Journal of the American Chemical Society最新文献_第7页

A Histidine-Mediated,Pendulum-Like Proton TransportMechanism Is Required for the High Catalytic Activity of [FeFe]-Hydrogenases 组氨酸介导的钟摆式质子转运机制是[FeFe]-氢化酶高催化活性的必要条件

IF 15 1区化学

Journal of the American Chemical Society Pub Date : 2026-10-17 DOI: 10.1021/jacs.6c14410

Jifu Duan,Zhaoya Yang,Oliver Lampret,Federica Arrigoni,Lukas van Impel,Feng Zheng,Julian Kleinhaus,Ulf-Peter Apfel,Claudio Greco,Luca De Gioia,Eckhard Hofmann,Anja Hemschemeier,Thomas Happe

{"title":"A Histidine-Mediated,\u0000Pendulum-Like Proton Transport\u0000Mechanism Is Required for the High Catalytic Activity of [FeFe]-Hydrogenases","authors":"Jifu Duan,Zhaoya Yang,Oliver Lampret,Federica Arrigoni,Lukas van Impel,Feng Zheng,Julian Kleinhaus,Ulf-Peter Apfel,Claudio Greco,Luca De Gioia,Eckhard Hofmann,Anja Hemschemeier,Thomas Happe","doi":"10.1021/jacs.6c14410","DOIUrl":"https://doi.org/10.1021/jacs.6c14410","url":null,"abstract":"Abstract [FeFe]-hydrogenases are molecular hydrogen (H2) converting enzymes that employ a hexanuclear iron complex, the H-cluster, as the catalytic cofactor, and a proton transfer pathway (PTP) that enables efficient proton-coupled electron transfer (PCET). Recent phylogenetic analyses have revealed different groups of [FeFe]-hydrogenases. Although only very few members of other groups have been characterized, current knowledge suggests that high catalytic activity is predominantly associated with group A members. Here, we show that metal ions inhibit group A [FeFe]-hydrogenases by binding to three specific residues at the entrance of the PTP. Exchanging residue H565 of Clostridium pasteurianum CpI results in a metal-insensitive protein variant with wild-type-like activity. In contrast, exchanging S320 and H569 in CpI, and their counterparts in additional group A [FeFe]-hydrogenases results in enzymes with markedly decreased activities and large overpotential requirements. These features are consistent with important roles of both residues in catalytic proton transfer. CpI structures reveal that H569, locally anchored by E278, can be present in two conformations, such that we propose a histidine-dependent pendulum mechanism for exchanging protons between the bulk solvent and the PTP, which is well supported by theoretical calculations. In doing so, our study broadens understanding of how histidine mobility, governed by neighboring residues in the vicinity, contributes to the fundamental concept of PCET.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"38 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149210388","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}

引用次数: 0

Aliphatic DiazoniumChemistry through Hydroquinone-BasedNitrate Reduction for Deaminative Halogenation and Nitrate Ester Formation 以对苯二酚为基础的硝酸盐还原脱氨卤化和硝酸盐酯生成的脂肪族重氮化学

IF 15 1区化学

Journal of the American Chemical Society Pub Date : 2026-10-17 DOI: 10.1021/jacs.6c14581

Tim Schulte,Marco Fattalini,Ahmet Altun,Felix Waldbach,Tobias Ritter

引用次数: 0

AccessingDiverse C(sp3)-Rich CyclophaneLinkers in Macrocyclic Peptides via Nickel-Mediated Deaminative MacrocyclicArylation 通过镍介导的脱胺大环芳基化在大环肽中获得多种富含C（sp3）的环phanelinkers

IF 15 1区化学

Journal of the American Chemical Society Pub Date : 2026-10-17 DOI: 10.1021/jacs.6c16752

Zhenning Li,Yun Hong,Danielle M. Schultz,Dipannita Kalyani,Amelie Dion,Mary P. Watson

引用次数: 0

Supramolecular Mask-MediatedRegioselective bis-Bingel-Functionalizationof M3N@I h -C80 (M = Lu, Sc) 超分子掩膜介导M3N@I h -C80的区域选择性双宾格功能化（M = Lu, Sc）

IF 15 1区化学

Journal of the American Chemical Society Pub Date : 2026-10-16 DOI: 10.1021/jacs.6c16243

Valentina Iannace,Clara Sabrià,Sheng Zhu,Olga A. Stasyuk,Miquel Solà,Teodor Parella,Sergio Fernández,Felipe Gándara,Inhar Imaz,Daniel Maspoch,Jianyuan Zhang,Ferran Feixas,Xavi Ribas

