Jahn—Teller coupling in the [Xtilde] 2E ground states of the CF3O and CF3S radicals

The Jahn—Teller and spin—orbit coupling in the ground states of the CF3O and CF3S radicals have been investigated experimentally by dispersed fluorescence spectroscopy. These spectra are analysed using a theoretical model that simultaneously includes spin—orbit coupling and multimode Jahn—Teller coupling, both linear and quadratic. We find that in each of these radicals a moderate linear Jahn—Teller effect exists in ν6, with a much smaller coupling in ν5. These results are compared and contrasted with those for the related radicals CH3O and CH3S. The experimental data and theoretical analyses of these four radicals represent the most thorough investigations to date of the combined effects of spin—orbit and Jahn—Teller coupling.