2-硝基丙烯热解反应机理和电子密度拓扑研究

采用密度泛函DFT（B3LYP）方法，在6311G＊＊，6—311＋＋G＊＊以及cc-pvtz基组水平上，计算了2-硝基丙烯在热解反应过程中反应物、过渡态和中间体的几何结构，研究了各反应沿极小能量途径反应分子几何构型的变化，并通过电子密度拓扑分析，讨论了反应过程中化学键断裂、生成的变化规律．结果表明，2-硝基丙烯的热解反应存在2种反应机理，一是甲基上的H原子进攻硝基上的O原子直接生成CH2CCH2和HNO2，反应位垒为199．6kJ/mol；二是O原子进攻亚甲基C原子首先生成四元环状中间体，住垒为200．3kJ／mol，环状中间体进一步发生C—C键和N-0断裂生成CH2CNO和CH2O，此反应是一个一步反应，位垒为144．7M／mol，所得环状中间体的分解反应机理与现有的AM1的研究结果不同．

Pyrolytic Reaction Mechanism of 2-Nitropropene and Its DFT Study

The pyrolytic reaction mechanisms of 2-nitropropene were studied systematically by DFT(B3LYP).The geometries of the reactant,transition states and intermediates were totally optimized at 6-311G**,6-311++G** and cc-pvtz level.The geometries change of reacting molecule and charge along the MEP(mini-energy path) were discussed.Through topological analysis of the electronic density,the topological characters of the major critical points along the reaction pathway were analyzed,the change rules of the chemical b...