Published online by Cambridge University Press: 15 February 2011
The H2O3PCH(C6H4)2CH2PO3H2 and H2O3PO(C6H4)2OPO3H2 acids were synthesizedT and used to obtain new pillared zirconium phosphonates and organic phosphates in which the pillars are tilted with respect to the layers. The Zr(O3PCH2(C6H4)2CH2PO3) and Zr(O3PO(C6H4)2OPO3) obtained have a good thermal resistance and the distance between the inorganic α-layers joined by the organic pillars is 14.7 and 13.8 Å, respectively. Structural models suggest that the biphenyl groups in the solids are tilted at 140° and 137° with respect to the perpendicular at the layer plane. Solid solutions of the two derivatives over the whole range of composition have also been obtained; the distance between the α-layers changes from 14.7 to 13.8 Å in a continuous way as the diphosphate groups replace the diphosphonate ones, allowing us to suppose a variation of the tilting angles. Attempts to remove the phosphoester in the mixed derivatives by hydrolytic attack, and to replace some pillars with phosphite groups are described.