VIBRATIONAL RELAXATION AND INTERNAL CONVERSIONS IN THE CN RADICAL IN SOLID NEON

Abstract

The CN radicals are formed in. solid neon in two distinct trapping sites. The CN fluorescence following a selective excitation of individual vibrational levels of the $B^{2}\Sigma^{+}$ and $A^{2}\Pi$ electronic state was studied. The high vibrational levels of both the A and states can be populated by sequential two photon processes. The $A \rightarrow X, B \rightarrow X$, and $B \rightarrow$ A systems are all seen in emission. CN in the two sites shows a differential shift of $\sim 70 cm^{-1}$ between the A and B electronic states. The relaxation behaviour is governed by internal conversions between the A, B, and X vibrational manifolds and shows a strong multiphonon energy gap law.