{"title":"Unimolecular Decomposition Mechanism of the Pyrazolo-Triazine Fused-Ring Skeletons: Quantum Chemistry Modeling","authors":"Zixuan Yang, Enliang Liu, Junjun Zhao, Shuangfei Zhu, Shuhai Zhang","doi":"10.1002/qua.70094","DOIUrl":"https://doi.org/10.1002/qua.70094","url":null,"abstract":"<div>\u0000 \u0000 <p>To obtain the thermal decomposition mechanism and key intermediates of pyrazolo-triazine fused-ring skeletons (PT1∼PT10), the decay pathways were studied by using the M062X method for optimization and DLPNO-CCSD(T)/cc-pVTZ methods for energies. Results showed that the most stable structure of the pyrazolo-triazine fused-ring is characterized by a structure with two C<b><span></span></b>H bonds connected on the triazine ring (PT9). Notably, the H transfer has become the main reaction to promote the ring-opening reaction. The introduction of the O atom changes the dominant reaction pathway. Except for PT9 and PT10, the position arrangement of N atoms in the molecule significantly affects its decomposition path and stability. On the one hand, structures containing three or more N atoms directly connected are the most likely to undergo a ring-opening reaction, while other structures tend to undergo H transfer reactions. On the other hand, an increase in the number of N atoms directly connected further reduces the stability. These conclusions were expected to contribute significantly to the design and application of novel high energy density materials.</p>\u0000 </div>","PeriodicalId":182,"journal":{"name":"International Journal of Quantum Chemistry","volume":"125 15","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144725603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Computational and Spectroscopic Insights Into 4-Methoxychalcone as a Potential Acetylcholinesterase Inhibitor: A DFT and Molecular Docking Approach","authors":"S. Sumathi, N. Karthik, S. Jeyavijayan","doi":"10.1002/qua.70092","DOIUrl":"https://doi.org/10.1002/qua.70092","url":null,"abstract":"<div>\u0000 \u0000 <p>4-Methoxychalcone (4MC) is investigated for its potential as an acetylcholinesterase (AChE) inhibitor to treat Alzheimer's disease (AD). We investigated the electrical, vibrational, and structural properties of 4MC with computational and spectroscopic methods. In order to improve the molecular geometry, investigate the stability and reactivity of the chemical in both gas and DMSO phases, density functional theory (DFT) was performed using the B3LYP/6-311++G(d,p) basis set. Potential energy surface (PES) analysis identified the most stable conformer. Experimental methods such as FT-Raman, FT-IR, x-ray diffraction (XRD), UV–Vis, and NMR spectroscopy were employed to verify the computational predictions. Comparing the measured UV–visible spectra with the theoretical time-dependent DFT-calculated spectra is a good instance. Analysis of the molecule's reactivity and electron transfer behavior was done by looking at its frontier molecular orbitals. In the gas phase, a HOMO-LUMO energy gap of ∼3.84 eV suggests relatively high chemical reactivity, which could contribute to potential bioactivity. Intermolecular interactions and charge transfer properties were revealed by the investigations of Hirshfeld surface, Mulliken charge, natural bond orbital (NBO), and molecular electrostatic potential (MEP). The wave function-based topology investigations, including localized orbital locator (LOL), electron localization function (ELF), Reduced Density Gradient (RDG), and non-covalent interaction (NCI) characteristics, have been extensively studied. Molecular docking revealed a strong binding affinity of 4MC (−9.8 kcal/mol) with AChE, comparable to that of the standard drug donepezil. Molecular dynamic (MD) simulations confirmed complex stability through root mean square deviation (RMSD), root mean square fluctuation (RMSF), and radius of gyration (<i>R</i><sub><i>g</i></sub>). Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) results showed favorable pharmacokinetics with good BBB permeability, high intestinal absorption, and low toxicity, supporting 4MC's potential as a candidate for Alzheimer's therapy.</p>\u0000 </div>","PeriodicalId":182,"journal":{"name":"International Journal of Quantum Chemistry","volume":"125 15","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144716665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. A. Taha, A. S. Shalabi, M. M. Assem, Kamal A. Soliman
