Ionothermal synthesis and crystal structure of a new layered nickel(II) diphosphate, DRM-1

A new layered ammonium nickel(II) diphosphate, (NH(4))(2)[Ni(3)(P(2)O(7))(2)(H(2)O)(2)], has been synthesized ionothermally in the ionic liquid 1-butyl-3-methyl imidazolium bromide and characterized by powder X-ray diffraction, elemental analysis, scaning electron microscopy, thermogravimetry etc. The results of the characterization show that the crystal adopts the monoclinic space group P2(1)/a with the lattice constants a=9.23529(2) angstrom, b=7.98489(2) angstrom. c=9.40772(2) angstrom, beta=100.2608(2)degrees and Z=2. Its structure consists of chains of cis- and trans-edge-sharing [NiO(6)](-)octahedra linked via [P(2)O(7)] units to form layers of [Ni(3)(P(2)O(7))(2) (H(2)O)(2)](2-) in the ab plane. Adjacent layers are separated in the c-direction by ammonium ions. (C) 2010 Elsevier B.V. All rights reserved.