Coordination polymers and polygons using di-pyridyl-thiadiazole spacers and substituted phosphorodithioato NiII complexes: potential and limitations for inorganic crystal engineering

Coordinatively unsaturated P-substituted dithiophosphonato, dithiophosphato, and dithiophosphito complexes {[NiIJ(MeO)2PS2)2] (1), [Ni((EtO)2PS2)2] (2), [Ni(MeOdtp)2] (3), and [Ni((Ph)2PS2)2] (4)} were reacted with the bis-functional ligands 3,5-di-(4-pyridyl)-1,2,4-thiadiazole (L1) and 3,5-di-(3-pyridyl)-1,2,4-thiadiazole (L2) to give the coordination polymers (1–4·L1)∞, (3·L2)∞, and (4·L2·2C7H8)∞ and the discrete dimers (1–2·L2)2, all characterised by single crystal X-ray diffraction. A comparison of the structures shows that L1 can be exploited for the predictable assembly of undulating chains independent of the nature of the NiII complex, while L2 allows for the existence of different supramolecular constructs ensuing from different ligand conformations deriving from the rotation of the pyridyl rings.