HYDROTHERMAL SYNTHESIS AND CHARACTERIZATION OF 2 VANADIUM ORGANOPHOSPHONATES - VO(C6H5PO3)1-Y(CH3PO3)Y-BULLET-1.5H2O, Y = 0.50 AND 0.75

Synthesis of phases in the VO(C6H5P03)1-y(CH3PO3)y.xH2O system has been investigated by reaction Of V2O3+C6H5PO3H2+CH3PO3H2 under hydrothermal conditions at 200-degrees-C. Two discrete compounds with compositions, VO(C6H5PO3)0.50(CH3PO3)0.50.1.5H2O and VO(C6HPO3)0.25(CH3PO3)0.75.1.5H2O, have been isolated. A continuous solid solution series of the type found in some similar zirconium organphosphonate systems is not observed under the synthesis conditions used here. Both intermediate compositions are layered compounds with interlayer separations of 11.2 and 19.4 angstrom for y = 0.5 and 0.75 respectively. On the basis of the compositions, the X-ray powder diffraction data, and the results of magnetic susceptibility measurements, structural models for the two compounds are proposed. The data indicate that the y = 0.75 phase is an unusual example of a regularly interstratified inorganic-organic layered compound.