UV resonance Raman studies of ClNO in solution

The first resonance Raman spectra of nitrosyl chloride (ClNO) in solution obtained with excitation resonant with the A-band are reported. For ClNO dissolved in cyclohexane, intensity is observed for transitions corresponding to all three normal coordinates: the bend, NCl stretch and NO stretch. This observation demonstrates that excited-state structural evolution occurs along these coordinates following photoexcitation resonant with the A-band. Resonance Raman depolarization ratios measured at excitation wavelengths spanning the A-band are reported. The depolarization ratios are found to be less that 1/3 consistent with at least two electronic transitions contributing to the A-band absorption intensity.