Studies on the effect of cholera substitution in the oxine molecule on the extraction of cadmium [II] into n-butanol

ABSTRACT

Extraction studies were undertaken with cadmium [II] in the presence of oxine and its chloro derivatives to derive information on the effect of substitution in the oxine molecule. Oxine, 5-chlorooxine and 5, 7-dichlorooxine form complexes with cadmium in the pH range7.9-8.4, 7 .8-8.2 and 7.0-7.6 respectively which was extract into n-butanol giving fairly intense yellow colour. The extracting species are found to be monomeric in cadmium in all the systems. pH dependence of log D plots revealed the release of two protons in the process of extraction. The optimum pH for extraction of cadmium chelates of 5-chlorooxine and 5, 7-dichlorooxine have drifted towards lower side when compared with that of cadmium. [Il]-oxine chelate. Bathochromic shifts were observed in the case of cadmium [II]-chlorooxine systems. The values of the conditional extraction constants suggest that the order of efficacy of extraction is as follows Oxine < 5-chlorooxine < 5,7-dichlorooxine