The metal–ligand bond in tropolone complexes of aluminium and silicon. A study based on X-ray emission and X-ray photoelectron spectra
X-Ray photoelectron and X-ray emission (Al-Kβ1,3, Si-Kβ1,3, O-Kα) spectra from the tris(‘tropolonate’) complexes [Al(C7H5O2)3] and [Si(C7H5O2)3][PF6] have been measured. These spectra show that the bond between the ligand and aluminium or silicon has both σ and π components. This observation is rationalised using simple molecular orbital theory.