natural-orbital coupled-cluster singles and doubles (LPNO-CCSD) method. Such discontinuities arise as a result of variations in both the dimensions and character of the pairwise virtual-orbital domains resulting from changes in the strength of the field. Using several small-molecule test cases - water, fluoroethylene, hypofluorous acid and <i>cis</i>-1,3-butadiene we observe that, although the discontinuities in the correlation energy are small (typically 1 μ<i>E</i>_<i>h</i>), they can yield substantial errors in higher-order electric-field-dependent properties computed using finite-difference techniques. For the static hyperpolarizability (third derivative of the energy with respect to the field) of water, for example, the discrepancies between LPNO-CCSD and canonical-MO CCSD methods can exceed 100%. Furthermore, weak-field displacements that should normally decrease errors in numerical differentiation can yield orders-of-magnitude errors due to magnification of the energy discontinuities by small field-displacement denominators. For larger molecules, such fields can produce dramatic errors in the static polarizability (second derivative of the energy with respect to the field) and hyperpolarizability even with very tight PNO cutoffs. The use of basis sets containing diffuse functions, which are essential for reliable predictions of field-dependent response properties, tend to exacerbate the observed errors. In addition, the use of fixed virtual PNO dimensions does no resolve the problem due to mixing of the PNOs relative to zero-field orbitals as a result of large condition numbers of the pair-correlation densities.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145306384","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":"Blue-Shifting Hydridic Hydrogen Bonds in Complexes of (Me₃Si)₃SiH.","authors":"Maximilián Lamanec, Vladimír Špirko, Svatopluk Civiš, Pavel Hobza","doi":"10.1021/acs.jpca.5c05765","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c05765","url":null,"abstract":"<p><p>Hydridic hydrogen bonds, formed by X-H···Y interactions with negatively charged hydrogen, expand the conventional view of H-bonding beyond elements that are more electronegative than hydrogen. Using a highly polarizable silane donor (Me₃Si)₃SiH, we systematically examined various electron acceptors (σ- and π-hole) and observed both red and blue shifts in the X-H stretching frequency. We provide the first experimental evidence of a blue-shifting hydridic bond and report the largest experimental blue shift for any hydrogen-bonded system. Thermodynamic, spectroscopic, and theoretical analyses show that the dispersion energy is crucial for stabilizing these complexes and reproducing their spectral signatures. Notably, the IR band intensity increases for red-shifting bonds and increases or decreases for blue-shifting hydridic bonds, offering a distinct spectroscopic fingerprint. Adiabatic ALMO-EDA calculations indicate that red shifts in hydridic bonds primarily arise from electrostatics and dispersion rather than charge transfer. It can be thus concluded that protonic as well as hydridic hydrogen bonds exhibit similar spectral manifestations, namely, the red or blue shift of the X-H stretching frequency connected with the intensity increase or decrease. These findings broaden hydrogen-bonding paradigms for diverse chemical applications.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145298040","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":"Ditetrel Bonding from Reactive Strained Propellane and Cyclic Carbocation as an Electron Donor/Acceptor.","authors":"Linhao Yang, Xin Yang, Shili Deng, Liyuan Sun, Yi Zeng","doi":"10.1021/acs.jpca.5c06054","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c06054","url":null,"abstract":"<p><p>The binary ditetrel bond (DTB) complexes between separate strained [1.1.1]propellane (Lewis base) and five- or six-membered cyclic carbocations containing chalcogen oxygen and/or sulfur atom (Lewis acid) were first theoretically investigated at the B3LYP(D3)/def2-TZVP level. All of the binary complexes offer substantial thermodynamic advantages with binding energies (<i>E</i>_b) of more or less -10 kcal mol^-1. The five-membered carbocation complexes are