Knowledge Bank

CH/D-Ne complexes were generated in a free-jet expansion, and detected by laser excitation of bands associated with the $CH/DA2\Delta -X2\Pi$ and $B2\Sigma -X2\Pi$ 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 $B\prime \prime =0.149cm-1$. Hence the van der Waals bond lengthens on excitation to the B state. Two strong complex features were seen in conjunction with the monomer $A-X0-0$ 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.