Cadmium and mercury dihalides were reacted with benzopyridine- and benzopyrazine-type N-donor
ligands as Lewis bases. The solid-state structures of 13 novel reaction products were studied by X-ray diffraction.
Eleven of the structures can be classified as one-dimensional halide-bridged polymers of
composition [MĲμ-X)2ĲL)]∞, in which the metal ion displays a coordination number of five, while the
remaining two structures exhibit one-dimensional dimers that are linked by long, semi-coordinate M–
X⋯M–X interactions to form pseudo-halide-bridged polymers. Four of the structures contain Cd2+ as the
metal ion, while the remaining nine have Hg2+ as the metal ion. Although all the halide-bridged polymers
show a coordination number of five, two different metal cation geometries are displayed. A detailed comparison
of all structural results, which includes related compounds from the literature and allows for the
study of the effect of an increase in the width of the N-donor ligand on the halide-bridged chain geometries
and other structural features, concludes the discussion.