{"title":"Supramolecular Mask-Mediated\u0000Regioselective bis-Bingel-Functionalization\u0000of M3N@I\u0000 h\u0000 -C80 (M = Lu, Sc)","authors":"Valentina Iannace,Clara Sabrià,Sheng Zhu,Olga A. Stasyuk,Miquel Solà,Teodor Parella,Sergio Fernández,Felipe Gándara,Inhar Imaz,Daniel Maspoch,Jianyuan Zhang,Ferran Feixas,Xavi Ribas","doi":"10.1021/jacs.6c16243","DOIUrl":"https://doi.org/10.1021/jacs.6c16243","url":null,"abstract":"Abstract Exohedral functionalization of endohedral metallofullerenes (EMFs) is essential for exploiting these intriguing molecules as novel materials in applications such as biomedicine and organic solar cell device design. In the case of trimetallic nitride template EMFs (TNT-EMFs), many functionalization methods effective for empty fullerenes are inaccessible or less efficient due to the presence of the encapsulated cluster. This inner cluster increases the electron density on the carbon cage surface, reducing its reactivity. Moreover, it has been demonstrated that the inner cluster controls both the reactivity and regioselectivity of bare TNT-EMFs. The supramolecular mask strategy (SMS) has yielded promising results in the functionalization of C60 and C70 and, for the first time, is applied here to endohedral fullerenes to achieve mono- and bis-functionalization of Lu3N@Ih-C80 and Sc3N@Ih-C80. Encapsulation of both TNT-EMFs within a tetragonal prismatic cage host is crucial for enhancing their reactivity, enabling bis-functionalization under milder conditions and with shorter reaction times. Comprehensive spectroscopic and spectrometric characterization, combined with molecular dynamics (MD) simulations and density functional theory (DFT) calculations, identified the most favorable and stable bis-adducts by considering the positive alignment between the geometry imposed by the inner cluster and that allowed by the tetragonal prismatic nanocapsule mask. This resulted in preferential formation of five bis-adducts (out of 27 possible), two of them bearing a 120° angle between the addends and aligning with the inner TNT cluster trigonal geometry.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"22 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149210414","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}

引用次数: 0

Isolation of a Silver(0)Dimer with a Direct Ag–AgBond 具有直接ag - ag键的银(0)二聚体的分离

IF 15 1区化学

Journal of the American Chemical Society Pub Date : 2026-10-16 DOI: 10.1021/jacs.6c16456

Tianze Xu,Yafei Li,Xinggao Ji,Jie Zeng,Congqing Zhu,Jin Xie,Qin Zhu

引用次数: 0

Enantioselective Couplingof Unactivated Alkenes withα-Imino Esters via Alkylzirconium Radical Intermediates 未活化烯烃与α-亚胺酯通过烷基锆自由基中间体的对映选择性偶联

IF 15 1区化学

Journal of the American Chemical Society Pub Date : 2026-10-16 DOI: 10.1021/jacs.6c17862

Jialin Huang,Liying Fu,Leheng Sun,Zequan Xiang,Xingda Zhao,Xiaoqiang Ma,Depeng Zhao

{"title":"Enantioselective Coupling\u0000of Unactivated Alkenes with\u0000α-Imino Esters via Alkylzirconium Radical Intermediates","authors":"Jialin Huang,Liying Fu,Leheng Sun,Zequan Xiang,Xingda Zhao,Xiaoqiang Ma,Depeng Zhao","doi":"10.1021/jacs.6c17862","DOIUrl":"https://doi.org/10.1021/jacs.6c17862","url":null,"abstract":"Abstract Converting simple hydrocarbon feedstocks into stereochemically complex molecules remains a central goal of synthetic chemistry. α-Tetrasubstituted amino acids, which feature densely substituted stereogenic centers and important applications in chemical biology and medicinal chemistry, are particularly challenging to access through direct catalytic methods. Here, we report a photoinduced nickel-catalyzed asymmetric alkylation of α-imino esters using alkylzirconium intermediates generated directly from unactivated alkenes. By merging hydrozirconation chemistry with asymmetric radical coupling, the method enables precise control over transient alkyl radicals and their stereoselective incorporation into imine electrophiles. The transformation provides rapid access to diverse α-tetrasubstituted amino acid derivatives from abundant alkene feedstocks, including challenging internal, cyclic, and gaseous alkenes, while accommodating minimally differentiated alkyl substituents. In addition, a copper-catalyzed asymmetric coupling of alkylzirconium reagents with isatin imines was developed. Together, these transformations establish alkene-derived alkylzirconium chemistry as a versatile platform for the asymmetric synthesis of structurally diverse, enantioenriched nitrogen-containing compounds from simple hydrocarbon feedstocks.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149210410","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}

