			10min:

LABORATORY DETECTION AND PURE ROTATIONAL SPECTRUM OF VCl⁺ BY VELOCITY MODULATION SPECTROSCOPY.

D. T. HALFEN AND L. M. ZIURYS, Department of Chemistry, Department of Astronomy, and Steward Observatory, University of Arizona, Tucson, AZ, 85721.

The pure rotational spectrum of VCl⁺ has been measured using millimeter-wave direct absorption techniques incorporating velocity modulation for ion selection. This work is the first laboratory observation of this species. VCl⁺ was created in an AC glow discharge of gas-phase VCl₄ and argon. Rotational transitions of the ³⁵Cl and ³⁷Cl isotopomers have been measured originating in four fine structure components of this ion, each which exhibit hyperfine structure arising from the ⁵¹V nuclear spin (I = 7/2). The current data suggest a ⁴ Phi _r or ⁴ Delta _r ground state. Additional spectroscopic measurements are in progress and the latest results will be presented.