The Journal of Physical Chemistry A最新文献

{"title":"Subpicosecond Dynamics of Rydberg Excitons Produced from Ultraviolet Excitation of Neutral Cuprite (Cu2O)n Clusters, n < 13","authors":"Chase H. Rotteger, Carter K. Jarman, Madison M. Sobol, Shaun F. Sutton, Scott G. Sayres","doi":"10.1021/acs.jpca.4c05013","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c05013","url":null,"abstract":"The ultrafast dynamics of subnanometer neutral cuprite clusters (Cu₂O)_<i>n</i>, <i>n</i> &lt; 13, are examined with pump probe spectroscopy. Upon absorption of an ultraviolet (400 nm) photon, all clusters exhibit a subpicosecond lifetime that we attribute to carrier recombination. Density functional theory (DFT) shows a change in the structural motif between small planar clusters and three-dimensional structures at <i>n</i> = 4. This transition is accompanied by a change in the excited state relaxation behavior, marking the onset for which lifetimes increase gradually with size. Time-dependent DFT calculations show that the excited state lifetimes align with calculated topological parameters and charge carrier delocalization associated with the formation of Rydberg excitons. Terminal Cu atoms are found to be important for the production of Rydberg excitons at the lowest optically allowed excited state. Upon excitation, the electron resides on terminal Cu atoms and the hole becomes delocalized across the remainder of the cluster.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.781,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258510","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":"Enthalpy of the Cerium (Ce) Chemi-Ionization Reaction and CeO⁺, CeC⁺, and CeCO⁺ Bond Energies Determined by Energy-Resolved Guided Ion Beam Mass Spectrometry Experiments.","authors":"Talley A Fenn, Brandon C Stevenson, P B Armentrout","doi":"10.1021/acs.jpca.4c04257","DOIUrl":"10.1021/acs.jpca.4c04257","url":null,"abstract":"<p><p>Cerium (Ce) oxide, carbide, and carbonyl cation bond energies and the exothermicity of the Ce chemi-ionization (CI) reaction with atomic oxygen were investigated using guided-ion beam tandem mass spectrometry (GIBMS). The kinetic energy dependent product cross sections for reactions of Ce⁺ with O₂, CO, and CO₂ and CeO⁺ with O₂, CO, Xe, and Ar were measured using GIBMS. For the reactions of Ce⁺ with O₂ and CO₂, CeO⁺ is formed through an exothermic reaction, whereas CeO⁺ formation is endothermic in the reaction with CO. This reaction also forms CeC⁺ and CeCO⁺ is formed in the reaction of Ce⁺ with CO₂, both in endothermic processes. Reactions of CeO⁺ with all four gases led to endothermic collision-induced dissociation as well as exchange reactions to form CeO₂⁺ for the O₂ and CO reactants. Bond dissociation energies (BDEs) at 0 K were determined through analyses of the kinetic energy dependent cross sections for all endothermic reactions. We determined that the BDEs of CeO⁺, CeC⁺, and CeCO⁺ are 8.46 ± 0.15, 3.93 ± 0.16, and ≥0.25 ± 0.07 eV, respectively, where the CeO⁺ BDE is a weighted average of 6 independent 0 K threshold measurements. The CeO⁺ BDE is combined with the ionization energy (IE) of Ce to determine an exothermicity of 2.91 ± 0.15 eV for the Ce + O → CeO⁺ + e^- chemi-ionization reaction. Combined with neutral BDEs from the literature, the thermochemistry determined here also provides IE(CeO) = 5.03 ± 0.12 eV and IE(CeC) = 6.50 ± 0.16 eV. Theoretical calculations for ground and some excited states were performed for CeO⁺, CeC⁺, and CeCO⁺ to provide insight into the bonding and a comparison with the experimentally determined BDEs for each molecule.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142124218","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":"Low-Scaling, Efficient and Memory Optimized Computation of Nuclear Magnetic Resonance Shieldings within the Random Phase Approximation Using Cholesky-Decomposed Densities and an Attenuated Coulomb Metric.","authors":"Viktoria Drontschenko, Christian Ochsenfeld","doi":"10.1021/acs.jpca.4c02773","DOIUrl":"10.1021/acs.jpca.4c02773","url":null,"abstract":"<p><p>An efficient method for the computation of nuclear magnetic resonance (NMR) shielding tensors within the random phase approximation (RPA) is presented based on our recently introduced resolution-of-the-identity (RI) atomic orbital RPA NMR method [Drontschenko, V. <i>J. Chem. Theory Comput.</i> 2023, 19, 7542-7554] utilizing Cholesky decomposed density type matrices and employing an attenuated Coulomb RI metric. The introduced sparsity is efficiently exploited using sparse matrix algebra. This allows for an efficient and low-scaling computation of RPA NMR shielding tensors. Furthermore, we introduce a batching method for the computation of memory demanding intermediates that accounts for their sparsity. This extends the applicability of our method to even larger systems that would have been out of reach before, such as, e.g., a DNA strand with 260 atoms and 3408 atomic orbital basis functions.