Physical Chemistry Chemical Physics最新文献

{"title":"Peroxymonosulfate activated M-MOF-74 (M = Co, Fe, Ni) visible light photocatalysts for methylene blue degradation enhancement","authors":"Jiaqi Li, Yidan Zhang, Pingyu Luo, Chun Li, Fanming Zeng, Tiantian Sun, Hanhui Lei, Xiaoteng Liu, Chunbo Liu","doi":"10.1039/d5cp00544b","DOIUrl":"https://doi.org/10.1039/d5cp00544b","url":null,"abstract":"Persulphate-based advanced oxidation technology efficiently and cost-effectively removes organic dyes from water but designing stable photocatalytic systems and understanding their reaction mechanisms remain key challenges. Metal–organic frameworks (MOFs) have attracted considerable research attention for degrading organic pollutants owing to their high porosity, tunable structure, and ease of modification. In this study, a series of M-MOF-74 (M = Co, Fe, Ni) photocatalysts are synthesized by a hydrothermal method for methylene blue (MB) degradation. Among them, the Co-MOF-74 photocatalytic synergetic peroxymonosulfate system exhibits high catalytic activity after 30 min of visible light irradiation. MB degradation efficiency reaches 94.8%, and the reaction rate constant is 0.210 min<small>⁻¹</small>, which is approximately 19.44 times higher than the reaction rate constant of the original Co-MOF-74. Compared with Fe-MOF-74 and Ni-MOF-74, Co-MOF-74 exhibits better photocatalytic performance due to the dynamic changes in the valence state of cobalt, which more effectively facilitate the activation of PMS. In addition, this study analyses the possible degradation pathways of MB in water and toxicological evaluations of intermediate products, providing new insights for the effective removal of dyes in water.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"143 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143910109","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":"A computational study on the photophysics of methylpheophorbide a","authors":"Hernán Rueda Bueno, Julio R. Pinzón, Martha C. Daza, Markus Doerr","doi":"10.1039/d4cp04829f","DOIUrl":"https://doi.org/10.1039/d4cp04829f","url":null,"abstract":"Pheophorbide a is a dephytylation and demetallation product of chlorophyll a isolated from plants and algae. Pheophorbide a has been used as a photosensitizer to treat microbes, cancer and multidrug resistance. Methylpheophorbide a (MPh) or its methyl ester is another photosensitizer with interesting photophysical properties such as stronger absorption at longer wavelengths compared to the absorption of porphyrins and a high singlet oxygen production quantum yield (<em>Φ</em><small>_Δ</small> = 0.62). To gain deeper insight into the photophysics of MPh, a computational protocol was employed that allows the elucidation of the photophysical properties of methylpheophorbide a (MPh). This protocol uses Fermi's golden rule within a path integral formalism. Time-dependent density functional theory (TD-DFT) calculations at the CAM-B3LYP/def2-SVP(C-PCM) level of theory were performed. Our calculations reproduce acceptably well the vibronic structure of the Q-band of the absorption spectrum of MPh. After photoexcitation, MPh can decay to the ground state <em>via</em> fluorescence or it can undergo intersystem crossing. Three triplet excited states (T<small>₁</small>, T<small>₂</small> and T<small>₃</small>) are found below the S<small>₁</small> state with an overall spin-vibronic ISC rate constant of 6.14 × 10<small>⁷</small> s<small>⁻¹</small>, in good agreement with the experimental value of 7.90 × 10<small>⁷</small> s<small>⁻¹</small>. The calculated fluorescence rate is approximately five times higher than the experimental value, which can be attributed to an overestimation of the adiabatic energy of the S<small>₁</small> state and to the inherent limitations of the approach employed. Consistent with the experimentally observed behavior, our calculations predict that MPh is not phosphorescent.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"56 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143910110","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":"Proton transfer kinetics modulated by single-residue substitution in photobasic FR-1V/hCRABPII","authors":"Jiajia Meng, Gaoshang Li, Xiaolu Bai, Siteng Zhao, Jin Dai, Yin Song, Xubiao Peng, Qing Zhao","doi":"10.1039/d5cp00710k","DOIUrl":"https://doi.org/10.1039/d5cp00710k","url":null,"abstract":"Fluorescent proteins with large Stokes shifts have become indispensable in biological imaging due to their improved signal-to-noise ratio and reduced self-absorption. While traditional photoacid systems have optimization limitations, photobasic fluorescent proteins provide a promising alternative <em>via</em> novel excited-state proton transfer (ESPT) mechanisms. We study how single amino acid variations affect the photophysical properties of FR-1V/hCRABPII <em>via</em> microenvironment regulation. We used femtosecond time-resolved transient absorption spectroscopy (fs-TA) to compare two mutants: M3/FR-1V (K40E) and