Electronic absorption spectra of molecular cations

Abstract
The absorption spectra of the radical cations of C6F6, m‐C6H4F2 and p‐C6H4F2 in solid Ne are obtained using a novel waveguide technique to increase the effective pathlength. Sharp, structured spectra are obtained for all three ions despite the face that the quantum yields for emission from the upper state are respectively 1:10−3: −4. Broad, relatively unstructured absorptions are attributed to C6H5F+ and C6H6+.