Pub Date : 2025-11-01DOI: 10.1016/j.chemphys.2025.112995
Xiujuan Zhang, Wentao Li
Dynamics studies were performed on the Sr+(4d2D) + H2(v = 0, 1; j = 0) reaction based on diabatic potential energy surfaces. The results demonstrate that the reaction pathway Sr+(4d2D) + H2 is the primary mechanism for SrH+ formation, exhibiting significantly higher reactivity compared to the Sr+(5s2S) + H2 reaction. Calculated dynamical properties including reaction probabilities, integral cross sections, and differential cross sections for SrH+ formation, reveal that vibrational excitation of the H2 reactant substantially enhances reactivity. Furthermore, the differential cross sections are predominantly forward-scattered, indicating that the abstraction mechanism dominates the reaction.
{"title":"Nonadiabatic dynamics study of the Sr+(4d2D) + H2(v = 0, 1; j = 0) reaction","authors":"Xiujuan Zhang, Wentao Li","doi":"10.1016/j.chemphys.2025.112995","DOIUrl":"10.1016/j.chemphys.2025.112995","url":null,"abstract":"<div><div>Dynamics studies were performed on the Sr<sup>+</sup>(4d<sup>2</sup>D) + H<sub>2</sub>(<em>v</em> = 0, 1; <em>j</em> = 0) reaction based on diabatic potential energy surfaces. The results demonstrate that the reaction pathway Sr<sup>+</sup>(4d<sup>2</sup>D) + H<sub>2</sub> is the primary mechanism for SrH<sup>+</sup> formation, exhibiting significantly higher reactivity compared to the Sr<sup>+</sup>(5s<sup>2</sup>S) + H<sub>2</sub> reaction. Calculated dynamical properties including reaction probabilities, integral cross sections, and differential cross sections for SrH<sup>+</sup> formation, reveal that vibrational excitation of the H<sub>2</sub> reactant substantially enhances reactivity. Furthermore, the differential cross sections are predominantly forward-scattered, indicating that the abstraction mechanism dominates the reaction.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 112995"},"PeriodicalIF":2.4,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474613","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}
Understanding the effects of different environments and alkali metal substitution on the excited-state intramolecular proton transfer (ESIPT) process and emission mechanisms of luminescent materials is crucial for the design of next-generation solid-state emitters. In this study, the photophysical properties of three alkali-metal-substituted salicylidene diamine derivatives, GS-Li, GS-Na, and GS-K, were systematically investigated in methanol solution and in the solid, based on density functional theory (DFT) and quantum mechanics/molecular mechanics (QM/MM) approaches. In methanol, all three compounds exhibit barrierless ESIPT processes accompanied by twisted intramolecular charge transfer (TICT), resulting in fluorescence quenching. In the solid state, the crystal structure of GS-K exhibits characteristics resembling a hybrid of GS-Li and GS-Na. Therefore, our discussion focuses primarily on GS-Li and GS-Na, both of which display pronounced aggregation-induced emission (AIE) properties. GS-Li exhibits strong K* fluorescence emission through a barrierless ESIPT process coupled with an intramolecular charge transfer (ICT) mechanism. GS-Na undergoes barrierless ground-state intramolecular proton transfer (GSIPT) and exhibits K* fluorescence in the excited state. This work provides a comprehensive understanding of the ESIPT mechanisms and emission behaviors of these derivatives. It reveals the interplay among TICT, ICT, and ESIPT processes under different environments, offering valuable insights for the design and development of highly efficient luminescent materials with combined ESIPT and AIE characteristics.