more stable, with -<i>E</i>_b values larger by 2-4 kcal mol^-1 than those of the six-membered ones. A comparison between the ternary and the more saturated complexes shows that the saturation of the cyclic carbocation species favors complexation. The ultralong bridgehead C1-C2 bond also influences the DTB interaction; the binary systems, wherein the wing -CH₂ group of [1.1.1]propellane is substituted by SiH₂ with a C1-C2 bond of 2.0 Å, serving as a Lewis base, are predicted to have -<i>E</i>_b values more than ∼1-3 kcal mol^-1 compared with those of their corresponding [1.1.1]propellane dyads and triads. The energy decomposition analysis (sobEDA), together with the extended transition state combined with natural orbitals for chemical valence (ETS-NOCV), offers in-depth insights into the nature of the interaction. The independent gradient model based on the Hirshfeld partition (IGMH) and the quantum theory of atoms in the molecule (AIM) analyses visualize the existence of substantial DTB interactions.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145306417","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 Hybrid Quantum Computing Method for UV-Vis Spectroscopy of Solvated Molecules at Room Temperature.","authors":"Carlos Bistafa, Josh J M Kirsopp, Antonio Márquez Romero, Jumpei Koyama, Michal Krompiec","doi":"10.1021/acs.jpca.5c02811","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c02811","url":null,"abstract":"<p><p>We developed a method to include solvent effects on electronic transition calculations using quantum computing, employing the subspace-search variational quantum eigensolver (SSVQE) algorithm and the average solvent electrostatic configuration (ASEC) model. The SSVQE algorithm is used to calculate the energy of ground and excited states of organic molecules, and the ASEC model is used to describe the electrostatic contribution of the solvent effect at room temperature. By comparing the results with complete active space configuration interaction calculations, we demonstrate that the solvent effect is properly accounted for in the calculation of each state energy value performed by the quantum algorithm. Furthermore, the gas-liquid shift of the electronic transitions is also correctly described, with values that present semiquantitative agreement with results obtained through more sophisticated treatment using classical computers and experimental values, demonstrating that the solvation model is robust even when paired with quantum algorithms. The ASEC-SSVQE method opens the possibility of using noisy intermediate-scale quantum devices to study the spectroscopy properties of solvated molecules, with the inclusion of thermodynamic effects.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145306420","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":"How Important Are Dimers for Interpreting the Chiroptical Properties of Carboxylic Acids? A Case Study with [5]-Ladderanoic Acid.","authors":"Andrew R Puente, Prasad L Polavarapu","doi":"10.1021/acs.jpca.5c04282","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c04282","url":null,"abstract":"<p><p>Chiroptical spectroscopy is sensitive to the formation of intermolecular interactions for chiral molecules. Experimental Vibrational Circular Dichroism (VCD), Vibrational Raman Optical Activity (ROA), and Optical Rotatory Dispersion (ORD) data of (-)-[5]-ladderanoic acid in chloroform have been analyzed using theoretical predictions for both monomeric and dimeric structures of (<i>R</i>)-[5]-ladderanoic acid to better understand their utility for the interpretation of experimental data. B3LYP, B3PW91, and M06-2X functionals, with and without dispersion corrections, and the 6-31+G(2d,p) basis set were used for theoretical predictions. It is found that dimer contributions are important to better reproduce the experimental vibrational absorption and associated VCD spectra, and a monomer:dimer ratio of 30:70 is indicated at the B3LYP level. However, no significant improvement is evident from dimer contributions to reproduce the experimental Raman and associated ROA spectra, and a monomer:dimer ratio of 100:0 is indicated at the B3LYP level. Boltzmann population-weighted specific rotations are predicted to be negative for both monomeric and dimeric conformations of (<i>R</i>)-[5]-ladderanoic acid, and quantitative agreement with the experimental ORD of (-)-[5]-ladderanoic acid is obtained with a 70:30 mixture of monomers and dimers.