Anisotropic Electrical Conductivity of a Single-Crystalline Oxo-Bridged Cr₄^IIIMo₂^VI Heterometallic Complex

Abstract

A new oxo-bridged chromium–molybdenum heterometallic complex, O-CrMoHC ([Cr4(MoO4)2­O2(OAc)4(DMF)4]·2DMF), was synthesized by using a simple solvothermal reaction. In this complex, the octahedrally coordinated Cr­(III) and tetrahedrally coordinated Mo­(VI) metal centers are bridged by oxo ligands. O-CrMoHC has in-plane π-conjugation systems, which are interconnected by noncoordinating DMF molecules. The crystals show anisotropic conductivity with respect to the crystal planes, and theoretical calculations were used to study their origins. The O-CrMoHC single crystals exhibited that a relatively high electrical conductivity with an average value of 5.37 × 10–7 S/cm was observed along the [01–1] direction, but the current level was very low along the [100] direction. This is the first report of anisotropic conductivity observed in the single crystal of a monomeric heterometallic complex.