The spin-rotation interactions in the methoxy radical

Abstract
The spin-rotation coupling splitting in the à 2 A 1 state of CH3O has for the first time been spectrally resolved and measured using a very high resolution laser induced fluorescence apparatus. Both the spin-rotation parameters for the à state and the previously measured ones of the Xtilde; state are discussed in terms of first and second order contributions. A good understanding of all the measured constants is obtained, including the major Jahn-Teller induced contribution in the ground state.