The Journal of Physical Chemistry A最新文献_第3页

Helium Nanodroplet Infrared Spectroscopic Studies of CH₄⁺ and ¹³CH₃^.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-12-19 Epub Date: 2024-12-04 DOI: 10.1021/acs.jpca.4c06858

Amandeep Singh, Sofia H Allison, Andrew Abhisek A Azhagesan, Andrey F Vilesov

引用次数: 0

Super-Resolved Fluorescence Lifetime Imaging of Single Cy3 Molecules and Quantum Dots Using Time-Correlated Single Photon Counting with a Four-Pixel Fiber Optic Array Camera.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-12-19 DOI: 10.1021/acs.jpca.4c05143

Liam A Koch, Megan K Dunlap, Duncan P Ryan, James H Werner, Peter M Goodwin, Christopher M Green, Sebastián A Díaz, Igor L Medintz, Kimihiro Susumu, Michael H Stewart, Martin P Gelfand, Alan Van Orden

{"title":"Super-Resolved Fluorescence Lifetime Imaging of Single Cy3 Molecules and Quantum Dots Using Time-Correlated Single Photon Counting with a Four-Pixel Fiber Optic Array Camera.","authors":"Liam A Koch, Megan K Dunlap, Duncan P Ryan, James H Werner, Peter M Goodwin, Christopher M Green, Sebastián A Díaz, Igor L Medintz, Kimihiro Susumu, Michael H Stewart, Martin P Gelfand, Alan Van Orden","doi":"10.1021/acs.jpca.4c05143","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c05143","url":null,"abstract":"Time-resolved single molecule localization microscopy (TR-SMLM) with a 2 × 2 pixel fiber optic array camera was combined with time-correlated single photon counting (TCSPC) to obtain super-resolved fluorescence lifetime images of individual Cy3 dye molecules and individual colloidal CdSe/CdS/ZnS core/shell/shell semiconductor quantum dots (QDs). The characteristic blinking and bleaching behavior of the Cy3 and the blinking behavior of the QD emitters were used as distinguishing optical characteristics to isolate them and determine their centroid locations with spatial resolution below the optical diffraction limit. TCSPC was used to characterize the fluorescence lifetime and intensity corresponding to each emitter location. The mean centroid locations of the QDs could be determined with a precision of ∼1-4 nm, and the mean centroid locations of the Cy3 molecules could be determined with a precision of ∼2-9 nm, depending on the number of photons collected during the observation time. In a super-resolved fluorescence lifetime image with a single Cy3 dye molecule and a single QD separated by ∼34 nm, the two emitters were distinguished based on the average photon arrival times with respect to the excitation laser pulse observed during time intervals when only one emitter was in the on state, ∼6 ns for Cy3 and ∼17 ns for the QD. The mean distance between the two emitters was determined with a precision of ∼8 nm. The feasibility of using this super-resolved fluorescence lifetime imaging technique to investigate QD-dye complexes that use Förster resonance energy transfer (FRET) and/or electron transfer to form optical biosensors is discussed.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142862539","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}

引用次数: 0

Experimental and Theoretical X-ray Absorption Near Edge Structure Study of UO_x Systems at the U L₃ Edge.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-12-19 Epub Date: 2024-12-04 DOI: 10.1021/acs.jpca.4c05814

Daniil Novichkov, Tatiana Poliakova, Iurii Nevolin, Alexey Averin, Aleksandra Smirnova, Petr Matveev, Stepan Kalmykov

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Informing Empirically Fitted Density Functionals about the Physics of Interelectronic Interactions.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-12-19 Epub Date: 2024-12-06 DOI: 10.1021/acs.jpca.4c05085

Timofey V Losev, Ilya D Ivanov, Igor S Gerasimov, Nikolai V Krivoshchapov, Michael G Medvedev

