溴代类卡宾H_2CMBr(M=Na,K)的结构与稳定性

Structures and Stabilities of Brocarbenoids H_2CMBr(M = Na,K)

本文用RHF/3-21G解析梯度方法研究了溴代类卡宾H_2CMBr(M=Na,K)势能面的主要特征,得到了它们各自的三种平衡构型及两种异构化的过渡态构型,并用二级微扰方法进行了能量的相关能校正,计算了振动频率,以确证平衡构型和过渡态.计算结果表明,溴代类卡宾H_2CMBr(M=Na,K)的三元环构型是最稳定的几何构型,其它的两种构型σ-配合物和p-配合物,也是势能面上的极值点,但能量相对较高,不稳定.本文分析了各构型的特点,对其化学反应特性进行了评估.

Main characters of the potential energy surface of brocarbenoids H2CMBr(M= Na,K) have been studied by RHF/3 - 21G* gradient method. Three equilibrium structures and two isomerization transition states are located. The electron correlation energies have been calculated at the second - order (MP2) perturbation theory and harmonic vibrational frequencies have also been executed. Energies of the equilibrium states are in the order of 1 (three-membered ringform)<3(p - complex)<2(σ- complex). 1 is predicted to be the form in which H2C MBr exists and takes part in reactions. The Mulliken populations and zero ?point energies are also given.