Giovanni Bressan, Khalid M. Siddiqui, Eleanor K. Ashworth, Pratip Chakraborty, Dipanjan Banerjee, Erico M. Braun, Stephen R. Meech, James N. Bull
Conjugated molecules incorporating the oxindole motif offer a versatile scaffold for designing high-performance, light-responsive materials that exploit photomolecular rotor motion. Violacein, a purple coloured oxindole-based pigment produced by bacterial strains in superglacial Antarctic ice melts, serves as a natural photoprotectant. Using ultrafast spectroscopy combined with explicitly-solvated potential energy surfaces, we characterise the excited-state relaxation mechanism in violacein to involve initial relaxation to planar locally excited (LE) state(s), followed by passage through a twisted charge-transfer (CT) state along the molecular rotor coordinate to a nearby isomerising-like conical intersection seam. Propagation over the excited-state barrier connecting the LE and CT states along the photomolecular rotor axis leads to a strong viscosity dependence of the excited state lifetimes (ca. 4 ps in acetonitrile and 100 ps in ethylene glycol). These dynamics, leading to efficient electronic-to-vibrational energy conversion, coupled with a fast rate for thermal conversion of the possible Z photoisomer back to the starting E isomer, confer violacein with desirable photoprotectant properties.
{"title":"Photomolecular rotor dynamics of the oxindole-based photoprotective bacterial pigment violacein","authors":"Giovanni Bressan, Khalid M. Siddiqui, Eleanor K. Ashworth, Pratip Chakraborty, Dipanjan Banerjee, Erico M. Braun, Stephen R. Meech, James N. Bull","doi":"10.1039/d5cp04151a","DOIUrl":"https://doi.org/10.1039/d5cp04151a","url":null,"abstract":"Conjugated molecules incorporating the oxindole motif offer a versatile scaffold for designing high-performance, light-responsive materials that exploit photomolecular rotor motion. Violacein, a purple coloured oxindole-based pigment produced by bacterial strains in superglacial Antarctic ice melts, serves as a natural photoprotectant. Using ultrafast spectroscopy combined with explicitly-solvated potential energy surfaces, we characterise the excited-state relaxation mechanism in violacein to involve initial relaxation to planar locally excited (LE) state(s), followed by passage through a twisted charge-transfer (CT) state along the molecular rotor coordinate to a nearby isomerising-like conical intersection seam. Propagation over the excited-state barrier connecting the LE and CT states along the photomolecular rotor axis leads to a strong viscosity dependence of the excited state lifetimes (<em>ca.</em> 4 ps in acetonitrile and 100 ps in ethylene glycol). These dynamics, leading to efficient electronic-to-vibrational energy conversion, coupled with a fast rate for thermal conversion of the possible <em>Z</em> photoisomer back to the starting <em>E</em> isomer, confer violacein with desirable photoprotectant properties.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"10 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145729141","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}
Takako Kudo,Katherine N Ferreras,Taiji Nakamura,Akira Imanishi,Ryuta Ikutomo,Mark S Gordon
Alternating Si/C belt-shaped annulenes, H2nSinCn (n = 3, 4, 5, 6, and 10), representing a third class of annulenes beyond the planar and Möbius types, were investigated through quantum chemical calculations. Notably, the Si-C bond length alternation is not observed regardless of the number of π electrons (e.g., 4n or 4n + 2). For the smaller molecules (n = 3 and 4), the belt-shaped isomers were found to be less thermodynamically stable than their planar counterparts, benzene (n = 3) and cyclooctatetraene (n = 4), due to distorted π orbitals and strained ring structures. The quasi-atomic orbital (QUAO) analysis reveals that the planar n = 3 Si/C annulene exhibits delocalized π bonding with weak aromatic stabilization, while its belt-shaped counterpart shows hybridization-induced π localization and antiaromatic character. Both n = 4 systems (planar and belt-shaped) are intrinsically antiaromatic, although geometric distortion in the belt isomer partially alleviates this destabilization. As the ring size increases (n ≥ 5), the Si-C π orbitals become increasingly localized due to geometric constraints, in contrast with the uniform delocalization observed in the all-carbon analog H20C20. Notably, in the larger annulenes (n = 5, 6, and 10), the curvature of the belt structure imposes a ceiling on π conjugation. These results underscore the key role of geometry and QUAO asymmetry in modulating antiaromaticity in Si/C belt systems.
