Rare Earth Complexes of Some Amino Acids : A Potentiometric Study

Laxmi Narayan Institute of Technology, Nagpur University, Nagpur

Manuscript received 9 September 1976, accepted 18 March 1977

Stability constants of 1 : 1 complexes of Sc(III), Y(III), La(III), Ce(III), Pr(III) and Nd(III) with Glycine, Asparagine and Glutamine at 30°, at an ionic strength of 0.2 M NaCIO₄ have been determined by irving-Rossotti pH-titration technique. Free energies of the above said complexes are also reported The trend of stability constants irrespective of amino acids under investigation of found is be Sc(III)> Y(III)>Nd(III)>Pr(III)>Ce(III)>La(III). In terms of amino acids the stability. constants of any particular rare earth ion decreased in order Glycine>Glutamine> Asparagine.