Photoelectron spectra of metal tetrahydroborates

Abstract

Helium-(I) and -(II) excited photoelectron spectra of the metal tetrakis(tetrahydroborates) M(BH₄)₄(M = Zr, Hf, or U) and the He(I) spectrum of Al(BH₄)₃ are reported. A simple molecular-orbital model is developed to account for features in the spectra associated with ligand ionizations. Final-state structure and cross-section variations for the outermost metal f subshells in U(BH₄)₄ and Hf(BH₄)₄ are discussed in relation to the expected atomic behaviour.