A layered aluminum phosphate, [C2N2H10] [Al2(OH)2H2O(PO4)2]H2O, by the amine phosphate route

A layered aluminum phosphate, I, [C2N2H10][Al-2(OH)(2)H2O(PO4)(2)]H2O, with AI:P ratio of 1:1 has been prepared using a novel synthetic route wherein the amine phosphate, [C2N2H10][HPO4], was reacted with Al3+ ions under hydrothermal conditions. I crystallizes in the triclinic splice group P(-1) (No. 2); a=6.614(1), b=9.918(1), c=10.38 1(1) Angstrom, alpha=115.3(1), beta=90.2(1), gamma=90.8(1)degrees; V=615.6(2) Angstrom(3); Z=2, D-calc=2.029 g cm(-3); mu (MoK alpha)=0.565 mm(-1). The final R=0.07 and wR(2)=0.17 and S=1.15 have been obtained for 198 parameters. The layered structure of I has Al both in trigonal bi-pyramidal and octahedral coordinations and the polyhedra are so connected as to give rise to 3-membered Al2P rings and infinite Al-O(H)-Al linkages. The structure is closely related to the mineral tancoite. (C) 2000 Elsevier Science Ltd. All rights reserved.