Study of the upper spin-orbit state of the chloroiodomethane cation by mass-analyzed threshold ionization

The vibrational spectrum for CH2ClI+ in the upper spin-orbit state was obtained by VUV-MATI spectrometry. The frequency of Cl-C-I bending was most affected by the spin-orbit interaction. This suggests that the avoided crossing between the lower and upper spin-orbit states occurred along a direction close to the Cl-C-I bending coordinate.