Conformation selective electronic excitation of iodocyclohexane and Franck-Condon region photodissociation dynamics from emission spectroscopy

Conformation selective resonance emission spectra are reported for gas-phase iodocyclohexane with excitation wavelengths of 199.8 and 204.2 nm. These spectra reveal seven Franck-Condon active vibrational modes for the axial conformation and eleven Franck-Condon vibrations for the equatorial conformation, and indicate that the initial dynamics on the B- and C-states have a complex multidimensional character with contributions from the CCC, CCH and HCI bending motions, torsional motions, and CI, CC, and CH stretching motions for both conformations. The resonance emission spectra are generally consistent with the previously reported assignments of the far ultraviolet absorption spectra.