Ultraviolet photoelectron spectroscopy of complexes of bromine with n-donors in the vapor phase

Abstract

He I photoelectron spectra of gas-phase complexes formed by Br₂ 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 Br₂ 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 Et₂O...Br₂ and a C_s form for Et₂S...Br₂. The nature and magnitude of the interactions are found to be comparable as reflected by the computed binding energy and quantum of charge transfer.