Pub Date : 2026-02-06DOI: 10.1021/acs.jpclett.5c03723
Shelby T. Davis, Daniel Gibney, Jan-Niklas Boyn
Iron–sulfur (Fe–S) clusters are ubiquitous cofactors known to perform critical biological functions like multielectron transfer and redox catalysis within complex enzymatic frameworks, making them promising targets for the rational design of modular, bioinspired catalysts and materials. Advancements have been made toward establishing structure–function-activity relationships through synthesis and structural characterization of biomimetic Fe–S clusters. However, their conformational plasticity and multiconfigurational character pose significant challenges in capturing the underlying electronic structure. The treatment of both strong and dynamic correlation effects is integral in bridging the gap between electronic and physical structure to rationalize metallocluster reactivity. Here, we employ a computationally tractable, multireference methodology that captures both strong and dynamic correlation effects to simulate a series of chemically and electronically diverse, site-differentiated [4Fe-4S]+ clusters, elucidating the effects of cooperative electron correlation and primary coordination sphere modification on electron and spin (de)localization, geometric isomerism, and chemical reactivity.
{"title":"Disentangling Cooperative Electron Correlation and Primary Coordination Sphere Effects in [4Fe-4S]+ Structural Isomerism and π-Acid Activation","authors":"Shelby T. Davis, Daniel Gibney, Jan-Niklas Boyn","doi":"10.1021/acs.jpclett.5c03723","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c03723","url":null,"abstract":"Iron–sulfur (Fe–S) clusters are ubiquitous cofactors known to perform critical biological functions like multielectron transfer and redox catalysis within complex enzymatic frameworks, making them promising targets for the rational design of modular, bioinspired catalysts and materials. Advancements have been made toward establishing structure–function-activity relationships through synthesis and structural characterization of biomimetic Fe–S clusters. However, their conformational plasticity and multiconfigurational character pose significant challenges in capturing the underlying electronic structure. The treatment of both strong and dynamic correlation effects is integral in bridging the gap between electronic and physical structure to rationalize metallocluster reactivity. Here, we employ a computationally tractable, multireference methodology that captures both strong and dynamic correlation effects to simulate a series of chemically and electronically diverse, site-differentiated [4Fe-4S]<sup>+</sup> clusters, elucidating the effects of cooperative electron correlation and primary coordination sphere modification on electron and spin (de)localization, geometric isomerism, and chemical reactivity.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"12 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-06DOI: 10.1021/acs.jpclett.5c03885
Chamathka Dehiwala Liyanage, Anietie W. Williams, Qiaoling Fan, Mariya Aleksich, Thilini M. Dinamithra, Brian G. Willis, Kerry Gilmore, J. Nathan Hohman
We introduce the use of scanning tunneling microscopy (STM) on microcrystalline metal–organic chalcogenolates (MOChas). We demonstrate the suitability of these compounds as STM substrates directly after drop casting onto graphitic surfaces, followed by chemical treatment. We successfully imaged 1-dimensional (1D) silver(I) methyl 2-mercaptobenzoate (2MMB) and the archetypical 2-dimensional (2D) MOCha, silver(I) benzeneselenolate (mithrene). The resolution afforded by STM was used to make new insights into the surface chemistry and displacement reactions. We observed the annealing and displacement reactions of mithrene and 2MMB and the transformation of the former into 2D silver(I) n-nonaneselenolate. MOCha crystals are amenable to STM imaging directly as-prepared from powders, despite the presence of its insulating organic units. We observed defects, crystal growth dynamics, and the formation of grains and superstructures. Visualizing such topographical heterogeneities could prove vital for understanding bulk functionality in this optoelectronic material class.
