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Title: Density Functional Study on the Reactivity of Carbenes Toward 1,2-H Shifts
Authors: Hu, Ching-Han
Contributors: 化學系
Date: 2001-02
Issue Date: 2012-05-03T06:17:02Z
Publisher: 中國化學會
Abstract: The 1, 2-H shifter actions of simple carbenes (CH2Y-C-X) have been studied using density functional theory (DFT). The influence of the substituent X and Y groups on the activation energy (E(subscript a)) of 1, 2-H shifits were ex am med The 'bystander' Y sub stitu ents lower E(subscript a) in the order of Me, F>C1, Br>H. Our analy sis shows that the X effect is more sig nifi cantthan the by stander Y effect. X substitutions in crease E(subscript a) of carbenes in the order of F>C1>Br>Me>H. The in flu ence of X on E(subscript a) is governed by the singlet-triplet energy separation (△E(subscript S-T)) of the carbene, i.e., E(subscript a) of a carbene is larger as its △E(subscript S-T)in creases due to an X sub stitution. The X effect was also found to be re lated to the magni hide of the exothermicity: E(subscript a) of re action is smaller when there action is more exothermic. Or I gin of the Y effect is at tribeted to the inter play between two factors late ness' of transition state on the potential energy surface, and the exothermicity of the reaction.
Relation: J. Chin. Chem. Soc., 48(1): 5-12
Appears in Collections:[化學系] 期刊論文

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