15min:
LASER EXCITATION AND DISPERSED FLUORESCENCE SPECTRA OF PtC2.

ROBERT R. BOUSQUET, HIYUN KIM, TIMOTHY C. STEIMLE, Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287.

The laser excitation spectrum of molecules produced in a molecular beam formed by laser ablation of a platinum rod in the presence of a methane/argon mixture in a supersonic free-jet expansion has been recorded. A series of bands observed at 18200, 18440 and 18660~cm-1 is attributed to PtC2. The molecule is proposed to have a T-shaped structure with C2v symmetry, analogous to YC2 . The dispersed fluorescence spectra observed by pumping the bands show progressions in both nu2 (a1, Pt-(C2) st. ) and nu3 (b2, Pt-(C2) rock ) in addition to several bands involving combinations of these modes. Preliminary analysis has yielded frequencies nu2'' = 485 cm-1 and nu3'' = 223 cm-1. Isotopic substitution spectra have also been recorded using carbon-13 substituted methane in the carbon source. A discussion of the vibrational analysis will be given.