{"title":"Ambient Tunneling Microscopy of Surface Annealing and Ligand Exchange Reactions on Metal–Organic Chalcogenolates","authors":"Chamathka Dehiwala Liyanage, Anietie W. Williams, Qiaoling Fan, Mariya Aleksich, Thilini M. Dinamithra, Brian G. Willis, Kerry Gilmore, J. Nathan Hohman","doi":"10.1021/acs.jpclett.5c03885","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c03885","url":null,"abstract":"We introduce the use of scanning tunneling microscopy (STM) on microcrystalline metal–organic chalcogenolates (MOChas). We demonstrate the suitability of these compounds as STM substrates directly after drop casting onto graphitic surfaces, followed by chemical treatment. We successfully imaged 1-dimensional (1D) silver(I) methyl 2-mercaptobenzoate (2MMB) and the archetypical 2-dimensional (2D) MOCha, silver(I) benzeneselenolate (mithrene). The resolution afforded by STM was used to make new insights into the surface chemistry and displacement reactions. We observed the annealing and displacement reactions of mithrene and 2MMB and the transformation of the former into 2D silver(I) <i>n</i>-nonaneselenolate. MOCha crystals are amenable to STM imaging directly as-prepared from powders, despite the presence of its insulating organic units. We observed defects, crystal growth dynamics, and the formation of grains and superstructures. Visualizing such topographical heterogeneities could prove vital for understanding bulk functionality in this optoelectronic material class.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"69 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-06DOI: 10.1021/acs.jpclett.5c03908
Yangjun Hou, Xiong Xu, Guangwei Zhai, Chang Niu, Jiaxin Gan, Min Li, Hui Wang
We investigate the magnetic exchange interaction, magnetic anisotropy (MAE), and magnetocaloric effect (MCE) of ternary transition metal chalcogenides A2MX4 (A = Ti or V; M = W or Mo; X = S or Se). We find that Ti2WS4 and Ti2WSe4 exhibit large entropy changes of 5.97 and 5.51 μJ m–2 K–1, respectively, under a magnetic field near room temperature. Analysis based on perturbation theory indicates that strong second-nearest-neighbor exchange coupling plays an important role in MCE, along with a large MAE of ∼10 meV that is attributed to the coupling contributions of dx2–y2 and dz2 orbitals of the W atom. Moreover, strain and carrier doping effectively modulate the MAE and Curie temperature, leading to remarkable enhancement of the MCE. This work provides important insights into the design of two-dimensional materials with enhanced MCE and is expected to facilitate further advancements in room-temperature magnetic refrigeration for practical applications.
研究了三元过渡金属硫族化合物A2MX4 （A = Ti或V； M = W或Mo； X = S或Se）的磁交换相互作用、磁各向异性（MAE）和磁热效应（MCE）。在接近室温的磁场作用下，Ti2WS4和Ti2WSe4的熵变较大，分别为5.97和5.51 μJ m-2 K-1。基于微扰理论的分析表明，强次近邻交换耦合在MCE中起着重要作用，并且W原子的dx2-y2和dz2轨道的耦合贡献使MAE达到了~ 10 meV。此外，应变掺杂和载流子掺杂有效地调节了MCE和居里温度，从而显著提高了MCE。这项工作为增强MCE的二维材料的设计提供了重要的见解，并有望促进室温磁制冷在实际应用中的进一步发展。
{"title":"Giant Room-Temperature Magnetocaloric Effect in Two-Dimensional Ternary Transition Metal Chalcogenides","authors":"Yangjun Hou, Xiong Xu, Guangwei Zhai, Chang Niu, Jiaxin Gan, Min Li, Hui Wang","doi":"10.1021/acs.jpclett.5c03908","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c03908","url":null,"abstract":"We investigate the magnetic exchange interaction, magnetic anisotropy (MAE), and magnetocaloric effect (MCE) of ternary transition metal chalcogenides A<sub>2</sub>MX<sub>4</sub> (A = Ti or V; M = W or Mo; X = S or Se). We find that Ti<sub>2</sub>WS<sub>4</sub> and Ti<sub>2</sub>WSe<sub>4</sub> exhibit large entropy changes of 5.97 and 5.51 μJ m<sup>–2</sup> K<sup>–1</sup>, respectively, under a magnetic field near room temperature. Analysis based on perturbation theory indicates that strong second-nearest-neighbor exchange coupling plays an important role in MCE, along with a large MAE of ∼10 meV that is attributed to the coupling contributions of d<sub><i>x</i><sup>2</sup>–<i>y</i><sup>2</sup></sub> and d<sub><i>z</i><sup>2</sup></sub> orbitals of the W atom. Moreover, strain and carrier doping effectively modulate the MAE and Curie temperature, leading to remarkable enhancement of the MCE. This work provides important insights into the design of two-dimensional materials with enhanced MCE and is expected to facilitate further advancements in room-temperature magnetic refrigeration for practical applications.