The pure rotational spectrum of the ground vibrational state of SrCH3(X̃ 2A1)

The pure rotational spectrum of the SrCH3 radical (X̃ 2A1) has been recorded using millimeter/sub-mm direct absorption techniques in the range 162–371 GHz. These data are the first high resolution measurements of this symmetric top species. The K = 0, 1, 2, and 3 components in each of seventeen rotational transitions of SrCH3 were observed, including fine structure splittings. Rotational and spin-rotation parameters have been obtained for SrCH3, and its structural and electronic properties are compared with those of other strontium radicals and metal monomethyl compounds. Substantial spin-orbit interactions appear to influence the fine structure splittings in these metal monomethyl species.