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Intramolecular hydroamination of alkynes driven by isomeric Au_(36)(SR)_(24)nanocluster catalysts

Nano Research 2023年第3期16卷 3641-3648页

作者： Yuying Zhang Ancheng Tang Xiao Cai Jiayu Xu Guangjun Li Weigang Hu Xu Liu Mingyang Chen Yan Zhu School of Chemistry and Chemical Engineering Nanjing UniversityNanjing 210093China Center for Green Innovation School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China

It remains elusive to realize the distinct catalysis of isomeric catalysts because it becomes challenging to identify structural isomers in the polydisperse *** we investigate catalysis of two geometric isomers for 36-gold-atom nanoclusters with different Au cores arrangements but the same thiolate ligands,thereby providing access to isomer catalysts readily participate in a desired *** to the Au_(36)(SR)_(24)with a one-dimensional(1D)layout of Au4 tetrahedral units,the Au_(36)(SR)_(24)with a two-dimensional(2D)layout of Au4 tetrahedral units is more effective for the intramolecular hydroamination of *** study suggests that the exposed Au sties of the two Au_(36)(SR)_(24)catalysts favor different reaction intermediates and *** intramolecular H transfer leads to intermediates with the C-N and with C=N for the 1D and 2D Au_(36)(SR)_(24)respectively,and hence the different on-site and off-site pathways for the successive reaction steps account for the different performances of the two Au_(36)(SR)_(24)catalysts.

关键词： Au36 clusters isomeric structure catalytic activity catalysis

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DFT Predictions on structures and Stabilities of Eleven-vertex nido- and closo-Heteroboranes

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Chemical Research in Chinese Universities 2009年第2期25卷 247-256页

作者： LI Ping College of Chemistry Sichuan University Chengdu 610064 P. R. China

Based on the octadecahedron of eleven-vertex closo-borane, the eleven-vertex closo-heteroborane was suggested with nonmetallic atoms instead of the different nonequivalent boron, and the stabilities were predicted at G96PW91/6-31＋G（3d,2p） level. The small heteroatoms, C, N, O, preferentially occupy vertex 2 with the absolutely lowest relative energy to form the high stabilization closo-heteroboranes. They cap four-membered rings to satisfy the geometrical demand of short B--Z bonds. The electron attractions from the vicinal boron atoms make the frameworks shrink. Differently, Si and Ge preferentially substitute for boron at vertex 1 with six tight B--Z bonds and form stabilized molecules. P, As, S, and Se tend to occupy vertex 4 and the optimized structures belong to the nido configura- tions. In contrast to high electronegative heteroatoms, S and Se transfer less negative charges to framework and the electropositive heteroatoms, Si and Ge transfer more negative charges to framework to form the delocalization structures. The HOMO-LUMO gaps show that most of predicted clusters possess chemical stabilities. The substitutions of heteroatoms for boron atoms in eleven-vertex closo-heteroboranes are consistent with the topological charge stabilization rule proposed by Gimarc.

关键词： Eleven-vertex closo-heteroborane isomeric structure Stability Density functional theory(,DFT) prediction

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Theoretical Studies on the structures and Reactions of Halocarbenoids(Ⅰ)structures and Stability of Chlorocarbenoid CHCl_2

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Chemical Research in Chinese Universities 1997年第3期13卷 256-261页

作者： Li LI Ji-hai, FENG Sheng-yu,Liu Wei (Chemical College,Shandong University,Jinan, 250100) SHANDONG UNIV CHEM COLLJINAN 250100PEOPLES R CHINA

The chlorocarbenoid , CHCl2Li , was studied by means of ab initio molecular or- bital theory. Three equilibrium structures and two isomerization transition states were located. The calculations showed that the three-membered ring structure is the most stable. The 'classical tetrahedral' structure is not the local minimum on the potential energy surface.

关键词： Chlorocarbenoid isomeric structure Ab initio molecular orbital calcu- lation

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