Knowledge Bank

Rotationally resolved spectra for the CH/D-Ne $B2\Sigma -X2\Pi$ transition were reported $recently1$. Despite the low temperature conditions used to record these spectra $(\approx 4K)$, the analysis indicated the presence of "hot" bands. Fluorescence depletion techniques have been used to establish the hot band assignments unambiguously. These measurements also lead to reassignment of the ground state rotational structure, and determination of the ground and excited state dissociation energies $(D0\prime \prime =26.8,D0\prime =19.9cm-1)$. Subsequent modeling of the ground state shows that the diatomic spin-orbit coupling has been partially quenched by the interaction with Ne. These results have been interpreted using ab-initio potential energy surfaces. Laser excitation spectra for the $A2\Delta -X2\Pi$ transition of CH/D-Ne show complicated fine structure that it difficult to assign. Fluorescence depletion techniques are being used to establish excited state assignments. Specific rotational lines of the B-X system are excited by the monitor laser, in order to generate easily labeled A-X fluorescence depletion spectra. Preliminary results have yield an A state zero-point rotational constant of $0.136cm-1$ and dissociation energy of $D0\prime =23.2cm-1$. Further analysis of the D state structure will be presented. Work supported by NSF under grant CHE-9320094