Brady L. Slinger, Miguel Cohen Suarez, Jack C. Malek, Ross A. Widenhoefer
PtCl2(NCC6F5)2 catalyzes the reaction of electron-rich vinyl arenes with aryl diazirines in chloroform at 45 °C for 12 h to form 1,2-diarylcyclopropanes in >75% yield with cis/trans selectivity ranging from 3.0 to 10:1. The method is similarly applicable to the cyclopropanation of 1-aryl-1,3-butadienes, albeit with diminished diastereoselectivity (cis/trans = 0.5–2.6). Kinetic and deuterium-labeling experiments, in situ analysis of platinum coordination complexes, and DFT calculations support a mechanism for diazirine to alkene carbene transfer initiated by ligand displacement of a platinum(II) trans-bis(π-vinyl arene) complex with aryl diazirine to form a four coordinate trans-platinum π-vinyl arene σ-diazirine complex. The turnover-limiting oxidative addition of coordinated diazirine forms a five-coordinate Pt(IV) diazometallacyclobutane complex that undergoes facile Pt–N bond cleavage followed by expulsion of dinitrogen from the resulting C-bound aryldiazomethane complex to form a trans-platinum benzylidene complex. The concerted, outer-sphere attack of vinyl arene on the carbene carbon atom of the platinum benzylidene complex though a polarized transition state releases cyclopropane.
{"title":"Platinum(II)-Catalyzed Cyclopropanation of Vinyl Arenes and 1,3-Aryl Dienes Employing Aryl Diazirines as Carbene Precursors","authors":"Brady L. Slinger, Miguel Cohen Suarez, Jack C. Malek, Ross A. Widenhoefer","doi":"10.1021/jacs.5c14354","DOIUrl":"https://doi.org/10.1021/jacs.5c14354","url":null,"abstract":"PtCl<sub>2</sub>(NCC<sub>6</sub>F<sub>5</sub>)<sub>2</sub> catalyzes the reaction of electron-rich vinyl arenes with aryl diazirines in chloroform at 45 °C for 12 h to form 1,2-diarylcyclopropanes in >75% yield with cis/trans selectivity ranging from 3.0 to 10:1. The method is similarly applicable to the cyclopropanation of 1-aryl-1,3-butadienes, albeit with diminished diastereoselectivity (cis/trans = 0.5–2.6). Kinetic and deuterium-labeling experiments, <i>in situ</i> analysis of platinum coordination complexes, and DFT calculations support a mechanism for diazirine to alkene carbene transfer initiated by ligand displacement of a platinum(II) <i>trans</i>-bis(π-vinyl arene) complex with aryl diazirine to form a four coordinate <i>trans</i>-platinum π-vinyl arene σ-diazirine complex. The turnover-limiting oxidative addition of coordinated diazirine forms a five-coordinate Pt(IV) diazometallacyclobutane complex that undergoes facile Pt–N bond cleavage followed by expulsion of dinitrogen from the resulting C-bound aryldiazomethane complex to form a <i>trans</i>-platinum benzylidene complex. The concerted, outer-sphere attack of vinyl arene on the carbene carbon atom of the platinum benzylidene complex though a polarized transition state releases cyclopropane.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"18 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147507600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mihai Peterca, Dipankar Sahoo, Devendra S. Maurya, Floriane Gibault, Virgil Percec
Previously our laboratory reported complex helical columnar, cubic, tetragonal, and liquid quasicrystal periodic and quasiperiodic functional helical arrays (including homochiral) self-organized from supramolecular dendrimers. They have attracted the interest of theoreticians and have been discovered in many other areas of soft matter, creating a new field of research. Here we report the discovery, to the best of our knowledge, of an unprecedentedly complex Pmm cubic phase self-organized from 29 distorted globular supramolecular dendrimers with similar internal organization exhibiting five different shapes. This cubic periodic array resembles the tetragonal periodic structure, which is self-organized from 30 supramolecular dendrimers containing five differently distorted globular shapes. The thermodynamically controlled transition between these two closely related ordered arrays, hierarchically self-organized via a crown-like secondary structure, addresses key questions concerning the reversible conversion between tetragonal and cubic arrangements of 30 and 29 globular supramolecular dendrimers distorted in each case in five different ways. These results enlarge the diversity of periodic arrays of the Pmm space group, raising fundamental enquiries related to the origins of order and homochirality in natural sciences.
