FOURIER-TRANSFORM MICROWAVE SPECTROSCOPY OF LASER-ABLATED MgCl

$^{1}M.$ Bogey, C. Demuynek, and J. L. Destombes, Chem. Phys. Lett. 155, 265 (1989).Author Institution: Department of Pure and Applied Sciences, The University of TokyoRotational spectrum of the $^{24}Mg^{35}Cl$ radical in its $X^{2}\Sigma$ state has been measured using a Fourier-transform microwave spectrometer combined with a laser-ablation source. A Q-switched Nd:YAG laser (532 nm) was used to vaporize Mg atoms form a target rod located in the throat of a pulsed valve. The radical was produced by the reaction of ablated Mg with $Cl_{2}$ diluted in Ar inside a $5 mm \phi$ channel of 10 mm in length, and then pulsed through in a supersonic expansion. The $N=1-0$ transitions with fully-resolved hyperfine structure, observed at -14 GHz for the vibrational ground and the first excited states, were analyzed to derive accurate sets of spectroscopic constants, in combination with the previously reported data in the millimeter-wave $region.^{1}$ The spin-density distribution and the ionic character have been evaluated from the precisely determined magnetic hyperfine coupling and $eQq$ constants associated with the $^{35}Cl$ nucleus