Hydrothermal synthesis and characterization of a novel bimetallic polyoxocation, [Cu6(dtbbpy)6Mo7O26]2+ (dtbbpy=4,4′-ditertbutyl-2,2′-biyridine)

The hydrothermal reaction of CuSO4·5H2O, MoO3, 4,4′-ditertbutyl-2,2′-biyridine and H2O in the mole ratio 2:1.5:1:2500 yields [Cu6(dtbbpy)6Mo7O26]2[Mo8O26]·26H2O (1·26H2O). The structure of 1·26H2O consists of discrete α-[Mo8O26]4− anions and [Cu6(dtbbpy)6Mo7O26]2+ cations. The polyoxocation is constructed of an equatorial ring of three edge-sharing {MoO6} octahedra, capped on one face by a {Mo3Cu3O6} ring of corner-sharing molybdenum tetrahedra and copper square pyramids, and on the second face by a {Cu3MoO4} unit.