{"title":"Theoretical study of Si/C alternately substituted annulenes with a belt structure.","authors":"Takako Kudo,Katherine N Ferreras,Taiji Nakamura,Akira Imanishi,Ryuta Ikutomo,Mark S Gordon","doi":"10.1039/d5cp03030g","DOIUrl":"https://doi.org/10.1039/d5cp03030g","url":null,"abstract":"Alternating Si/C belt-shaped annulenes, H2nSinCn (n = 3, 4, 5, 6, and 10), representing a third class of annulenes beyond the planar and Möbius types, were investigated through quantum chemical calculations. Notably, the Si-C bond length alternation is not observed regardless of the number of π electrons (e.g., 4n or 4n + 2). For the smaller molecules (n = 3 and 4), the belt-shaped isomers were found to be less thermodynamically stable than their planar counterparts, benzene (n = 3) and cyclooctatetraene (n = 4), due to distorted π orbitals and strained ring structures. The quasi-atomic orbital (QUAO) analysis reveals that the planar n = 3 Si/C annulene exhibits delocalized π bonding with weak aromatic stabilization, while its belt-shaped counterpart shows hybridization-induced π localization and antiaromatic character. Both n = 4 systems (planar and belt-shaped) are intrinsically antiaromatic, although geometric distortion in the belt isomer partially alleviates this destabilization. As the ring size increases (n ≥ 5), the Si-C π orbitals become increasingly localized due to geometric constraints, in contrast with the uniform delocalization observed in the all-carbon analog H20C20. Notably, in the larger annulenes (n = 5, 6, and 10), the curvature of the belt structure imposes a ceiling on π conjugation. These results underscore the key role of geometry and QUAO asymmetry in modulating antiaromaticity in Si/C belt systems.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"14 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145718045","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}
Positron annihilation lifetime spectroscopy (PALS) and broadband dielectric spectroscopy (BDS) have evidenced fundamental change in structural and dynamical properties of room temperature ionic liquid (RTIL or IL) 1-Butyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)-imide ([BmIm][NTf2]) under confinement in SBA-15 nano-pores (average pore size ~5 nm). It is observed that the nano-confinement has transformed the fragility of the IL [BmIm][NTf2] from high to low, resulting in the reduction in ionic conductivity and diffusion coefficient of the ions inside the nano-pores at room temperature. However, in glassy phase (below 200K), an increase in both the ionic conductivity and diffusion coefficient as compared to that in the bulk is observed, which is due to an enhancement in molecular free volume under nano-confinement below 200K with respect to that in bulk. The result of this study is relevant for the fundamental understanding of the intriguing properties of [Bmim][NTf2] (IL) confined inside the nano-pores for their several important applications where they are employed in spatial confinements.
{"title":"Depletion of Liquid Fragility and Enhancement in Ionic Conductivity in the Glassy Phase of [BmIm][NTf2] Ionic Liquid under Nano-confinement: PALS and BDS Investigations","authors":"Shapath Bhandari, Jaideep Mor, Debasis Sen, Jitendra Bahadur, Kanaklata Pandey, Dhanadeep Dutta","doi":"10.1039/d5cp03463a","DOIUrl":"https://doi.org/10.1039/d5cp03463a","url":null,"abstract":"Positron annihilation lifetime spectroscopy (PALS) and broadband dielectric spectroscopy (BDS) have evidenced fundamental change in structural and dynamical properties of room temperature ionic liquid (RTIL or IL) 1-Butyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)-imide ([BmIm][NTf2]) under confinement in SBA-15 nano-pores (average pore size ~5 nm). It is observed that the nano-confinement has transformed the fragility of the IL [BmIm][NTf2] from high to low, resulting in the reduction in ionic conductivity and diffusion coefficient of the ions inside the nano-pores at room temperature. However, in glassy phase (below 200K), an increase in both the ionic conductivity and diffusion coefficient as compared to that in the bulk is observed, which is due to an enhancement in molecular free volume under nano-confinement below 200K with respect to that in bulk. The result of this study is relevant for the fundamental understanding of the intriguing properties of [Bmim][NTf2] (IL) confined inside the nano-pores for their several important applications where they are employed in spatial confinements.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"226 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145729208","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}
Kohei Tada, Kai Matsuyama, Sho Yamaguchi, Ryohei Kishi, Tomoo Mizugaki, Yasutaka Kitagawa
Ni3C exhibits high catalytic activities for hydrogen evolution and hydrogenation reactions; however, the electronic structure of the Ni3C surface has not been sufficiently investigated to clarify the interaction mechanism with H. In this study, we theoretically elucidate the fundamental rules governing the interaction between H atoms and Ni3C surfaces: (1) formal charge and valence of C are -2 and 2, respectively, (2) bonding Ni to C has a formal charge of +2, and (3) the formal valence of Ni 2+ is 2. Resonance structures based on these rules enable an a priori discussion of the geometries, electronic structures, and interactions of Ni3C surfaces with H atoms. Specifically, reconstruction of the Ni3C (113) surface, correlation between Ni-H bonding strength and the number of Ni-C interactions, and heterolytic dissociation of hydrogen have been derived, which are important for understanding Ni3C catalysis. These insights cannot be obtained from the d-band centre theory, nor can they be completely predicted using state-of-the-art machine learning interatomic potentials. This study clearly demonstrates the importance of understanding the degree of metal-carbon covalency for accurately interpreting the catalytic activity of metal carbides.
