Electronic transitions of hydrogen bonded complexes: an electron energy loss spectroscopic study

Electronic spectra of hydrogen bonded complexes have been studied by electron energy loss spectroscopy and assignments made based on experimental orbital energies from HeI photoelectron spectra and molecular orbital calculations. Electronic transitions of diethyl ether-HCl and SO2·HCl complexes show small shifts from those of HCl and the free electron donor, as expected of weakly interacting systems. Electronic spectra of the dimers of formic and acetic acids are markedly different from those of the monomers. Dimers show characteristic n→π* and π→π* transitions in the 7–11 eV region.