Propane-1,3-diammonium bis-[aqua-chlorido(4-hydroxy-pyridine-2,6-di- carboxyl-ato-κ3 O 2,N,O 6)mercurate(II)] tetra-hydrate

Abstract

The reaction of mercury(II) chloride dihydrate, propane-1,3-diamine and 4-hydroxy-pyridine-2,6-dicarboxylic acid in a 1:1:1 molar ratio in aqueous solution, resulted in the formation of the title compound, (C3H12N2)[Hg(C7H3NO5) Cl(H2O)]2·4H2O or (pnH2)[Hg(hypydc)Cl(H2O)]2·4H2O (where pn is propane-1,3-diamine and hypydcH2 is 4-hydroxy-pyridine-2,6-dicarboxylic acid). The metal atom is coordinated by one chloride group, one water mol-ecule cis to the chloride ligand and one (hypydc)2- ligand. The coordinated water mol-ecule is almost perpendicular to the plane of the aromatic ring of (hypydc)2-. The geometry of the resulting HgClNO3 coordination can be described as distorted square-pyramidal. This structure also contains propane-1,3-diammonium (site symmetry 2) as a counter-ion and four uncoordinated water mol-ecules. There is a wide range of non-covalent inter-actions consisting of hydrogen bonding [of the types O - H⋯O, N - H⋯O and C - H⋯O, with D⋯A ranging from 2.548 (5) to 3.393 (6) Å] and ion pairing.