HIGH-RESOLUTION ELECTRONIC SPECTROSCOPY OF ZNCH3 AND CDCH3

ZnCH3 and CdCH3 radicals have been prepared in a cold supersonic free jet expansion and their laser-induced-fluorescence spectrum recorded f or the A 2E <-- X 2A1 electronic transition. These spectra show well r esolved rotational and spin structure, which has been completely analy zed. This analysis yields the rotational constants and the components of the spin-rotation tensors in the A and X states of both radicals. T he observed constants are discussed in terms of the electronic structu re of the radicals. It is demonstrated that the upper F2 spin-orbit co mponent of the A 2E state of CdCH3 is strongly perturbed by another, d issociative electronic state. This leads to some predissociation of th e A 2E3/2 Component and a broadening of its lines. The rotational and fine structure in this state is also quite perturbed leading to an unu sual, but still interpretable spectrum.