{"title":"Toward a Deeper Understanding of H-Ni₃C Interactions: Rule-Based Insights","authors":"Kohei Tada, Kai Matsuyama, Sho Yamaguchi, Ryohei Kishi, Tomoo Mizugaki, Yasutaka Kitagawa","doi":"10.1039/d5cp02869h","DOIUrl":"https://doi.org/10.1039/d5cp02869h","url":null,"abstract":"Ni<small><sub>3</sub></small>C exhibits high catalytic activities for hydrogen evolution and hydrogenation reactions; however, the electronic structure of the Ni3C surface has not been sufficiently investigated to clarify the interaction mechanism with H. In this study, we theoretically elucidate the fundamental rules governing the interaction between H atoms and Ni<small><sub>3</sub></small>C surfaces: (1) formal charge and valence of C are -2 and 2, respectively, (2) bonding Ni to C has a formal charge of +2, and (3) the formal valence of Ni 2+ is 2. Resonance structures based on these rules enable an a priori discussion of the geometries, electronic structures, and interactions of Ni<small><sub>3</sub></small>C surfaces with H atoms. Specifically, reconstruction of the Ni<small><sub>3</sub></small>C (113) surface, correlation between Ni-H bonding strength and the number of Ni-C interactions, and heterolytic dissociation of hydrogen have been derived, which are important for understanding Ni<small><sub>3</sub></small>C catalysis. These insights cannot be obtained from the d-band centre theory, nor can they be completely predicted using state-of-the-art machine learning interatomic potentials. This study clearly demonstrates the importance of understanding the degree of metal-carbon covalency for accurately interpreting the catalytic activity of metal carbides.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"36 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145728694","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}
Muhammad Adrian, Kathrin Marina Eckert, M. Raquel Serial, Artyom Tsanda, Lukas Rennpferdt, Stefan Benders, Hoc Khiem Trieu, Tobias Knopp, Irina Smirnova, Alexander Penn
Stimuli-responsive gels demonstrate macroscopic changes upon exposure to external stimuli, offering potential for the development of adaptive chemical reactors. Early investigations into hydrogels established that crosslinked polymer networks experience reversible volume phase transitions, with temperature, pH, and solvent composition governing swelling and shrinking dynamics. Although hydrogels behavior in aqueous environments has been extensively characterized, lyogels that incorporate organic solvents remain comparatively underexplored, despite their potential for enhanced chemical compatibility and functional versatility. Here, we investigate how solvent polarity and crosslinking density govern the swelling behavior, pore formation, and molecular-scale dynamics of poly(N-isopropylacrylamide)-based lyogels. Using a combination of swelling measurement, scanning electron microscopy, and multiscale NMR relaxometry and diffusometry, we demonstrate that solvent polarity fundamentally alters lyogel structure and dynamics. Lyogels swollen in a high-polarity solvent exhibits macroporous networks and slower solvent exchange rates, whereas a low-polarity solvent induces shrinkage, denser microstructures, faster solvent exchange rates, and stronger surface interactions. These results establish a mechanistic framework linking thermodynamic affinity, solvent dynamics, and microstructural confinement to macroscopic gel responsiveness. This framework provides guidance for tailoring lyogels in dynamic environments, with potential applications in adaptable and tunable chemical reactors.