{"title":"Elucidating the activation mechanism of ESIPT dark state in Salicylidene Glycine Schiff bases via liquid–solid phase switching","authors":"Tianyu Cui, Siqi Wang, Xiaonan Wang, Yifu Zhang, Hui Li, Jixing Cai","doi":"10.1016/j.chemphys.2025.112981","DOIUrl":"10.1016/j.chemphys.2025.112981","url":null,"abstract":"<div><div>Understanding the effects of different environments and alkali metal substitution on the excited-state intramolecular proton transfer (ESIPT) process and emission mechanisms of luminescent materials is crucial for the design of next-generation solid-state emitters. In this study, the photophysical properties of three alkali-metal-substituted salicylidene diamine derivatives, GS-Li, GS-Na, and GS-K, were systematically investigated in methanol solution and in the solid, based on density functional theory (DFT) and quantum mechanics/molecular mechanics (QM/MM) approaches. In methanol, all three compounds exhibit barrierless ESIPT processes accompanied by twisted intramolecular charge transfer (TICT), resulting in fluorescence quenching. In the solid state, the crystal structure of GS-K exhibits characteristics resembling a hybrid of GS-Li and GS-Na. Therefore, our discussion focuses primarily on GS-Li and GS-Na, both of which display pronounced aggregation-induced emission (AIE) properties. GS-Li exhibits strong K* fluorescence emission through a barrierless ESIPT process coupled with an intramolecular charge transfer (ICT) mechanism. GS-Na undergoes barrierless ground-state intramolecular proton transfer (GSIPT) and exhibits K* fluorescence in the excited state. This work provides a comprehensive understanding of the ESIPT mechanisms and emission behaviors of these derivatives. It reveals the interplay among TICT, ICT, and ESIPT processes under different environments, offering valuable insights for the design and development of highly efficient luminescent materials with combined ESIPT and AIE characteristics.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 112981"},"PeriodicalIF":2.4,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474612","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}
In recent years, how to enhance the effect of field-free orientation has attracted the attention of many researchers. Here, we propose a scheme for generating field-free orientation of LiH molecules using a train of few-cycle/single-cycle terahertz pulses. Theoretical calculations indicate that the field-free orientation degree of LiH molecules gradually increases with the number of laser pulses. After the interaction with five terahertz laser pulses, the maximum field-free orientation degree of molecules reaches 0.8568. Under this condition, the duration during which the field-free orientation degree remains above 0.5 is 161.8 fs, which is sufficient for experimental utilization. When the temperature is below 20 K, the molecules orientation degree remains above 0.5. By sequentially discussing the relationship between the time delay of adjacent pulses and the rotational state population, we uncovered the control mechanism of the proposed scheme. Additionally, we examined the laser-pulse-induced changes in their angular distribution.
{"title":"Field-free orientation of LiH molecules controlled by a train of few-cycle/single-cycle terahertz laser pulses","authors":"Yuemin Leng, Wenqian Li, Yaoyao Wei, Shou Chai, Gaoren Wang, Yongchang Han, Jie Yu","doi":"10.1016/j.chemphys.2025.113003","DOIUrl":"10.1016/j.chemphys.2025.113003","url":null,"abstract":"<div><div>In recent years, how to enhance the effect of field-free orientation has attracted the attention of many researchers. Here, we propose a scheme for generating field-free orientation of LiH molecules using a train of few-cycle/single-cycle terahertz pulses. Theoretical calculations indicate that the field-free orientation degree of LiH molecules gradually increases with the number of laser pulses. After the interaction with five terahertz laser pulses, the maximum field-free orientation degree of molecules reaches 0.8568. Under this condition, the duration during which the field-free orientation degree remains above 0.5 is 161.8 fs, which is sufficient for experimental utilization. When the temperature is below 20 K, the molecules orientation degree remains above 0.5. By sequentially discussing the relationship between the time delay of adjacent pulses and the rotational state population, we uncovered the control mechanism of the proposed scheme. Additionally, we examined the laser-pulse-induced changes in their angular distribution.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 113003"},"PeriodicalIF":2.4,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145425060","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}
Pub Date : 2025-10-30DOI: 10.1016/j.chemphys.2025.112999
Qiuhui Zhao , Yaqi Jing , Jiale Zhang , Jiadan Xue , Jianjun Liu , Jianyuan Qin , Zhi Hong , Yong Du
Isoniazid (INH), a frontline anti-tuberculosis drug, faces rising resistance and hepatotoxicity, motivating crystal-engineering approaches. The INH-4-hydroxybenzoic acid (INH-HBA) cocrystal shows multiple polymorphs, its hydrate exists in two forms whose lattice water markedly alters hydrogen-bond topology and molecular packing. We combined terahertz time-domain spectroscopy (THz-TDS) and FT-Raman spectroscopy with periodic solid-state DFT and potential energy distribution (PED) analysis to assign vibrational modes and link spectral features to structural motifs. Hirshfeld surface analysis indicates form I is dominated by multi-directional OH...N contacts and an NH...O synthon that yields parallel layered packing. By contrast, form II uses lattice water to bridge OH...O/NH...O interactions and weak CH...O contacts, producing a cross-stacked three-dimensional network lacking dimers. Observed spectral differences are attributed to these distinct intermolecular interactions and associated vibrations. By integrating experimental and theoretical data, this study provides spectroscopic-structural insights into INH-HBA hydrate polymorphism, offering a foundation for pharmaceutical cocrystal identification and design.
