Crystal structure of an Hg<sup>II</sup>coordination polymer with an unsymmetrical dipyridyl ligand:<i>catena</i>-poly[[[dichloridomercury(II)]-μ-<i>N</i>-(pyridin-4-ylmethyl)pyridin-3-amine-κ<sup>2</sup><i>N</i>:<i>N</i>′] chloroform hemisolvate]
Acta crystallographica. Section E, Crystallographic communications