Abstract: The isomerization reactions of IClO2 were studied by density functional theory. Seven isomers were optimized and two newisomers (OIClOand IClOO) were gained, IRC calculations were also been processed to validate the connection relationship of the isomers. From the view of topological analysis of the electronic density, the topological characters of the major critical points along the reaction pathway were analyzed, the changing rules of the chemical bonds were discussed, and the energy transition states (ETS) and structure transition states (STS) were found.

Key words: IClO2, Isomerization, Energy transition state, Structure transition states