Crystal structure of 4,4'-(disulfanediyl)dibutanoic acid-4,4'-bipyridine (1/1)

4,4'-(Disulfanediyl) dibutanoic acid (dtba) and 4,4'-bipyridine (4,4'-bpy) crystallize in an 1: 1 ratio, leading to the title co-crystal with composition C8H14O4S2 center dot C10H8N2. A distinctive feature of the crystal structure is the geometry of the dtba moiety, which appears to be stretched [with a 9.98 (1)angstrom span between outermost carbons] and acts as an hydrogen-bonding connector, forming linear chains along [211] with the 4,4'-bpy moiety by way of O-H center dot center dot center dot N hydrogen bonds and C-H center dot center dot center dot O interactions. The influence of the molecular shape on the hydrogen-bonding pattern is analysed by comparing the title compound and two other 4,4'-bpy co-crystals with closely related molecules of similar formulation but different geometry, showing the way in which this correlates with the packing arrangement.