The pure rotational spectrum of the ground vibrational state of SrCH3((X)over-tilde (2)A(1))

The pure rotational spectrum of the SrCH3 radical ((X) over tilde (2)A(1)) 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.