Spectral Analysis and Photofragmentation Dynamics of the Perdeuteromethoxy Radical

The à 2 A 1 −X̃ 2 E electronic spectrum of the CD 3 O 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 ν 3, the C−O stretch, being a major promoting mode, while ν 2, the umbrella motion, is not. Unexpectedly the methyl rock, ν 6, also appears to be an effective promoting mode.