氢化卟吩内氢迁移反应的理论研究

Theoretical study on transfer reaction of inner hydrogen atoms inβ-dihydropor-phine

采用B3LYP／6-31G**方法在Gaussian03程序下,优化氢化卟吩的结构和能量,并寻找与内氢迁移反应相关的过渡态构型,通过比较,分析β位氢化对内氢迁移反应速率的影响。计算结果表明,β位氢化会迅速降低体系cis→trans的内氢迁移反应速率(达到10-4数量级),其影响明显高于β位取代。

A theoretical study of the mechanism and kinetics of the inner hydrogen atom-transfer process inβ-dihydroporphine （BH2 ） is presented. The structures and energies of reactants, products and transition-states in the transfer reaction of inner hydrogen atoms in BH2 are calculated with B3LYP/6-31 G＊ ＊ method under certain symmetry restriction. The calculated results show that compared with porphine （ PH2 ） , β-hydrogenation can decrease speeds of cis→trans reactions by a foctor of 10^ -4, the effects ofβ-hydrogenation are obviously larger than those of β-substitution.