Polymerization of MoV: Synthesis and Characterization of a Dinuclear MoV and a Hexanuclear Mixed‐Valence MoV/MoVI Complex

Abstract

Abstract1,3,5‐Trideoxy‐1,3,5‐tris(dimethylamino)‐cis‐inositol (tdci = L) reacts with MoCl5 in a mixture of MeOH/water at 80 °C to yield the pale purple syn‐[Mo2O4H(L)2]Cl3·14.5H2O (1Cl3·14.5H2O). Crystal data: space group P21/n, a = 8.797(2) Å, b = 25.439(5) Å, c = 23.077(5) Å, β = 90.44(3)°, V = 5164(2) Å3, Z = 4 for C24H84Cl3Mo2N6O24.5. In solutions of the dinuclear 13+, which were exposed to air for several weeks, slow formation of deep red crystals containing a novel, hexanuclear, mixed‐valence complex of composition [Mo4O8(L)2(MoO4)2]·≈27H2O (2·≈27H2O) was observed. The tetranuclear core of complex 2 was unambiguously identified by MS‐FAB spectrometry, and the entire structure was characterized by a crystal‐structure analysis: space group P21/c, a = 12.224(2) Å, b = 15.986(3) Å, c = 14.220(3) Å, β = 98.95(3)°, and V = 2744.9(9) Å3, Z = 2 for C24H109Mo6N6O49.5. The structure of the hexanuclear mixed‐valence complex 2 contains the well‐known [Mo4O8]4+ core in which two of the four MoV centers bond to MoVIO4 units by corner sharing. The remaining two MoV centers are each chelated by a tdci ligand. Cyclic voltammetry confirmed an irreversible reduction and oxidation of 13+ at a potential of about –1.15 V and +0.54 V vs. NHE, respectively. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)