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142138628","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":"Tailoring the Superatomic Characteristics and Optical Behavior of Metal-Free Boron Clusters via Ligand Engineering.","authors":"Jing Wang, Weiliu Fan, Shi-Bo Cheng, Jing Chen","doi":"10.1021/acs.jpca.4c04808","DOIUrl":"10.1021/acs.jpca.4c04808","url":null,"abstract":"<p><p>It is of great importance to understand how the number and type of ligands influence the properties of clusters through ligand engineering, as this knowledge is crucial for the rational design and optimization of functional materials. Herein, the geometrical structures, binding energies, and electronic properties of nonmetallic B_n (n = 20 and 40) clusters with CO, PEt₃, F, NO₂, and CN ligands are systematically explored based on density functional theory (DFT) calculations. Our findings demonstrate that the CO ligand acts as an electron donor when attached to these two boron clusters, in contrast to their role as electron acceptors in interactions with metal oxide and metal chalcogenide clusters. This emphasizes the necessity of considering the intrinsic properties of the host cluster when modifying with ligands. Moreover, it was observed that substituting PEt₃ with F, NO₂, or CN converted the B₂₀ cluster from an electron acceptor to an electron donor, thereby demonstrating the versatility in tuning the redox characteristics of boron clusters by selecting appropriate ligands. Intriguingly, the attachment of the PEt₃, F, NO₂, and CN ligands to B₂₀ can significantly modulate the electronic properties of B₂₀ to realize the formation of metal-free superalkali (B₂₀(PEt₃)_n, n = 3-5) and superhalogen (B₂₀F, B₂₀NO_2, and B₂₀CN) clusters. Furthermore, the structure, stability, and optical absorption of the charge transfer complex B₂₀(PEt₃)₃⁺B₂₀F were analyzed. This complex has been identified as an efficient material for harvesting visible light. Our findings provide insights into the effects of ligand variations on boron cluster functionalities, offering a new perspective for the design of advanced materials with tailored cluster properties through ligand engineering.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142131208","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":"Structural Effects on the Energy Disposal and Atomic Photofragment Alignment for the Photodissociation of Alkyl Iodides at Excitation Wavelengths of 254 and 268 nm","authors":"Javier Cachón, Pedro Recio, David Sorribes, Sonia Marggi Poullain, Luis Rubio-Lago, Luis Bañares","doi":"10.1021/acs.jpca.4c02217","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c02217","url":null,"abstract":"This work represents a step forward in the understanding of the widely studied photodynamics of alkyl iodides in the first absorption band. Ultraviolet (UV) photodissociation of several alkyl iodides (RI), specifically, a series of linear and ramified molecules with R = C_<i>n</i>H_2<i>n</i>+1, <i>n</i> = 1–4, at excitation wavelengths of 254 and 268 nm, which correspond to the maximum of the first absorption A-band, has been studied by combining resonance-enhanced multiphoton ionization (REMPI) detection of atomic photofragments I(²<i>P</i>_3/2) and I*(²<i>P</i>_1/2) and of pulsed slice imaging. Detailed examination of the total translational energy distributions of both atomic photofragments has been combined with stereodynamical information on the process obtained from the anisotropy β and alignment <i>a</i>₀²(∥) and Re[<i>a</i>₁²(∥, ⊥)] parameters to provide a description of the role played by the molecular structure of alkyl iodides in adiabatic and, especially, in nonadiabatic photodissociation dynamics through conical intersections or avoided crossings. The present results suggest that the linear structures couple more efficiently with the pure C–I reaction coordinate, whereas for the branched structures, the coupling with additional vibrational (bending) modes gains importance, showing the dissociation process a multidimensional character. In addition, a large degree of cofragment rotational alignment has been found for the small linear CH₃I and C₂H₅I and, unexpectedly, for the branched <i>t</i>-C₄H₉I (<i>C</i>_3<i>v</i> symmetry), whereas the rest of the alkyl iodides show low alignment parameters.