{"title":"NMR relaxometry probes solvent-polarity-dependent molecular interactions in stimuli-responsive lyogels","authors":"Muhammad Adrian, Kathrin Marina Eckert, M. Raquel Serial, Artyom Tsanda, Lukas Rennpferdt, Stefan Benders, Hoc Khiem Trieu, Tobias Knopp, Irina Smirnova, Alexander Penn","doi":"10.1039/d5cp04032a","DOIUrl":"https://doi.org/10.1039/d5cp04032a","url":null,"abstract":"Stimuli-responsive gels demonstrate macroscopic changes upon exposure to external stimuli, offering potential for the development of adaptive chemical reactors. Early investigations into hydrogels established that crosslinked polymer networks experience reversible volume phase transitions, with temperature, pH, and solvent composition governing swelling and shrinking dynamics. Although hydrogels behavior in aqueous environments has been extensively characterized, lyogels that incorporate organic solvents remain comparatively underexplored, despite their potential for enhanced chemical compatibility and functional versatility. Here, we investigate how solvent polarity and crosslinking density govern the swelling behavior, pore formation, and molecular-scale dynamics of poly(N-isopropylacrylamide)-based lyogels. Using a combination of swelling measurement, scanning electron microscopy, and multiscale NMR relaxometry and diffusometry, we demonstrate that solvent polarity fundamentally alters lyogel structure and dynamics. Lyogels swollen in a high-polarity solvent exhibits macroporous networks and slower solvent exchange rates, whereas a low-polarity solvent induces shrinkage, denser microstructures, faster solvent exchange rates, and stronger surface interactions. These results establish a mechanistic framework linking thermodynamic affinity, solvent dynamics, and microstructural confinement to macroscopic gel responsiveness. This framework provides guidance for tailoring lyogels in dynamic environments, with potential applications in adaptable and tunable chemical reactors.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"38 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145728695","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}
We report high-performance organometallic perovskite solar cells (PSCs) utilizing a thermodynamically stable hematite (α-Fe2O3) as an electron transport layer (ETL). The incorporation of an α-Fe2O3 layer could provide suitable energy band alignment with the perovskite, as well as induce a deep valence band maximum, which promotes electron extraction from the conduction band of the perovskite and facilitates hole blocking. Using the solar cell capacitance simulator (SCAPS-1D) software for the optimized PSC under the typical AM 1.5G light spectrum, it was predicted to achieve a competitive power conversion efficiency (PCE) of 25.62% with a high short circuit current (JSC) of 23.58 mA cm-2, an open circuit voltage (VOC) of 1.286 V, and a fill factor (FF) of 84.39%. Moreover, high thermal stability of PSCs with exposure to a high temperature of 85 °C can be attained. Through a series of optimization processes, we conclude that a thinner α-Fe2O3 layer (10 nm) improves charge extraction and the transmittance of the visible light, while the decreased defect density significantly reduces recombination rates, thereby enhancing VOC and PCE. An optimum perovskite thickness of 800 nm was found to maximize light absorption. Additionally, controlled acceptor doping concentration (NA) enhanced carrier extraction and quasi-Fermi level splitting (QFLS), while high series resistance (RS) and low shunt resistance (RSH) were demonstrated to limit FF and efficiency.
