Crystal structure of an Hg-II coordination polymer with an unsymmetrical dipyridyl ligand: catena-poly[[[dichloridomercury(II)]-mu-N-(pyridin-4-yl-methyl)pyridin-3-amine-kappa N-2:N '] chloroform hemisolvate]

The asymmetric unit of the title compound, {[HgLCl2]center dot 0.5CHCl(3)](n) (L = N-(pyridin-4-ylmethyl)pyridin-3-amine, C11H11N3), contains one Hg-II ion, one bridging L ligand, two chloride ligands and a chloroform solvent molecule with half-occupancy that is disordered about a crystallographic twofold rotation axis. Each Hg-II ion is coordinated by two pyridine N atoms from two symmetry related L ligands and two chloride anions in a highly distorted tetrahedral geometry with bond angles falling in the range 99.05 (17)-142.96 (7)degrees. Each L ligand bridges two Hg-II ions, forming polymeric zigzag chains propagating in [010]. In the crystal, the chains are linked by intermolecular N/C-H center dot center dot center dot Cl hydrogen bonds together with weak C-H center dot center dot center dot pi interactions, resulting in the formation of a three-dimensional supramolecular network, which is further stabilized by C-Cl center dot center dot center dot pi interactions between the solvent chloroform molecules and the pyridine rings of L [chloride-to-centroid distances = 3.442 (11) and 3.626 (13) angstrom]. In addition, weak Cl center dot center dot center dot Cl contacts [3.320 (5) angstrom] between the chloroform solvent molecules and the coordinating chloride anions are also observed.