{"title":"A Complex Cubic Liquid-Crystalline Phase Self-Organized from Five Differently Distorted Supramolecular Globular Dendrimers","authors":"Mihai Peterca, Dipankar Sahoo, Devendra S. Maurya, Floriane Gibault, Virgil Percec","doi":"10.1021/jacs.6c02186","DOIUrl":"https://doi.org/10.1021/jacs.6c02186","url":null,"abstract":"Previously our laboratory reported complex helical columnar, cubic, tetragonal, and liquid quasicrystal periodic and quasiperiodic functional helical arrays (including homochiral) self-organized from supramolecular dendrimers. They have attracted the interest of theoreticians and have been discovered in many other areas of soft matter, creating a new field of research. Here we report the discovery, to the best of our knowledge, of an unprecedentedly complex <i>Pm</i><i></i><math display=\"inline\"><mover><mi mathvariant=\"normal\">3</mi><mo accent=\"true\" stretchy=\"false\">¯</mo></mover></math><i>m</i> cubic phase self-organized from 29 distorted globular supramolecular dendrimers with similar internal organization exhibiting five different shapes. This cubic periodic array resembles the tetragonal periodic structure, which is self-organized from 30 supramolecular dendrimers containing five differently distorted globular shapes. The thermodynamically controlled transition between these two closely related ordered arrays, hierarchically self-organized via a crown-like secondary structure, addresses key questions concerning the reversible conversion between tetragonal and cubic arrangements of 30 and 29 globular supramolecular dendrimers distorted in each case in five different ways. These results enlarge the diversity of periodic arrays of the <i>Pm</i><i></i><math display=\"inline\"><mover><mi mathvariant=\"normal\">3</mi><mo accent=\"true\" stretchy=\"false\">¯</mo></mover></math><i>m</i> space group, raising fundamental enquiries related to the origins of order and homochirality in natural sciences.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"16 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147518950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The importance of spin-correlated radical pairs in biology is increasingly recognized, with roles in biological effects of weak magnetic fields and emerging quantum spin-based biomedical applications. Fluorescence microscopy provides sufficient sensitivity to study magnetic field effects on radical pair reactions in living cells, but conventional techniques cannot directly resolve their dynamics because most biologically relevant radical pairs are nonemissive. Additionally, the magnetic field response of the fluorescence signal is strongly influenced by the intensity of photoexcitation, making interpretation and reproducibility across laboratories difficult. To overcome these challenges, we introduce two novel microscopy techniques: single-color pump-probe (PP) and pump-field-probe (PFP) fluorescence. Here, we derive a mathematical framework linking PP and PFP signals to radical-pair kinetics and magnetic-field-dependent spin evolution and validate it through experiments on well-characterized flavin-based magnetic field sensitive photochemistry under cell-like conditions. These measurements demonstrate highly sensitive access to transient intermediates and dark-state kinetics, discriminate spectroscopically silent long-lived intermediates, disentangle multi component radical pair spin effects, and are confirmed by spin dynamics simulations. These approaches offer a sensitive and broadly applicable platform for quantifying and visualizing the quantum spin dynamics of radical pair reactions in biological systems.
