Theoretical studies on kinetics of isomerization reaction for 1, 5-diamino-tetrazole

The electronic properties of 1, 5-diamino-tetrazole(DAT) and isomerization reaction kinetics were studied based on density functional theory. The geometry structure, vibration frequencies, natural bonding orbital, and zero point energy (ZPE) of stationary points involved in the reaction was calculated at B3LYP/6-311G level of theory. The intrinsic reaction coordinate theory (IRC) was used to obtain the minimum energy path (MEP). The reaction potential energy curve was obtained by calculating the single point energy with CCSD (T) method. The rate constants are evaluated from 200 to 1000 K using transition state theory (TST), TST/Eckart and Canonical variational transition state theory (CVT). Results show that N(4) and N(9) in DAT molecule participate easily in coordination with metal atoms, forming a series of coordination compounds. The isomerization reaction for DAT displays azide-cyclization mechanism. At gaseous case, the reaction is exothermic and spontaneous, with lower reaction activation energy.