A Layered Aluminium Phosphate, [C₂N₂H₁₀][Al₂(OH)₂H₂O(PO₄)₂]H₂O, by the Amine Phosphate Route

A layered aluminum phosphate, I, [C2N2H10][Al2(OH)2H2O(PO4)2]H2O, with Al: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 space group P(-1) (No. 2); a = 6.614(1), b = 9.918(1), c = 10.381(1) Å, α = 115.3(1), β = 90.2(1), γ= 90.8(1)°; V= 615.6(2) Å3; Z = 2, D(calc)=2.029 g cm-3; μ(MoKα)=0.565 mm-1. The final R. =. 0.07 and wR2 = 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