Engineering polymers with variable topology ? bipyridine adducts of cadmium dithiophosphates

A series of 1∶1 adducts formed between Cd(S2P(OiPr)2)2 and the bifunctional ligands 4,4′-bipyridine (1), trans-1,2-bis(4-pyridyl)ethylene (2), 1,2-bis(4-pyridyl)ethane (3), trans-1,2-bis(2-pyridyl)ethylene (4), 1,2-bis(4-pyridyl)propane (5) and 4,4′-dipyridylsulfide (6) demonstrate variable polymer topology (linear, zigzag and arched) and cadmium atom coordination geometry (cis- and trans-N2S4) depending on the nature of the bridging ligand and steric influences of the ligands. Increasing the steric bulk of the Lewis acid, to Cd(S2P(OCy)2)2, results in comparable topologies with bipyridine ligands 1, 2, and 4 but, precludes polymer formation in the adduct formed with 5, a dimer being formed instead.