Reaction of N(2D) atoms with bromomethyl radicals: A theoretical study

The singlet potential energy surface for the N(2D) + CH2Br reaction has been studied employing both MP2 and DFT(B3LYP) methods. The energies of the involved species have been refined using the G2, CBS and CCSD(T) methods, respectively. The reaction proceeds through the formation of an initial intermediate which does not involve any activation barrier. Based on the singlet PES, the most exothermic products result from elimination of either HBr or H2, instead of elimination of either Br or H. The preferred channel is predicted to be HCN + HBr. The analysis of the possible spin crossing between the triplet and singlet [CH2NBr] potential surfaces suggests that the N(4S) + CH2Br reaction should take place with no change in the spin angular momentum.