{"title":"Polymorphic behavior in isoniazid-4-hydroxybenzoic acid hydrated cocrystals: A combined terahertz, Raman vibrational spectroscopy, and DFT analysis","authors":"Qiuhui Zhao , Yaqi Jing , Jiale Zhang , Jiadan Xue , Jianjun Liu , Jianyuan Qin , Zhi Hong , Yong Du","doi":"10.1016/j.chemphys.2025.112999","DOIUrl":"10.1016/j.chemphys.2025.112999","url":null,"abstract":"<div><div>Isoniazid (INH), a frontline anti-tuberculosis drug, faces rising resistance and hepatotoxicity, motivating crystal-engineering approaches. The INH-4-hydroxybenzoic acid (INH-HBA) cocrystal shows multiple polymorphs, its hydrate exists in two forms whose lattice water markedly alters hydrogen-bond topology and molecular packing. We combined terahertz time-domain spectroscopy (THz-TDS) and FT-Raman spectroscopy with periodic solid-state DFT and potential energy distribution (PED) analysis to assign vibrational modes and link spectral features to structural motifs. Hirshfeld surface analysis indicates form I is dominated by multi-directional O<img>H...N contacts and an <span><math><mrow><msubsup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow><mrow><mn>2</mn></mrow></msubsup><mrow><mo>(</mo><mn>8</mn><mo>)</mo></mrow></mrow></math></span> N<img>H...O synthon that yields parallel layered packing. By contrast, form II uses lattice water to bridge O<img>H...O/N<img>H...O interactions and weak C<img>H...O contacts, producing a cross-stacked three-dimensional network lacking <span><math><mrow><msubsup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow><mrow><mn>2</mn></mrow></msubsup><mrow><mo>(</mo><mn>8</mn><mo>)</mo></mrow></mrow></math></span> dimers. Observed spectral differences are attributed to these distinct intermolecular interactions and associated vibrations. By integrating experimental and theoretical data, this study provides spectroscopic-structural insights into INH-HBA hydrate polymorphism, offering a foundation for pharmaceutical cocrystal identification and design.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 112999"},"PeriodicalIF":2.4,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474614","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}
Pub Date : 2025-10-30DOI: 10.1016/j.chemphys.2025.113006
Guili He , Zhumei Luo , Chenghang Li , Shan Qing , Jing Zhang , Xiaohui Zhang
This study employs molecular dynamics (MD) simulations performed in LAMMPS to elucidate the microscopic mechanisms governing enhanced heat transfer in Al-Cu/H₂O hybrid nanofluids. Compared with Al/H₂O nanofluids, hybrid systems with optimized mixing ratios exhibit a 41.9 % improvement in thermal conductivity, while maintaining stable viscosity and a high specific heat capacity. Structural analysis reveals that sheet-like nanoparticles at an Al: Cu ratio of 40:60 form dense, solid-like interfacial nanolayers (RDF peak = 1.391) and promote molecular mobility by 10.29 %, demonstrating a synergistic coupling between interfacial ordering and molecular perturbation that jointly facilitates nanoscale heat transport. The phonon density of states analysis further indicates that low-frequency vibrational coupling between hydrogen bond dynamics and nanoparticle lattice modes dominates interfacial energy transfer. These findings elucidate the molecular origins of thermal enhancement and highlight the potential of hybrid nanofluids for efficient microchannel cooling, thereby bridging experimental advances with molecular-level understanding.
