Near UV spectra of furan and its derivatives

Abstract

Vapour-phase and solution spectra of eight furan derivatives have been investigated in the near UV region. Band systems disappearing from the solution spectra have been assigned to Rydberg transitions by comparing their vibronic envelopes with those of the corresponding band systems in the photoelectron spectra. In the case of the compounds investigated, the Rydberg transitions were found to originate from the uppermost π orbitals and terminate at 3s, 3p and 3p′ Rydberg orbitals. Solution spectra of the investigated substituted derivatives are in accordance with the presence of two valence transitions in the near UV region.