我们报道了利用热力学稳定的赤铁矿（α-Fe2O3）作为电子传输层（ETL）的高性能有机金属钙钛矿太阳能电池（PSCs）。α-Fe2O3层的掺入使其与钙钛矿形成合适的能带排列，并诱导出一个较深的价带最大值，促进了钙钛矿导带中电子的提取，有利于空穴的堵塞。利用太阳能电池电容模拟器（SCAPS-1D）软件对优化后的PSC在典型AM 1.5G光谱下的竞争功率转换效率（PCE）为25.62%，高短路电流（JSC）为23.58 mA cm-2，开路电压（VOC）为1.286 V，填充因子（FF）为84.39%。此外，暴露在85°C的高温下，psc具有很高的热稳定性。通过一系列的优化过程，我们发现α-Fe2O3层厚度越薄（10 nm），电荷萃取率和可见光透过率越高，缺陷密度越低，复合率越低，VOC和PCE越高，钙钛矿层厚度为800 nm时，光吸收效果越好。此外，受控受体掺杂浓度（NA）增强了载流子提取和准费米能级分裂（QFLS），而高串联电阻（RS）和低分流电阻（RSH）被证明限制了FF和效率。
{"title":"High-performance hematite-integrated perovskite solar cells.","authors":"Mustafa Kareem, Ethar Yahya Salih, Malatesh Akkur, Satish Kumar Samal, Sridharan Sundharam, Sanjeev Kumar","doi":"10.1039/d5cp04354a","DOIUrl":"https://doi.org/10.1039/d5cp04354a","url":null,"abstract":"<p><p>We report high-performance organometallic perovskite solar cells (PSCs) utilizing a thermodynamically stable hematite (α-Fe<sub>2</sub>O<sub>3</sub>) as an electron transport layer (ETL). The incorporation of an α-Fe<sub>2</sub>O<sub>3</sub> layer could provide suitable energy band alignment with the perovskite, as well as induce a deep valence band maximum, which promotes electron extraction from the conduction band of the perovskite and facilitates hole blocking. Using the solar cell capacitance simulator (SCAPS-1D) software for the optimized PSC under the typical AM 1.5G light spectrum, it was predicted to achieve a competitive power conversion efficiency (PCE) of 25.62% with a high short circuit current (<i>J</i><sub>SC</sub>) of 23.58 mA cm<sup>-2</sup>, an open circuit voltage (<i>V</i><sub>OC</sub>) of 1.286 V, and a fill factor (FF) of 84.39%. Moreover, high thermal stability of PSCs with exposure to a high temperature of 85 °C can be attained. Through a series of optimization processes, we conclude that a thinner α-Fe<sub>2</sub>O<sub>3</sub> layer (10 nm) improves charge extraction and the transmittance of the visible light, while the decreased defect density significantly reduces recombination rates, thereby enhancing <i>V</i><sub>OC</sub> and PCE. An optimum perovskite thickness of 800 nm was found to maximize light absorption. Additionally, controlled acceptor doping concentration (<i>N</i><sub>A</sub>) enhanced carrier extraction and quasi-Fermi level splitting (QFLS), while high series resistance (<i>R</i><sub>S</sub>) and low shunt resistance (<i>R</i><sub>SH</sub>) were demonstrated to limit FF and efficiency.</p>","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145712672","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}
Shiyang Ye, Keyi Pang, Yi Liang, Yuhe Bi, Zhengtuan Chen, Chenglin Lai, Yusheng Song, Jialong Zhao, Sheng Cao
ZnSeTe alloy quantum dots (QDs) have emerged as promising Cd- and Pb-free emissive materials for quantum dot light-emitting diodes (QLEDs), owing to their tunable optical properties, environmental friendliness, and potential to rival traditional cadmium-based systems. Since QLED performance critically depends on the optical quality of QDs and interfacial engineering, controlling surface defects, achieving compositional uniformity, and optimizing core-shell architectures have become central strategies. In this Perspective, we review recent advances in ZnSeTe QDs across the full visible spectrum. We first introduce the fundamental properties and synthesis strategies of ZnSeTe alloys, followed by discussion of blue-emitting QDs, where defect passivation and shell engineering have enabled high photoluminescence quantum yields (PL QYs) and QLEDs with external quantum efficiencies (EQEs) exceeding 20%. We then highlight green-emitting QDs, in which lattice mismatch mitigation and interfacial optimization have produced PL QYs above 90% and QLEDs with EQEs over 21%. The challenges of achieving stable red emission are also addressed, particularly those arising from Te precursor reactivity and spectral instability. Finally, we outline the remaining obstacles for the strict synthesis conditions, stability issues, and emission mechanisms of ZnSeTe QDs. This Perspective offers insights into the development of ZnSeTe QDs as environmentally sustainable materials for next-generation QLED applications.
