Disilver(I) trinickel(II) hydrogenphosphate bis(phosphate), Ag2Ni3(HPO4)(PO4)2

Abstract

The title compound, Ag2Ni3(HPO4)(PO4)2, has been synthesized by the hydro­thermal method. Its structure is formed by two types of chains running along the b axis. The first chain results from a linear and continuous succession of NiO6 octa­hedra linked to PO4 tetra­hedra by a common vertex. The second chain is built up from two adjacent edge-sharing octa­hedra (dimers) whose ends are linked to two PO4 tetra­hedra by a common edge. Those two types of chains are linked together by the phosphate groups to form polyhedral sheets parallel to the (001) plane. The three-dimensional framework delimits two types of hexa­gonal tunnels parallel to the a-axis direction, at (x, 1/2, 0) and (x, 0, 1/2), where the Ag atoms are located. Each silver cation is surrounded by eight O atoms. The same Ag+ coordination is found in other phosphates with the alluaudite structure, for example, AgMn3(PO4)(HPO4)2. Moreover, O—H⋯O hydrogen bonds link three PO4 tetra­hedra so as to build a three-dimensional network.