Electronic states of tetrahydrofuran molecules studied by electron collisions

Electronic states of tetrahydrofuran molecules were studied in the excitation energy range 5.5-10 eV using the technique of electron energy loss spectroscopy in the gas phase. Excitation from the two conformations, C(2) and C(s), of the ground state of the molecule are observed in the measured energy loss spectra. The vertical excitation energies of the (3)(n(o)3s) triplet state from the C(2) and C(s) conformations of the ground state of the molecule are determined to be 6.03 ± 0.02 and 6.25 ± 0.02 eV, respectively. The singlet-triplet energy splitting for the n(o)3s configuration is determined to be 0.31 eV. It is also found that excitation from the C(s) conformation of the ground state has a higher cross section than that from the C(2) conformation.