RYDBERG STATES OF POLYATOMIC FREE RADICALS

Open Shell acyl free radical produce closed shell cations that support sharp Rydberg states. Ion-detected absorption shows extensive structure in HCO and $CH_{3}O$. Presented here are the first resolved spectra of $CH_{3}O$ obtained by (1+1) double-resonant photoionization. These states are analyzed and used as intermediate to probe higher level Rydberg states near the ionization threshold.