{"title":"Molecular dynamics investigation of interfacial thermal transport for enhanced heat transfer in Al–Cu/H2O hybrid Nanofluids","authors":"Guili He , Zhumei Luo , Chenghang Li , Shan Qing , Jing Zhang , Xiaohui Zhang","doi":"10.1016/j.chemphys.2025.113006","DOIUrl":"10.1016/j.chemphys.2025.113006","url":null,"abstract":"<div><div>This study employs molecular dynamics (MD) simulations performed in LAMMPS to elucidate the microscopic mechanisms governing enhanced heat transfer in Al-Cu/H₂O hybrid nanofluids. Compared with Al/H₂O nanofluids, hybrid systems with optimized mixing ratios exhibit a 41.9 % improvement in thermal conductivity, while maintaining stable viscosity and a high specific heat capacity. Structural analysis reveals that sheet-like nanoparticles at an Al: Cu ratio of 40:60 form dense, solid-like interfacial nanolayers (RDF peak = 1.391) and promote molecular mobility by 10.29 %, demonstrating a synergistic coupling between interfacial ordering and molecular perturbation that jointly facilitates nanoscale heat transport. The phonon density of states analysis further indicates that low-frequency vibrational coupling between hydrogen bond dynamics and nanoparticle lattice modes dominates interfacial energy transfer. These findings elucidate the molecular origins of thermal enhancement and highlight the potential of hybrid nanofluids for efficient microchannel cooling, thereby bridging experimental advances with molecular-level understanding.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 113006"},"PeriodicalIF":2.4,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474616","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}
Pub Date : 2025-10-29DOI: 10.1016/j.chemphys.2025.113002
Feng Guo , BianTao Wu , YanXin Yang , ZhangSheng Liu , PeiZhong Feng
Cl-doped NiCo bimetallic fluorides are fabricated via a solvothermal process and subsequent fluoridization. During the fluoridization, the flower-like precursor NiCo-Cl layered double hydroxide (LDH) tends to be transformed into urchin-like morphology. As-obtained (Ni,Co)(F1-xClx)2 samples (NCFC-x, x = 0, 10, 15, 20 and 25) exhibit excellent electrochemical performance, among which NCFC-20 provides the highest specific capacitance of 2569 F g−1 at a current density of 2 A g−1 and remarkable cycling stability of 79.0 % capacity retention after 7000 cycles. Correspondingly, the assembled NCFC-20//active carbon asymmetric supercapacitor delivers a high energy density (37.3 Wh kg−1) at a power density of 850 W kg−1 and outstanding cycling stability of 88.7 % capacity retention after 6000 cycles. The superior electrochemical performance of NCFC-20 can be attributed to the synergistic effect of typical urchin-like structure and Cl ion doping. Such a material shows an enormous potential for applications in high-performance supercapacitor.