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"3 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Metal cation and halide anion defects in perovskite films play a pivotal role in determining the performance and stability of perovskite photodetectors. In this study, LiF was utilized as a passivation material, both doped into the perovskite bulk phase and applied as a passivation layer on the top surface of the perovskite film. LiF forms hydrogen bonds and strong ionic interactions with perovskites, effectively passivating lattice and surface defects. Furthermore, as an insulator, LiF suppresses bimolecular and defect-assisted recombination, thereby enhancing carrier mobility and device stability. The optimized LiF-passivated MAPbI3–xBrx perovskite photodetector achieved an external quantum efficiency (EQE) of up to 87.5%, a maximum detectivity of 4.48 × 1013 Jones, and a theoretical linear dynamic range of 157.52 dB. Remarkably, the device retained 82% of its EQE after 2400 h of maximum power point tracking.
{"title":"A Multifunctional LiF as Passivated Material for an Efficient and Stable Perovskite Photodetector","authors":"Lixiang Huang, Jia Yang, Yukun Wang, Guoxin Li, WeiFeng Wu, YeJun Xu","doi":"10.1021/acs.jpclett.5c03764","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c03764","url":null,"abstract":"Metal cation and halide anion defects in perovskite films play a pivotal role in determining the performance and stability of perovskite photodetectors. In this study, LiF was utilized as a passivation material, both doped into the perovskite bulk phase and applied as a passivation layer on the top surface of the perovskite film. LiF forms hydrogen bonds and strong ionic interactions with perovskites, effectively passivating lattice and surface defects. Furthermore, as an insulator, LiF suppresses bimolecular and defect-assisted recombination, thereby enhancing carrier mobility and device stability. The optimized LiF-passivated MAPbI<sub>3–<i>x</i></sub>Br<sub><i>x</i></sub> perovskite photodetector achieved an external quantum efficiency (EQE) of up to 87.5%, a maximum detectivity of 4.48 × 10<sup>13</sup> Jones, and a theoretical linear dynamic range of 157.52 dB. Remarkably, the device retained 82% of its EQE after 2400 h of maximum power point tracking.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"30 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-06DOI: 10.1021/acs.jpclett.5c03875
Zengxi Feng, Wei Wang, Jiming Wang, Xiaoyu Liang, Yi Shi, Min Wang
The reverse water–gas shift (RWGS) reaction is crucial for CO2 utilization toward carbon neutrality. However, its efficiency under mild conditions is limited by low-temperature activity and rapid deactivation from metal sintering in conventional catalysts, including the cost-effective but thermally unstable Cu-based systems. In this work, the introduction of Mn into CuZnAl catalysts was demonstrated to significantly enhance their performance in the low-temperature RWGS reaction by promoting more oxygen vacancy formation. MnCuZnAl-Red catalysts achieve superior 26% CO2 conversion and 98% CO selectivity at 400 °C, with a CO formation rate of 422 mmol gcat–1 h–1. Characterization confirms that Mn enhances CO2 adsorption and activation by generating abundant oxygen vacancies. In-situ Fourier infrared (FT-IR) spectroscopy reveals a surface associative pathway. This work highlights Mn’s role in enhancing RWGS activity through tailored oxygen chemistry.
