Theoretical calculations of the thermal decomposition kinetics of several tert-nitroalkanes in the gas phase

The theoretical study of the gas-phase pyrolysis kinetics of several tert-nitroalkanes, 2-methyl-2-nitropropane, 2-methyl-2-nitrobutane, and 2, 3-dimethyl-2-nitrobutane, has been carried out at the MP2/6-31G(d), B3LYP/6-31G(d), B3PW91/6-31G(d), levels of theory. The nitroalkanes yield the corresponding alkene and HNO2 gas in a rate determining step. The B3PW91/6-31G(d) method was found to give a reasonable good agreement with the experimental kinetic and thermodynamic parameters. The elimination of these reactions suggest a concerted non-synchronous five-membered cyclic transition state type of mechanism.