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.781,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258509","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":"Theoretical Study on the Correlation between Open-Shell Electronic Structures and Third-Order Nonlinear Optical Properties in One-Dimensional Chains of π-Radicals","authors":"Jinki Shoda, Masako Yokoyama, Wataru Yoshida, Hiroshi Matsui, Ryota Sugimori, Ryohei Kishi, Yasutaka Kitagawa","doi":"10.1021/acs.jpca.4c05200","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c05200","url":null,"abstract":"This paper theoretically investigated the correlation between the open-shell electronic structure and third-order nonlinear optical (NLO) properties of one-dimensional (1D) stacked chains of π-radicals. By employing the finite <i>N</i>-mer models consisting of methyl or phenalenyl radicals with different stacking distances, we evaluated the average and standard deviation of diradical characters <i>y</i>_<i>i</i> for <i>N</i>-mer models of π-radicals (<i>y</i>_av and <i>y</i>_SD). Then, we estimated these diradical characters at the limit of <i>N</i> → ∞. These <i>y</i>-based indices were helpful in discussing the correlation between the open-shell electronic structures and the second hyperpolarizability per dimer at the limit <i>N</i> → ∞, γ_∞ for the 1D chains with stacking distance alternation (SDA). The calculated γ_∞ values and the polymer/dimer ratio γ_∞/γ(<i>N</i> = 2) were enhanced significantly when both the stacking distance and SDA are small. We also found that the spin-unrestricted long-range-corrected (LC−)UBLYP method with the range-separating parameter μ = 0.47 bohr^–1 well reproduced the trend of γ_∞ of this type of 1D chain estimated at the spin-unrestricted coupled-cluster levels. The present study is expected to contribute to establishing the design guidelines for future high-performance open-shell molecular NLO materials.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.781,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258539","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":"Mechanistic Insight of High-Valent First-Row Transition Metal Complexes for Dehydrogenation of Ammonia Borane.","authors":"Amrita Gogoi, Mudit Dixit, Sourav Pal","doi":"10.1021/acs.jpca.4c04069","DOIUrl":"10.1021/acs.jpca.4c04069","url":null,"abstract":"<p><p>Designing an efficient and cost-effective catalyst for ammonia borane (<b>AB</b>) dehydrogenation remains a persistent challenge in advancing a hydrogen-based economy. Transition metal complexes, known for their C-H bond activation capabilities, have emerged as promising candidates for <b>AB</b> dehydrogenation. In this study, we investigated two recently synthesized C-H activation catalysts, <b>1</b> (Co^IV-dinitrate complex) and <b>2</b> (Ni^IV-nitrate complex), and demonstrated their efficacy for <b>AB</b> dehydrogenation. Using density functional theory calculations and a detailed analysis, we elucidated the <b>AB</b> dehydrogenation mechanism of these complexes. Our results revealed that both complexes <b>1</b> and <b>2</b> can efficiently dehydrogenate <b>AB</b> at room temperature, although the abstraction of molecular H₂ from these complexes requires slightly elevated temperatures. We utilized H₂ binding free energy calculations to identify potentially active sites and observed that complex <b>2</b> can release two equivalents of H₂ at a temperature slightly higher than room temperature. Furthermore, we investigated <b>AB</b> dehydrogenation kinetics and thermodynamics in iron (Fe)-substituted systems, complexes <b>3</b> and <b>4</b>. Our results showed that the strategic alteration of the central metal atom, replacing Ni in complex <b>2</b> with Fe in complex <b>4</b>, resulted in enhanced kinetics and thermodynamics for <b>AB</b> dehydrogenation in the initial cycle. These results underscore the potential of high-valent first-row transition metal complexes for facilitating <b>AB</b> dehydrogenation at room temperature. Additionally, our study highlights the beneficial impact of incorporating iron into such mononuclear systems, enhancing their catalytic activity.