Engineering polymers with variable topology – bipyridine adducts of cadmium dithiophosphates

Abstract

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.