PREPARATION AND CHARACTERIZATION OF ZIRCONIUM-PHOSPHATE PHOSPHONATES,ZRPO4(H2PO4)1-X(RPO2OH)X.NH2O WITH GAMMA-LAYER STRUCTURE (R = CH3, C3H7, C6H11)

The gamma-zirconium phosphate phosphonates, ZrPO4(H2PO4)1-x(RPO2OH)x.n H2O (R = CH3, C3H7, C6H11), have been prepared by total or partial rep lacement of the interlayer dihydrogen phosphate groups of gamma-ZrPO4H 2PO4.2H2O with RPO2(OH)- groups of the corresponding phosphonic acids. The following compounds: gamma-ZrPO4CH3PO2OH.2H2O (interlayer distanc e = 12.8 angstrom); gamma-ZrPO4C3H7PO2OH.1.2H2O (interlayer distance = 15.1 angstrom) and gamma-ZrPO4(H2PO4)0.33(C6H11PO2OH)0.67.H2O (interl ayer distance = 16.9 angstrom) were obtained. The partial replacement of H2PO4- groups when cyclohexyl phosphonic acid was used seems to be due to steric hindrances in the interlayer region. Some considerations on the structure of these compounds as well as some preliminary ion e xchange and intercalation properties are also reported.