{"title":"A Fluorescence Microscopy Platform for Time-Resolved Studies of Spin-Correlated Radical Pairs in Biological Systems","authors":"Noboru Ikeya, Jonathan R. Woodward","doi":"10.1021/jacs.5c21177","DOIUrl":"https://doi.org/10.1021/jacs.5c21177","url":null,"abstract":"The importance of spin-correlated radical pairs in biology is increasingly recognized, with roles in biological effects of weak magnetic fields and emerging quantum spin-based biomedical applications. Fluorescence microscopy provides sufficient sensitivity to study magnetic field effects on radical pair reactions in living cells, but conventional techniques cannot directly resolve their dynamics because most biologically relevant radical pairs are nonemissive. Additionally, the magnetic field response of the fluorescence signal is strongly influenced by the intensity of photoexcitation, making interpretation and reproducibility across laboratories difficult. To overcome these challenges, we introduce two novel microscopy techniques: single-color pump-probe (PP) and pump-field-probe (PFP) fluorescence. Here, we derive a mathematical framework linking PP and PFP signals to radical-pair kinetics and magnetic-field-dependent spin evolution and validate it through experiments on well-characterized flavin-based magnetic field sensitive photochemistry under cell-like conditions. These measurements demonstrate highly sensitive access to transient intermediates and dark-state kinetics, discriminate spectroscopically silent long-lived intermediates, disentangle multi component radical pair spin effects, and are confirmed by spin dynamics simulations. These approaches offer a sensitive and broadly applicable platform for quantifying and visualizing the quantum spin dynamics of radical pair reactions in biological systems.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"22 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147507602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rui-Qi Huang, Shao-Zhe Yi, Wen He, Ren-Fu Li, Ya-Nan Fan, Cheng-Yong Su, Mei Pan
In recent years, uranium-based metal–organic frameworks (MOFs) have garnered particular attention due to the accessible 5f orbitals and diverse coordination geometries of the U atom, as well as the tunability and functionality inherent to MOFs. Herein, we report a 2D-MOF (UO-TTP) featuring a tetranuclear uranyl cluster structure and unique thermal adaptive scintillating characters. UO-TTP exhibits a broad absorption band and can be excited through multiple pathways, from X-ray to one/two-photon excitation. At room temperature, UO-TTP exhibits a continuous emission peak centered at 550 nm, originating from the excited triplet states with hybrid CT characteristics and a long decay lifetime of ∼20 ms. However, at low temperatures, the emission spectra split into finger-type peaks, with lifetimes unexpectedly shortened to microsecond level. This thermal adaptive emission switch was also detected by X-ray excited luminescence (XEL) for the first time. Moreover, UO-TTP shows outstanding stability, with no significant weakening of its luminescence even after soaked in water, and manifests itself as a qualified scintillator in terms of linear response, detection limit, and stability. Based on the excellent optical properties of UO-TTP, we innovatively explored the application of this uranium-organic framework (UOF) in temperature–time dual-correlated information encryption and X-ray imaging under hot water conditions. This work not only reveals the uniqueness and advantages of luminescent UOFs, but also paves the way for in-depth research into actinide chemistry.
{"title":"Highly Water-Stable Uranyl-Cluster Based Metal–Organic Framework for Thermal Adaptive Scintillator","authors":"Rui-Qi Huang, Shao-Zhe Yi, Wen He, Ren-Fu Li, Ya-Nan Fan, Cheng-Yong Su, Mei Pan","doi":"10.1021/jacs.5c22949","DOIUrl":"https://doi.org/10.1021/jacs.5c22949","url":null,"abstract":"In recent years, uranium-based metal–organic frameworks (MOFs) have garnered particular attention due to the accessible 5f orbitals and diverse coordination geometries of the U atom, as well as the tunability and functionality inherent to MOFs. Herein, we report a 2D-MOF (UO-TTP) featuring a tetranuclear uranyl cluster structure and unique thermal adaptive scintillating characters. UO-TTP exhibits a broad absorption band and can be excited through multiple pathways, from X-ray to one/two-photon excitation. At room temperature, UO-TTP exhibits a continuous emission peak centered at 550 nm, originating from the excited triplet states with hybrid CT characteristics and a long decay lifetime of ∼20 ms. However, at low temperatures, the emission spectra split into finger-type peaks, with lifetimes unexpectedly shortened to microsecond level. This thermal adaptive emission switch was also detected by X-ray excited luminescence (XEL) for the first time. Moreover, UO-TTP shows outstanding stability, with no significant weakening of its luminescence even after soaked in water, and manifests itself as a qualified scintillator in terms of linear response, detection limit, and stability. Based on the excellent optical properties of UO-TTP, we innovatively explored the application of this uranium-organic framework (UOF) in temperature–time dual-correlated information encryption and X-ray imaging under hot water conditions. This work not only reveals the uniqueness and advantages of luminescent UOFs, but also paves the way for in-depth research into actinide chemistry.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"98 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147507646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The uncontrollable reconstruction of electrocatalysts, such as the detrimental overoxidation of Co3O4 during alkaline water oxidation, severely impedes the synergistic enhancement of activity and stability. Therefore, achieving adaptive electron transfer during reactions to maintain an active and stable state is critical, yet it remains largely unexplored. Herein, a novel catalyst in which metalloid boron selectively occupies the tetrahedral cobalt sites in Co3O4 is designed to overcome this dilemma, and its atomic structure is unequivocally confirmed by 11B-enriched neutron powder diffraction. The activity of octahedral cobalt is enhanced as boron suppresses covalent competition, while the operational stability is maintained through the adaptive electronic tuning of [BO4] units, which possess electrons delocalized over extended spatial dimensions. Specifically, electrons transfer from cobalt to boron at lower potentials to activate cobalt but reverse at higher potentials to sustain Co3+ states by suppressing overoxidation, as demonstrated by operando Raman spectroscopy, X-ray absorption spectroscopy, and quasi-in situ X-ray photoelectron spectroscopy. Consequently, (Co0.86B0.14)Co2O4 achieves superior activity and stability in both three-electrode and electrolytic cell systems, outperforming the vast majority of Co3O4-based catalysts. This study pioneers an adaptive regulation strategy by precisely anchoring [BO4] units, providing a general design principle for next-generation adaptive electrocatalysts that combine high activity with robust stability.
