作　　者： ; ; ; ; ;

机构地区： 东华理工大学核工程与地球物理学院放射性地质与勘探技术国防重点学科实验室

出　　处： 《计算机与应用化学》 2011年第11期1445-1450,共6页

摘　　要： 采用B3LYP/6-31G^(**)方法在Gaussian 03程序下,对氧杂紫菜嗪,硫杂紫菜嗪的稳定结构和能量进行优化,并寻找与内氢迁移反应相关的过渡态构型。计算结果表明,芳香性与各体系构象稳定性密切相关,但并不是决定构象稳定性的唯一因素;在中心空穴较小的紫菜嗪体系中,空间位阻,静电作用才是影响构象稳定性的关键因素。由于分子内氢键的存在,氧杂化会明显降低内氢迁移正负反应速率;而S杂化体系的IHAT速率降低则与静电斥力和空间位阻密切相关。 The theoretical study of the mechanism and kinetics of the inner hydrogen atom-transfer process in oxa- porphyrazine,thiaporphyrazine was presented.The structures and energies of reactants,products and transition-states in the transfer reaction of inner hydrogen atoms in OPzH and SPzH were calculated with B3LYP/6-31G＊＊ method under certain symmetry restriction.The results show that the relative stability of conformations are directly correlated to aromaticity,but aromaticity is not the only determining factor which affects the relative stability of conformations;while in the porphyrazine systems with smaller central holes,the steric hindrance and the electrostatic interaction are more important factors which should not be neglected.The results also represent that oxa- can reduce speeds of positive and negative reactions, which is due to the existence of intra-molecular hydrogen bonds;but the decrease of HAT reaction speeds of thia-systems is resulted from steric hindrance and electrostatic interaction.

关 键 词： 内氢迁移 的互变异构化 氧 硫杂紫菜嗪 卟吩 过渡态 结构变化

领　　域： [理学]