AB-INITIO STUDY OF XOCLO3 (X=CL, F, AND H) - IMPLICATIONS FOR FORMATION OF CLOCLO3 IN THE STRATOSPHERE

Although OClO photolysis was one of the first photochemical reactions to be studied, the primary photochemistry of OClO still remains contro versial. Several studies have demonstrated that Cl2O4 is one of the ma jor photolysis products of OClO, in addition to ClO + O and ClOO Thus there is a need to analyze the chemical properties of Cl2O4 and its re lated species. In the present study we have investigated the equilibri um structures and harmonic vibrational frequencies of chlorine perchlo rate (Cl2O4), fluorine perchlorate (FOClO3), and hydrogen perchlorate (HOClO3) at Hartree-Fock and MP2 levels using 6-31G basis set. Normal mode analysis has been carried out using ab initio derived force fiel ds at the correlation level for the 6-31G basis set. The calculated f requencies of XOClO3 (X = Cl, F, and H) molecules are discussed in com parison with those determined from experiment and with the correspondi ng vibrations of Cl2O7. In addition, the paper draws attention to the possible role of Cl2O4 formation in the polar stratosphere with releva nce to ozone layer depletion.