Theoretical Study of Decomposition Mechanism of Azoisobutyronitrile

The decomposition mechanisms of azoisobutyronitrile were systematically investigated. Density function theory B3LYP/6-311G*, B3LYP/6-311+G* and BHandH/6-31+G** methods were employed to optimize the geometry parameters of the reactants, transition states, possible intermediates and products based on the detailed potential energy surfaces scanned with AM1. The reaction mechanisms were also analyzed theoretically. The results indicate that the decomposition of azoisobutyronitrile is a two-bond (three body) synchronouscleavage process in the ground state (CH3)2CNC-N=N-CCN(CH3)2→2(CH3)2CNC·+N2; and is a twobond asynchronous cleavage process while in the triple state (CH3)2CNCN=N-CCN(CH3)2→(CH3)2CNCN=N· · ·CCN(CH3)2→2(CH3)2CNC·+N2. The calculations rationalize and verify all experimental facts.