Physical Chemistry Chemical Physics最新文献

{"title":"Study on Thermodynamic Performance of Nano-Silicide Filled Epoxy Resin Composite Materials","authors":"Hang Zhang, Zhijin Zhang, Chao Liu, Xingliang Jiang, Jianlin Hu, Qin Hu","doi":"10.1039/d5cp01471a","DOIUrl":"https://doi.org/10.1039/d5cp01471a","url":null,"abstract":"The performance requirements for epoxy resin (EP) used in ultra-high voltage power systems are becoming increasingly demanding, with frequent incidents of breakdowns occurring. Studies have shown that the incorporation of silicide nanomaterials (SiO2, Si3N4, SiC) into EP composites holds significant potential for enhancing thermodynamic properties. However, there is currently no clear consensus on the specific composition and proportion of these materials for improving the thermodynamic performance of EP. Furthermore, most studies rely on traditional experimental methods, while molecular simulation techniques can predict the properties of EP composites and guide experimental designs, thereby conserving resources. This study presents a molecular simulation of EP composites filled with SiO2, Si3N4, and SiC nanoparticles. The results indicate that the EP/SiC composite exhibits the most stable Mean Square Displacement (MSD), with more compact internal bonding and the highest interfacial binding energy of - 3026 kJ/mol. Compared to EP, the Young’s Modulus of Elasticity (E) of the three composites is improved by approximately 3.24% to 4.10%, the Glass Transition Temperature (Tg) is increased by approximately 10.75% to 12.80%, and the thermal conductivity is reduced by approximately 5.9% to 8.9%. Among the EP/SiO2, EP/Si3N4, and EP/SiC composites, the EP/SiC composite demonstrates superior overall thermodynamic properties. For the composites with 1.5% SiO2, Si3N4, and 1.0%, 1.5%, and 2.0% SiC (wt.%), the 1.5%-EP/SiC shows the best thermodynamic performance. Experimentally, composites with 0.5% SiO2, Si3N4, SiC, and 1.5% SiC were prepared, and their thermodynamic properties were evaluated. The experimental results show that the storage modulus of the different silicide-based composites shows minimal variation, increasing by approximately 11% compared to EP. The Tg is enhanced by 1.6% to 4.7%, and the thermal conductivity ranges from 0.125 to 0.147 W/m·K, which is lower than that of EP (0.164 W/m·K). Compared to 0.5%-EP/SiC, the 1.5%-EP/SiC composite exhibits superior thermodynamic performance, with a 35.0% increase in storage modulus, a 9.8% increase in Tg, and a thermal conductivity of 0.154 W/m·K. The results of this study provide valuable insights for improving the thermodynamic properties of EP.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"50 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144153828","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 Investigation of a Two-Dimensional Magnesium Carbide Monolayer: Tunable Bandgap, Light Carriers, and Strain-Induced Topological and Semiconductor-to-Metal Transitions","authors":"Mosayeb Naseri, Shahram Yalameha, Sergey Gusarov","doi":"10.1039/d5cp00644a","DOIUrl":"https://doi.org/10.1039/d5cp00644a","url":null,"abstract":"In this study, we present a comprehensive theoretical investigation of the strain-dependent elastic, electronic, and optical properties of a novel two-dimensional (2D) magnesium carbide (Mg2C) monolayer using density functional theory. Our calculations confirm the high energetic, dynamic, and mechanical stability of the monolayer, highlighting its robustness and suitability for flexible electronic and nanomechanical applications. The electronic band structure analysis demonstrates that strain engineering significantly modulates the bandgap, with compressive strain reducing it and tensile strain increasing it, making the material highly adaptable for strain-controlled semiconductor devices, photodetectors, and nano-electronic applications. Furthermore, we find that compressive strain induces a topological phase transition, transforming the Mg2C monolayer from a normal insulator to a topological insulator, as evidenced by the band inversion and the emergence of a non-zero ℤ2 invariant. This opens up possibilities for utilizing this material in quantum spintronics and dissipationless electronic devices. The optical properties exhibit substantial strain-induced shifts, with variations in the dielectric function, absorption coefficient, and optical conductivity. Enhanced absorption in the visible to ultraviolet range and tunable optical conductivity suggest potential applications in optoelectronic devices, including photovoltaics, optical modulators, and sensors. The ability to fine-tune the electronic and optical properties through external strain makes this material highly promising for next-generation flexible and tunable optoelectronic technologies. Future experimental studies are encouraged to validate these theoretical predictions and explore real-time mechanical deformation effects, further expanding the potential applications of this intriguing 2D Mg2C monolayer.