A spectroscopic study of the excited states of dimethylzinc, dimethylcadmium, and dimethylmercury

The absorption cross sections of dimethylzinc, dimethylcadmium, and dimethylmercury are measured from 3000 to 1750 Å using a computerized spectrometer with 0.6 Å resolution. Structured continua with long progressions of vibrational peaks are observed for all three molecules. This vibrational structure, which is explained by a direct, asymmetric dissociation process resulting in a methyl radical and a metal–monomethyl molecule, is identified with vibrational modes in the fragments. A discussion of the electronic states of metal–alkyl molecules is given.