采用溶剂热法和随后的氟化法制备了掺杂cl的NiCo双金属氟化物。在氟化过程中，花状前体NiCo-Cl层状双氢氧化物（LDH）倾向于转变为海胆状形态。所得（Ni,Co）（F1-xClx）2样品（NCFC-x, x = 0, 10, 15, 20和25）表现出优异的电化学性能，其中NCFC-20在电流密度为2 a g−1时的最高比电容为2569 F g−1，循环7000次后的循环稳定性为79.0%。相应的，组装的NCFC-20//活性炭不对称超级电容器在850 W kg - 1的功率密度下具有较高的能量密度（37.3 Wh kg - 1），并且在6000次循环后具有88.7%的容量保持率。NCFC-20优异的电化学性能可归因于典型的胆状结构和Cl离子掺杂的协同作用。这种材料在高性能超级电容器中显示出巨大的应用潜力。
{"title":"Urchin-like cl-doped NiCo bimetallic fluorides for high-performance asymmetric supercapacitors","authors":"Feng Guo , BianTao Wu , YanXin Yang , ZhangSheng Liu , PeiZhong Feng","doi":"10.1016/j.chemphys.2025.113002","DOIUrl":"10.1016/j.chemphys.2025.113002","url":null,"abstract":"<div><div>Cl-doped NiCo bimetallic fluorides are fabricated via a solvothermal process and subsequent fluoridization. During the fluoridization, the flower-like precursor NiCo-Cl layered double hydroxide (LDH) tends to be transformed into urchin-like morphology. As-obtained (Ni,Co)(F<sub>1-x</sub>Cl<sub>x</sub>)<sub>2</sub> samples (NCFC-x, x = 0, 10, 15, 20 and 25) exhibit excellent electrochemical performance, among which NCFC-20 provides the highest specific capacitance of 2569 F g<sup>−1</sup> at a current density of 2 A g<sup>−1</sup> and remarkable cycling stability of 79.0 % capacity retention after 7000 cycles. Correspondingly, the assembled NCFC-20//active carbon asymmetric supercapacitor delivers a high energy density (37.3 Wh kg<sup>−1</sup>) at a power density of 850 W kg<sup>−1</sup> and outstanding cycling stability of 88.7 % capacity retention after 6000 cycles. The superior electrochemical performance of NCFC-20 can be attributed to the synergistic effect of typical urchin-like structure and Cl ion doping. Such a material shows an enormous potential for applications in high-performance supercapacitor.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 113002"},"PeriodicalIF":2.4,"publicationDate":"2025-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145425050","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}
Pub Date : 2025-10-28DOI: 10.1016/j.chemphys.2025.113001
Mais Khazaleh, Bilal Aladerah, Abdalla Obeidat
In this study, we employed Density Functional Theory (DFT) combined with high-throughput computational screening to explore the magnetic and structural properties of full Heusler alloys with the general formula X₂YZ, aiming to identify promising candidates for rare-earth-free permanent magnet applications. A total of 360 distinct compounds were generated using 3d transition metals for X and Y, and main group elements for Z. After the initial filtration based on thermodynamic preference for tetragonal symmetry, 41 compounds were retained for further investigation. Among these, three compounds, Co2CrGe, Co2CrSi, and Co2FeGa, exhibited saturation magnetization values greater than 0.5 T. Dynamical stability revealed that Co2CrGe and Co2FeGa are dynamically stable, while Co2CrSi was excluded from further analysis. Magnetocrystalline anisotropy energy (MCA) calculations yielded values of 2.4 MJ/m3 for Co2CrGe and 3.1 MJ/m3 for Co2FeGa, corresponding to high anisotropy fields () of 9.4 and 9.8 MA/m, respectively. Furthermore, Monte Carlo simulations revealed Curie temperatures () of 418 K for Co2CrGe and 654 K for Co2FeGa. These findings underscore the potential of Co2CrGe and Co2FeGa as high-performance, rare-earth-free permanent magnets. Our work demonstrates the power of high-throughput DFT-based screening to accelerate the discovery of novel magnetic materials with targeted functional properties.
