The Journal of Physical Chemistry A最新文献

{"title":"Attosecond Probing of Coherent Vibrational Dynamics in CBr₄.","authors":"Jen-Hao Ou, Diptarka Hait, Patrick Rupprecht, John E Beetar, Todd J Martínez, Stephen R Leone","doi":"10.1021/acs.jpca.4c05210","DOIUrl":"10.1021/acs.jpca.4c05210","url":null,"abstract":"<p><p>A coherent vibrational wavepacket is launched and manipulated in the symmetric stretch (a₁) mode of CBr₄, by impulsive stimulated Raman scattering (ISRS) from nonresonant 400 nm laser pump pulses with various peak intensities on the order of tens of 10¹² W/cm². Extreme ultraviolet (XUV) attosecond transient absorption spectroscopy (ATAS) records the wavepacket dynamics as temporal oscillations in XUV absorption energy at the bromine M_4,5 3d_3/2,5/2 edges around 70 eV. The results are augmented by nuclear time-dependent Schrödinger equation simulations. Slopes of the (Br 3d_3/2,5/2)^-110a₁* core-excited state potential energy surface (PES) along the a₁ mode are calculated to be -9.4 eV/Å from restricted open-shell Kohn-Sham calculations. Using analytical relations derived for the small-displacement limit and the calculated slopes of the core-excited state PES, a deeper insight into the vibrational dynamics is obtained by retrieving the experimental excursion amplitude of the vibrational wavepacket and the amount of population transferred to the vibrational first-excited state as a function of pump-pulse peak intensity. Experimentally, the results show that XUV ATAS is capable of resolving oscillations in the XUV absorption energy on the order of a few to tens of meV with tens of femtosecond time precision. This corresponds to change in C-Br bond length on the order of 10^-4 to 10^-3 Å. The results and the analytic relationships offer a clear physical picture, on multiple levels of understanding, of how the pump-pulse peak intensity controls the vibrational dynamics launched by nonresonant ISRS in the small-displacement limit.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11514008/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decomposition and Growth Pathways for Ammonium Nitrate Clusters and Nanoparticles.","authors":"Ubaidullah S Hassan, Miguel A Amat, Robert Q Topper","doi":"10.1021/acs.jpca.4c04630","DOIUrl":"10.1021/acs.jpca.4c04630","url":null,"abstract":"<p><p>Understanding the formation and decomposition mechanisms of aerosolized ammonium nitrate species will lead to improvements in modeling the thermodynamics and kinetics of aerosol haze formation. Studying the sputtered mass spectra of cation and anion ammonium nitrate clusters can provide insights as to which growth and evaporation pathways are favored in the earliest stages of nucleation and thereby guide the development and use of accurate models for intermolecular forces for these systems. Simulated annealing Monte Carlo optimization followed by density functional theory optimizations can be used reliably to predict minimum-energy structures and interaction energies for the cation and anion clusters observed in mass spectra as well as for neutral nanoparticles. A combination of translational and rotational mag-walking and sawtooth simulated annealing methods was used to find optimum structures of the various heterogeneous clusters identifiable in the mass spectra. Following these optimizations with ωB97X-D3 density functional theory calculations made it possible to rationalize the pattern of peaks in the mass spectra through computation of the binding energies of clusters involved in various growth and dissociation pathways. Testing these calculations against CCSD(T) and MP2 predictions of the structures and binding energies for small clusters demonstrates the accuracy of the chosen model chemistry. For the first time, the peaks corresponding with all detectable species in both the positive and negative ion mass spectra of ammonium nitrate are identified with their corresponding structures. Thermodynamic control of particle growth and decomposition of ions due to loss of ammonia or nitric acid molecules is indicated. Structures and interaction energies for larger (<i>NH</i>₄<i>NO</i>₃)<i>_n</i> nanoparticles are also presented, including the prediction of new particle morphologies with trigonal pyramidal character.