ULTRAVIOLET PHOTOELECTRON-SPECTROSCOPY OF COMPLEXES OF BROMINE WITH N-DONORS IN THE VAPOR-PHASE

He I photoelectron spectra of gas-phase complexes formed by Br-2 with diethyl ether and diethyl sulphide have been studied and interpreted using ab initio MO calculations. The key spectral features are assigned to the highest occupied molecular orbitals derived from Br-2 and the donor molecule whose ionization potentials are shifted to lower and higher binding energies, respectively. All-electron and effective core potential calculations yield a C-2v structure for Et(2)O...Br-2 and a C-s form for Et(2)S...Br-2. The nature and magnitude of the interactions are found to be comparable as reflected by the computed binding energy and quantum of charge transfer.