Chemical Physics最新文献

{"title":"Investigation of the Structural, Vibrational, Electronic, and optical properties of energetic Nitrogen-Rich azidotetrazolates XCN7 (X = N2H5, NH4, K, Cs)","authors":"Supratik Mukherjee ,&nbsp;G Vaitheeswaran","doi":"10.1016/j.chemphys.2024.112537","DOIUrl":"10.1016/j.chemphys.2024.112537","url":null,"abstract":"<div><div>In this work, we present a detailed and comparative study of four salts of 5-azido-1H-tetrazole using Density Functional Theory (DFT) based computational methods. The salts, containing the <span><math><mrow><mi>C</mi><msubsup><mi>N</mi><mrow><mn>7</mn></mrow><mo>-</mo></msubsup></mrow></math></span> anion, include hydrazinium azidotetrazolate (N₂H₅CN₇), ammonium azidotetrazolate (NH₄CN₇), potassium azidotetrazolate (KCN₇), and cesium azidotetrazolate (CsCN₇). These compounds are collectively represented as XCN₇, where X  = N₂H₅, NH₄, K, and Cs. We found that the incorporation of van der Waals interactions was crucial in aligning the theoretical ground state structures with experimental data. Mechanical stability of all the compounds within their respective space groups was verified by calculating the elastic constants and bulk modulus. Vibrational frequency analysis revealed that N₂H₅CN₇ and NH₄CN₇, containing N<img>H bonds, exhibited frequencies around 3300 cm⁻¹, while the metal salts KCN₇ and CsCN₇, lacking N<img>H bonds, showed frequencies below 2000 cm⁻¹. Born effective charge calculations indicated strong covalency within the tetrazole ring and between C, N, and H atoms, contrasted by the ionic nature of the metal atoms. Using the TB-mBJ potential, we accurately computed the electronic structure and optical properties, predicting bandgaps and absorption edges for these XCN₇ compounds. The partial density of states analysis highlighted the significant role of C and N <em>p</em> states in the sensitivity of these compounds. Optical property evaluations confirmed that these compounds are optically anisotropic, exhibiting low sensitivity in the visible region but high sensitivity in the UV and far UV regions. These insights are crucial for predicting and controlling their reactivity, stability, and performance in various applications, particularly in the field of energetic materials.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"590 ","pages":"Article 112537"},"PeriodicalIF":2.0,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722409","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":"Identifying stable Nb-O clusters using evolutionary algorithm and DFT: A foundation for machine learning potentials","authors":"Ilya S. Popov,&nbsp;Albina A. Valeeva,&nbsp;Andrey N. Enyashin","doi":"10.1016/j.chemphys.2024.112533","DOIUrl":"10.1016/j.chemphys.2024.112533","url":null,"abstract":"<div><div>Crystal structure of the bulk NbO can be described as the NaCl (B1) lattice with equimolar 25 % content of ordered vacancies in both sublattices. While numerous studies have explored the phase stability ranges and crystallography of niobium oxides under various temperatures and pressures, the atomic structure of these compounds as small clusters remains unsolved. Understanding this structure is crucial for investigating the formation and growth of niobium oxide nanoparticles and thin films. In this work, the evolutionary algorithms guided by DFT calculations were employed to identify the most viable structures of Nb_nO_m clusters with indices 1 ≤ n ≤ 6, 0 ≤ m ≤ 6. The indices of clusters with enhanced stability and higher probabilities of formation during stochastic synthesis processes were proposed. Additionally, a machine learning potential for the Nb-O system was derived from the accumulated set of DFT calculations of Nb_nO_m clusters.