Spectral Analysis and Photofragmentation Dynamics of the Perdeuteromethoxy Radical

The ÃA1 -X̃2E electronic spectrum of the CD3O radical has been investigated in detail. By using a variety of techniques, including rotational structure analysis, over 65 bands terminating on different vibronic levels of the à state have been assigned. The branching ratios for fluorescence decay vs photofragmentation of these same levels have also been determined. The detailed spectroscopic mapping of the à state vibronic structure is used to interpret the dynamical observations. The fragmentation is found to be rather mode specific, with ν3, the C-O stretch, being a major promoting mode, while ν2, the umbrella motion, is not. Unexpectedly the methyl rock, ν6, also appears to be an effective promoting mode.