title: The mechanism and kinetics of decomposition of 5-aminotetrazole.
abstract: The pathway and ab initio direct kinetics of the decomposition 5-aminotetrazole (5-ATZ) to HN(3) and NH(2)CN was investigated. Reactant, products and transition state were optimized with MP2 and B3LYP methods using 6-311G** and aug-cc-pVDZ basis sets. The intrinsic reaction coordinate curve of the reaction was calculated using the MP2 method with 6-311G** basis set. The energies were refined using CCSD(T)/6-311G**. Rate constants were evaluated by conventional transition-state theory (CVT) and canonical variational transition-state theory (TST), with tunneling effect over 300 to 2,500 K. The results indicated that the tunneling effect and the variational effect are small for the calculated rate constants. The fitted three-parameter expression calculated using the CVT and TST methods are k(T) = 4.07 x 10(11) x T(0.84) x e((-2.42 x 10(4))/T)s(-1) and k(T) = 2.09 x 10(11) x T(0.89) x e((-2.36 x 10(4))/T)s(-1), respectively.
authors.affiliation: State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, PR China. zhangjianguobit@yahoo.com.cn
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Zhang
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Feng
authors.forename: Shao-Wen
authors.initials: SW
authors.lastname: Zhang
authors.forename: Tong-Lai
authors.initials: TL
authors.lastname: Zhang
authors.forename: Hui-Hui
authors.initials: HH
authors.lastname: Zheng
mesh_terms: D000641:Ammonia / Q000138:chemical synthesis; D003486:Cyanides; D007700:Kinetics; D008958:Models, Molecular; D011789:Quantum Theory; D013777:Tetrazoles / Q000737:chemistry*
chemical_list: D003486:Cyanides; D013777:Tetrazoles; C001573:5-amino-1H-tetrazole; D000641:Ammonia; C026524:ammonium cyanide