M15/FR-1V (K40H). M3/FR-1V demonstrated multi-component dynamics, including rapid ESPT and subsequent conformational relaxation, resulting in efficient fluorescence channels. In contrast, M15/FR-1V exhibits rapid excited-state decay, slower ESPT, and enhanced nonradiative deactivation. Global fitting analysis identified two competitive transfer channels: a favorable conformation that promotes protonated Schiff base formation and radiative transition, and an unfavorable conformation that inhibits proton transfer and non-radiative relaxation. This study offers new molecularlevel insights into the amino acid regulation of ESPT networks in photobasic fluorescent proteins, laying the groundwork for the rational design of next-generation fluorescent imaging tools.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"99 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143910111","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":"Applications of the density functional method combined with the electron-positron correlation-polarization potential to positron binding to hydrocarbons and water clusters","authors":"Daisuke Yoshida, Toshiyuki Takayanagi, Yukiumi Kita, Tomomi Shimazaki, Masanori Tachikawa","doi":"10.1039/d5cp00893j","DOIUrl":"https://doi.org/10.1039/d5cp00893j","url":null,"abstract":"We present benchmark calculations using the electron-positron correlation-polarization potential (CPP) method with the atomic polarizability model to evaluate the positron affinities of key categories of polyatomic hydrocarbons and water microclusters. The universal model parameter of the generalized gradient approximation for CPP is optimized based on the experimentally measured positron affinities of the representative hydrocarbon molecules. Using this method, the positron affinities and positron binding features of water clusters up to the hexamer are investigated. The present CPP calculations revealed reasonable size-dependence on positron binding energies and conformer-dependent properties for each cluster size for these water clusters. The bound positrons are also trapped internally within cavities of the three-dimensional water clusters, similar to the behavior of bound excess electrons in water cluster anions. However, since the positronic binding energies are smaller than the electronic binding energies in water cluster anions, the bound positrons exhibit delocalized features extending into the electronegative oxygen atoms of the water molecules acting as the multiple hydrogen donor. Such behavior differs from the water cluster anions, resulting in isomeric conformational dependence.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"19 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143910115","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":"Predicting a new class of diamond-supported transition-metal single-atom catalysts for hydrogen evolution","authors":"Sheng Qin, Ke Ding, Kaiye Zheng, Bifa Ji, Yongping Zheng, Yongbing Tang","doi":"10.1039/d5cp00870k","DOIUrl":"https://doi.org/10.1039/d5cp00870k","url":null,"abstract":"Carbon materials containing sp<small>²</small> C have been widely discussed as single-atom catalyst supports while diamond with pure sp<small>³</small> C has not been studied as supports yet. Here we performed density functional theory (DFT) calculations to screen a group of diamond-supported transition-metal single-atom catalysts for the hydrogen evolution reaction (HER). We modelled metals supported on a pristine surface and in single-vacancy and double-vacancy forms of diamond (111) and discussed their stability. Cr and Co in the single-vacancy form, as well as Sc, Ti, Cr, Mn, Fe, and Co in the double-vacancy form were predicted to have relatively high HER activity levels.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"47 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143910471","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":"Intramolecular proton bonding in aliphatic dicarboxylate anions: dynamic conformational landscapes and spectral signatures","authors":"Marcos de Lucas, Juan Ramón Avilés Moreno, Giel Berden, Jonathan Martens, Jos Oomens, Francisco Gamez, Bruno Martínez-Haya","doi":"10.1039/d5cp00571j","DOIUrl":"https://doi.org/10.1039/d5cp00571j","url":null,"abstract":"Carboxylate moieties are central to organic chemistry and a main driving force of biomolecular recognition. Their diffuse anionic structure is prone to build proton-mediated supramolecular bonds with a marked delocalization of charge, a chemical motif that is key to processes of proton storage and transfer. We investigate intramolecular proton bonding interactions in benchmark aliphatic dicarboxylate anions of the form HOOC(CH<small>₂</small>)<small>_n-2</small>COO<small>^-</small> (n=4-8), hence succinate, glutarate, adipate, pimelate and suberate. Infrared ion spectroscopy is employed to expose the vibrational fingerprints of the mass-selected anions isolated at room temperature. Ab initio Molecular Dynamics calculations are applied to