引用次数: 0

Dynamics and Structureof Room Temperature Ionic Liquids:Ultrafast IR Experiments and MD Simulations of the Ion Cage Model 室温离子液体的动力学和结构：离子笼模型的超快红外实验和MD模拟

IF 15 1区化学

Journal of the American Chemical Society Pub Date : 2026-10-16 DOI: 10.1021/jacs.6c11518

Laura C. Leibfried,Maolin Sha,Michael D. Fayer

{"title":"Dynamics and Structure\u0000of Room Temperature Ionic Liquids:\u0000Ultrafast IR Experiments and MD Simulations of the Ion Cage Model","authors":"Laura C. Leibfried,Maolin Sha,Michael D. Fayer","doi":"10.1021/jacs.6c11518","DOIUrl":"https://doi.org/10.1021/jacs.6c11518","url":null,"abstract":"Abstract Dynamics in room-temperature ionic liquids (ILs) and the solvation of charged and neutral molecules are important to applications of ILs in battery technology, organic synthesis, and many other areas. Using ultrafast IR spectroscopy, pulse-field-gradient (pfg) NMR, and MD simulations, we investigated three ionic liquids that share the same cation but differ in their anions. IR polarization-selective pump-probe and 2D IR experiments were performed on a negatively charged probe, thiocyanate, to investigate IL dynamics. It was found that thiocyanate is an excellent surrogate for the IL anions. We employed a neutral probe, methylthiocyanate, to determine how a neutral solute’s dynamics and interactions differ from those of the RTIL ions. The pfg-NMR experiments, performed on all liquids and species, measured the translational diffusion constants. Extensive molecular dynamics simulations were performed to understand the experimental observables within the IL cage model, in which cations surround an anion (anion cage), and anions surround a cation (cation cage) for all ionic species, including the ionic probe. The neutral probe is surrounded by a combination of cations and anions (neutral probe cage). The cage model shows that the dynamical properties, including translational diffusion, orientational diffusion, and viscosity, are determined by the cage escape time, te, i.e., the time for an ion to leave the group of ions surrounding an ion of the opposite charge or the neutral probe. It is observed that te is correlated with the slowest component of the cage structural fluctuations measured by 2D IR.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"412 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149210411","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}

引用次数: 0

Constructing DinuclearCd2-PorphyrinMotifs in Metal–Organic Frameworks to Accelerate IntersystemCrossing for Boosting Photocatalytic Aerobic Oxidation 在金属-有机框架中构建核cd2 -卟啉基序以加速系统间的交叉以促进光催化有氧氧化

IF 15 1区化学

Journal of the American Chemical Society Pub Date : 2026-10-16 DOI: 10.1021/jacs.6c15716

Danhui Zhao,Qian Xu,Feifei Zhang,Jishi Chen,Xianzhen Xu,Jianfei Xia,Yuanyuan Sun,Xin Zhou,Chuantao Hou

{"title":"Constructing Dinuclear\u0000Cd2-Porphyrin\u0000Motifs in Metal–Organic Frameworks to Accelerate Intersystem\u0000Crossing for Boosting Photocatalytic Aerobic Oxidation","authors":"Danhui Zhao,Qian Xu,Feifei Zhang,Jishi Chen,Xianzhen Xu,Jianfei Xia,Yuanyuan Sun,Xin Zhou,Chuantao Hou","doi":"10.1021/jacs.6c15716","DOIUrl":"https://doi.org/10.1021/jacs.6c15716","url":null,"abstract":"Abstract Dinuclear metalloporphyrin cores remain elusive in metal–organic frameworks (MOFs), despite their potential to direct spin–orbit coupling and triplet sensitization for efficient singlet oxygen (1O2) generation. Herein, we report a structurally precise series of Cd-porphyrin MOFs to elucidate how porphyrin-core nuclearity and coordination geometry influence 1O2 photosensitization. Solvothermal regulation affords three crystalline porous frameworks featuring a free-base porphyrin core (QPF-8), a mononuclear Cd-porphyrin unit (QPF-9), and a dinuclear Cd2-porphyrin motif (QPF-10). QPF-8 serves as an additional free-base reference, whereas the closely related QPF-9 and QPF-10 provide a direct platform for probing how mono- and dinuclear porphyrin coordination environments influence photophysical properties. QPF-10 exhibits a measured 1O2 quantum yield of 0.68, compared with 0.50 for QPF-9. Spectroscopic analyses and theoretical calculations associate the dinuclear motif with enhanced metal-porphyrin orbital mixing and a 4.59-fold increase in the calculated S1–T1 spin–orbit coupling matrix element (from 3.14 to 14.40 cm–1), supporting more effective triplet photosensitization. Consistent with these photophysical properties, QPF-10 demonstrates superior catalytic activity in the aerobic photooxidation of 1,5-dihydroxynaphthalene. Notably, its activity is approximately twice that of the archetypal PCN-224(Zn) and also exceeds that of the Pt-based QPF-1(Pt). These results identify dinuclear porphyrin coordination as a structural strategy for enhancing triplet photosensitization in crystalline heterogeneous catalysts.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"192 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149210451","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}

