Structure and vibrational spectra of tungstovanadate compounds containing an anion of the Keggin type. The structure of the salt (C2N2H10)2[VW11V1O40]·6H2O

An x-ray structural study of single crystals of (C2N~HI0) 2 • [VWIIVIO40].6HzO has been carried out (Syntex P21 automatic diffractometer, MoK~ radiation, 1242 reflections). The unit cell parameters are: a = 16.295(3), c = 27.917(14) ~, V = 6419.6 ~3, dcalc = 4.66 g/cm 3, Z = 6, space group R3-m. The basic fragments of the structure are: a) a Keggin heteropolyanion (HPAn) with a V atom at the center; b) water molecules joining the HPAn to one another; and c) statistically disordered EDA molecules (not located structurally), whose presence in the compound was confirmed by chemical analysis and vibrational spectroscopy. It has been shown possible to use the IR and Raman spectra to identify compounds of this type.