{"title":"Adsorption Characteristics of Various Gases on Li- and Na-Decorated C24N24 Nanocages: A Computational Study","authors":"R. A. Taha, A. S. Shalabi, M. M. Assem, Kamal A. Soliman","doi":"10.1002/qua.70088","DOIUrl":"https://doi.org/10.1002/qua.70088","url":null,"abstract":"<div>\u0000 \u0000 <p>This study explores the adsorption properties of Li- and Na-decorated C<sub>24</sub>N<sub>24</sub> nanocages and their interactions with SO<sub>2</sub>, SCO, H<sub>2</sub>S, CS<sub>2</sub>, HCHO, and CH<sub>4</sub> gas molecules. The introduction of Li and Na atoms significantly enhances gas adsorption due to increased binding energies and modified electronic properties. The adsorption of SO<sub>2</sub>, SCO, H<sub>2</sub>S, CS<sub>2</sub>, HCHO, and CH<sub>4</sub> on Li-and Na-decorated C<sub>24</sub>N<sub>24</sub> demonstrates varying interaction strengths compared to pristine C<sub>24</sub>N<sub>24</sub>. The decorated nanocages exhibit altered electronic structures, with changes in energy gaps and charge transfer upon gas adsorption. Frontier molecular orbital analysis indicates improved reactivity, suggesting potential suitability for gas sensing applications. However, recovery times reveal limitations in sensing abilities for certain gases. The ΔG for all gases adsorbed on C<sub>24</sub>N<sub>24</sub>, Li- and Na-decorated C<sub>24</sub>N<sub>24</sub> at 298.15 K and 1 atm are nonspontaneous, except for SO<sub>2</sub> and HCHO on Li- and Na-decorated C<sub>24</sub>N<sub>24</sub>. The results demonstrate that Li- and Na-decorated C<sub>24</sub>N<sub>24</sub> nanocages exhibit high sensitivity and fast desorption for SO<sub>2</sub>, highlighting their potential for practical gas sensing applications.</p>\u0000 </div>","PeriodicalId":182,"journal":{"name":"International Journal of Quantum Chemistry","volume":"125 15","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144716729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"First-Principles Study of Elastic Anisotropy and Thermal Conductivity of Ca-Doped Zn-Mg Intermediate Phase Mg2Zn11","authors":"Shanming Fan, Liheng Li, Mingjun Peng, Yonghua Duan, Huarong Qi, Xiaolong Zhou, Mengnie Li","doi":"10.1002/qua.70089","DOIUrl":"https://doi.org/10.1002/qua.70089","url":null,"abstract":"<div>\u0000 \u0000 <p>The significance of Mg<sub>2</sub>Zn<sub>11</sub> in Zn-Mg alloy systems has sparked considerable interest. In this work, the phase stability, elasticity, electronic characteristics, and thermal conductivity of Ca-doped Mg<sub>2</sub>Zn<sub>11</sub> were explored based on the first-principles calculations. The calculated results show that doping with Ca at the 2Mg and 4–6Mg sites enhances the stability, Ca doping changes the elastic properties, and increases the ductility of Mg<sub>2</sub>Zn<sub>11</sub>. Moreover, Ca doping changes the elastic anisotropy in different directions. Besides, doping Ca at the 1Mg–4Mg sites also improves the thermal conductivity of Mg<sub>2</sub>Zn<sub>11</sub>. These findings shed light on the potential benefits of doping in enhancing the overall performance of Mg<sub>2</sub>Zn<sub>11</sub> in Zn-Mg alloys.</p>\u0000 </div>","PeriodicalId":182,"journal":{"name":"International Journal of Quantum Chemistry","volume":"125 15","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144714890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Structural Properties of Pt-Doped Co(111) and the Effect of CO Adsorption on Alloy Surfaces: A DFT Study","authors":"Jian-Hui Zhang, Jing Liu, Ya-Dian Xie, Hong-Mei Mu, Jia Liu, Wen-Ya Li, Yan-Li Leng","doi":"10.1002/qua.70090","DOIUrl":"https://doi.org/10.1002/qua.70090","url":null,"abstract":"<div>\u0000 \u0000 <p>The construction of active sites with low loadings of noble and nonnoble metals is regarded as a promising strategy for the rational design of catalysts. Herein, we investigated the Pt-doped Co(111) surfaces and the characteristics of CO adsorption on Pt<sub>n</sub>/Co(111) (<i>n</i> = 0–3) using Density Functional Theory. The research results indicate that the stable structures with surface cobalt atoms substituted by platinum atoms have a platinum coverage not exceeding 1/2 ML. In addition, an examination of the adsorption behavior of CO on Pt<sub>n</sub>/CO (111) (<i>n</i> = 0–3) surfaces was conducted. The determined adsorption energies for CO on four surfaces were −1.707, 1.712, −1.667, and −1.647 eV, respectively. Notably, the sequence of adsorption energy is as follows: Pt/Co(111) > Co(111) > Pt<sub>2</sub>/Co(111) > Pt<sub>3</sub>/Co(111). The study confirms that optimal CO adsorption energy on the Co (111) surface is achieved with a single Pt atom doping, indicating potential for high catalytic activity even at low rates of Pt loading.</p>\u0000 </div>","PeriodicalId":182,"journal":{"name":"International Journal of Quantum Chemistry","volume":"125 15","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144705472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}