{"title":"Mn-Promoted CuZnAl Oxide for Enhanced Low-Temperature Reverse Water–Gas Shift Reaction","authors":"Zengxi Feng, Wei Wang, Jiming Wang, Xiaoyu Liang, Yi Shi, Min Wang","doi":"10.1021/acs.jpclett.5c03875","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c03875","url":null,"abstract":"The reverse water–gas shift (RWGS) reaction is crucial for CO<sub>2</sub> utilization toward carbon neutrality. However, its efficiency under mild conditions is limited by low-temperature activity and rapid deactivation from metal sintering in conventional catalysts, including the cost-effective but thermally unstable Cu-based systems. In this work, the introduction of Mn into CuZnAl catalysts was demonstrated to significantly enhance their performance in the low-temperature RWGS reaction by promoting more oxygen vacancy formation. MnCuZnAl-Red catalysts achieve superior 26% CO<sub>2</sub> conversion and 98% CO selectivity at 400 °C, with a CO formation rate of 422 mmol g<sub>cat</sub><sup>–1</sup> h<sup>–1</sup>. Characterization confirms that Mn enhances CO<sub>2</sub> adsorption and activation by generating abundant oxygen vacancies. In-situ Fourier infrared (FT-IR) spectroscopy reveals a surface associative pathway. This work highlights Mn’s role in enhancing RWGS activity through tailored oxygen chemistry.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"3 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-06DOI: 10.1021/acs.jpclett.5c03830
Wenbin Zhang, Ziyang Xia, Cheng Chen, Yaru Gao, Gang Fang, Bin Cai, Ming Cheng
Precise perovskite interface modification is regarded as a highly promising strategy to enhance the performance of efficient perovskite solar cells (PSCs). Herein, star-shaped small-molecule interface passivation material (IPM) TB-CZ (N,N′,N″-((benzene-1,3,5-triyltris(1H-benzo[d]imidazole-2,1-diyl))tris(benzene-4,1-diyl))tris(9-ethyl-N-(9-ethyl-9H-carbazol-3-yl)-9H-carbazol-3-amine)) was designed and synthesized to regulate the perovskite/spiro-OMeTAD interface. The core of TB-CZ is a nitrogen-rich benzimidazole compound in which the C–N and C═N groups can effectively passivate the Pb2+ defects in perovskites through multidentate coordination interactions. The side chain is equipped with a methoxy-free carbazole group, a design that significantly improves the material solubility and thus enhances the quality of perovskite films. The perovskite modified by TB-CZ can effectively optimize its energy levels, promoting hole extraction and transport. Consequently, the TB-CZ-modified PSCs achieve a power conversion efficiency (PCE) of 24.9% at an active area of 0.055 cm2 and maintain a commendable PCE of 22.0% even at an upscaled active area of 1 cm2, thereby showcasing its outstanding performance. Moreover, the modified device demonstrates remarkable long-term stability by retaining 81% of its initial PCE after storage for 1000 h under ambient conditions without any encapsulation. This work provides a strategy for the rational design of star-shaped passivation materials to enhance the PCE and stability of the PSCs.
{"title":"Enhancing Perovskite Solar Cell Performance via Engineering the Hole Transport Interface with Star-Shaped Nitrogen-Rich Material","authors":"Wenbin Zhang, Ziyang Xia, Cheng Chen, Yaru Gao, Gang Fang, Bin Cai, Ming Cheng","doi":"10.1021/acs.jpclett.5c03830","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c03830","url":null,"abstract":"Precise perovskite interface modification is regarded as a highly promising strategy to enhance the performance of efficient perovskite solar cells (PSCs). Herein, star-shaped small-molecule interface passivation material (IPM) TB-CZ (<i>N</i>,<i>N</i>′,<i>N</i>″-((benzene-1,3,5-triyltris(1<i>H</i>-benzo[<i>d</i>]imidazole-2,1-diyl))tris(benzene-4,1-diyl))tris(9-ethyl-<i>N</i>-(9-ethyl-9<i>H</i>-carbazol-3-yl)-9<i>H</i>-carbazol-3-amine)) was designed and synthesized to regulate the perovskite/spiro-OMeTAD interface. The core of TB-CZ is a nitrogen-rich benzimidazole compound in which the C–N and C═N groups can effectively passivate the Pb<sup>2+</sup> defects in perovskites through multidentate coordination interactions. The side chain is equipped with a methoxy-free carbazole group, a design that significantly improves the material solubility and thus enhances the quality of perovskite films. The perovskite modified by TB-CZ can effectively optimize its energy levels, promoting hole extraction and transport. Consequently, the TB-CZ-modified PSCs achieve a power conversion efficiency (PCE) of 24.9% at an active area of 0.055 cm<sup>2</sup> and maintain a commendable PCE of 22.0% even at an upscaled active area of 1 cm<sup>2</sup>, thereby showcasing its outstanding performance. Moreover, the modified device demonstrates remarkable long-term stability by retaining 81% of its initial PCE after storage for 1000 h under ambient conditions without any encapsulation. This work provides a strategy for the rational design of star-shaped passivation materials to enhance the PCE and stability of the PSCs.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"58 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-05DOI: 10.1021/acs.jpclett.5c03952
