Synthesis and characterization of Ti₅Te₄-type molybdenum cluster compounds, A_xMo₅As₄(A = Cu, Al, or Ga)

Abstract

A new series of molybdenum cluster compounds of the general formula A_xMo₅As₄(A = Cu, Al, or Ga) has been synthesized. They are isostructural with the host Mo₅As₄(Ti₅Te₄-type) consisting of trans-vertex shared Mo6 octahedral chains. Investigations by X-ray photoelectron and Auger electron spectroscopies revealed a charge transfer from A to Mo₅As₄ in A_xMo₅As₄. The occurrence of metallic (Cu_xMo₅As₄) and non-metallic (Al₂Mo₅As4 and Ga₂Mo₅As₄) properties in this isostructural series of solids is consistent with the electronic structure of Ti₅Te₄-type solids involving M-M bonding in the cluster chains.