Ab initio study of the thermal isomerization of quadricyclane to norbornadiene

被引：13

作者：

Qin, CY ^{[1
]}

Zhao, ZD ^{[1
]}

Davis, SR ^{[1
]}

机构：

[1] Univ Mississippi, Dept Chem & Biochem, University, MS 38677 USA

来源：

JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM | 2005年 / 728卷 / 1-3期

基金：

美国国家科学基金会;

关键词：

isomerization; biradical; transition state;

D O I：

10.1016/j.theochem.2005.04.036

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

CASSCF calculations have been performed to understand the thermal isomerization of quadricyclane (Q) to norbornadiene (N) which occurs via aWoodward-Hoffmann forbidden pathway. The activation barrier is calculated to be 34 kcal mol(-1) at the MCQDPT2/6-31G(d,p) //MCSCF(8,8)/6-31G(d,p) level, consistent with the 33 kcal mol(-1) experimental value of Frey [H.M. Frey, J. Am. Chem. Soc. (1964) 3651. The transition state has high biradical character and the structure belongs to point group C-1, whereas both Q and N belong to point group C-2V. The reaction is found to be highly asynchronous with one bond cleaving entirely before the transition state and the second bond cleaving afterward on the intrinsic reaction coordinate. (c) 2005 Elsevier B.V. All rights reserved.

引用

页码：67 / 70

页数：4