AB-INITIO STUDY ON PHOTOLYSIS OF CHLORINE NITRATE AND ITS ISOMERS (II) - INVESTIGATION OF REACTION-MECHANISM OF CLONO2-]CLO+NO2

The reaction mechanism of photolysis for chlorine nitrate that causes ozone lost in the stratosphere ClONO2 --> ClO + NO2 has been studied b y using ab initio calculation method. Two transition states TS2a and T S2b have been found, but it is difficult to overcome so high energy ba rrier to get to TS2a, and it is easy to pass TS2b over 4.20 similar to 4.35 eV energy barrier from the initial state(conformation (B) or (D) ) to the final state. However only 1.20 eV is required to pass TS2b fr om ClO+NO2 to ClONO2, so reaction path (2) is a reversible reaction.