synthesis and solution complexation studies of a new schiff base ligand

a new schiff base ligand, 2,2'-{pyridine-2,6-diylbis[nitrilo(e)methylylidene]}bis(4 bromophenol),has been synthesized by reaction of the 2,6-diamino pyridine with 5-bromo salicylaldehyde at ethanolunder refluxing. the structure of the synthesized compound resulted from the ir, 1hnmr, ms anduv spectroscopy and elemental analysis data. formation constant (kf) value of it’s complexes withcu2+, ni2+, cd2+, co2+ and hg2+ has been determined conductometrically. the formation constants ofthe resulting 1:1 complexes have been calculated from the computer fitting of the molar conductance- mole ratio data at different temperatures. the stability of the complexes to vary in acetonitrilesolvent was in the order of cu2+ > cd2+ > co2+ > hg2+ > ni2+. the enthalpy and entropy changes ofthe complexation reactions have been evaluated from the temperature dependence of formationconstants.