A Polarographic Study on Some Complexes of Pb2+and Cd2+with Macrocyclic Polyethers (Crown Ethers)

Abstract
Complexation constants of Pb2+ and Cd2+ nitrates with 5 crown compounds (18-crown-6, dicyclohexyl-18-crown-6, benzo-15-crown-5, dibenzo-24-crown-8 and 12-crown-4) were determined by DC and AC polarographic measurements in aqueous medium using 0.1 HNO3, as supporting electrolyte. The complexes of Pb2+ with 18-crown-6 and dicyclohexyl-18-crown-6 were very stable which may be attributed to the partially covalent bonds formed by this metal ion.