Potentiometric examination of complexation equilibria of some phenoxyacetic acid derivatives with Cu(ll), Cd(ll) and Zn(IB)

摘要

The stability constants of binary complexes of 2,4-dichlorophenoxyacetic acid (2,4-D), (4-chloro-2-methylphenoxy)acetic acid (2,4-MCPA) and (4-chloro-2-methylphenoxy) propionic acid (2,4-MCPA) with Cu(ll), Cd(ll) and Zn(ll) have bean calculated at 298 K and at ionic strength μ = 0.1 (NaNO3). Potentiometric measurements display three hydroxide complexes: MH_-1A, MH_-1A2 and MH_-2A2. With regard to the successive complexes, no other system represents this type of complexes under our experimental conditions. The order of capacity of complexation compared to metal for the three ligands