POLYDENTATE CARBOXYAMIDE LIGANDS AS ANALYTICAL REAGENTS

Biphenyl bridged, binucleating and polydentate macromolecular ligand s eries, H-2L, possessing two terminal -NH-CO-A-COOH, carboxyamide moiet ies (where A=-CH2-CH2- or -CH=CH- or ortho-phenylene linkage), has bee n synthesised and was found to be a set of potential analytical reagen ts as H-2L suspensions for conductometric and pH-metric aqueous acid-b ase titrations on one hand and as Na2L aqueous solutions for gravimetr ic analysis of several bivalent metal ions on the other. Due to the la rge separation between the two carboxyamide coordinating moieties, onl y Na2L formation at any mixing of NaOH and H-2L and only one wave in t he pH-metric titration of H-2L suspension against a standard NaOH, wer e observed. Further, the solutions of Na2L were found to be satisfacto ry turbidimetric reagents for Cu(II), Zn(II), Ni(II), Cu(II), La(III) and UO2II ions in the concentration range 10(-5)-10(-3)M.