Chlorido[(E)-2-hydr-oxy-6-(isonicotinoyl-hydrazonometh-yl)phen-yl]mercury(II) monohydrate.

The asymmetric unit of the title compound, [Hg(C(13)H(10)N(3)O(2))Cl]·H(2)O, contains two independent mercury(II) complexes with slightly different conformations, related via a pseudo-inversion centre, and two water mol-ecules. The Hg(II) atoms show a typical linear geometry to a C atom of the benzene ring and to a Cl atom. A benzene C and the azomethine N atom chelate the Hg(II) atoms with weak intra-molecular Hg⋯N bonding distances of 2.735 (3) and 2.739 (3) Å, respectively. The resulting five-membered metallacycles are nearly coplanar with the benzene rings [dihedral angles = 0.9 (1) and 0.7 (1)°], while the pyridine rings make dihedral angles with the benzene units of 58.17 (1) and 56.58 (1)°. In the crystal structure, the Hg(II) complexes are linked by hydr-oxy donor and pyridine acceptor groups into chains along [010]. The water mol-ecules connect the complexes through inter-molecular O-H⋯O(carbon-yl) bonds in the a-axis direction, and the azomethine H atoms donate towards the water O atoms, forming a three-dimensional network of inter-molecular O-H⋯N, O-H⋯O and N-H⋯O hydrogen bonds.