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142102230","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":"Efficient Structural Relaxation Based on the Random Phase Approximation: Applications to Water Clusters.","authors":"Muhammad N Tahir, Honghui Shang, Jia Li, Xinguo Ren","doi":"10.1021/acs.jpca.4c02411","DOIUrl":"10.1021/acs.jpca.4c02411","url":null,"abstract":"<p><p>We report an improved implementation for evaluating the analytical gradients of the random phase approximation (RPA) electron-correlation energy based on atomic orbitals and the localized resolution of the identity scheme. The more efficient RPA force calculations allow us to relax the structures of medium-sized water clusters. Particular attention is paid to the structures and energy orderings of the low-energy isomers of (H₂O)_<i>n</i> clusters with <i>n</i> = 21, 22, and 25. It is found that the RPA energy ordering of the low-energy isomers of these water clusters is rather sensitive to the basis set used. For the five low-energy isomers of (H₂O)₂₅, the RPA energy ordering still undergoes a change by increasing the basis set to the quadruple to quintuple level. The standard RPA underbinds the water clusters, and this underbinding behavior becomes more pronounced by increasing the basis size to the complete basis set (CBS) limit. The renormalized single excitation (rSE) correction remedies this underbinding, giving rise to a noticeable overbinding behavior at finite basis sets. However, as the CBS limit is approached, RPA+rSE yields an accuracy for the binding energies that is comparable to that of the best available double hybrid functionals, as demonstrated for the WATER27 test set.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142138627","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":"Tri-<i>n</i>-butyl Phosphate vs Tri-<i>iso</i>-amyl Phosphate Complexation with Th(IV), U(VI), and Nd(III): From Theory to Experiment.","authors":"Aditya Ramesh Sachin, Balija Sreenivasulu, Cherukuri Venkata Siva Brahmananda Rao, Suresh Ammath, Gopinadhanpillai Gopakumar","doi":"10.1021/acs.jpca.4c02523","DOIUrl":"10.1021/acs.jpca.4c02523","url":null,"abstract":"<p><p>The complexation behavior of tri-<i>iso</i>-amyl phosphate (TiAP) and tri-<i>n</i>-butyl phosphate (TBP) ligands with U(VI), Th(IV), and Nd(III) was investigated using density functional theory (DFT). Quantum chemical calculations yielded identical coordination geometries for TBP and TiAP complexes. Calculated complexation energies indicated a preferential extraction of U(VI) followed by Th(IV) over Nd(III), aligning with solvent extraction experiments conducted in the cross-current mode. Notably, during the separation of Th(IV) from RE(III), an increase in Th(IV) loading in the organic phase suppressed RE(III) extraction. Further analysis highlighted the crucial role of structural features (symmetry and dipole moment) in the extraction behavior of complexes. Energy decomposition analysis underscored the essential role of geometric strain and dispersion interaction energies in deciding the stability of the complexes.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142138637","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":"Effect of Electron-Donating Substituents and an Electric Field on the ΔEST of Selected Imidazopyridine Derivatives: A DFT Study","authors":"Paras, Vivek, Sanjay Sharma, C. N. Ramachandran","doi":"10.1021/acs.jpca.4c04355","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c04355","url":null,"abstract":"A series of thermally activated delayed fluorescent (TADF) molecules having an imidazopyridine acceptor, a benzene linker, and a 9,9-dimethyl-9,10-dihydroacridine donor are designed and examined using a quantum chemical approach. The above framework spatially separates the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), minimizing their overlap, ultimately resulting in a reduced energy gap between the excited singlet and triplet states (Δ<i>E</i>_ST). The impact of electron-donating substituents (-Me, -Et, -<i>t</i>-Bu, -OMe, and -NMe₂) on the donor moiety of the parent molecule 2-(4-(9,9-dimethylacridin-10(9H)-yl)phenyl)imidazo[1,2-<i>a</i>]pyridine-3,6-dicarbonitrile (Ac-CNImPy) is investigated. The calculated results revealed that for a given substituent, the para-substituted derivatives exhibit relatively less Δ<i>E</i>_ST, compared to that of the respective ortho- and meta derivatives. The value of Δ<i>E</i>_ST decreased with an increase in the electron-donating capacity of the substituent. Additionally, the Δ<i>E</i>_ST of the disubstituted derivatives is found to be less than that for the monosubstituted derivatives. The charge transport studies revealed that molecules with strong electron-donating substituents act as electron transporters. The effect of an external electric field (EEF) on Δ<i>E</i>_ST of the parent molecule Ac-CNIMPY and its derivative is also examined and revealed that the Δ<i>E</i>_ST can be further reduced by applying an electric field of appropriate strength in a direction perpendicular to the dipole moment of the molecule and in the plane of the acceptor moiety.","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.781,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258537","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}