{"title":"Informing Empirically Fitted Density Functionals about the Physics of Interelectronic Interactions.","authors":"Timofey V Losev, Ilya D Ivanov, Igor S Gerasimov, Nikolai V Krivoshchapov, Michael G Medvedev","doi":"10.1021/acs.jpca.4c05085","DOIUrl":"10.1021/acs.jpca.4c05085","url":null,"abstract":"Further progress in constructing highly accurate density functionals by enforcing known laws of interelectron interactions is slow, so fitting techniques are usually employed nowadays. These approaches were shown to lead to overfitting when a functional becomes unreliable for properties on which it was not trained on. An approach to maintain the correct physical behavior of a functional during its training is required to build more complex and accurate functionals, including those based on neural networks. We devise such an approach and apply it to reparameterize the heavily fitted and popular M06-2X functional on its original training set. The resulting physics-informed functionals piM06-2X and piM06-2X-DL approached the accuracy of M06-2X in thermochemical tasks and the accuracy of PBE0 in electron densities, taking the best out of both worlds. Surprisingly, we find that a very similar performance can be achieved directly by using the PBE-2X functional without any fitting. The proposed approach should be indispensable for training future neural-network-based functionals.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"10921-10928"},"PeriodicalIF":2.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142783356","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}

引用次数: 0

Correlation between Noncovalent Bond Strength and Spectroscopic Perturbations within the Lewis Base.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-12-19 Epub Date: 2024-12-05 DOI: 10.1021/acs.jpca.4c07382

Steve Scheiner, Mariusz Michalczyk, Wiktor Zierkiewicz

引用次数: 0

State-to-State Time-Dependent Quantum Dynamics Studies of the Si(³P) + OH(X ²Π) → OSi(X ¹Σ_g⁺) + H(²S) Reaction Based on a New HOSi(X²A') Potential Energy Surface.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-12-19 Epub Date: 2024-12-04 DOI: 10.1021/acs.jpca.4c06439

Lulu Zhang, Juan Zhao, Yiran Wang, Yuzhi Song, Dong Liu

{"title":"State-to-State Time-Dependent Quantum Dynamics Studies of the Si(3P) + OH(X 2Π) → OSi(X 1Σg+) + H(2S) Reaction Based on a New HOSi(X2A') Potential Energy Surface.","authors":"Lulu Zhang, Juan Zhao, Yiran Wang, Yuzhi Song, Dong Liu","doi":"10.1021/acs.jpca.4c06439","DOIUrl":"10.1021/acs.jpca.4c06439","url":null,"abstract":"Quantum and quasi-classical dynamics calculations were conducted for the reaction of Si with OH on the latest potential energy surface (PES), which is obtained by fitting tens of thousands of ab initio energy points by using the many-body expansion formula. To obtain an accurate PES, all energy points calculated with aug-cc-pVQZ and aug-cc-pV5Z basis sets were extrapolated to the complete basis set limit. The accuracy of our new PES was verified by comparing the topographic characteristics and contour maps of potential energy with other works. In addition, the anharmonic vibrational frequencies of HOSi and HSiO based on the present ab initio and PES by means of quantum dynamics methods were calculated. Dynamics information such as reaction probability, integral cross sections (ICS), product distribution, and rate constants was obtained on the new HOSi(X2A') PES. The dynamic information calculated using the quasi-classical trajectory method and time-dependent wave packet method is generally in good agreement, except for the vibrational state-resolved ICSs of product. The calculated differential cross section and capture time reveal that the reaction is primarily governed by the complex formation mechanism.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"10837-10850"},"PeriodicalIF":2.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142778786","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}

引用次数: 0

Local Wave Function Embedding: Correlation Regions in PNO-LCCSD(T)-F12 Calculations.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-12-19 Epub Date: 2024-12-05 DOI: 10.1021/acs.jpca.4c06852

