The crystal structure of polymeric magnesium bis(p-nitrophenolate) dihydrate: [Mg(O2NC6H4O)(2)(OH2)(2)](infinity)

The crystal and molecular structure of polymeric magnesium bis(p-nitrophenolate) dihydrate, [Mg(O2NC6H4O)(2)(OH2)(2)](infinity), C12H12MgN2O8, has been determined at room temperature. The orange crystals are monoclinic, space group C2 with unit cell dimensions a = 21.183(2) Angstrom, b = 3.667(4) Angstrom, c = 10.357(2) Angstrom, beta = 117.227(7)degrees, Z = 2 and D-x = 1.562 Mg m(-3). The structure was solved by direct methods and refined by a full-matrix least-squares procedure on F-2 to final R = 0.062 using 960 reflections. The Mg2+ cation (which lies on a two-fold axis) exists in a slightly distorted octahedral geometry with the basal plane being defined by four water molecules and the axial positions by two oxygen donor atoms derived from two symmetry related NO2 groups. Each pair of coordinated water molecules links a neighbouring Mg2+ centre leading to the formation of columns of edge-shared octahedra. These columns are Linked via hydrogen bonding contacts involving the non-coordinating n atoms of the p-nitrophenoxide and the Mg...OH2 groups.