A new octa-Mn-substituted poly(polyoxotungstate).

A novel octa-Mn-substituted silicotungstate (ST) [H2N(CH3)2]8H19Na4{[K(H2O)4WO4][SiMnW10O38]3}[SiMnW10O38]·27H2O (1) has been made by the hydrothermal reaction of the trivacant [A-α-SiW9O34]10- ({SiW9}) building block with Mn2+ and Mn7+ cations in the presence of dimethylamine hydrochloride and systematically characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD) and single crystal X-ray diffraction. 1 is a tetrameric cluster formed by a hexa-MnII substituted cyclic trimeric {[K(H2O)4WO4][SiMnW10O38]3} unit and a {SiMnW10O38} fragment via two W-O-MnIII linkers. Furthermore, its electrochemistry, thermal stability and magnetic properties have been studied.