Propane-1,2-diammonium bis-(pyridine-2,6-dicarboxyl-ato-3 O,N,O′)nickelate(II) tetra-hydrate

Abstract

The reaction of nickel(II) nitrate hexa-hydrate, propane-1,2-diamine and pyridine-2,6-dicarboxylic acid in a 1:2:2 molar ratio in aqueous solution resulted in the formation of the title compound, (C3H12N2)[Ni(C7H3NO4)2] ·4H2O or (p-1,2-daH2)[Ni(pydc)2]·4H2O (where p-1,2-da is propane-1,2-diamine and pydcH2 is pyridine-2,6-dicarboxylic acid). The geometry of the resulting NiN2O4 coordination can be described as distorted octa-hedral. Considerable C=O⋯π stacking inter-actions are observed between the carboxyl-ate C=O groups and the pyridine rings of the (pydc)2- fragments, with O⋯π distances of 3.1563 (12) and 3.2523 (12) Å and C=O⋯π angles of 95.14 (8) and 94.64 (8)°. In the crystal structure, a wide range of non-covalent inter-actions, consisting of hydrogen bonding [O - H⋯O, N - H⋯O and C - H⋯O, with D⋯A distances ranging from 2.712 (2) to 3.484 (2) Å], ion pairing, π-π [centroid-to-centroid distance = 3.4825 (8) Å] and C=O⋯π stacking, connect the various components to form a supra-molecular structure. © 2008.