Studies on the reactions BrNCX→BrXCN (X=O, S, Se)

The reactions of BrNCO to BrOCN, BrNCS to BrSCN and BrNCSe to BrSeCN have been studied at MP2/6-311++G(2df)//B3LYP/6-311++G(2df) level. Geometries of the reactants, transition states and products have been optimized and geometries of the transition states are found for the first time. The reasons of why BrNCO, BrSCN and BrSeCN are easily detected instead of BrOCN, BrNCS and BrNCSe have been explained successfully. The breakage and formation of the chemical bonds in the reactions have been discussed by the topological analysis method of electronic density. The calculated results show that there are two kinds of structure transition states in topic reactions. [Copyright &y& Elsevier]