Vk. Turchaninov et al., THE STUDY OF BENZIMIDAZOLES .8. THE RELATION BETWEEN THEIR UV AND PHOTOELECTRON-SPECTRA, Russian chemical bulletin, 42(10), 1993, pp. 1683-1689
The nature of the first two long-wave bands in the UV spectra of 2-sub
stituted benzimidazoles has been analyzed on the basis of photoelectro
n spectra (PES). Three basic types of spectroscopic situations are typ
ical of these compounds: 1) a change in the sequence of the occupied M
O of the ground state does not influence the order of the excited ener
gy levels; 2) when the pi-levels are in the same order, inversion of t
he excited states occurs; 3) reversal of the occupied pi-MO of the gro
und state causes the inversion of the excited states.