CLASSICAL TRAJECTORY STUDY OF THE CIS-TRANS ISOMERIZATION AND F-O DISSOCIATION OF FONO

Classical trajectory calculations were carried out to investigate whet her nonstatistical behavior is exhibited in two unimolecular processes of nitrosyl hypofluorite: CI) cis-trans isomerization and (II) F-O bo nd dissociation to produce F and ONO. For this purpose, an analytical potential function that describes these two processes was developed ba sed on ab initio and experimental data reported in the literature. Tot al and individual rate constants were evaluated under two different ty pes of initial sampling conditions: microcanonical (statistical) distr ibution of vibrational energy and selective excitation of vibrational modes. Under statistical initial conditions, the rates of isomerizatio n are calculated to be substantially larger than the rates of F-O diss ociation, although the branching ratios decrease as energy increases. In addition, the isomerization and dissociation reactions are faster w hen they occur from the trans isomer. Dissociation was found to be sli ghtly faster than isomerization when energy was selectively deposited in certain vibrational modes of trans-FONO. Our results predict that b oth intrinsic and apparent non-RRKM behavior are present in the dynami cs of the processes studied.