SPECTROSCOPIC AND CRYSTAL STRUCTURE INVESTIGATION OF A NEW BISMUTH (III) CONTAINING POLYOXOMETALATE CLUSTER

A new polyoxometalate cluster containing bismuth (III) was synthesized as a neutral salt. The cluster, which corresponds to the formula Na11H[H(2-x)Bi2W20O70(HWO3)center dot 46H(2)O (x = 1.4), comprises two Bi-III heteroatoms with an unshared electron pair and W-VI atoms as metal centres. Structural investigation of the new substance was performed by FT-IR, Raman, electronic spectroscopy and by X-ray diffraction, as well. According to the single-crystal X-ray diffraction analysis, the [H(2-x)Bi2W20O70(HWO3)(x)](12-) (x=1.4) polyoxometalate molecule consists of two B beta-[BiW9O33] pseudo-Keggin type units, which are connected by two WO2 and by two facial WO2(OH) groups. The determined molecular formula, which can be abbreviated as Bi2W21.4, shows that the new polyoxometalate is a mixture of the complete parent cluster Bi2W22 and of its dilacunary derivative Bi2W20, in a proportion of 70% : 30%.