The Stability of Beryllium Complexes with Organic Ligands. II. Amino Carboxylic Acids.

Chemistry Division, Bhabha Atomic Research Centre, Trombay, Bombay 85. Manuscript received 20 June 1972; accepted 30 January 1973 The stability constants of complexes of beryllium with glycine, iminodiacetic acid, nitrilo­triacetic acid and ethylenediaminetetraacetic acid have been determined by pH titration method at 35° and an ionic strength of 0.1M. The stability constants of complexes of related metal ions—aluminium and magnesium with these ligands have also been determined under the above condi­tions for comparison. It is found that among the ions, the stability of the complexes increases as Mg2+< Be2+ < Al3+, which is expected from the variations in their charge and radii. The utility of log K -pK relationship as a diagnostic measure to find out the number of groups which are coordinated is examined. It is found that in the cases of ligands, nitrilotriacetic acid and ethy­lene diaminetetraacetic acid, the maximum number of groups coordinated are only three