rationalize the fluxional character of the shared proton and its impact on the cyclic structure adopted by the anion. Our findings indicate that anions with shorter alkyl chains are constrained to symmetrically shared protons in anti-anti configurations of the carboxylate moieties. Longer chain lengths increase the conformational flexibility of the alkyl backbone and stabilize anti-syn configurations with asymmetric proton sharing. As a result, the vibrational spectrum evolves towards progressively more differentiated carboxylic and carboxylate stretching modes. In all systems, the dynamic character of the proton bond can be recognized through a characteristic broad O-H stretching band that narrows down and blue shifts as proton delocalization is reduced in the larger anions.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"12 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143910282","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":"Influence Mechanism of Vacancy Defects Effect on the Intrinsic Electronic Properties of h-BN and the Thermodynamic and Dielectric Properties of h-BN/PI Interface","authors":"Lujia Wang, Guangliang Liu, Wenyu Ye, Jianwen Zhang, Dingyu Bao","doi":"10.1039/d5cp00928f","DOIUrl":"https://doi.org/10.1039/d5cp00928f","url":null,"abstract":"Polyimide (PI), known for its excellent properties, has been widely applied across various fields. However, its thermodynamic and dielectric properties require further enhancement. Hexagonal boron nitride (h-BN) is commonly employed as a nano-modifier to enhance the properties of the PI matrix. However, the vacancy defects in h-BN limit the improvement of the composite's properties. In this study, molecular simulation techniques are utilised to investigate the effects of vacancy defects on the electronic properties of h-BN and the interfacial properties of h-BN/PI composites. The simulation results indicate that as the number of vacancy defects increases, the distortion of the h-BN geometric structure becomes more severe. Among the single-atom vacancy defects, N-atom vacancies exert a more significant impact on the geometrical structure and insulating properties of h-BN. Two defect levels are introduced into the energy band structure of the diatomic vacancy defect model, thereby weakening the insulating performance of h-BN. The band structure of the three-atom vacancy defect model undergoes greater changes, with additional defect levels introduced into the band gap, resulting in reduced insulating performance and a semi-metallic state in h-BN. As the number of vacancy defects increases, the thermal conductivity and mechanical properties of the h-BN/PI interface deteriorate. In contrast, B-atom vacancies have a more pronounced effect on interfacial heat transfer, whereas N-atom vacancies more significantly affect mechanical properties. The free volume fraction of the model increases as the vacancy defect rate rises, leading to an increase in the relative dielectric constant of the h-BN/PI interface. This paper comprehensively examines the effects of vacancy defects on the interfacial properties of h-BN/PI composites, providing a foundation for the application of h-BN as a filler in the functional modification of PI.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"115 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143910283","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":"Mechanism of azeotrope elimination in the ethyl propionate–ethanol system using ionic liquid HMIMOAc as an entrainer: Experimental and theoretical insights","authors":"Shuyan Liu, Xiuyu Du, Kuan Ji, Lili Lv, Yu Zhou","doi":"10.1039/d5cp01219h","DOIUrl":"https://doi.org/10.1039/d5cp01219h","url":null,"abstract":"Ionic liquids (ILs) are highly effective entrainers for extractive distillation of azeotropes, owing to their unique physicochemical properties. However, the intrinsic molecular mechanisms underlying the role of ILs in azeotropic separation process remain insufficiently understood. To investigate the intrinsic causes of the azeotropy elimination by ILs, the study focused on the v(O−D) region of the ethanol employing both experimental and theoretical methods to investigate the microstructural properties of the ethyl propionate (EP)−ethanol azeotrope before and after separation by the 1-hexyl-3-methylimidazole acetate (HMIMOAc). The key findings are as follows: (1) The interaction between HMIMOAc and ethanol issignificantly stronger than that between EP and ethanol. (2) The interaction between [OAc]− in HMIMOAc and ethanol plays a critical role in eliminating the azeotropy. (3) Ethanol self-aggregates, EP−ethanol interaction complexes, and HMIMOAc−ethanol interaction complexes, were identified andcharacterized using excess spectroscopy and quantum chemical calculations.