title: Synthesis, properties and X-ray crystal structure of a new heteropolyacid supermolecular charge-transfer complex [(VB1)2DMFHPMo12O40.5DMF].
abstract: The title complex [(VB(1))(2)DMFHPMo(12)O(40).5DMF, VB(1) = vitamin B(1) (thiamine chloride), DMF = N,N-dimethylformamide] has been synthesized and characterized by elemental analysis, IR, UV-Vis, electron spin resonance, X-ray photoelectron spectroscopy and cyclic voltammetry methods. The X-ray crystal structure revealed that there is one independent molecule in the unit cell of the title complex that contains one mixed-valence heteropolyanion, two VB(1)(+) cations and six DMF molecules. The title complex possesses a centrosymmetrical arrangement in the unit cell, with the P atom at the symmetry center of the heteropolyanion and with eight O atoms surrounding the central P atom, such that two sets of PO(4) tetrahedra are formed. The PO(4) tetrahedra and MoO(6)(6-(7-)) octahedra are disordered in the heteropolyanion. The bond distances of P-O(a) and Mo=O(d) are in the ranges 1.57 (4)-1.70 (4) A and 1.61 (2)-1.67 (2) A, respectively.