The reaction of mercury(II) chloride dihydrate, propane-1,3- diamine and 4-hydroxypyridine-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)]24H2O (where pn is propane-1,3-diamine and hypydcH2 is 4-hydroxypyridine-2,6- dicarboxylic acid). The metal atom is coordinated by one chloride group, one water molecule cis to the chloride ligand and one (hypydc)2 ligand. The coordinated water molecule 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 molecules. There is a wide range of non-covalent interactions 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) A ° ] and ion pairing.
