Syntheses and structures of ammonium transition-metal dialuminium tris­(phosphate) dihydrates (NH(4))MAl(4)(PO(4))(3)·2H(2)O (M = Mn and Ni)

The structures of ammonium manganese(II) dialuminium tris­(phosphate) dihydrate, (NH(4))MnAl(2)(PO(4))(3)·2H(2)O, and ammonium nickel(II) dialuminium tris­(phosphate) dihydrate, (NH(4))NiAl(2)(PO(4))(3)·2H(2)O, were determined using single-crystal diffraction data. The structures of title compounds are isotypic to cobalt aluminophosphate, (NH(4))CoAl(2)(PO(4))(3)·2H(2)O (LMU-3) [Panz et al. (1998 ▸). Inorg. Chim. Acta, 269, 73–82], in which a three-dimensional network of vertex-sharing AlO(5) and PO(4) moieties delineate twelve-membered channels in which ammonium, NH(4) (+), and transition-metal cations (M = Mn(2+) and Ni(2+)) reside as charge compensators for the anionic [Al(2)(PO(4))(3)](3–) aluminophosphate framework. In both structures, the N atom of the ammonium cation, the transition-metal ion and one of the P atoms lie on crystallographic twofold axes.