AbstractThe impact of cooperativity between intermolecular interactions is demonstrated by the molecular self‐recognition properties of highly enantioselective epi‐cinchona bifunctional thiourea organocatalysts. Low‐temperature NMR experiments in inert solvents have revealed two sets of nonequivalent resonances in equal population for thiourea‐modified members of the epi‐quinine and epi‐quinidine families. In solution, the predominance of an asymmetric (C1) dimeric self‐assembly with noteworthy structural motifs became evident: simultaneous intra‐ and intermolecular thiourea hydrogen bonding and a CH/π interaction were observed. Both the stereochemical and the diverse conformational features of the system favor the observed quinoline T‐shaped aromatic π–π stacking interaction. The structure findings are supported by quantitative proton–proton distance data that were available from NOE buildup curves. The 3D structure of the dimeric assembly has been modeled in agreement with the H–H distance restraints. Owing to the geometrical preference associated with the dimerization process, the self‐assembled bifunctional system is interpreted as a charge‐transfer complex with the potential for catalyst self‐activation.
Ion- and Liquid-Assisted Grinding: Improved Mechanochemical Synthesis of Metal-Organic Frameworks Reveals Salt Inclusion and Anion Templating
作者:Tomislav Friščić、David G. Reid、Ivan Halasz、Robin S. Stein、Robert E. Dinnebier、Melinda J. Duer
DOI:10.1002/anie.200906583
日期:2010.1.18
Just a pinch of salt: Small amounts of salts accelerate and direct the mechanochemical construction of metal–organicframeworks (MOFs) from a metal oxide (see scheme; ILAG= ion‐ and liquid‐assisted grinding). The resulting rapid and room‐temperature synthesis demonstrates the ability to control mechanosynthesis of metal–organic compounds by templating, as well as the ability to use mechanochemistry
Efficient Ammonia Electrosynthesis from Nitrate on Strained Ruthenium Nanoclusters
作者:Jie Li、Guangming Zhan、Jianhua Yang、Fengjiao Quan、Chengliang Mao、Yang Liu、Bo Wang、Fengcai Lei、Lejing Li、Alice W. M. Chan、Liangpang Xu、Yanbiao Shi、Yi Du、Weichang Hao、Po Keung Wong、Jianfang Wang、Shi-Xue Dou、Lizhi Zhang、Jimmy C. Yu
DOI:10.1021/jacs.0c00418
日期:2020.4.15
rate (mostly <10 mmol gcat-1 h-1), small partial current density (<1 mA cm-2), and high-selectivity hydrogen-evolving side-reaction. Herein, we report that room-temperature nitrate electroreduction catalyzed by strained ruthenium nanoclusters generates ammonia at a higher rate (5.56 mol gcat-1 h-1) than the Haber-Bosch process. The primary contributor to such performance is hydrogen radicals, which
Catalytic water oxidation by an <i>in situ</i> generated ruthenium nitrosyl complex bearing a bipyridine-bis(alkoxide) ligand
作者:Yingying Liu、Siu-Mui Ng、Shek-Man Yiu、Tai-Chu Lau
DOI:10.1039/d1dt01918j
日期:——
Oxidative degradation and transformation of catalysts are commonly observed in water oxidation by molecular catalysts, especially when a highly oxidizing reagent such as (NH4)2[Ce(NO3)6] [Ce(IV)] is used. We report herein the synthesis of a ruthenium(III) complex bearing an oxidative resistant bipyridine-bis(alkoxide) ligand, [Ru(bdalk)(pic)2]+ (1, H2bdalk = 2,2′-([2,2′-bipyridine]-6,6′-diyl)bis(propan-2-ol)
作者:Enrique Contreras、Rachel Nixon、Chloe Litts、Wenxin Zhang、Francis M. Alcorn、Prashant K. Jain
DOI:10.1021/jacs.2c01272
日期:2022.6.22
Ammonia is a promising liquid-phase carrier for the storage, transport, and deployment of carbon-free energy. However, the realization of an ammonia economy is predicated on the availability of green methods for the production of ammonia powered by electricity from renewable sources or by solar energy. Here, we demonstrate the synthesis of ammonium fromnitrate powered by a synergistic combination
We report an inherent oxide anchoring strategy to synthesize monolithic single atom electrodes. The prepared Ru single atom electrode exhibited exceptional electrochemical chlorine evolution and nitrate reduction performances. The scalability and bifunctionality of Ru single atom electrode highlight its great potential of electrochemical applications.