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11514028/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DFT Investigation on Palladium-Catalyzed [2 + 2 + 1] Spiroannulation between Aryl Halides and Alkynes: Mechanism, Base Additive Role, and Solvent and Ligand Effects.","authors":"Xue Tan, Wen-Ji Bai, Yu-Bing Shi, Liangfei Duan, Wei-Hua Mu","doi":"10.1021/acs.jpca.4c04423","DOIUrl":"10.1021/acs.jpca.4c04423","url":null,"abstract":"<p><p>Transition metal-catalyzed spiroannulations are practical strategies for constructing spirocyclic skeletons of pharmaceutical and biological significance, yet the microscopic mechanism still lacks in-depth explorations. Here, the palladium-catalyzed [2 + 2 + 1] spiroannulation between aryl halides and alkynes was studied by employing the density functional theory (DFT) method. Based on comprehensive explorations on a couple of possible reaction pathways, it is found that the reaction probably experiences C-I oxidative addition, alkyne migration insertion, Cs₂CO₃-assisted aryl C-H activation, C-Br bond oxidative addition, C-C coupling, arene dearomatization and reductive elimination in sequence and leads to the formation of the spiro[4,5]decane pentacyclic product (<b>P</b>) ultimately. Among these, the C-Br bond oxidative addition step acts as the rate-determining step (RDS) of the whole reaction, featuring a practical free energy barrier of 32.4 kcal·mol^-1 at 130 °C. Computationally predicted kinetics such as half-life transferred from the RDS step's barrier on the optimal reaction pathway (1.2 × 10¹ h) coincides well with corresponding experimental results (91% yield of the spiro[4,5]decane pentacyclic product <b>P</b> after reacting 10 h at 130 °C). In addition, theoretical predictions regarding the solvent/ligand effects and base additive role in the reaction, rationalized by distortion-interaction/natural population/noncovalent interaction analyses, are also in good agreement with experimental data and trend. This good agreement between experiment and theory makes sense for new designations and further experimental improvements of such Pd-catalyzed transformations.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142405739","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":"Knowles Partitioning at the Multireference Level.","authors":"Ágnes Szabados, András Gombás, Péter R Surján","doi":"10.1021/acs.jpca.4c04279","DOIUrl":"10.1021/acs.jpca.4c04279","url":null,"abstract":"<p><p>A multireference generalization of the partitioning introduced recently by Knowles (<i>J. Chem. Phys.</i> 2022 156, 011101) is presented with the aim to study electronic systems at a medium level of correlation. The multireference formalism applied is the general framework of multiconfiguration perturbation theory (MCPT).</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142398728","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":"Releasing Preferentially Sequestered Na⁺ from Its Confinement by Beauvericin: A Single Water Molecule is the Accomplice.","authors":"Kien X Vo, Keisuke Hirata, James M Lisy, Masaaki Fujii, Shun-Ichi Ishiuchi","doi":"10.1021/acs.jpca.4c04515","DOIUrl":"10.1021/acs.jpca.4c04515","url":null,"abstract":"<p><p>Beauvericin (Bv) is a natural ionophore capable of transporting ions across biological membranes. Mass spectrometry and infrared spectroscopy show that Bv specifically captures sodium ions with a unique 6-fold coordination in its cavity, which illustrates how ions are carried through the membrane. But with no reports on how ions are released from Bv at the interface, a complete picture of the ion transport process has yet to be established. In this study, conformational changes of Bv complexes with alkali metal ions upon hydration were investigated using infrared spectroscopy and computational calculations. The addition of a single water molecule to Na⁺Bv pries the ion away from the 6-fold cavity to the amide face of the ionophore, evidence of the first step of ion release. In contrast, there is little impact on the other M⁺Bv complexes, with the ion bound to the three carbonyl groups on the amide face. Analysis of the carbonyl C═O and water OH stretching modes reveals the competition between ion-ionophore, ion-water, and water-ionophore interactions and demonstrates how water actively participates in ion transport by initiating ion release from the ionophore.