Electron states of 1:2 addition compounds of TiCl₄ with diethyl ether and diethyl sulfide: hel photoelectron and electron energy loss spectroscopy studies

Abstract

Electron states of 1:2 addition compounds of TiCl₄ with diethyl ether and diethyl sulfide in the vapor phase have been studied by HeI photoelectron (UVPES) and electron energy loss spectroscopies (EELS). The peaks in the photoelectron spectra of the complexes are assigned by comparison with the orbital energies from ab initio MO calculations on model compounds TiCl₄-2(CH₃)₂O and TiCl₄-2(CH₃)₂S. Lone pair orbitals of chlorine are shifted to lower binding energy by 1.6 eV; the π type oxygen lone pair is shifted to higher binding energy by 1.8 eV and the σ type lone pair of oxygen by 2.4 eV in the TiCl₄-2(C₂H₅)₂O complex. The magnitude of shifts in the Cl and S lone pairs in the TiCl₄-(C₂H₅)₂S are lower than that in the diethyl ether complex. Electronic excitation in TiCl₄ and TiCl₄-2(C₂H₅)₂O are obtained by electron energy loss spectroscopy. A band at 3.6 eV observed in the case of the TiCl₄-2(C₂H₅)₂O complex molecule is assigned to the Cl(3p) ligand to Ti⁴⁺(3d) charge transfer. An energy level diagram of the TiCl₄-2(C₂H₅)₂O was drawn from the UVPES and EELS results describing the electronic transitions in the complex molecule.