文献类型：期刊文献

英文题名：Role of Organic Fluoride Salts in Stabilizing Niobium Oxo-Clusters Catalyzing Epoxidation

作者：Zhou, Qingqing[1];Xu, Beibei[2,3];Tang, Xuan[1];Dai, Sheng[4,5];Ding, Bingjie[1];Li, Difan[1];Zheng, Anna[1];Zhang, Tong[1];Yao, Yefeng[2,3];Gong, Xueqing[1];Hou, Zhenshan[1,6]

机构：[1]East China Univ Sci & Technol, Res Inst Ind Catalysis, Key Lab Adv Mat, Shanghai 200237, Peoples R China;[2]East China Normal Univ, Phys Dept, Shanghai 200062, Peoples R China;[3]East China Normal Univ, Shanghai Key Lab Magnet Resonance, Shanghai 200062, Peoples R China;[4]East China Univ Sci & Technol, Sch Chem & Mol Engn, Inst Fine Chem, Key Lab Adv Mat, Shanghai 200237, Peoples R China;[5]East China Univ Sci & Technol, Sch Chem & Mol Engn, Inst Fine Chem, Feringa Nobel Prize Scientist Joint Res Ctr, Shanghai 200237, Peoples R China;[6]East China Normal Univ, Sch Chem & Mol Engn, Shanghai Key Lab Green Chem & Chem Proc, Shanghai 200062, Peoples R China

年份：2021

卷号：37

期号：27

起止页码：8190

外文期刊名：LANGMUIR

收录：;EI(收录号：20213010672938);WOS:【SCI-EXPANDED(收录号:WOS:000674276700014)】；

基金：The authors thank the National Natural Science Foundation of China (21773061, 21978095) and the Open Research Fund of Shanghai Key Laboratory of Green Chemistry and Chemical Processes for support. Y.F. thanks the Ministry of Science and Technology of the People's Republic of China (Grant No. 2018YFF01012504) and the Microscale Magnetic Resonance Platform of ECNU for financial support. S.D. acknowledges the Fundamental Research Funds for the Central Universities (JKVJ1211022) and the support by Shanghai Rising-star Program (20QA1402400) and the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning. Additional support was provided by the Frontiers Science Center for Materiobiology and Dynamic Chemistry and the Feringa Nobel Prize Scientist Joint Research Center.

语种：英文

外文关键词：Coordination reactions - Fluorine compounds - Salts - Catalyst activity - Epoxidation - Fluorine - Hydrogen bonds

摘要：We present here that easily available organic salts can stabilize/modify niobium (Nb) oxo-clusters. The as-synthesized Nb oxo-clusters have been characterized by various methods. These Nb oxo-clusters were catalytically active for the epoxidation of allylic alcohols and olefins with H2O2 as an oxidant. Notably, Nb-OC@TBAF-0.5 appeared as highly dispersed nanosized particles and showed the highest catalytic activity, which can be attributed to the following reasons on the basis of characterization. First, the strong coordination of fluorine ions with Nb sites and the steric protection with bulky organic cations led to high stabilization and dispersion of the oxo-clusters in the course of the reaction. Second, a hydrogen-bond interaction between the coordinated fluorine atom and the -OH group of allylic alcohol favored the epoxidation reaction. Third, the electron density of Nb sites decreased due to the strong electron-withdrawing ability of F- adjacent to Nb sites, thus promoting the electrophilic oxygen transfer to the C=C bond.