{"title":"Emerging ZnSeTe Quantum Dots as the Sustainable Solution for High-Performance Full-Color QLEDs","authors":"Shiyang Ye, Keyi Pang, Yi Liang, Yuhe Bi, Zhengtuan Chen, Chenglin Lai, Yusheng Song, Jialong Zhao, Sheng Cao","doi":"10.1039/d5cp03540f","DOIUrl":"https://doi.org/10.1039/d5cp03540f","url":null,"abstract":"ZnSeTe alloy quantum dots (QDs) have emerged as promising Cd- and Pb-free emissive materials for quantum dot light-emitting diodes (QLEDs), owing to their tunable optical properties, environmental friendliness, and potential to rival traditional cadmium-based systems. Since QLED performance critically depends on the optical quality of QDs and interfacial engineering, controlling surface defects, achieving compositional uniformity, and optimizing core-shell architectures have become central strategies. In this Perspective, we review recent advances in ZnSeTe QDs across the full visible spectrum. We first introduce the fundamental properties and synthesis strategies of ZnSeTe alloys, followed by discussion of blue-emitting QDs, where defect passivation and shell engineering have enabled high photoluminescence quantum yields (PL QYs) and QLEDs with external quantum efficiencies (EQEs) exceeding 20%. We then highlight green-emitting QDs, in which lattice mismatch mitigation and interfacial optimization have produced PL QYs above 90% and QLEDs with EQEs over 21%. The challenges of achieving stable red emission are also addressed, particularly those arising from Te precursor reactivity and spectral instability. Finally, we outline the remaining obstacles for the strict synthesis conditions, stability issues, and emission mechanisms of ZnSeTe QDs. This Perspective offers insights into the development of ZnSeTe QDs as environmentally sustainable materials for next-generation QLED applications.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"15 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145728696","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}
Torquoselectivity in the electrocyclic ring-opening of perfluoro-3,4-dimethylcyclobutene is investigated through electron density-based approaches, including DFT, QTAIM, and stress tensor analysis. The study examines electronic redistribution and bonding patterns along the reaction pathway to elucidate and predict atypical stereochemical outcomes, such as the formation of the Z,Z isomer, with the aim of enhancing stereocontrol beyond the scope of traditional orbital-based models. A previously developed model based on Sanderson's electronegativity equalization principle is employed to compute the local reactivity indices. To identify the local contributions most relevant to the global properties, multiple regression analysis is applied. This approach allowed us to establish meaningful correlations between global and local descriptors, offering a deeper insight into the reactivity patterns observed in the studied reactions. Alongside, information-theoretic descriptors are employed to uncover the electronic structure basis of reaction pathway selectivity and molecular stability.
{"title":"Unraveling unusual torquoselectivity in ring-opening electrocyclic reactions: a DFT perspective.","authors":"Arpita Poddar,Jesús Sánchez-Márquez,Alejandro Morales-Bayuelo,Pratim Kumar Chattaraj","doi":"10.1039/d5cp04207k","DOIUrl":"https://doi.org/10.1039/d5cp04207k","url":null,"abstract":"Torquoselectivity in the electrocyclic ring-opening of perfluoro-3,4-dimethylcyclobutene is investigated through electron density-based approaches, including DFT, QTAIM, and stress tensor analysis. The study examines electronic redistribution and bonding patterns along the reaction pathway to elucidate and predict atypical stereochemical outcomes, such as the formation of the Z,Z isomer, with the aim of enhancing stereocontrol beyond the scope of traditional orbital-based models. A previously developed model based on Sanderson's electronegativity equalization principle is employed to compute the local reactivity indices. To identify the local contributions most relevant to the global properties, multiple regression analysis is applied. This approach allowed us to establish meaningful correlations between global and local descriptors, offering a deeper insight into the reactivity patterns observed in the studied reactions. Alongside, information-theoretic descriptors are employed to uncover the electronic structure basis of reaction pathway selectivity and molecular stability.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"29 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145710882","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}
Design and implementation of high-performance thermoelectric (TE) devices pose significant challenges from both theoretical and experimental perspectives. Utilizing experimentally synthesized eight-carbon-wide armchair graphene nanoribbons with built-in periodic divacancies (DV8-aGNR), we address these challenges with three effective strategies: periodic pores, nonplanarity, and vertical junctions, all with the goal of minimizing phonon thermal conductivity and achieving a high figure of merit ZT. Through the first-principles calculation, we firstly study the TE performance of DV8-aGNR revealing that the periodic divacancies and nonplanarity characteristics can effectively reduce phonon thermal conductivity while enhancing electric conductance. A maximum ZT value of 0.64 at room temperature and 0.87 at 500 K in DV8-aGNR is 337% and 414% times that of the armchair graphene nanoribbon with the same width. Then the proposed van-der Waals junction further restricts phonon transmission and exhibits improved TE properties, with ZT values rising to 1.70 and 1.97 at 300 and 500 K, respectively. The enhancement of ZT observed in DV8-aGNR and its vertical junction underscores the potential of our strategies for developing carbon-based TE devices with high performance.
