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 techn iques in the range 162-371 GHz. These data are the first high resoluti on measurements of this symmetric top species. The K=0, 1, 2, and 3 co mponents in each of seventeen rotational transitions of SrCH3 were obs erved, including fine structure splittings. Rotational and spin-rotati on parameters have been obtained for SrCH3, and its structural and ele ctronic properties are compared with those of other strontium radicals and metal monomethyl compounds. Substantial spin-orbit interactions a ppear to influence the fine structure splittings in these metal monome thyl species.