LASER EXCITED SPECTRA OF THE SINGLET MOLECULAR OXYGEN-IODINE REACTION AND POPULATIONS OF INTERMEDIATE STATES

Author Institution: Laboratolre de Spectrometrie lonique et MoleculatreAs reported in the previous paper the mechanism of dissociation of $1_{2}$ by $O_{2}$ Is poorly known. It is a multi-step process. In order to find the Intermediate states of l2 involved we have systematically explored excitation spectra of the flame with a dye laser pumped by a copper vapour laser. Moreover some high resolution spectra have been obtained in the 810 -830 nm range with a styryl dye pumped by an $Ar^{4}$ laser. From inversion of the excitation spectra we have found that high vibrational levels of the $l_{2}$ ground state until $v \sim 45$ are involved. These vibrtional populations vary with the region of the flame explored. With a frequency doubled dye laser we succeeded to detect a relatively high population of the $A^{\prime}2u$ state through $A^{\prime}2u$ state through $A2u \rightarrow D2g$ excitation. Unfortunately the D2g state is spectroscoplcally too poorly known to obtain relable inversion of the spectra