Hans-Joachim Werner, Andreas Hansen

{"title":"Local Wave Function Embedding: Correlation Regions in PNO-LCCSD(T)-F12 Calculations.","authors":"Hans-Joachim Werner, Andreas Hansen","doi":"10.1021/acs.jpca.4c06852","DOIUrl":"10.1021/acs.jpca.4c06852","url":null,"abstract":"Many chemical reactions affect only a rather small number of bonds, leaving the largest part of the chemical and geometrical structure of the molecules nearly unchanged. In this work we extended the previously proposed region method [J. Chem. Phys. 128, 144106 (2008)] to PNO-LCCSD(T)-F12. Using this method, we investigate whether accurate reaction energies for larger systems can be obtained by correlating only the electrons in a region of localized molecular orbitals close to the reaction center at high-level (PNO-LCCSD(T)-F12). The remainder is either treated at lower level (PNO-LMP2-F12) or left uncorrelated (Hartree-Fock frozen core). It is demonstrated that indeed the computed reaction energies converge rather quickly with the size of the correlation regions toward the results of the full calculations. Typically, 2-3 bonds from the reacting atoms need to be included to reproduce the results of the full calculations to within ±0.2 kcal/mol. We also computed spin-state energy differences in a large transition metal complex, where a factor of 15 in computation time could be saved, still yielding a result that is within ±0.1 kcal/mol of the one obtained in a full PNO-LCCSD(T)-F12 calculation.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"10936-10947"},"PeriodicalIF":2.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142783357","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}

引用次数: 0

Influence of Noncovalent Interaction on the Nucleophilicity and Electrophilicity of Metal Centers in [M^II(S₂CNEt₂)₂] (M = Ni, Pd, Pt).

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-12-19 Epub Date: 2024-12-09 DOI: 10.1021/acs.jpca.4c05706

Zixuan Shen, Xiaoyan Li, Yanli Zeng, Xueying Zhang

{"title":"Influence of Noncovalent Interaction on the Nucleophilicity and Electrophilicity of Metal Centers in [MII(S2CNEt2)2] (M = Ni, Pd, Pt).","authors":"Zixuan Shen, Xiaoyan Li, Yanli Zeng, Xueying Zhang","doi":"10.1021/acs.jpca.4c05706","DOIUrl":"10.1021/acs.jpca.4c05706","url":null,"abstract":"A systematic theoretical study was performed on the electrophilic and nucleophilic properties of Group 10 square-planar metal compounds [MII(S2CNEt2)2] (M = Ni 1, Pd 2, and Pt 3) and their complexes. The nucleophilic metal center and coordinated sulfur atom in [M(S2CNEt2)2] facilitate the formation of metal-involving and conventional noncovalent bonds. The presence a heavier metal center results in a more negative electrostatic potential and a larger nucleophilicity, which in turn leads to the formation of stronger metal-involving noncovalent bonds than those formed by a lighter metal center. The NiII center was observed to display electrophilic-nucleophilic dualism with regard to noncovalent interactions, forming both a metal-involving halogen bond (Ni···I) with iodine chloride (ICl) and a semicoordination bond (Ni···N) with N-bases. The nucleophilicity and electrophilicity of the NiII center are enhanced in the ternary complexes LB···1···XCl (X = H, I; LB = NH3, NHCH2, pyridine) due to the push-pull mechanism. The N···Ni semicoordination bond exerts a push effect on the dz2 orbital of the NiII center, while the Ni···X noncovalent bond provides a symbiotic pull effect on this orbital. Furthermore, the formation of metal-involving noncovalent bonds may enhance the electrophilic ability of the PdII and PtII center, resulting in the formation of stable ternary complexes Py···2/3···XCl (X = H, I), which are characterized by M···N and M···X interactions.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"10796-10807"},"PeriodicalIF":2.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142798739","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}

引用次数: 0

Potentials of Mean Force and Solvent Effects of the CN^- + CH₃X (X = F, Cl, Br, and I) Reactions by the N-Side Attack in Aqueous Solution.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-12-19 Epub Date: 2024-12-09 DOI: 10.1021/acs.jpca.4c05367