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"590 ","pages":"Article 112533"},"PeriodicalIF":2.0,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142744520","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":"Electrochemical probing of encapsulation process for polymeric micelles","authors":"João Gabriel da Silva Andrade ,&nbsp;Rafael da Silva ,&nbsp;Fernando Rodrigues de Carvalho","doi":"10.1016/j.chemphys.2024.112534","DOIUrl":"10.1016/j.chemphys.2024.112534","url":null,"abstract":"<div><div>Many of the drugs used in pharmaceutical formulations are not photoactive. Cyclic voltammetry and differential pulse voltammetry can unveil hidden information about the binding mechanism between the host and guest. This work aims to demonstrate that electrochemical techniques can be used to monitor the binding mechanism. The electrochemical reversibility, stability, and the effect of time were investigated. Also, the kinetics parameter, binding constant, and apparent diffusion coefficient were estimated. The reversibility and stability increased when toluidine blue was in the surfactant medium. The effect of time showed that the toluidine blue did not permeate the copolymeric micelles. Although F-127 copolymer is more hydrophilic, the toluidine blue, bonded more effectively in P-123 (<em>K_b</em> = 3,846 L/mol) than in F-127 (<em>K_b</em> = 184 L/mol). The kinetics parameter corroborated with the <em>K_b</em>. The <em>D_app</em> found in P-123 and F-127 micelles followed an unexpected trend, 3.7 and 4.8 μcm² s⁻¹, respectively.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"590 ","pages":"Article 112534"},"PeriodicalIF":2.0,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142744521","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":"Mechanistic insights into the hydrogen evolution reaction catalyzed by ConMoP (n = 1–5) clusters","authors":"Tinghui Wu,&nbsp;Zhigang Fang","doi":"10.1016/j.chemphys.2024.112527","DOIUrl":"10.1016/j.chemphys.2024.112527","url":null,"abstract":"<div><div>To investigate the catalytic activity of Co<em>_n</em>MoP (n = 1–5) clusters with water molecules for hydrogen evolution reaction (HER), a systematic analysis was performed using density functional theory (DFT). Using the B3LYP functional and def2-TZVP basis set, the structures of the clusters with different spin multiplicities were optimized and theoretically calculated using the Gaussian16 software package. To evaluate the catalytic performance of these clusters, we focused on analyzing their HOMO-LUMO energy gaps, Gibbs free energy changes (Δ<em>G</em>), and electron density distributions. The results show that the Δ<em>G</em>_H* value of configuration 1-a is closest to 0, indicating its excellent catalytic performance for HER; additionally, the Co atom was identified as the primary active site. Configuration (5-b)-H_ads exhibited the smallest energy gap, demonstrating the strongest catalytic activity. Configurations 1-a, 2-a, and 5-b were identified as the most promising catalysts in this series of clusters. This study reveals the behavior of transition metal clusters in catalytic reactions and provides a reference for future experimental and theoretical research.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"590 ","pages":"Article 112527"},"PeriodicalIF":2.0,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142744522","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":"Quantum chemical modeling of the structure and stability of hydrated and sulfated stannic acid complexes","authors":"T.S. Zyubina ,&nbsp;A.S. Zyubin ,&nbsp;R.V. Pisarev ,&nbsp;A.V. Pisareva ,&nbsp;Yu.A. Dobrovolsky","doi":"10.1016/j.chemphys.2024.112532","DOIUrl":"10.1016/j.chemphys.2024.112532","url":null,"abstract":"<div><div>Various H₂SnO₃ complexes and their hydrated and sulfated derivatives are calculated within the framework of the cluster approximation with the B3LYP, ωB97XD DFT functionals and the LanL2DZ(Sn), 6-31G**(O,S,H) and DGDZVP basis sets, and taking into account periodic boundary conditions with the PBE functional and the basis of the projector-augmented plane waves PAW. It was found that among the considered hydrated forms, the most energetically preferred are nanostructures in the form of ultrathin bars with a Sn₂O₂ cross section of the composition SnO₂/1.5H₂O and SnO₂/2H₂O. For sulfated complexes, two types of structures can be formed: with H₂SO₄ molecules adsorbed onto the surface of the hydrate shell around SnO₂, and more stable structures with SO₄²⁻ anions directly bound to Sn atoms on the surface of the tin oxide backbone.