Electronic structure of imides by UV photoelectron spectroscopy and INDO/S calculations: hydantoin and urazole

Abstract He(I) excited photoelectron spectra of hydantoin, 1-methylhydantoin and urazole are presented and discussed. The spectra are assigned by comparison with the spectrum of succinimide and by INDO/S calculations. The electronic structure of the imido group of succinimide is not substantially perturbed by the replacement of one or two CH 2 groups by NH groups. The HOMO is mainly localized on the additional nitrogen atoms in both the title compounds.