ME08		10min4:00

L. A. KALEDIN, J. P. PARRISH AND M. C. HEAVEN, Department of Chemistry, Emory University, Atlanta, GA 30322.

The laser absorption spectrum of the TiCl⁺ molecular ion was observed for the first time in a hollow cathode discharge. The discharge was driven at 25 kHz at powers in the range of 80-100 W. Peak currents of 0.5 A occured during the conducting half-cycles. Flowing samples of TiCl₄ in Ar were discharged. 235 lines of the ⁴⁸Ti³⁵Cl⁺ [17.9]³ -X³ (0,0) band and 122 lines of the ⁴⁸Ti³⁷Cl⁺ [17.9]³ -X³ (0,0) band were recorded at resolution 0.02 cm^-1. This band system was observed previously in the emission spectrum of TiCl⁺ but the electronic assignments for the lower and upper states of the transition are revised here. Rotational constants (in cm^-1) and internuclear distances r₀ (in nm) for the [17.9]³ (v=0) and X³ (v=0) states of ⁴⁸Ti³⁵Cl⁺ and ⁴⁸Ti³⁷Cl⁺ are respectively:

TABLE

These results are in excellent agreement with the predictions based on the ligand field theory models . The symmetry for the ground state of the TiCl⁺ molecular ion is determined to be X³ . Work supported by AFOSR under grant F19628-90-C-025.