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"35 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144153831","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":"Photoswitching Dynamics of a Guanidine Anion Receptor","authors":"Yingzhong Ma, Jeffrey Einkauf, Xinyou Ma, Duy-Khoi Dang, Paul Zimmerman, Radu Custelcean, Benjamin Doughty, Vyacheslav Bryantsev","doi":"10.1039/d5cp00233h","DOIUrl":"https://doi.org/10.1039/d5cp00233h","url":null,"abstract":"Photoswitchable molecules involving large-scale structural changes such as <em>E</em>/<em>Z</em> photoisomerization offer remarkable opportunities for light-stimulated catch-and-release chemical separations. While the feasibility of this photochemically driven mechanism has been demonstrated in pioneering studies, the electronic excited-state relaxation processes and its concomitant structural changes of such a functional photoswitcher remains largely unexplored. Here, we investigate an exceptional photoswitchable molecule, 2-pyridyl-diiminoguanidinium (2PyDIG), which exhibits strong and selective anion binding, along with an extraordinary capability for light-induced release of a guest ion. Through time-resolved fluorescence measurements, multireference and time-dependent density functional theory calculations we reveal the dynamics underlying electronic excited state relaxation and photoisomerization central to photoswitching. A very rapid and dominant decay component was found that is consistent with radiationless de-excitation from S<small>₁</small> to S<small>₀</small> through conical intersections. This process competes effectively with the slower photoisomerization process taking place in 94 ps. We further identified the underlying causes through theoretical calculations and potential routes towards improved photoisomerization efficiencies.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"6 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144153824","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":"Machine learning-assisted design of the molecular structure of p-phenylenediamine antioxidants","authors":"Zongya Wu, Shuai Sun, Chaokun Huang, Li Zhou, Yanlong Luo, Xiujuan Wang","doi":"10.1039/d5cp00483g","DOIUrl":"https://doi.org/10.1039/d5cp00483g","url":null,"abstract":"This study employed machine learning to predict the solubility parameter (<em>δ</em>) and bond dissociation energy (BDE) of antioxidant molecules, focusing on <em>p</em>-phenylenediamine derivatives with varying carbon chain lengths, side group positions, and functional groups (–CH<small>₃</small>, –OH, and –NH<small>₂</small>). The multilayer perceptron (MLP) model, enhanced by data augmentation and genetic algorithms, was developed to correlate the “molecular structure–descriptor–target parameter” relationship. The model achieved high prediction accuracy (coefficient of determination &gt;0.86, relative percent difference &gt;2.62). SHapley Additive exPlanations analysis revealed molecular polarity as the key factor influencing antioxidant performance. Molecules with –NH<small>₂</small> side groups exhibited lower BDE values. A <em>p</em>-phenylenediamine derivative with ‘CH<small>₃</small>[CH<small>₂</small>]<small>₁₃</small>CH(NH<small>₂</small>)–’ connected to an aniline group showed optimal properties (Δ<em>δ</em> = 0.02 (J cm<small>⁻³</small>)<small>^0.5</small>, BDE = 289.46 kJ mol<small>⁻¹</small>). Molecular simulations confirmed that the proposed antioxidant has excellent compatibility, anti-migration, and antioxidant activity in triglyceride oil. This study demonstrates the utility of MLP models for designing high-efficiency antioxidants for edible oils.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"43 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144153826","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 in Methylated G–C: Nuclear Quantum Effects and Water-Assisted Hopping","authors":"Juliana Gonçalves de Abrantes, Adam Pestana Motala, Ian Riddlestone, Louie Slocombe, Marco Sacchi","doi":"10.1039/d5cp00854a","DOIUrl":"https://doi.org/10.1039/d5cp00854a","url":null,"abstract":"Methylation of DNA nucleobases is a naturally occurring process in living organisms. Usually, it functions as a gene regulation marker and is connected to inheritable epigenetic effects. However, the methylation of guanine in the O6 position due to external agents disrupts the hydrogen bonding between pairing bases and may have mutagenic effects. In this paper, we use density functional theory (DFT) to investigate the Double Proton Transfer (DPT) between methyl-guanine (mG) and cytosine. We compare the DPT dynamics between mG-C and unmethylated G-C using ab initio nuclear quantum dynamics as implemented in the Nuclear-Electronic Orbital (NEO-DFT) approach, where the protons involved in the transfer are described at the same quantum-mechanical level as the electrons of the system. We find that nuclear quantum effects facilitate the DPT for both systems but increase the rate of point mutations for the canonical base pair G-C more significantly. Noteworthy, when similar calculations are performed in the presence of explicit solvent and strand separation, the DPT mechanism becomes assisted by water, lowering the energy barrier of the reaction.