An analysis of the [M(bpy)3]n+ (bpy = 2,2′-bipyridine) complexes with halide counterions in the Cambridge Structural Database reveals a common structural motif in two thirds of the compounds. This interaction involves the formation of 12 short C-H...X contacts between halide ions lying within sheets of the cations and H-3 and H-3′ of six [M(bpy)3]n+ complex cations. A second motif, also involving 12 short contacts, but with H-6 and H-5, is identified between halide ions lying between sheets of the [M(bpy)3]n+ cations
