Experimental

R factor = 0.046; wR factor = 0.111; data-to-parameter ratio = 23.0. In the centrosymmetric dinuclear title compound, [Hg2Cl4(C6H8N2)2], the Hg II ion is four-coordinated by one pyridine N atom from a 2-amino-4-methylpyridine ligand, one terminal Cl atom and two bridging Cl atoms. A distorted tetrahedral geometry is formed around each HgII ion. The crystal packing is stabilized by intra- and intermolecular N— H Cl hydrogen bonding. There are also – stacking interactions in the structure, with centroid-to-centroid distances of 3.594 (6) Å. Related literature For a coordination compound of 2-amino-4-methylpyridine, see: Arab Ahmadi et al. (2011). For proton-transfer compounds of 2-amino-4-methylpyridine, see: Gharbia et al