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"97 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144145757","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":"Semicoordinate and Halogen Bonding to Group 10 and Group 8 Metals","authors":"Steve Scheiner","doi":"10.1039/d5cp01662b","DOIUrl":"https://doi.org/10.1039/d5cp01662b","url":null,"abstract":"A series of square planar systems are constructed, placing a Group 10 metal atom at the center, connected to two ditopic ligands by four M-S bonds. DFT calculations show that the metal can form a noncovalent bond with an approaching NH3 ligand, with a strength that varies from 10.8 kcal/mol for Ni, down to 1.8 kcal/mol for Pt. This pattern conforms to the charge on the M which reverses from positive to negative in this same order. A XCCH molecule (X=I,Cl) can approach the metal system in a perpendicular configuration. Although this geometry suggests halogen bonding through electron donation from M to the X σ-hole, detailed scrutiny of the electronic structure shows the strongest element to be noncovalent semicoordinate bonding, involving charge transfer from X lone pairs to M. Other stable configurations place the XCCH unit parallel to the metal system, also held together by a semicoordinate bond. Group 8 metals form a shorter and stronger covalent bond with NH3. While Os forms perpendicular arrangements with XCCH, Fe and Ru do not.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"35 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144145481","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":"How the ionic liquid [C2C1Im][OTf] affects the stability of Pt(111) during potential cycling","authors":"Felix Hilpert, Yunsheng Qiu, Leopold Lahn, Kevin Höllring, Nicola Taccardi, Peter Wasserscheid, Olga Kasian, Ana-Suncana Smith, Karl Mayrhofer, Valentin Briega-Martos, Serhiy Cherevko, Olaf Brummel, Joerg Libuda","doi":"10.1039/d5cp00391a","DOIUrl":"https://doi.org/10.1039/d5cp00391a","url":null,"abstract":"Modifying electrocatalysts with ionic liquids (ILs) not only allows for precise control of selectivity but also often directly impacts the stability of the electrocatalyst. In this work, we study how the IL 1-ethyl-3-methylimidazolium trifluoromethanesulfonate [C<small>₂</small>C<small>₁</small>Im][OTf] influences the electrochemical stability of the Pt(111) surface in acidic electrolyte (0.1 M HClO<small>₄</small>) during oxidation and reduction cycles (ORCs; 0.05 – 1.5 V<small>_RHE</small>). We used complementary electrochemical in-situ methods, namely, cyclic voltammetry (CV), online inductively coupled plasma mass spectrometry (ICP-MS), and electrochemical scanning tunneling microscopy (EC-STM) in combination with an algorithmic pattern recognition approach. In the absence of the IL, Pt(111) dissolves during oxidative cycling via cathodic transient dissolution. In consecutive cycles, small Pt clusters are formed, which grow with increasing cycle number. In the presence of the IL, the dissolution rate increases by a factor of 5 and an additional anodic dissolution pathway occurs. The changes in the dissolution behavior during ORCs, however, have only minor impact on the morphological changes and the adsorption sites formed. We explain latter observation by the dominance of morphological changes due to the formation and reduction of an amorphous oxide layer, as opposed to dissolution and redeposition.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"33 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144145483","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":"Photophysics of Resveratrol Derivatives for Singlet Oxygen Formation","authors":"Mariana Yoshinaga, Josene M Toldo, Willian R. Rocha, Mario Barbatti","doi":"10.1039/d5cp00840a","DOIUrl":"https://doi.org/10.1039/d5cp00840a","url":null,"abstract":"Trans-resveratrol, a naturally occurring antioxidant, undergoes significant pho-tochemical transformations upon UV irradiation, producing photoisomers and derivatives such as cis-resveratrol, 2,4,6-trihydroxy-phenanthrene (THP), and resveratrone. Using quantum chemical methods, we investigated the photo-physical properties of these species, including their absorption spectra, fluores-cence, and intersystem crossing (ISC) rates, to assess their potential for singlet oxygen generation. Our results indicate that while trans- and cis-resveratrol ex-hibit limited ISC, resveratrone and THP exhibit competitive ISC and fluores-cence rates, making them suitable photosensitizers for singlet oxygen produc-tion at the same excitation energy as trans-resveratrol. However, THP is exper-imentally more abundant than resveratrone upon trans-resveratrol excitation and also demonstrates favorable ISC properties, suggesting that it plays a pre-dominant role in singlet oxygen generation. These findings highlight the potential of resveratrone and THP in photodynamic applications, expanding the functional versatility of resveratrol-derived compounds.