Dicobalt(II) lead(II) hydrogenphosphate(V) phosphate(V) hydroxide monohydrate

The title compound, Co2Pb(HPO4)(PO4)OH H2O, which was synthesized under hydrothermal conditions, crystallizes in a new structure type. Except for two O atoms in general positions and two Co atoms on centres of symmetry, all other atoms in the asymmetric unit (1 Pb, 2 Co, 2 P, 8 O and 4 H) are located on mirror planes. The structure is built up from two infinite linear chains, viz. 1 1[CoO2/1(H2O)2/2O2/2] and 1 1[CoO2/1(OH)2/2O2/2], of edge-sharing CoO6 octahedra running along [010]. Adjacent chains are linked to each other through PO4 and PO3(OH) tetrahedra, leading to the formation of layers parallel to (100). The three-dimensional framework is formed by stacking along [100] of adjacent layers that are held together by distorted PbO8 polyhedra. Hydrogen bonds of the type O—H O involving the water molecule are very strong, while those O atoms involving the OH groups form weak bifurcated and trifurcated hydrogen bonds.