Studies on thermodynamics and kinetics about pyrolysis mechanism of carbonmatrix precursor CH3ArCH2NH2

Based on the experiment, the pyrolysis mechanism of carbon matrix precursor CH3ArCH2NH2 was further studied by quantum chemistry computation. Using th e AM1 and DFT UB3LYP/3-21G* method in Gaussian 98 program package, thermody namic and kinetic data were calculated for 5 designed pyrolysis paths of th e compound. The calculation result shows that the reaction producing CH3ArC H2. and NH2. is the main pyrolysis reaction path and the calculated activat ion energy is E-a = 230.78 kJ/mol by AM1 method and is E-a= 321.18 kJ/mol b y DFT method, which could be understood by analyzing the geometry parameter s, spin densities and charges of some atoms in reactants and free radicals produced. Compared with experimental data of bond enthalpy, the calculated results by DFT coincide well, The geometry parameters of the produced free radicals also shows that, after the compound CH3ArCH2NH2 as carbon matrix c ompound are pyrolyzed, the plane orientation of the produced free radicals will benefit the formation of a fused aromatic ring structure.