ROTATIONALLY-RESOLVED ELECTRONIC SPECTRA FOR THE CH-Ne and CD-Ne VAN DER WAALS COMPLEXES

Abstract

CH/D-Ne complexes were generated in a free-jet expansion, and detected by laser excitation of bands associated with the $CH/D A^{2} \Delta-X^{2} \Pi$ and $B^{2}\Sigma-X^{2}\Pi$ transitions. The monomer B-X 0-0 and 1-0 transitions were each accompanied by four strong features of the complex. Rotational analysis of the origin band yielded rotational constants of (CH-Ne) $B^{\prime}=0.117$ and $B^{\prime \prime}=0.149 cm^{-1}$. Hence the van der Waals bond lengthens on excitation to the B state. Two strong complex features were seen in conjunction with the monomer $A-X 0-0$ transition. The rotational structures of these features were much more congested than those of the $B-X$ bands. A preliminary analysis yields an A state rotational constant which is slightly larger than that of the ground state, implying that the intermolecular bond shortens on excitation to the A state. Results from detailed analyses of the $A-X$ and $B-X$ systems will be presented.