EMI Y. OKABAYASHI, TOSHIAKI OKABAYASHI AND MITSUTOSHI TANIMOTO, Department of Chemistry, Faculty of Science, Shizuoka University, Oya 836, Shizuoka.

The rotational spectrum of platinum monocyanide, PtCN, was observed by employing a source-modulation microwave spectrometer. The PtCN species was generated in a dc glow discharge through the mixture of CH3CN and Ar by a sputtering reaction with a platinum sheet on a cathode. Paramagnetic lines were observed every 6GHz and assigned to three isotopomers, 194PtCN, 195PtCN, and 196PtCN. There was no Lambda-type doubling, but hyperfine splitting due to 195Pt nucleous for 195PtCN. The hyperfine structure could be fitted to either 2 Pi3/2 or 2 Delta5/2 case(c) Hamiltonian within experimental error.

%From analysis of the huperfine strucuture, the ground states was found to be Omega=3/2

The nuclear - spin interaction constant CI was derived to be around 0.2 MHz, which was one order of magnitude larger than that of 195PtCO (CI = 0.0242 MHz). This result implies that low-lying electronic states would exist comparatively near to the ground electronic state, as in the case of NiCN.