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"590 ","pages":"Article 112532"},"PeriodicalIF":2.0,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142744518","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 and spectral characterizations of mono-nitrogen doped C70 fullerene by soft X-ray spectroscopy","authors":"Zhi-Ang Jiang,&nbsp;Hai-Bo Li,&nbsp;Hao-Qing Zhu,&nbsp;Yong Ma,&nbsp;Xiu-Neng Song","doi":"10.1016/j.chemphys.2024.112523","DOIUrl":"10.1016/j.chemphys.2024.112523","url":null,"abstract":"<div><div>C70 fullerene and its five mono-nitrogen-doped C69N derivatives were identified by calculated x-ray photoelectron spectroscopy (XPS) and near-edge x-ray absorption fine structure (NEXAFS) spectra on density functional theory (DFT) level. The results show that the NEXAFS spectra are more ideal to identify C69N isomers accurately. Furthermore, the relationship between the spectra and local structures is discussed as well. The analysis of XPS and NEXAFS spectra for C69N isomers can help in understanding the preparation and modification of these materials and providing a theoretical foundation for the development of nitrogen-doped fullerenes.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"590 ","pages":"Article 112523"},"PeriodicalIF":2.0,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701713","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":"The tunable electronic and optical properties of WS2/PtO2 heterojunctions are calculated by first principles","authors":"Weiwei Duan ,&nbsp;Xing Wei ,&nbsp;Kanghao Liang,&nbsp;Yan Zhang,&nbsp;Yun Yang,&nbsp;Jian Liu,&nbsp;Ye Tian,&nbsp;Li Duan","doi":"10.1016/j.chemphys.2024.112524","DOIUrl":"10.1016/j.chemphys.2024.112524","url":null,"abstract":"<div><div>In this paper, the optical and electrical characteristics of WS₂/PtO₂ heterojunction are calculated by first principles method. The results show that WS₂/PtO₂ heterojunction is a semiconductor heterojunction with an indirect bandgap of 0.7 eV and a Type-Ⅱ band distribution, which can achieve rapid division and transport of photogenerated carriers. Its narrow band gap has a unique electronic structure and tunability, which shows great application potential in high-performance optoelectronic devices and solar cells. When we apply biaxial strain and electric field, the WS₂/PtO₂ heterojunction has semiconductor–metal transition. This transformation can be used in electronic devices to regulate the carrier concentration and transport characteristics in electronic devices. It also shows excellent properties in optics. The above shows that the stable structure and tunable electronic properties make WS₂/PtO₂ heterojunctions hold significant promise for future optoelectronic devices and other applications.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"591 ","pages":"Article 112524"},"PeriodicalIF":2.0,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164753","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":"Investigation on the development of Novel PAM structure as high-performance clay inhibitor in HT/HP conditions by using functional groups","authors":"Matamba Musungayi Georges ,&nbsp;Kai Wang ,&nbsp;Jiafang Xu ,&nbsp;Mbombo Musau Christelle ,&nbsp;Wetshondo Osomba Dominique ,&nbsp;Camara Moussa","doi":"10.1016/j.chemphys.2024.112517","DOIUrl":"10.1016/j.chemphys.2024.112517","url":null,"abstract":"<div><div>Polyacrylamide (PAM) molecular structures are not stable at higher temperatures, limiting their effectiveness in water-based drilling fluid (WBDF) applications. This study focuses on identifying functional groups that can enhance the thermal stability of PAM structure. It presents a comprehensive and comparative analysis of the swelling inhibition capacity of both low and high molecular weight (MW) PAM-based polymers at high temperature and high pressure (HT/HP). The mechanism by which modified PAM interacts with and adsorbs to the clay (Na-MMT) surface is examined, along with an analysis of the surface properties of the clay minerals. Therefore, molecular dynamic (MD) simulation results revealed that the Novel PAM polymers with high MW containing ethyl and benzyl groups demonstrate greater stability and more controlled deformation behavior compared to conventional PAM at HT conditions. Surface modification and hydrophobic effects were observed in the interactions between polymers and Na-MMT. Low MW PAM-based polymers showed larger fluctuations in d-spacing, indicating various or more disruptive interactions. In contrast, the