Tamil Selvan Kannan, Uma Kurakula, Raghavender Medishetty, Goutam Kumar Kole
This study offers a comprehensive structure–property correlation of a novel olefin E-1-(4′-pyridyl)-2-(4″-quinolinyl) ethylene (PQE) and its N-methylated derivative (MPQE) and demonstrates how crystal packing, hydration, and conjugation collectively dictate their solid-state photoreactivity and photochromic, thermosalient, photophysical, and electrochemical properties. PQE exhibited a quantitative [2 + 2] photocycloaddition reaction forming its head-to-tail dimer, which further exhibited a reversible cleavage of the cyclobutane ring. Crystals of PQE exhibited a color change under UV light, indicating photochromic behavior. Two different crystal forms, namely, MPQE and hydrated MPQE·2.25H2O, were obtained by tuning the crystallization medium. Despite having suitable stacking of MPQE cations, MPQE·2.25H2O remained photoinert; however, it exhibited a thermosalient behavior due to dehydration-induced lattice strain. MPQE displayed bathochromic spectral shifts in comparison to neutral PQE, indicating the effect of N-quaternization. The dimer, BPBQCB, displayed hypsochromic and hypochromic spectral shifts compared to PQE, for loss of conjugation. Their redox characteristics have been explored. Such observation of multifunctional behavior is rare and offers potentials for various applications.
{"title":"Photochromic, Thermosalient, Photophysical, and Electrochemical Properties of Pyridyl–Quinolinyl–Ethylene-Derived Multifunctional Organic Materials","authors":"Tamil Selvan Kannan, Uma Kurakula, Raghavender Medishetty, Goutam Kumar Kole","doi":"10.1021/acs.jpclett.5c03952","DOIUrl":"https://doi.org/10.1021/acs.jpclett.5c03952","url":null,"abstract":"This study offers a comprehensive structure–property correlation of a novel olefin <i>E</i>-1-(4′-pyridyl)-2-(4″-quinolinyl) ethylene (<b>PQE</b>) and its <i>N</i>-methylated derivative (<b>MPQE</b>) and demonstrates how crystal packing, hydration, and conjugation collectively dictate their solid-state photoreactivity and photochromic, thermosalient, photophysical, and electrochemical properties. <b>PQE</b> exhibited a quantitative [2 + 2] photocycloaddition reaction forming its <i>head-to-tail</i> dimer, which further exhibited a reversible cleavage of the cyclobutane ring. Crystals of <b>PQE</b> exhibited a color change under UV light, indicating photochromic behavior. Two different crystal forms, namely, <b>MPQE</b> and hydrated <b>MPQE·2.25H</b><sub><b>2</b></sub><b>O</b>, were obtained by tuning the crystallization medium. Despite having suitable stacking of <b>MPQE</b> cations, <b>MPQE·2.25H</b><sub><b>2</b></sub><b>O</b> remained photoinert; however, it exhibited a thermosalient behavior due to dehydration-induced lattice strain. <b>MPQE</b> displayed bathochromic spectral shifts in comparison to neutral <b>PQE</b>, indicating the effect of <i>N</i>-quaternization. The dimer, <b>BPBQCB</b>, displayed hypsochromic and hypochromic spectral shifts compared to <b>PQE</b>, for loss of conjugation. Their redox characteristics have been explored. Such observation of multifunctional behavior is rare and offers potentials for various applications.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"57 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-05DOI: 10.1021/acs.jpclett.6c00010
Oleg V. Boyarkin, Andrei Zviagin, Ruslan Yamaletdinov
UV-induced phosphorescence from the lowest triplet state T1 of tryptophan (Trp) residues is widely used to monitor the structural dynamics of host proteins on long time scales. Probing the intrinsic properties of this optically “dark” state requires studies of Trp isolated in the gas phase, which are challenging due to low sample concentrations and the need to monitor the triplet over extended time scales. We discovered that excitation of cold, protonated noncovalent TrpH+–(H2O)n complexes (n ≥ 6) by UV light of specific wavelengths induces evaporation of two water molecules and promotes tryptophan to the triplet state. Subsequent photofragmentation dynamic, monitored by mass spectrometry and ion spectroscopy, yields rate constants for intrinsic triplet-state quenching via phosphorescence and reverse intersystem crossing. The T1 lifetime is approximately 1 s at 7 K and is dominated by phosphorescence; it decreases to tens of milliseconds at ∼40 K and is estimated to be ∼10 ms at room temperature.
