DISPERSED FLUORESCENCE SPECTROSCOPY OF $CHD_{2}O$: A PSEUDO-JAHN-TELLER MOLECULE WITH INTERESTING EMISSION SPECTRA

Abstract

Methoxy radical (CH$_3$O) is an important intermediate in the combustion of hydrocarbon fuels. It is also an interesting target for theoretical studies, since the doubly degenerate ground $\widetilde{X} ^{2}E$ electronic state exhibits Jahn-Teller (JT) activity. Upon asymmetric deuteration the electronic state splits into two pseudo-degenerate states. To address the issue of the reduction of symmetry in JT active systems we report the laser excited, dispersed fluorescence (DF) spectra of CHD$_{2}$O. A comprehensive model Hamiltonian which includes linear and quadratic JT coupling terms is developed and used to assign ground state vibronic levels up to 2000 cm$^{-1}$ above the vibrationless level. The experimental observations and intensity simulations for 5 DF traces, from the $3^{4}$, $3^{2}5^{\prime 1}$, $3^2 5^ {\prime\prime 1}$, $3^2 6^{\prime 1}$, $3^2 6^{\prime\prime 1}$ vibrational levels of the $\widetilde{A} ^2 A^{\prime}$ state, will be presented.