insertion of high MW PAM-based polymer resulted in significantly narrower and lower d-spacing fluctuation ranges. The Novel PAM exhibited superior performance, providing lower d-spacing fluctuations compared to both low MW PAM-based polymers and standard PAM. Across a temperature range from 300 to 600°K, the Novel PAM consistently improved polymer adsorption on the Na-MMT surface compared to standard PAM. Indicating that the modifications effectively reduce the interaction between Na-MMT particles and water molecules while enhancing the interaction between the polymer and Na-MMT, potentially leading to more stable structures in HT/HP environments. The enhanced stability suggests that Novel PAM is more suitable for WBDF applications, as it is less prone to structural changes and can maintain its integrity under harsh conditions. The modifications provide the polymer with better resilience, potentially leading to improved performance in practical applications.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"590 ","pages":"Article 112517"},"PeriodicalIF":2.0,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701714","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":"Modulated electronic properties of borophene nanoribbons using copper and oxygen atoms","authors":"Weihua Wang,&nbsp;Junchi Ma,&nbsp;Yuxuan Wang,&nbsp;Fushi Jiang,&nbsp;Kunpeng Zhou,&nbsp;Peifang Li","doi":"10.1016/j.chemphys.2024.112520","DOIUrl":"10.1016/j.chemphys.2024.112520","url":null,"abstract":"<div><div>The electronic and optical properties of borophene nanoribbons, influenced by the adsorption of copper (Cu) and oxygen (O) atoms in various configurations, were studied using first-principles calculations. The findings indicated that the most stable configuration, with the minimum adsorption energy of −9.09 eV, was achieved with double-upper center adsorbed double O atoms. By varying the adsorption positions and the number of Cu and O atoms, borophene nanoribbons were successfully tuned to transform into direct and indirect band-gap semiconductors. In particular, borophene nanoribbons with single and double-upper center adsorbed Cu atoms exhibited direct band gaps of 0.083 eV and 0.185 eV, respectively. In contrast, the double-upper center adsorbed double O atoms configuration resulted in an indirect band gap of 0.039 eV. The results further demonstrated that the Fermi levels crossed into the valence band, displaying p-type degenerate semiconductor characteristics for configurations with single and double-upper center adsorbed Cu atoms as well as double-upper center adsorbed double O atoms.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"590 ","pages":"Article 112520"},"PeriodicalIF":2.0,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701812","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":"Construction of dual-output molecular logic circuit based on bovine serum albumin loaded with two fluorescent compounds","authors":"Yulin Mo ,&nbsp;Shirong Dong ,&nbsp;Haibin Lin","doi":"10.1016/j.chemphys.2024.112531","DOIUrl":"10.1016/j.chemphys.2024.112531","url":null,"abstract":"<div><div>Most fluorescent compounds have only one fluorescence emission peak, it is difficult to directly construct double-output or triple-output molecular logic devices using a single fluorescent compound. Therefore, this paper proposes using bovine serum albumin (BSA) as a carrier to load 5-sulfosalicylic acid and fluorescein isothiocyanate at different sites of BSA to synthesize the L₁/L₂@BSA complex, and based on fluorescence resonance and electron exchange energy transfer (or hybrid FRET-DET) to construct a dual-output molecular logic circuit. This construction of double-output molecular logic devices based on the combination of two fluorescent compounds using BSA as a carrier can not only perform controllable screening and combination according to the requirements of excitation wavelength or emission wavelength, but perhaps also build an ideal research model for exploring the energy transfer mechanism of multi-molecular coupled exciton fields.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"590 ","pages":"Article 112531"},"PeriodicalIF":2.0,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701712","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}