{"title":"Selective Boron Occupation at Tetrahedral Cation Sites in Co3O4 Enables Self-Adaptive Electron Transfer for Enhanced Water Oxidation","authors":"Fang Yang, Qian Zhu, Xiangyan Hou, Haijin Ni, Zhiyu Shao, Na Liang, Mengpei Jiang, Xiaofeng Wu, Yangguang Li, Huaqiao Tan, Xiangdong Yao, Keke Huang, Shouhua Feng","doi":"10.1021/jacs.5c21174","DOIUrl":"https://doi.org/10.1021/jacs.5c21174","url":null,"abstract":"The uncontrollable reconstruction of electrocatalysts, such as the detrimental overoxidation of Co<sub>3</sub>O<sub>4</sub> during alkaline water oxidation, severely impedes the synergistic enhancement of activity and stability. Therefore, achieving adaptive electron transfer during reactions to maintain an active and stable state is critical, yet it remains largely unexplored. Herein, a novel catalyst in which metalloid boron selectively occupies the tetrahedral cobalt sites in Co<sub>3</sub>O<sub>4</sub> is designed to overcome this dilemma, and its atomic structure is unequivocally confirmed by <sup>11</sup>B-enriched neutron powder diffraction. The activity of octahedral cobalt is enhanced as boron suppresses covalent competition, while the operational stability is maintained through the adaptive electronic tuning of [BO<sub>4</sub>] units, which possess electrons delocalized over extended spatial dimensions. Specifically, electrons transfer from cobalt to boron at lower potentials to activate cobalt but reverse at higher potentials to sustain Co<sup>3+</sup> states by suppressing overoxidation, as demonstrated by operando Raman spectroscopy, X-ray absorption spectroscopy, and quasi-in situ X-ray photoelectron spectroscopy. Consequently, (Co<sub>0.86</sub>B<sub>0.14</sub>)Co<sub>2</sub>O<sub>4</sub> achieves superior activity and stability in both three-electrode and electrolytic cell systems, outperforming the vast majority of Co<sub>3</sub>O<sub>4</sub>-based catalysts. This study pioneers an adaptive regulation strategy by precisely anchoring [BO<sub>4</sub>] units, providing a general design principle for next-generation adaptive electrocatalysts that combine high activity with robust stability.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"2 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147518945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Protein pumps in the cell membrane are capable of actively moving solutes uphill to build concentration gradients, a process pivotal to biological energy conversion. These pumps dissipate light or chemical energy to generate and maintain a nonequilibrium steady state. Achieving continuous unidirectional displacement of substrates or (sub)components in artificial molecular systems is a tremendous challenge. In this work, we realize the repeated transit of a molecular axle through a photoswitchable macrocyclic ring. The axle contains different termini, which have different shape complementarities with the interconverting ring isomers. This approach allows one to invert the relative heights of the kinetic barriers for ring slippage over the axle termini and to change the stability of the pseudorotaxane complex (formed between the ring and the axle). Under steady-state irradiation conditions, this modulation of kinetic barriers results in an effective and continuous unidirectional translation of the axle with respect to the ring by an energy ratcheting mechanism. Further, photoconversion is enhanced by the bound axle, which adds to the directionality of the system by an information ratcheting effect. This work brings opportunities toward substrate pumping across membranes to generate and maintain electrochemical gradients using light.