Yanzhen Zhu, Yixuan Li, Dunyou Wang

{"title":"Potentials of Mean Force and Solvent Effects of the CN- + CH3X (X = F, Cl, Br, and I) Reactions by the N-Side Attack in Aqueous Solution.","authors":"Yanzhen Zhu, Yixuan Li, Dunyou Wang","doi":"10.1021/acs.jpca.4c05367","DOIUrl":"10.1021/acs.jpca.4c05367","url":null,"abstract":"A combined multilevel quantum mechanics and molecular mechanics approach is performed to investigate the nucleophilic substitution reactions of CN- + CH3X (X = F, Cl, Br, and I) by the N-side attack in aqueous solution. The water molecules are treated microscopically using an explicit SPC/E model, and the potentials of mean force are characterized by both the DFT and CCSD(T) levels of theory for the solute. Calculations demonstrate that the shielding effect of the solvent reduces the nucleophile-substrate and substrate-leaving group interactions in solution, leading to stationary point structures that are quite different from those in the gas phase. The structure and charge evolution along the reaction paths reveal that the reaction is not only a synchronous bonding and bond-breaking Walden-inversion mechanism but also a synchronous charge transfer process. The activation barriers calculated at the CCSD(T) level of theory are 27.5 (F), 22.6 (Cl), 21.7 (Br), and 21.2 (I) kcal/mol, respectively, which are larger than the corresponding experimental values for the C-side attack. The polarization effect of water molecules causing solute polarization contributes to the activation barrier in the order of F > Cl > Br > I. The solvent energy contribution to the activation barrier is in the order of F < Cl < Br < I because the F leaving group has the most compact transition state structure and the I leaving group has the loosest transition state structure. As a result, the total contributions of the solvent effects to the activation barriers are 7.9 (F), 10.7 (Cl), 15.3 (Br), and 15.7 (I) kcal/mol. Our results show that the solvent effects have a significant influence on both the structure and the energetics of the N-side attack reactions in aqueous solution.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":"10766-10774"},"PeriodicalIF":2.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142798743","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}

引用次数: 0

Photoelectron Imaging Spectroscopic and Geometric Configuration and Chemical Bond Analysis of Rh(CN)_n^-1/0 (n = 1-3) Clusters.

IF 2.7 2区化学

The Journal of Physical Chemistry A Pub Date : 2024-12-19 DOI: 10.1021/acs.jpca.4c07031

Saifei Wang, Shanjun Chen, Yan Chen, Jie Hou, Song Li, Xiaoqian Shao

{"title":"Photoelectron Imaging Spectroscopic and Geometric Configuration and Chemical Bond Analysis of Rh(CN)n-1/0 (n = 1-3) Clusters.","authors":"Saifei Wang, Shanjun Chen, Yan Chen, Jie Hou, Song Li, Xiaoqian Shao","doi":"10.1021/acs.jpca.4c07031","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c07031","url":null,"abstract":"We obtained the photoelectron spectra of Rh(CN)- using the negative ion photoelectron velocity-map imaging (NI-PEVMI) technique and revealed the photodesorption process of Rh(CN)-. The vertical detachment energy (VDE) and adiabatic detachment energy (ADE) of Rh(CN)- have both been experimentally reported to be 2.04 (3) eV. The Franck-Condon (FC) simulation of the ground state of Rh(CN)- was conducted to facilitate a more accurate identification of the experimental photoelectron spectra. The existence of isomer Rh(NC)- was confirmed by the FC simulation result. The vibration frequencies of Rh(CN) and Rh(NC) measured by photoelectron spectroscopy are 462 (50) cm-1 and 471 (50) cm-1, respectively. Based on density functional theory, the stable geometries of Rh(CN)n-1/0 (n = 1-3) clusters were obtained, the values of VDEs and ADEs were calculated, and the photoelectron spectroscopy (PES) was simulated. These can provide theoretical guidance for the experimental study of rhodium cyanide complexes in the future. Finally, we also conduct molecular orbital analysis, natural population analysis, natural resonance theory, and electron localization function analysis to further reveal the nature of the interaction between transition metal Rh and (CN)n ligand. Through the study of Rh(CN)n-1/0 (n = 1-3) complexes, it is found that the transition metal rhodium (Rh) is more inclined to cyanide arrangement.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142862537","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}

引用次数: 0