10min:

XIAOYONG LIU, VADIM L. STAKHURSKY, ERIC D. OLMON, VLADIMIR A. LOZOVSKY, TERRY A. MILLER, C. BRADLEY MOORE, Department of Chemistry, The Ohio State University, 120 W. 18th Avenue, Columbus, OH 43210.

Multimode Jahn-Teller analysis of the e modes in the X state of the CH₃O radical has been initiated using the SOCJT program with special attention being paid to the asymmetric C-H stretch mode (n₄) for which there are several relevant experimental observations. Dispersed Fluorescence (DF) spectra have been recorded via excitation of A ²A₁ 3ⁿ4¹ (n=1,2,3) combination levels for CH₃O. DF spectra have also been obtained upon 3ⁿ(4')¹ (n=1,2) LIF excitation for the CHD₂O isotopomer. For both isotopomers the observed spectra reveal the quartet vibronic structure in the C-H stretch mode region. The observed quartet structure exhibits a large ( 130 cm^-1 for CH₃O and 160 cm^-1 for CHD₂O) separation; each component is further split into doublets ( 25 cm^-1 and 35 cm^-1 respectively for CH₃O and CHD₂O). In addition, the rotationally resolved structure of the ₄ C-H stretch band of CH₃O, recorded via stimulated emission pumping technique was compared with that recently obtained from IR spectra. The implications of the rovibronic structure for the vibronic assignments will be discussed.