Tetrahedral d0 and d10 transition metal ions sharing edges in the solid state: electronic structure and bonding

Abstract

The bonding and electronic structure in one- and two-dimensional copper–vanadium sulfides, based on tight binding band calculations, has been studied. Theoretical evidence for the existence of weak donor–acceptor interactions from the d¹⁰ copper(I) ion toward the empty d orbitals of V^V is discussed. Maximization of the number of d¹⁰–d⁰ interactions explains the structural choice among alternative distributions of the transition metal ions within the sulfide matrix. The double chains of Ba₂Cu₃VS₆ and the layers of KCu₂VS₄ have an electron deficiency associated with the presence of hypervalent sulfur bridges that slightly enhances the Cu· · ·V interaction.