{"title":"High-throughput screening of full Heusler alloys (X₂YZ) for advanced permanent magnets: computational insights","authors":"Mais Khazaleh, Bilal Aladerah, Abdalla Obeidat","doi":"10.1016/j.chemphys.2025.113001","DOIUrl":"10.1016/j.chemphys.2025.113001","url":null,"abstract":"<div><div>In this study, we employed Density Functional Theory (DFT) combined with high-throughput computational screening to explore the magnetic and structural properties of full Heusler alloys with the general formula X₂YZ, aiming to identify promising candidates for rare-earth-free permanent magnet applications. A total of 360 distinct compounds were generated using 3d transition metals for X and Y, and main group elements for Z. After the initial filtration based on thermodynamic preference for tetragonal symmetry, 41 compounds were retained for further investigation. Among these, three compounds, Co<sub>2</sub>CrGe, Co<sub>2</sub>CrSi, and Co<sub>2</sub>FeGa, exhibited saturation magnetization values greater than 0.5 T. Dynamical stability revealed that Co<sub>2</sub>CrGe and Co<sub>2</sub>FeGa are dynamically stable, while Co<sub>2</sub>CrSi was excluded from further analysis. Magnetocrystalline anisotropy energy (MCA) calculations yielded values of 2.4 MJ/m<sup>3</sup> for Co<sub>2</sub>CrGe and 3.1 MJ/m<sup>3</sup> for Co<sub>2</sub>FeGa, corresponding to high anisotropy fields (<span><math><msub><mi>H</mi><mi>a</mi></msub></math></span>) of 9.4 and 9.8 MA/m, respectively. Furthermore, Monte Carlo simulations revealed Curie temperatures (<span><math><msub><mi>T</mi><mi>c</mi></msub></math></span>) of 418 K for Co<sub>2</sub>CrGe and 654 K for Co<sub>2</sub>FeGa. These findings underscore the potential of Co<sub>2</sub>CrGe and Co<sub>2</sub>FeGa as high-performance, rare-earth-free permanent magnets. Our work demonstrates the power of high-throughput DFT-based screening to accelerate the discovery of novel magnetic materials with targeted functional properties.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 113001"},"PeriodicalIF":2.4,"publicationDate":"2025-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145425051","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}
Pub Date : 2025-10-28DOI: 10.1016/j.chemphys.2025.112994
Md. Alauddin , Seung Min Park
This research examines the photodissociation dynamics of thymine cluster cations (dimers to tetramers) under various laser wavelengths using TOF mass spectrometry and computational simulations. Protonated thymine (TH+) emerges as the primary fragment, driven by intradimer proton transfer (IPT) in the excited neutral or ionic states. Fragmentation pathways vary with cluster size and excitation energy, with larger clusters showing lower intensity in dissociation. Computational results confirm IPT as a stabilizing mechanism in dimers. Atom-centered Density Matrix Propagation (ADMP) simulations reveal that hydrogen bonds remain stable up to 400 fs, with IPT and structural fluctuations occurring within the first 200 fs, indicating rapid intracluster dynamics.
{"title":"Photodissociation and proton transfer dynamics in thymine cluster cations: A TOF mass spectrometry and ADMP simulation study","authors":"Md. Alauddin , Seung Min Park","doi":"10.1016/j.chemphys.2025.112994","DOIUrl":"10.1016/j.chemphys.2025.112994","url":null,"abstract":"<div><div>This research examines the photodissociation dynamics of thymine cluster cations (dimers to tetramers) under various laser wavelengths using TOF mass spectrometry and computational simulations. Protonated thymine (TH<sup>+</sup>) emerges as the primary fragment, driven by intradimer proton transfer (IPT) in the excited neutral or ionic states. Fragmentation pathways vary with cluster size and excitation energy, with larger clusters showing lower intensity in dissociation. Computational results confirm IPT as a stabilizing mechanism in dimers. Atom-centered Density Matrix Propagation (ADMP) simulations reveal that hydrogen bonds remain stable up to 400 fs, with IPT and structural fluctuations occurring within the first 200 fs, indicating rapid intracluster dynamics.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 112994"},"PeriodicalIF":2.4,"publicationDate":"2025-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145681705","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}
Pub Date : 2025-10-28DOI: 10.1016/j.chemphys.2025.113004
Igor S. Kovalev , Alexander S. Novikov , Grigory V. Zyryanov
The electronic properties of polyacetylene (PA) isomers and their doped derivatives were investigated using density functional theory (DFT) at the PM3/B3LYP/def2-TZVP level. By studying a series of oligomers with increasing conjugation length, we determined the asymptotic band gaps to be 1.26 eV for trans-PA and 2.01 eV for cis-PA, rationalizing the higher conductivity of the trans-isomer. A novel nonlinear extrapolation method was developed to accurately predict the band gap of the infinite polymer from a minimal set of oligomer calculations. Furthermore, we demonstrate a dramatic band gap reduction—up to 97 %—upon p-doping via oxidation or bromination, and n-doping via deprotonation or reduction, confirming the transition to a metal-like state. The insulating nature of polytetrafluoroethylene (PTFE) was concurrently verified. Our findings provide a robust computational framework for screening optimal dopants to maximize PA conductivity.
