A mixed-valence, hexadecamolybdenum cluster with an MoVI cubane "jewel" in a "setting" of five molybdateVI-linked dinuclear MoV units

Abstract

The hexadecanuclear, mixed-valence cluster [Mo16O 42(OH)2(3-iPrC3H3N2) 12]·n H2O (1), has been synthesized and characterized by X-ray crystallography, IR spectroscopy and mass spectrometry. The C2-symmetric complex consists of a cubane Mo4 VIO4 "jewel" held in a 10-point "setting" comprised of five dinuclear MoV units tethered together by two tetrahedral MoVI centers. The dinuclear units are ligated by twelve 3-isopropylpyrazole units that interact with the Mo-O framework through a network of hydrogen bonds. Structural parameters, charge requirements, and bond valence sum analyses support the assignment of + 5 and +6 oxidation states to the dinuclear and cubane/tetrahedral Mo centers, respec..