引用次数: 0

A Negative TemperatureEffect on the Reversible Conversionbetween Redox Tautomers of CoIII(OH) and CoIV(O) Complexes Bearing a Redox-Non-Innocent Tetraamido MacrocyclicLigand 负温度对CoIII（OH）和CoIV(O)氧化还原互变异构体可逆转化的影响

IF 15 1区化学

Journal of the American Chemical Society Pub Date : 2026-10-16 DOI: 10.1021/jacs.6c15641

Deesha D. Malik,Yong-Min Lee,Shunichi Fukuzumi,Wonwoo Nam

{"title":"A Negative Temperature\u0000Effect on the Reversible Conversion\u0000between Redox Tautomers of CoIII(OH) and CoIV(O) Complexes Bearing a Redox-Non-Innocent Tetraamido Macrocyclic\u0000Ligand","authors":"Deesha D. Malik,Yong-Min Lee,Shunichi Fukuzumi,Wonwoo Nam","doi":"10.1021/jacs.6c15641","DOIUrl":"https://doi.org/10.1021/jacs.6c15641","url":null,"abstract":"Abstract Elucidating highly reactive intermediates in catalytic reactions relies heavily on cryogenic trapping techniques, where intermediates observed in solution are generally assumed to remain unchanged upon flash-freezing at 77 K. Herein, we demonstrate a striking exception to this long-standing assumption. A cobalt(III)-hydroxo complex bearing a tetraamido macrocyclic ligand radical cation (1: [(TAML•+)CoIII(OH)]−), which is readily observed in solution, is rapidly and quantitatively converted upon freezing to the corresponding cobalt(IV)-oxo complex containing a protonated TAML ligand (2: [(H-TAML)CoIV(O)(HOTf)]−) in the presence of HOTf in acetone. Remarkably, the conversion of 1 to 2 exhibits a negative temperature effect, becoming significantly faster at lower temperatures. Eyring analysis afforded activation parameters of ΔH‡ = −6.0(5) kcal mol–1 and ΔS‡ = −96(7) cal K–1 mol–1. Mechanistic studies reveal that this interconversion proceeds through an acid-assisted proton-coupled electron-transfer (PCET) pathway in which HOTf binding to the redox noninnocent TAML•+ ligand promotes intramolecular electron transfer from the CoIII center to the TAML•+ ligand, coupled with proton transfer from the hydroxo ligand to the TAML framework to produce 2. While the equilibrium constant for the exothermic binding of HOTf increases at lower temperatures, the intrinsic rate constant of the subsequent intramolecular PCET step decreases. Consequently, the overall conversion becomes faster upon cooling because of the interplay between these two processes. This study provides the first example of a negative temperature effect on the reversible conversion between two redox tautomers, demonstrating that cryogenic cooling can drive, rather than simply trap, the interconversion of transient intermediates.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"16 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149210404","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}

引用次数: 0

One-PotChirality-Assisted Synthesis of Shape-PersistentNanobelts with Very High Dissymmetry Factors 单手性辅助合成具有非常高不对称因子的形状持久纳米带

IF 15 1区化学

Journal of the American Chemical Society Pub Date : 2026-10-16 DOI: 10.1021/jacs.6c13913

Yogendra Singh,Jakob H. Alberts,Sven M. Elbert,Moritz P. Schuldt,Anusha Sounder Rajan,Frank Rominger,Margit Brückner,Tobias Kirschbaum,Michael Mastalerz

引用次数: 0