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"73 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143910158","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":"Deciphering the Electronic Structure and Conformational Stability of 2-Pyridinecarboxaldehyde","authors":"Hyojung Kim, Sung Man Park, Chan Ho Kwon","doi":"10.1039/d5cp00792e","DOIUrl":"https://doi.org/10.1039/d5cp00792e","url":null,"abstract":"The conformational structures and ionisation dynamics of 2-pyridinecarboxaldehyde (2-PCA) were explored using high-resolution vacuum ultraviolet mass-analysed threshold ionisation (VUV-MATI) spectroscopy, complemented by Franck–Condon (FC) simulations and quantum chemical calculations. The precise adiabatic ionisation energy of 2-PCA was determined to be 76,589 ± 4 cm⁻¹ (9.4958 ± 0.0005 eV), which is notably lower than the previous values obtained from electron impact ionisation studies. The vibrationally resolved VUV-MATI spectrum of the molecule confirmed that ionisation predominantly originates from its s-trans conformer, with no significant contribution from its s-cis conformer, indicating that the interconversion barrier effectively limits the population of this species under supersonic expansion conditions. Molecular and natural bond orbital analyses revealed that the highest occupied molecular orbital of the s-trans conformer is primarily composed of a nitrogen nonbonding orbital, which interacts with the oxygen lone pairs of the formyl group. This interaction stabilises the electronic structure of the conformer, resulting in an increased ionisation energy compared with pyridine. FC analysis further demonstrated that vibrational excitations in the cationic state are predominantly associated with the in-plane ring and formyl bending modes, producing distinct vibrational progressions in the VUV-MATI spectrum. These findings provide not only valuable insights into the electronic structure, conformational stability, and ionisation dynamics of 2-PCA, but also a deeper understanding of the effect of functional-group substitution in pyridine derivatives. Moreover, the results underscore the effectiveness of VUV-MATI spectroscopy in resolving conformer-specific ionisation processes, paving the way for further investigations into the electronic properties of heterocyclic molecules.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"15 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143910153","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":"Inter and Intra-Stacking Influenced Charge Hoping Interactions in Core-Substituted Squarylium Dye Derivatives: A Computational Investigation","authors":"Rupali Raosaheb Deshmukh, Harshada Anand Barve, Krishna Chaitanya Gunturu","doi":"10.1039/d4cp04570j","DOIUrl":"https://doi.org/10.1039/d4cp04570j","url":null,"abstract":"The stacking arrangement and associated interactions within crystal packing of ten core substituted squaraine (CSQ) dyes that are symmetric dicyanovinyl (DCV) acceptor group functionalized squaraine derivatives with distinct electron rich side donor moieties containing various substituents have been assessed by computational methods. Out of three sets, two are containing indolenine and quinolinium donor moieties as side substitution. In first set, the halogen substituent’s on indolenine donor moieties (such as –Cl, –Br, and –I) exhibit monoclinic polymorphism while –F substituted one is with triclinic polymorphism. Though, triclinic and orthorhombic polymorphs are known for the absence of any substituent. Another group of two CSQ dyes has quinolinium donor units that differ in length of alkyl chain substitution found in monoclinic polymorphism. The next set of CSQ contains monoclinic polymorphism in which one indolenine CSQ contains a chiral center while the other one is with benzothiazole ring. Here, we investigate the impact of DCV acceptor moiety present at the central C4 ring of squaraine dyes along with functionalization of side donor groups on the inter and intra-stacking patterns at crystal packing to establish the charge transfer protocol. Theoretical calculations including geometrical analysis, internal reorganization energy, charge transfer integral, drift mobility and interaction energy along with complete investigation of the Hirshfeld surface analysis have been performed. The distinctive geometrical changes upon electron gain and loss have been observed at different moieties of the respective CSQ i.e. side aromatic rings and central C4 ring respectively. Inter or intra-stack cofacial interactions between side substituted donor rings offer electron transfer character while participation of slip-stacked central C4 rings proportionate hole transfer character in all CSQs. Although much meager participation of DCV group in inter and intra-stacking interactions of all motifs studied, indirect influence is noted through geometrical impacts. Such packing effects give insights into inter- and intra-stack interactions, possibly guiding experimentalists' ideas for shaping and using promising squaraine derivatives in advanced functional materials.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"18 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143910157","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}