Electronic structure and photoelectron spectroscopy of Al(Me3CNCHCHNCMe3)2 and Ga(Me3CNCHCHNCMe3)2

Abstract

The He I and He II spectra of M(Me₃CNCHCHNCMe₃)₂(M = Al or Ga) have been recorded. A complex band structure arising from ionization of the π₃ levels of the diazadiene ligands can be understood by reference to the structural distortion from idealized D_2d symmetry observed in the ground state. Other higher-lying bands are assigned to π₂ and n₊ and n_– ionizations. The electronic structure of the neutral molecules is discussed and the differences in bond lengths between the rings is attributed to a Jahn–Teller distortion that traps two electrons in the π₃ orbital of one ring and one in the π₃ orbital of the other.