{"title":"DFT investigation of band gap and conductivity in pristine and doped Polyacetylene oligomers: A new extrapolation approach","authors":"Igor S. Kovalev , Alexander S. Novikov , Grigory V. Zyryanov","doi":"10.1016/j.chemphys.2025.113004","DOIUrl":"10.1016/j.chemphys.2025.113004","url":null,"abstract":"<div><div>The electronic properties of polyacetylene (PA) isomers and their doped derivatives were investigated using density functional theory (DFT) at the PM3/B3LYP/def2-TZVP level. By studying a series of oligomers with increasing conjugation length, we determined the asymptotic band gaps to be 1.26 eV for <em>trans</em>-PA and 2.01 eV for <em>cis</em>-PA, rationalizing the higher conductivity of the <em>trans</em>-isomer. A novel nonlinear extrapolation method was developed to accurately predict the band gap of the infinite polymer from a minimal set of oligomer calculations. Furthermore, we demonstrate a dramatic band gap reduction—up to 97 %—upon p-doping via oxidation or bromination, and n-doping via deprotonation or reduction, confirming the transition to a metal-like state. The insulating nature of polytetrafluoroethylene (PTFE) was concurrently verified. Our findings provide a robust computational framework for screening optimal dopants to maximize PA conductivity.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 113004"},"PeriodicalIF":2.4,"publicationDate":"2025-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145425054","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}
The host-guest chemistry of cucurbit[7]uril with toxic G-series chemical warfare agents (CWAs), including Tabun, Sarin, and Cyclosarin is discussed in this study to investigate sensing potential of CB[7] for these CWA’s. Thermodynamic stability of these complexes ranges from −37.54 to −47.55 kcal/mol, with cyclosarin (GF) displaying the most favorable binding with CB[7]. These interactions of cyclosarin with CB[7] are also supported by NCI/RDG, QTAIM, and EDA analyses. NBO analysis indicates that GB@CB[7] has the highest charge transfer (−0.997 e-) compared to GA@CB[7] and GF@CB[7], which is further supported by the electron density difference analysis. The significant reduction in the energy gap of GF@CB[7] (1.08 eV), as compared to the bare CB[7] surface, enhances the conductivity and selectivity of CB[7] for cyclosarin. The results of current research will be of great value to the experimental researchers, and will help them to develop new sensors to identify toxic substances.
{"title":"Host-guest combination of chemical warfare agents with cucurbit[7]Uril: a theoretical investigation","authors":"Areeg Sajjad , Abdualziz Alsharif , Sehrish Sarfaraz , Mubeen Naz , Muhammad Yar , Khurshid Ayub , Mohamed Mohamed Soliman , Ahmed Gaber","doi":"10.1016/j.chemphys.2025.112998","DOIUrl":"10.1016/j.chemphys.2025.112998","url":null,"abstract":"<div><div>The host-guest chemistry of cucurbit[7]uril with toxic G-series chemical warfare agents (CWAs), including Tabun, Sarin, and Cyclosarin is discussed in this study to investigate sensing potential of CB[7] for these CWA’s. Thermodynamic stability of these complexes ranges from −37.54 to −47.55 kcal/mol, with cyclosarin (GF) displaying the most favorable binding with CB[7]. These interactions of cyclosarin with CB[7] are also supported by NCI/RDG, QTAIM, and EDA analyses. NBO analysis indicates that GB@CB[7] has the highest charge transfer (−0.997 e<sup>-</sup>) compared to GA@CB[7] and GF@CB[7], which is further supported by the electron density difference analysis. The significant reduction in the energy gap of GF@CB[7] (1.08 eV), as compared to the bare CB[7] surface, enhances the conductivity and selectivity of CB[7] for cyclosarin. The results of current research will be of great value to the experimental researchers, and will help them to develop new sensors to identify toxic substances.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 112998"},"PeriodicalIF":2.4,"publicationDate":"2025-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145425052","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}
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