15min:
ROTATIONAL SPECTROSCOPY OF ZnCCH (X2 Sigma+)AT MICROWAVE AND MILLIMETER WAVELENGTHES.

J. MIN, D. T. HALFEN, M. SUN, B. T. HARRIS, L. M. ZIURYS, University of Arizona, Deptment of Chemistry and Biochemitry and Steward Observatory, Tucson, AZ-85721.

The pure rotational spectrum of ZnCCH (X2 Sigma+) has been measured using Fourier transform microwave (FTMW) and direct absorption millimeter/submillimeter methods in the frequency range of 7-260 GHz. This is the first study of ZnCCH by any spectroscopic technique. In the FTMW system, the molecule was synthesized using discharge assisted laser ablation spectroscopy (DALAS) from a mixture of 0.05% acetylene in argon and the ablation of a zinc rod. In the millimeter-wave spectrometer, the radical was created from the reaction of zinc vapor, produced in a Broida-type oven, with HCCH in a DC discharge. Spectra of the main isoplogue, 64ZnCCH, as well as 66ZnCCH, 68ZnCCH, ZnCCD and Zn13C13CH have been recorded. The data have been analyzed with a 2 Sigma Hamiltonian and rotational, spin-rotation and H, D and 13C hyperfine parameters have been determined. The structure is being calculated based on the rotational constants and will be presented. Interpretation of the hyperfine constants will also be discussed.