{"title":"Light-Driven Supramolecular Pumping by Changing Shape Complementarity","authors":"Jorn de Jong, Sander J. Wezenberg","doi":"10.1021/jacs.6c00405","DOIUrl":"https://doi.org/10.1021/jacs.6c00405","url":null,"abstract":"Protein pumps in the cell membrane are capable of actively moving solutes uphill to build concentration gradients, a process pivotal to biological energy conversion. These pumps dissipate light or chemical energy to generate and maintain a nonequilibrium steady state. Achieving continuous unidirectional displacement of substrates or (sub)components in artificial molecular systems is a tremendous challenge. In this work, we realize the repeated transit of a molecular axle through a photoswitchable macrocyclic ring. The axle contains different termini, which have different shape complementarities with the interconverting ring isomers. This approach allows one to invert the relative heights of the kinetic barriers for ring slippage over the axle termini and to change the stability of the pseudorotaxane complex (formed between the ring and the axle). Under steady-state irradiation conditions, this modulation of kinetic barriers results in an effective and continuous unidirectional translation of the axle with respect to the ring by an energy ratcheting mechanism. Further, photoconversion is enhanced by the bound axle, which adds to the directionality of the system by an information ratcheting effect. This work brings opportunities toward substrate pumping across membranes to generate and maintain electrochemical gradients using light.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"30 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147518947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yiqiang Jiang, Zetong Jia, Zhen Zhang, Yu Zhou, Li-Chuan Chen, Yuting Li, Hua Zhang, Meiling Su, Jie Bai, Junyang Liu, Jin-Chao Dong, Tao Wang, Jian-Feng Li, Wenjing Hong
Proton tunneling, a fundamental quantum mechanical tunneling effect, profoundly determines catalytic pathways in proton-coupled electron transfer (PCET) reactions, yet it has long been overlooked because of the challenge in deciphering its contribution under ambient conditions. Advancing the on-chip electrochemical mechanically controllable break junction approach, we immobilized a single benzothiadiazole molecule to monitor the PCET reaction that occurred on this molecular catalyst via conductance tracking. Through repeated thousands of molecular junction suspensions, we statistically identified four key PCET intermediates from thousands of PCET reaction cycles by correlating the conductance evolution with Raman spectroscopy, thereby extracting each rate constant, the Kinetic Isotope Effect of elementary steps, and the evolution probabilities of each PCET pathway. Further temperature-dependent kinetic experiments revealed an efficient tunneling-mediated route over the classical thermodynamic pathway, which is further supported by the analysis of the microscopic PCET kinetics. The population of the tunneling route increased from 13% to 42% under varied conditions, indicating a tunable modulation of the reaction at room temperature. Our single-molecule method establishes a general mechanistic platform for quantifying reaction mechanisms in room-temperature multistep electrocatalysis. It provides the opportunity to evaluate the promotion of proton tunneling. This advancement can guide the development of energy-efficient electrocatalytic systems that leverage quantum tunneling.