{"title":"Fate of the Triplet State of Tryptophan Isolated in the Gas Phase","authors":"Oleg V. Boyarkin, Andrei Zviagin, Ruslan Yamaletdinov","doi":"10.1021/acs.jpclett.6c00010","DOIUrl":"https://doi.org/10.1021/acs.jpclett.6c00010","url":null,"abstract":"UV-induced phosphorescence from the lowest triplet state T<sub>1</sub> of tryptophan (Trp) residues is widely used to monitor the structural dynamics of host proteins on long time scales. Probing the intrinsic properties of this optically “dark” state requires studies of Trp isolated in the gas phase, which are challenging due to low sample concentrations and the need to monitor the triplet over extended time scales. We discovered that excitation of cold, protonated noncovalent TrpH<sup>+</sup>–(H<sub>2</sub>O)<sub><i>n</i></sub> complexes (<i>n</i> ≥ 6) by UV light of specific wavelengths induces evaporation of two water molecules and promotes tryptophan to the triplet state. Subsequent photofragmentation dynamic, monitored by mass spectrometry and ion spectroscopy, yields rate constants for intrinsic triplet-state quenching via phosphorescence and reverse intersystem crossing. The T<sub>1</sub> lifetime is approximately 1 s at 7 K and is dominated by phosphorescence; it decreases to tens of milliseconds at ∼40 K and is estimated to be ∼10 ms at room temperature.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"84 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-05DOI: 10.1021/acs.jpclett.6c00192
Linyang Li, Junjun Wu, Ao Xia, Xun Zhu, Qiang Liao
Lignin, an abundant natural organic polymer and renewable resource, presents grand challenges in efficient depolymerization into value-added products. Herein, we propose an innovative green mechanochemical (contact-electro-catalysis; CEC) strategy to completely degrade the lignin model compounds (99.98% within 330 min) in a chemical-free, environmentally benign, and highly efficient manner. This is enabled by ultrasound-induced contact electrification to generate electrons and reactive oxygen species (ROS). Comprehensive mechanistic investigations reveal that ROS play a predominant role in lignin depolymerization. Furthermore, the possible thermal effect of CEC on the lignin depolymerization was also considered. Extensive characterization demonstrates the exceptional recyclability of the CEC reagent with a recovery rate of up to 92%. This approach not only exhibits outstanding performance in accelerating lignin depolymerization but also underscores the immense potential of mechanochemistry as a sustainable technology for biomass and lignin valorization.
