New layer and three-dimensional 4,4′-bipyridinium salts of Cl−, [MCl6]2− (M = Os, Pt) and [FeCl5]2− contain NH⋯(Cl)2⋯HN interactions which form hydrogen bonded ribbons which in turn give one-, two-, or three-dimensional periodic networks; two related families of homologous motifs are present in these salts together with those of square planar, polymeric and tetrahedral [MCl4]2− (M = Pt, Pd, Mn, Cd, Pb, Co, Zn, Hg), planar [Cu2Cl6]2− and square pyramidal [SbCl5]2− dianions.