{"title":"Deciphering Proton Tunneling in Single-Molecule Chemical Reactions","authors":"Yiqiang Jiang, Zetong Jia, Zhen Zhang, Yu Zhou, Li-Chuan Chen, Yuting Li, Hua Zhang, Meiling Su, Jie Bai, Junyang Liu, Jin-Chao Dong, Tao Wang, Jian-Feng Li, Wenjing Hong","doi":"10.1021/jacs.6c01107","DOIUrl":"https://doi.org/10.1021/jacs.6c01107","url":null,"abstract":"Proton tunneling, a fundamental quantum mechanical tunneling effect, profoundly determines catalytic pathways in proton-coupled electron transfer (PCET) reactions, yet it has long been overlooked because of the challenge in deciphering its contribution under ambient conditions. Advancing the on-chip electrochemical mechanically controllable break junction approach, we immobilized a single benzothiadiazole molecule to monitor the PCET reaction that occurred on this molecular catalyst via conductance tracking. Through repeated thousands of molecular junction suspensions, we statistically identified four key PCET intermediates from thousands of PCET reaction cycles by correlating the conductance evolution with Raman spectroscopy, thereby extracting each rate constant, the Kinetic Isotope Effect of elementary steps, and the evolution probabilities of each PCET pathway. Further temperature-dependent kinetic experiments revealed an efficient tunneling-mediated route over the classical thermodynamic pathway, which is further supported by the analysis of the microscopic PCET kinetics. The population of the tunneling route increased from 13% to 42% under varied conditions, indicating a tunable modulation of the reaction at room temperature. Our single-molecule method establishes a general mechanistic platform for quantifying reaction mechanisms in room-temperature multistep electrocatalysis. It provides the opportunity to evaluate the promotion of proton tunneling. This advancement can guide the development of energy-efficient electrocatalytic systems that leverage quantum tunneling.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"58 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147507647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anton Natter Perdiguero, Sandro Fischer, Alrika R. Lischke, Benjamin P. Manser, Alexandria Deliz Liang
Using genetic code expansion, canonical amino acid residues can be site-specifically substituted by noncanonical amino acids (ncAAs) with modified chemical properties. This technique has enabled detailed enzymatic studies, the design of enzymes that catalyze novel reactions, and the engineering of enzymes with improved function. In proteins, histidine can play versatile roles in catalysis, including as an acid, a base, a nucleophile, and a coordinating ligand to a catalytic metal. However, the current scope of histidine-like ncAAs that can be incorporated is limited. Herein, we develop a toolkit consisting of nine new aminoacyl-tRNA synthetase/tRNA pairs for the site-specific genetic encoding of an expanded set of 12 new histidine-like ncAAs. The 12 ncAAs feature broadly tuned nitrogen pKaH, alternative heterocycles, and varying substitution patterns. We profile the substrate specificity of the developed aaRS/tRNA pairs and uncover many mutually orthogonal substrate specificities, which we validate for six combinations of dual encoded histidine-like ncAAs. We expect that the tools presented herein will be broadly applicable to study histidine residues in catalysis and to tune the properties of histidine residues for enzyme engineering and design.
{"title":"Genetic Incorporation of Diverse Noncanonical Amino Acids for Histidine Substitution","authors":"Anton Natter Perdiguero, Sandro Fischer, Alrika R. Lischke, Benjamin P. Manser, Alexandria Deliz Liang","doi":"10.1021/jacs.5c19599","DOIUrl":"https://doi.org/10.1021/jacs.5c19599","url":null,"abstract":"Using genetic code expansion, canonical amino acid residues can be site-specifically substituted by noncanonical amino acids (ncAAs) with modified chemical properties. This technique has enabled detailed enzymatic studies, the design of enzymes that catalyze novel reactions, and the engineering of enzymes with improved function. In proteins, histidine can play versatile roles in catalysis, including as an acid, a base, a nucleophile, and a coordinating ligand to a catalytic metal. However, the current scope of histidine-like ncAAs that can be incorporated is limited. Herein, we develop a toolkit consisting of nine new aminoacyl-tRNA synthetase/tRNA pairs for the site-specific genetic encoding of an expanded set of 12 new histidine-like ncAAs. The 12 ncAAs feature broadly tuned nitrogen p<i>K</i><sub>a</sub>H, alternative heterocycles, and varying substitution patterns. We profile the substrate specificity of the developed aaRS/tRNA pairs and uncover many mutually orthogonal substrate specificities, which we validate for six combinations of dual encoded histidine-like ncAAs. We expect that the tools presented herein will be broadly applicable to study histidine residues in catalysis and to tune the properties of histidine residues for enzyme engineering and design.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"51 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147507601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ya-Hao Du, Hui Yang, Yao-Lu Ye, Peng Ouyang, Yu-Shuai Feng, Huan Ye, Xiao Zhang, Fei-Fei Cao
Interface integration is crucial for achieving rapid lithium-ion transport and conversion under high mass loading and represents a key strategy for constructing high-energy-density quasi-solid-state lithium metal batteries (QSSLMBs). However, Li deposition at the electrode interface during cycling tends to generate significant mechanical stress, leading to interface delamination, increased impedance, and rapid battery failure. Herein, we design a mixed ionic-electronic conductive composite anode by integrating gel electrolyte into a three-dimensional hollow MXene/Li scaffold. This architecture enables dynamic volume accommodation while guiding uniform Li deposition into internal cavities via lithiophilic sites and curved pore geometry, effectively suppressing dendrite growth and interfacial stress. The resulting all-in-one QSSLMBs achieve over 1750 h in symmetric cells and maintain 72.6% capacity after 1000 cycles at 1 C in a LiFePO4 full cell. When paired with a high loading LiNi0.9Co0.05Mn0.05O2 cathode (31.5 mg cm–2), a single-layer and projected 13-layer pouch cells achieve an energy density of 392 Wh kg–1 and 561 Wh kg–1, demonstrating its potential for durable, high-energy QSSLMBs.
