Mobile Carrier Properties of N2O2- and N3O2-Type Schiff Base Molecules Towards Copper(II) Ions

Mobile carrier properties of two schiff base ligands, named bis(2-hydroxypropiophenone)-1,2-propanediimine (n2o2) and bis(1'-hydroxy-2'-acetonaphthone)-2,2'-diiminodiethylamine (n3o2), dissolved in dichloromethane for the extraction of copper(ii) ions froman ammonium buffer feed phase into a nitric acid solution (receiving phase) were investigated andcompared. the parameters influencing the transport efficiency such as ph of the feed phase,chemical composition of the receiving phase, carrier concentration in the membrane and timedependency of the process were studied and discussed. addition of sodium dodecysulfate (sds), ananionic surfactant, to the receiving phase enhances significantly the process efficiency. this revealsthat the transport is controlled by the kinetics of decomplexation at the stripping interface. thetransported amount of copper ions from ammonium buffer (ph 7) into the receiving phase includinghno3 and sds across a dichloromethane layer containing n2o2 and n3o2, at 20 ºc, was found tobe 90.6 (±0.7) % and 97.4 (±0.4) % after 4 h, respectively. the selectivity of the processes towardscopper ions were tested by performing the competitive transport experiments on the mixturecontaining pb2+, ni2+, cd2+, zn2+ and co2+ ions. although n3o2 possess higher transport efficiencywith respect to that of n2o2, both ligands present adequate selectivity for separation of cu(ii) ions.