Poly[mercury(II)-di--chloro--pyrazine-? 2 N:N']

In [HgCl2(Pyp)]n (Pyp = pyrazine, C4H4N2), chloride-bridged HgCl4/2 strands are connected into layers by pyrazine mol­ecules. The Hg atom is on a site of symmetry 2/m, the unique Cl atom is on a mirror plane, the unique N atom is on a twofold rotation axis, and the unique C and H atoms are in general positions.