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453504","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":"Laser Spectroscopic Characterization of Supersonic Jet-Cooled 2,6-Diazaindole (26DAI).","authors":"Bhavika Kalal, Simran Baweja, Surajit Maity","doi":"10.1021/acs.jpca.4c04249","DOIUrl":"10.1021/acs.jpca.4c04249","url":null,"abstract":"<p><p>The article presents a comprehensive laser spectroscopic characterization of a nitrogen-rich indole derivative, namely, 2,6-diazaindole (26DAI), in the gas phase. A supersonic jet-cooled molecular beam of 26DAI was characterized using two-color resonant two-photon ionization (2C-R2PI) and laser-induced fluorescence spectroscopy (LIF) to investigate the electronic excitation. The S₁ ← S₀ origin transition was obtained at 33915 cm^-1, which was red-shifted from that of one (indole) and two (7-azaindole) nitrogen-containing indole derivatives by 1317 and 713 cm^-1, respectively. The molecular orbital and energy analysis for the S₁ ← S₀ transition shows the significant stabilization of LUMO on subsequent N-insertion, resulting in the lowering of the S₁ ← S₀ (ππ*) transition energy. The single vibronic level fluorescence spectrum from the vibrationless S₁ state of the molecule was recorded. The spectrum displayed an extensive Franck-Condon activity until 2500 cm^-1 for the vibrational modes of the S₀ state of the 26DAI molecule. The experimental ground state vibrational frequencies were compared to the calculated ones obtained at three different levels of theories. More accurate results were found at DFT B3LYP-D4 than those at the wave function-based MP2 and CCSD levels of theories. Further, the N-H stretching frequency of 26DAI in the S₀ state was measured at 3524 cm^-1 using fluorescence-dip infrared (FDIR) spectroscopy. The stability of 26DAI against ionization radiation was probed by measuring the two-color photoionization energy (IE_2P) of 26DAI at 71866 cm^-1. The IE_2P value is significantly higher than those of N-poor counterparts (indole and 7-azaindole). The NBO charges and spin density (SD) values of the 26DAI molecule have shown that electronegative N(6) makes the cationic ground state less stable due to the position of the positive centers on the N atom. The results provided insights into the stability of N-rich biomolecules against photodamage. The current investigation can shed light on nature's way of stabilizing biomolecules with a possible N-insertion mechanism.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453494","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":"Mechanism for Site-Selective Hydroboration of C70 Fullerene with Borane by DFT-D3 Study","authors":"Jong Woan Choi,&nbsp;Bo Mi Kim*,&nbsp;Eiji Osawa,&nbsp;Ji Young Lee*,&nbsp;Changhoon Lee* and Kee Hag Lee*,&nbsp;","doi":"10.1021/acs.jpca.4c0435110.1021/acs.jpca.4c04351","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c04351https://doi.org/10.1021/acs.jpca.4c04351","url":null,"abstract":"&lt;p &gt;We studied the hydroboration of the C&lt;sub&gt;70&lt;/sub&gt; fullerene using both B3LYP-D3(BJ)/6-311G(d,p) and M06-2X-D3/6-311G(d,p) levels of theory, incorporating the empirical dispersion interaction, and Fukui index calculations. Potential energy surfaces (PESs) and Gibbs free energy surfaces (GFESs) were calculated for the pathways from four BH&lt;sub&gt;3&lt;/sub&gt; adducts (located at the &lt;b&gt;&lt;i&gt;AB&lt;/i&gt;&lt;/b&gt;, &lt;b&gt;&lt;i&gt;CC&lt;/i&gt;&lt;/b&gt;, &lt;b&gt;&lt;i&gt;D&lt;/i&gt;&lt;/b&gt;, and &lt;b&gt;&lt;i&gt;E&lt;/i&gt;&lt;/b&gt; sites) on the C&lt;sub&gt;70&lt;/sub&gt; to eight products formed by the 1,2-addition of BH&lt;sub&gt;3&lt;/sub&gt; across the four [6,6]-ring fused bonds (&lt;b&gt;&lt;i&gt;AB&lt;/i&gt;&lt;/b&gt;, &lt;b&gt;&lt;i&gt;CC&lt;/i&gt;&lt;/b&gt;, &lt;b&gt;&lt;i&gt;DE&lt;/i&gt;&lt;/b&gt;, and &lt;b&gt;&lt;i&gt;EE&lt;/i&gt;&lt;/b&gt;) and across the two [5,6]-ring fused bonds (&lt;b&gt;&lt;i&gt;AA&lt;/i&gt;&lt;/b&gt; and &lt;b&gt;&lt;i&gt;DD&lt;/i&gt;&lt;/b&gt;). These pathways are two-step consecutive reactions. We denoted the positions on the fullerene cage as &lt;b&gt;&lt;i&gt;A&lt;/i&gt;&lt;/b&gt; through &lt;i&gt;E&lt;/i&gt;, from the pole to the equator, based on the D&lt;sub&gt;5h&lt;/sub&gt; symmetry of the C&lt;sub&gt;70&lt;/sub&gt; fullerene. In the first step reaction, the product ratios for the four adduct intermediates should be as the primary intermediate BH&lt;sub&gt;3&lt;/sub&gt;(&lt;b&gt;&lt;i&gt;D&lt;/i&gt;&lt;/b&gt;), the secondary intermediate BH&lt;sub&gt;3&lt;/sub&gt;(&lt;b&gt;&lt;i&gt;AB&lt;/i&gt;&lt;/b&gt;), the tertiary intermediate BH&lt;sub&gt;3&lt;/sub&gt;(&lt;b&gt;&lt;i&gt;CC&lt;/i&gt;&lt;/b&gt;), and the minor intermediate BH&lt;sub&gt;3&lt;/sub&gt;(&lt;b&gt;&lt;i&gt;E&lt;/i&gt;&lt;/b&gt;), based on the Fukui indices. In addition, in the second step reaction, transition states (TSs) from four adduct intermediates to eight product isomers, namely, BH&lt;sub&gt;2&lt;/sub&gt;(&lt;b&gt;&lt;i&gt;A&lt;/i&gt;&lt;/b&gt;)H (&lt;b&gt;&lt;i&gt;B&lt;/i&gt;&lt;/b&gt;) to BH&lt;sub&gt;2&lt;/sub&gt;(&lt;b&gt;&lt;i&gt;E&lt;/i&gt;&lt;/b&gt;)H (&lt;b&gt;&lt;i&gt;E&lt;/i&gt;&lt;/b&gt;), were obtained using the QST2 method. The calculated reaction coordinates showed exothermic reactions for all bonds except the &lt;b&gt;&lt;i&gt;EE&lt;/i&gt;&lt;/b&gt; bond. We also confirmed the transition states by frequency calculations and intrinsic reaction coordinate (IRC) analyses. The PESs and GFESs suggest spontaneous processes for the four isomers, of which the primary products are BH&lt;sub&gt;2&lt;/sub&gt;(&lt;b&gt;&lt;i&gt;A&lt;/i&gt;&lt;/b&gt;)H (&lt;b&gt;&lt;i&gt;B&lt;/i&gt;&lt;/b&gt;) and its isomer BH&lt;sub&gt;2&lt;/sub&gt;(&lt;b&gt;&lt;i&gt;B&lt;/i&gt;&lt;/b&gt;)H (&lt;b&gt;&lt;i&gt;A&lt;/i&gt;&lt;/b&gt;), the secondary product is BH&lt;sub&gt;2&lt;/sub&gt;(&lt;b&gt;&lt;i&gt;C&lt;/i&gt;&lt;/b&gt;)H (&lt;b&gt;&lt;i&gt;C&lt;/i&gt;&lt;/b&gt;), and the tertiary product is BH&lt;sub&gt;2&lt;/sub&gt;(&lt;b&gt;&lt;i&gt;D&lt;/i&gt;&lt;/b&gt;)H (&lt;b&gt;&lt;i&gt;D&lt;/i&gt;&lt;/b&gt;), all formed through adduct intermediates. Therefore, through the hydroboration reaction of C&lt;sub&gt;70&lt;/sub&gt;, we could predict and design the site selectivity of C&lt;sub&gt;70&lt;/sub&gt; by controlling the energy barrier of the transition state in the second step of the reaction. This implies that we could selectively synthesize mainly BH&lt;sub&gt;2&lt;/sub&gt;(&lt;b&gt;&lt;i&gt;B&lt;/i&gt;&lt;/b&gt;)H (&lt;b&gt;&lt;i&gt;A&lt;/i&gt;&lt;/b&gt;) isomers across the AB-[6,6]-ring fused bond and also design BH&lt;sub&gt;2&lt;/sub&gt;(&lt;b&gt;&lt;i&gt;D&lt;/i&gt;&lt;/b&gt;)H(&lt;b&gt;&lt;i&gt;D&lt;/i&gt;&lt;/b&gt;) isomers across the DD-[5,6]-ring fused bond. Also, the calculations of formation rate constants can well simulate the experimental ratio of two C&lt;sub&gt;70&lt;/sub&gt;H&lt;sub&gt;2&lt;/sub&gt; isomers by the hydrolysis of BH&lt;sub&gt;2&lt;/sub&gt;(&lt;b&gt;&lt;i&gt;A&lt;/i&gt;&lt;/b&gt;)H(&lt;b&gt;&lt;i&gt;B&lt;/i&gt;&lt;/b&gt;), BH&lt;sub&gt;2&lt;/sub&gt;(&lt;b&gt;&lt;i&gt;B&lt;/i&gt;&lt;/b&gt;)H(&lt;b&gt;&lt;i&gt;A","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142608740","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":"Thermal Decomposition of 2-Cyclopentenone.","authors":"Kathryn Narkin, Heather R Legg, Glenna J Brown, Khaled El-Shazly, Thaddeus D Martin, Mia Jarrell, Laura R McCunn, Zhijian Chen, Carol A Parish","doi":"10.1021/acs.jpca.4c05532","DOIUrl":"10.1021/acs.jpca.4c05532","url":null,"abstract":"<p><p>The thermal decomposition of 2-cyclopentenone, a cyclic oxygenated hydrocarbon that occurs in the pyrolysis of biomass, has been studied in a combined experimental and theoretical approach. Gas-phase pyrolysis was performed at temperatures ranging from 1000 to 