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145306399","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":"Competition between S_N2 and E2 Pathways in CN^- + RI/RF Systems: Effects of Reactive Centers, Substitution, and Leaving Groups.","authors":"Xu Liu, Mingyu Jia, Shiqi Tian, Hui Li, Boxue Pang, Yang Wu","doi":"10.1021/acs.jpca.5c01919","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c01919","url":null,"abstract":"<p><p>This study examines how substitution degrees in S_N2 reactions using CN^- and alkyl halides (RI/RF) are determined through detailed electronic structure calculations. The results reveal that for ambident nucleophile CN^-, sp³ hybridized C dominates S_N2 pathways at low substitution degrees (α = 1-2), while sp hybridized N demonstrates superior reactivity at high substitution degrees (α = 3). However, E2 pathways consistently favor C as the reactive center, regardless of the substitution degree. For CN^- + RI systems, S_N2 barriers increase significantly with α-methyl substitution, with activation strain model (ASM) analysis identifying strain energy as the primary influence of barrier heights, showing strong correlation with geometric distortion parameters (%<i>D</i>^‡, <i>R</i>² = 0.81-0.99). Conversely, E2 pathways maintain relatively stable geometric distortion through the concerted cleavage of C^α-I and H^β-C^β bonds, resulting in gradually decreasing barriers. Notably, the superior leaving group I leads to lower S_N2 transition state barriers than E2 at α = 1-2, attributable to the weak C-I bond and minimal steric hindrance. At α = 3, increased steric bulk stabilizes the E2 pathway, providing an explanation for the experimentally observed significant rate enhancement at α = 3. In contrast, for CN^- + RF systems, the barrier difference between E2 and S_N2 pathways becomes smaller with increasing substitution degrees. This suggests distinct substitution degree-dependent trends in rate constants between systems containing leaving groups F and I.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145298022","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":"On the Strength of Ouroboros Hydrogen Bonds.","authors":"Garrett D Santis, Sotiris S Xantheas","doi":"10.1021/acs.jpca.5c05827","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c05827","url":null,"abstract":"<p><p>Contrary to the traditional inter-molecular hydrogen bonds (HBs), the strength of intra-molecular (ouroboros) HBs (IMHBs) is not uniquely and in most instances not even well-defined. The problem arises from the difficulty in separating IMHBs into distinct fragments without breaking covalent bonds, making the zero energy reference level not uniquely defined. We propose a novel, spectroscopy-based approach to estimate the strength of an IMHB from the corresponding vibrational frequency. Our approach relates hydrogen bond energies to changes in vibrational frequencies via <math><mi>Δ</mi><msubsup><mi>E</mi><mi>e</mi><mrow><mi>H</mi><mi>B</mi></mrow></msubsup><mo>=</mo><mn>0.43</mn><mfrac><mrow><mrow><mi>k</mi><mi>c</mi><mi>a</mi><mi>l</mi></mrow><mo>/</mo><mrow><mi>m</mi><mi>o</mi><mi>l</mi></mrow></mrow><msqrt><mrow><mi>c</mi><msup><mi>m</mi><mrow><mo>-</mo><mn>1</mn></mrow></msup></mrow></msqrt></mfrac><msqrt><mrow><mi>Δ</mi><msub><mi>ω</mi><mrow><mi>H</mi><mi>B</mi></mrow></msub><mo>+</mo><mi>Δ</mi><msub><mi>ω</mi><mi>M</mi></msub></mrow></msqrt></math>, where <i>E</i>_<i>e</i>^HB is the hydrogen bond energy, Δω_HB is the hydrogen bond redshift, and Δω_M is the frequency shift of the isolated HB donor with respect to water and ammonia. We report a universal trend for estimating the hydrogen bond strength using the vibrational frequencies, 0.43 kcal/mol per square root of a wavenumber, and apply it to diverse intra-molecular hydrogen bonds and multihydrogen bonded complex systems. The new method produces results that are similar to more expensive computational methods and can utilize either experimental or theoretical vibrational frequencies to yield strengths of HBs. The proposed energetic-spectral relationship based on experimental infrared (IR) spectra produced values of ∼6.0 kcal/mol for peptide HBs in α helices and β sheets. It also suggests that the HBs in the A-T nucleotide base pair are stronger than in the C-G base pair. The proposed method shows promise in describing the major energetic driver that determines structure through hydrogen bonding, where previous methods have failed.