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"37 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144145753","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 of imide side-chain functionality in the doping characteristics of naphthalenediimide derivatives as electron transport materials","authors":"Wai Kin Yiu, Lewis Mackenzie, Dylan Wilkinson, Marcin Giza, Benjamin Vella, Michele Cariello, Stephen Sproules, Graeme Cooke, Pablo Docampo","doi":"10.1039/d5cp00828j","DOIUrl":"https://doi.org/10.1039/d5cp00828j","url":null,"abstract":"Achieving effective doping in n-type organic molecular charge transport materials is critical for the development of high-performance optoelectronic devices. However, the role of side-chains in doping reactions remains incompletely understood in some systems. This study focuses on naphthalenediimide (<strong>NDI</strong>) derivatives, which offer simple synthetic protocols and potentially lower costs compared to traditional fullerene-derived materials. In particular, we explore two functionalised <strong>NDI</strong> derivatives, comparing one with polar ethylene glycol side-chains (<strong>NDI-G</strong>) to a non-polar variant with branched alkyl side-chains (<strong>NDI-EtHx</strong>). Our results show that the effectiveness and speed of the doping reaction with (4-(1,3-dimethyl-2,3-dihydro-1<em>H</em>-benzoimidazol-2-yl)phenyl)dimethylamine (<strong>N-DMBI)</strong> is much higher with the more polar <strong>NDI-G</strong> derivative. We postulate that this arises partly from the closer interactions between the dopant and the <strong>NDI</strong> molecule, facilitated by the polar glycol side-chains. As a result, thin films reach conductivities exceeding 10<small>⁻²</small> S cm<small>⁻¹</small>. We additionally demonstrate their incorporation into efficient perovskite solar cells, demonstrating the effectiveness of the doping process. We investigate this process with a combination of spectroscopy and density functional theory (DFT) modelling, showing that a complex is likely formed between the resulting <strong>N-DMBI</strong> cation and the <strong>NDI</strong> radical anion which then promotes electron transfer to a neutral <strong>NDI</strong> molecule, thereby generating free charge in the film. These findings underscore the importance of synthetic design on the doping behaviour, with the incorporation of ethylene glycol side-chains emerging as an effective strategy to achieve better electrical conductivity for NDI based systems.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"33 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144145755","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 Spectrum from van der Waals to Donor–Acceptor Bonding","authors":"Daniela Rodrigues Silva, Lucas de Azevedo Santos, Matthijs A.J.G. Koning, Célia Fonseca Guerra, Trevor A. Hamlin","doi":"10.1039/d5cp01533b","DOIUrl":"https://doi.org/10.1039/d5cp01533b","url":null,"abstract":"The chemical bond between halogenated borane Lewis acids and a variety of Lewis bases of varying strength (from strong to weak: NH₃, MeCN, N₂) has been quantum chemically explored using dispersion-corrected relativistic density functional theory (DFT) at ZORA-BLYP-D3(BJ)/TZ2P. We propose a unified picture of chemical bonding that exists on a continuum where weaker van der Waals (commonly referred to as “noncovalent”) interactions at longer distances transition into stronger donor–acceptor (commonly referred to as covalent) complexes at shorter distances. Remarkably, depending on the strength of the Lewis base, an intermediate regime is observed where both van der Waals and donor–acceptor complexes are observed. This study demonstrates that a covalent component is ubiquitous across the bonding spectrum, with the stability of the minima on potential energy surfaces determined by the strength of the Lewis acid-base interaction. We advocate for classifying Lewis pairs as strongly or weakly bonded based on whether their covalent interaction is strong enough to overcome the geometric penalty of bond formation. This work elucidates the fuzzy boundaries within chemical bonding.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"239 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144145754","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}