{"title":"High thermoelectric figure of merit in nonplanar graphene nanoribbons with periodic divacancies","authors":"Jianing Wang, Jie Meng, Weiyi Wang, Qunxiang Li","doi":"10.1039/d5cp02340h","DOIUrl":"https://doi.org/10.1039/d5cp02340h","url":null,"abstract":"Design and implementation of high-performance thermoelectric (TE) devices pose significant challenges from both theoretical and experimental perspectives. Utilizing experimentally synthesized eight-carbon-wide armchair graphene nanoribbons with built-in periodic divacancies (DV8-aGNR), we address these challenges with three effective strategies: periodic pores, nonplanarity, and vertical junctions, all with the goal of minimizing phonon thermal conductivity and achieving a high figure of merit ZT. Through the first-principles calculation, we firstly study the TE performance of DV8-aGNR revealing that the periodic divacancies and nonplanarity characteristics can effectively reduce phonon thermal conductivity while enhancing electric conductance. A maximum ZT value of 0.64 at room temperature and 0.87 at 500 K in DV8-aGNR is 337% and 414% times that of the armchair graphene nanoribbon with the same width. Then the proposed van-der Waals junction further restricts phonon transmission and exhibits improved TE properties, with ZT values rising to 1.70 and 1.97 at 300 and 500 K, respectively. The enhancement of ZT observed in DV8-aGNR and its vertical junction underscores the potential of our strategies for developing carbon-based TE devices with high performance.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"148 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753208","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}
Reductive dehalogenases in organohalide-respiring bacteria underpin anaerobic bioremediation of chlorinated pollutants but rarely effective for reductive defluorination of per- and polyfluoroalkyl substances. However, the physicochemical basis for this selectivity remains unclear. Here, we integrate quantum chemistry and molecular dynamics to evaluate constraints on microbial reductive defluorination. The scarcity of naturally occurring organofluorine has imposed limited evolutionary selective pressure, explaining the absence of robust defluorination pathways. Using quantum mechanical calculation, we show that organoflurines have low bioavailability, due to increasingly unfavorable solvation free energies for fluorinated ethenes in both polar and nonpolar solvents, impeding cellular uptake. Using molecular dynamics simulation, we show that the substrate recognition by reductive dehalogenase is compromised, due to progressively weaker van der Waals energies as chlorines are replaced by fluorines. Tetrafluorinated ligand can form hydrogen bonds with polar residues and preferentially stabilised in a sub-pocket away from the catalytic site. Using quantum mechanics calculation with a cluster model of the active site, we show that the reductive cleavage of C–F bond has prohibitively high energy barriers. Together, these results explain the limited anaerobic microbial reductive defluorination of linear per- and polyfluoroalkyl substances and highlight why engineering applications are unlikely to succeed. The workflow provides a screening framework for assessing biodegradability of new organofluorines prior to industrial deployment.
{"title":"From bioavailability scarcity to energy barriers: limitations of anaerobic microbial reductive defluorination","authors":"Yi Ren, Wen-Hao Deng, Mike Manefield","doi":"10.1039/d5cp03866a","DOIUrl":"https://doi.org/10.1039/d5cp03866a","url":null,"abstract":"Reductive dehalogenases in organohalide-respiring bacteria underpin anaerobic bioremediation of chlorinated pollutants but rarely effective for reductive defluorination of per- and polyfluoroalkyl substances. However, the physicochemical basis for this selectivity remains unclear. Here, we integrate quantum chemistry and molecular dynamics to evaluate constraints on microbial reductive defluorination. The scarcity of naturally occurring organofluorine has imposed limited evolutionary selective pressure, explaining the absence of robust defluorination pathways. Using quantum mechanical calculation, we show that organoflurines have low bioavailability, due to increasingly unfavorable solvation free energies for fluorinated ethenes in both polar and nonpolar solvents, impeding cellular uptake. Using molecular dynamics simulation, we show that the substrate recognition by reductive dehalogenase is compromised, due to progressively weaker van der Waals energies as chlorines are replaced by fluorines. Tetrafluorinated ligand can form hydrogen bonds with polar residues and preferentially stabilised in a sub-pocket away from the catalytic site. Using quantum mechanics calculation with a cluster model of the active site, we show that the reductive cleavage of C–F bond has prohibitively high energy barriers. Together, these results explain the limited anaerobic microbial reductive defluorination of linear per- and polyfluoroalkyl substances and highlight why engineering applications are unlikely to succeed. The workflow provides a screening framework for assessing biodegradability of new organofluorines prior to industrial deployment.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"46 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753210","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：