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145297989","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":"Influence of Sulfur Oxidation States on the Photophysical Properties of Naphthalimide-Based Donor-Acceptor Systems.","authors":"Andrés R Urdaneta M, Marcelo Puiatti, Gustavo A Pino, Liliana B Jimenez","doi":"10.1021/acs.jpca.5c06126","DOIUrl":"https://doi.org/10.1021/acs.jpca.5c06126","url":null,"abstract":"<p><p>This study explores the correlation between the photophysical properties and the oxidation state of the sulfur bridge in NI-SO_<i>n</i>-PhOMe (<i>n</i> = 0, 1, 2), which connects naphthalimide and <i>p</i>-methoxyphenyl units. The investigations were conducted in solution and in the solid state, with comparisons made to NI-PhOMe, where the two moieties are directly linked via a carbon-carbon bond. In the sulfur-bridged derivatives, aggregation-induced emission (AIE) was observed, the characteristics of which are influenced by intermolecular interactions and the nature of the medium in which insoluble aggregates form. In contrast, NI-PhOMe exhibited conventional solvatochromism typical of donor-acceptor <b>(</b>D-A) push-pull systems. A detailed analysis is presented on the influence of the oxidation state of the sulfur atom on key properties, including the D-A character induced by naphthalimide substitution, as well as the charge transfer (CT) contribution that governs its photophysical behavior.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145298037","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":"Electronic Spectra of Cryogenically Cooled Na+-Pyrene and K+-Pyrene Complexes","authors":"Patrick Watkins,&nbsp;, ,&nbsp;Chang Liu,&nbsp;, ,&nbsp;Jack T. Buntine,&nbsp;, ,&nbsp;Samuel J. P. Marlton,&nbsp;, and ,&nbsp;Evan J. Bieske*,&nbsp;","doi":"10.1021/acs.jpca.5c05782","DOIUrl":"10.1021/acs.jpca.5c05782","url":null,"abstract":"<p >The Na⁺-pyrene and K⁺-pyrene complexes are investigated using two-color resonance enhanced photodissociation action spectroscopy in a cryogenic ion trap and through complementary density functional theory calculations. Both complexes are predicted to have π-bound structures in which the metal cation lies above the plane of the pyrene molecule, with calculated binding energies of 10570 and 8150 cm^–1, respectively. Electronic spectra of Na⁺-pyrene and K⁺-pyrene over the 26,000–33,000 cm^–1 range exhibit S₁(B_2u) ← S₀(A_g) and S₂(B_1u) ← S₀(A_g) band systems associated with excitation of the pyrene chromophore. The S₁(B_2u) ← S₀(A_g) band systems of Na⁺-pyrene and K⁺-pyrene are dominated by progressions in Franck–Condon active a_g vibrational modes, whereas transitions involving b_3g vibrational modes, which are prominent in the spectrum of the bare pyrene molecule by virtue of Herzberg–Teller coupling, are relatively weak or absent altogether. The S₁ ← S₀ origin transitions are shifted to lower energy from the corresponding pyrene transitions by 273 cm^–1 for Na⁺-pyrene and 246 cm^–1 for K⁺-pyrene. Density functional theory calculations predict that an attached Na⁺ or K⁺ cation has a minor effect on the pyrene vibrational frequencies but enhances the intensity of the weak S₁ ← S₀ transition while reducing slightly the intensity of the S₂ ← S₀ transition, explaining the relative dominance of vibronic transitions involving a_g vibrational modes in the S₁ ← S₀ spectra of Na⁺-pyrene and K⁺-pyrene. The strong, broad S₂(B_1u) ← S₀(A_g) vibronic bands of Na⁺-pyrene and K⁺-pyrene are also displaced to lower energy compared to the corresponding bands of the bare pyrene molecule.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"129 42","pages":"9756–9764"},"PeriodicalIF":2.8,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145290348","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}