Electronic absorption spectra of photoreaction intermediates of 7-hydroxyquinoline monomer in a low-temperature argon matrix and time-dependent density-functional-theory calculations

Electronic absorption spectra of three photoreaction intermediates produced from 7-hydroxyquinoline monomer in a low-temperature argon matrix were measured. By comparison with the calculated spectral patterns obtained by the time-dependent density-functional-theory calculation, the absorption bands around 460, 360 and 260 nm were assigned to the keto form, quinolinoxyl radical, and 7-ketene, respectively.