Synthesis, characterization and structure determination of two isotypes of a layered aluminophosphate with a new 2D network topology

Two isotypes of a new layered aluminophosphate, further denoted MDAP-3 and MDAE-1, have been synthesized under hydrothermal conditions using N-methyl-1,3-propanediamine and N-methyl-ethylenediamine, respectively. MDAP-3, with the empirical formula [Al2(HPO4)(PO4)2](C4N2H14)(H2O), crystallizes in the orthorhombic space group image (No. 33) with image, image, image, image, image and image. The second solid, MDAE-1, with the empirical formula [Al2(HPO4)(PO4)2](C3N2H12)(H2O), crystallizes in the same space group with image, image, image, image, image and image. The two compounds possess the same layer topology. Inorganic layers contain PO3=O, PO3OH, AlO4 and AlO6 polyhedra, linked together to generate a new 4×8 net. MDAP-3 and MDAE-1 represent the first examples of two-dimensional layered aluminophosphates with the Al2P3O12 stoichiometry, and containing AlO6 octahedra.