The rate of exchange of propylenediaminetetraacetic acid with its cadmium complex

Abstract

The polarimetric rates of exchange between optically active propylene- diaminetetraacetic acid (PDTA) and its cadmium complex, and that between ethylenediaminetetraacetic acid (EDTA) and the cadmium propylenediaminetetraacetato complex, have been measured in the pH range 4.75-7.00. An analysis of the reaction kinetics indicates that the exchange, in either case, occurs simultaneously by a first-order and second-order process, and it is concluded that both bimolecular and unimolecular pathways are operative in the exchange process.