{"title":"Toward Chemical-Free Depolymerization of Lignin Surrogate: A Mechanistic Insight into Contact-Electro-Catalysis","authors":"Linyang Li, Junjun Wu, Ao Xia, Xun Zhu, Qiang Liao","doi":"10.1021/acs.jpclett.6c00192","DOIUrl":"https://doi.org/10.1021/acs.jpclett.6c00192","url":null,"abstract":"Lignin, an abundant natural organic polymer and renewable resource, presents grand challenges in efficient depolymerization into value-added products. Herein, we propose an innovative green mechanochemical (contact-electro-catalysis; CEC) strategy to completely degrade the lignin model compounds (99.98% within 330 min) in a chemical-free, environmentally benign, and highly efficient manner. This is enabled by ultrasound-induced contact electrification to generate electrons and reactive oxygen species (ROS). Comprehensive mechanistic investigations reveal that ROS play a predominant role in lignin depolymerization. Furthermore, the possible thermal effect of CEC on the lignin depolymerization was also considered. Extensive characterization demonstrates the exceptional recyclability of the CEC reagent with a recovery rate of up to 92%. This approach not only exhibits outstanding performance in accelerating lignin depolymerization but also underscores the immense potential of mechanochemistry as a sustainable technology for biomass and lignin valorization.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"12 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Concurrent thermally activated delayed fluorescence (TADF) and room-temperature phosphorescence (RTP) within one molecular family remain rare. Here we implement carborane-number engineering in o-carborane-functionalized triphenylamines (TPA-1Cb/2Cb/3Cb) to program the S1-Tn landscape (S1 = lowest singlet excited state; Tn = low-lying triplet states). Increasing the carborane count reshapes S1-Tn alignments and facilitates intersystem crossing and Tn-assisted reverse intersystem crossing, while aggregate confinement suppresses nonradiative decay, enabling dual-channel emission. Spectroscopy and transient absorption establish solution-phase TADF for TPA-2Cb/3Cb and solid-state, air-robust TADF/RTP coexistence under ambient atmosphere with ultralong TADF lifetimes of 67.4 ms (TPA-2Cb) and 105.3 ms (TPA-3Cb). TD-DFT based on crystal structures attributes channel allocation to carborane-count-dependent tuning of ΔE(S1-Tn) and finite spin–orbit coupling (SOC), whereas TPA-1Cb remains RTP-dominant due to large S1-T1/T2 separations. These results define a compact route to time-programmable, dual emission and offer a generalizable design principle for building concurrent TADF/RTP in carborane-based luminophores.
{"title":"Programming the Excited-State Landscape Via Carborane Count for Dual TADF/RTP","authors":"Yangtao Shao, Xubin Wang, Hexi Wei, Xinli Li, Rongrong Huang, Shiwei Yin, Haonan Peng, Yu Fang","doi":"10.1021/acs.jpclett.6c00063","DOIUrl":"https://doi.org/10.1021/acs.jpclett.6c00063","url":null,"abstract":"Concurrent thermally activated delayed fluorescence (TADF) and room-temperature phosphorescence (RTP) within one molecular family remain rare. Here we implement carborane-number engineering in <i>o</i>-carborane-functionalized triphenylamines (TPA-1Cb/2Cb/3Cb) to program the S<sub>1</sub>-T<sub>n</sub> landscape (S<sub>1</sub> = lowest singlet excited state; T<sub>n</sub> = low-lying triplet states). Increasing the carborane count reshapes S<sub>1</sub>-T<sub>n</sub> alignments and facilitates intersystem crossing and T<sub>n</sub>-assisted reverse intersystem crossing, while aggregate confinement suppresses nonradiative decay, enabling dual-channel emission. Spectroscopy and transient absorption establish solution-phase TADF for TPA-2Cb/3Cb and solid-state, air-robust TADF/RTP coexistence under ambient atmosphere with ultralong TADF lifetimes of 67.4 ms (TPA-2Cb) and 105.3 ms (TPA-3Cb). TD-DFT based on crystal structures attributes channel allocation to carborane-count-dependent tuning of Δ<i>E</i>(S<sub>1</sub>-T<sub>n</sub>) and finite spin–orbit coupling (SOC), whereas TPA-1Cb remains RTP-dominant due to large S<sub>1</sub>-T<sub>1</sub>/T<sub>2</sub> separations. These results define a compact route to time-programmable, dual emission and offer a generalizable design principle for building concurrent TADF/RTP in carborane-based luminophores.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"34 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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