1400 K in a pulsed, microtubular reactor. Products were identified by FTIR spectroscopy following their isolation in a low-temperature argon matrix. The following products were identified: carbon monoxide, ketene, propenylketene, vinylacetylene, ethylene, propene, acrolein, acetylene, propyne, and propargyl radical. Computational results identify three different decomposition channels involving a H atom migration, and producing prop-2-enylketene (Pathway 1), prop-1-enylketene (Pathway 2), and a second conformation of prop-2-enylketene (Pathway 3). A fourth decomposition pathway involves simultaneous rupture of two C-C bonds forming a high energy cyclopropenone intermediate that further reacts to form ethylene, acetylene, and carbon monoxide. Finally, a fifth pathway to the formation of acrolein and acetylene was identified that proceeds via a multistep mechanism, and an interconversion from 2-cyclopentenone to 3-cyclopentenone was identified computationally, but not observed experimentally.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11514027/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling Many-Body Interactions in Water with Gaussian Process Regression.","authors":"Yulian T Manchev, Paul L A Popelier","doi":"10.1021/acs.jpca.4c05873","DOIUrl":"10.1021/acs.jpca.4c05873","url":null,"abstract":"<p><p>We report a first-principles water dimer potential that captures many-body interactions through Gaussian process regression (GPR). Modeling is upgraded from previous work by using a custom kernel function implemented through the KeOps library, allowing for much larger GPR models to be constructed and interfaced with the next-generation machine learning force field FFLUX. A new synthetic water dimer data set, called WD24, is used for model training. The resulting models can predict 90% of dimer geometries within chemical accuracy for a test set and in a simulation. The curvature of the potential energy surface is captured by the models, and a successful geometry optimization is completed with a total energy error of just 2.6 kJ mol^-1, from a starting structure where water molecules are separated by nearly 4.3 Å. Dimeric modeling of a flexible, noncrystalline system with FFLUX is shown for the first time.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11514001/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142405740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Single-Atom Doped Fullerene (MN₄-C₅₄) as Bifunctional Catalysts for the Oxygen Reduction and Oxygen Evolution Reactions.","authors":"Junkai Xu, Yunhao Wang, Xiaoxue Yu, Jianjun Fang, Xianfang Yue, Breno R L Galvão, Jing Li","doi":"10.1021/acs.jpca.4c03413","DOIUrl":"10.1021/acs.jpca.4c03413","url":null,"abstract":"<p><p>Development of high-performance oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) catalysts is crucial to realizing the electrolytic water cycle. C₆₀ is an ideal substrate material for single atom catalysts (SACs) due to its unique electron-withdrawing properties and spherical structure. In this work, we screened for a novel single-atom catalyst based on C₆₀, which anchored transition metal atoms in the C₆₀ molecule by coordination with N atoms. Through first-principles calculations, we evaluated the stability and activity of MN₄-C₅₄ (M = Fe, Co, Ni, Cu, Rh, Ru, Pd, Ag, Pt, Ir, Au). The results indicate that CuN₄-C₅₄, which is based only on earth-abundant elements, exhibited low overpotentials of 0.46 and 0.47 V for the OER and ORR, respectively, and was considered a promising bifunctional catalyst, showing better performance than the noble-metal ones. In addition, according to the linear relationship of intermediates, we established volcano plots to describe the activity trends of the OER and ORR on MN₄-C₅₄. Finally, d-band center and crystal orbital Hamiltonian populations methods were used to explain the catalytic origin. Suitable d-band centers lead to moderate adsorption strength, further leading to good catalytic performances.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453506","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}