{"title":"Integrating Gel Electrolyte/Anode with Mixed Ionic-Electronic Network for Stable Quasi-Solid-State Lithium Metal Batteries","authors":"Ya-Hao Du, Hui Yang, Yao-Lu Ye, Peng Ouyang, Yu-Shuai Feng, Huan Ye, Xiao Zhang, Fei-Fei Cao","doi":"10.1021/jacs.6c01313","DOIUrl":"https://doi.org/10.1021/jacs.6c01313","url":null,"abstract":"Interface integration is crucial for achieving rapid lithium-ion transport and conversion under high mass loading and represents a key strategy for constructing high-energy-density quasi-solid-state lithium metal batteries (QSSLMBs). However, Li deposition at the electrode interface during cycling tends to generate significant mechanical stress, leading to interface delamination, increased impedance, and rapid battery failure. Herein, we design a mixed ionic-electronic conductive composite anode by integrating gel electrolyte into a three-dimensional hollow MXene/Li scaffold. This architecture enables dynamic volume accommodation while guiding uniform Li deposition into internal cavities via lithiophilic sites and curved pore geometry, effectively suppressing dendrite growth and interfacial stress. The resulting all-in-one QSSLMBs achieve over 1750 h in symmetric cells and maintain 72.6% capacity after 1000 cycles at 1 C in a LiFePO<sub>4</sub> full cell. When paired with a high loading LiNi<sub>0.9</sub>Co<sub>0.05</sub>Mn<sub>0.05</sub>O<sub>2</sub> cathode (31.5 mg cm<sup>–2</sup>), a single-layer and projected 13-layer pouch cells achieve an energy density of 392 Wh kg<sup>–1</sup> and 561 Wh kg<sup>–1</sup>, demonstrating its potential for durable, high-energy QSSLMBs.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"31 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147507648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Catalytic hydrogenations of nitroarenes are fundamental processes in organic chemistry, allowing for atom-efficient and clean synthesis of valuable amines. Recently, earth-abundant metals have attracted considerable interest in this field. Surprisingly, despite more than a century of developments in heterogeneous catalysis, in the present study, we describe for the first time a specific manganese-based single-atom catalyst that allows the selective hydrogenation of various nitroarenes. The corresponding amines were obtained with a high selectivity, especially for nitrostyrene. In the hydrogenation process, the addition of H2O was found to promote the activity of Mn1–N-C/Al2O3. Mechanistic control experiments indicated that the heterolytic activation of hydrogen may be a contributing factor. This work provides an effective approach for the design of completely new Mn-based heterogeneous hydrogenation catalysts.
{"title":"A Heterogeneous Manganese Catalyst for the Selective Hydrogenation of Nitroarenes","authors":"Jianglin Duan, Wu Li, Yujing Ren, Kathrin Junge, Matthias Beller","doi":"10.1021/jacs.5c19788","DOIUrl":"https://doi.org/10.1021/jacs.5c19788","url":null,"abstract":"Catalytic hydrogenations of nitroarenes are fundamental processes in organic chemistry, allowing for atom-efficient and clean synthesis of valuable amines. Recently, earth-abundant metals have attracted considerable interest in this field. Surprisingly, despite more than a century of developments in heterogeneous catalysis, in the present study, we describe for the first time a specific manganese-based single-atom catalyst that allows the selective hydrogenation of various nitroarenes. The corresponding amines were obtained with a high selectivity, especially for nitrostyrene. In the hydrogenation process, the addition of H<sub>2</sub>O was found to promote the activity of Mn<sub>1</sub>–N-C/Al<sub>2</sub>O<sub>3</sub>. Mechanistic control experiments indicated that the heterolytic activation of hydrogen may be a contributing factor. This work provides an effective approach for the design of completely new Mn-based heterogeneous hydrogenation catalysts.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"17 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147507789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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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