Order of Stability of Metal Complexes

Abstract

IN a recent communication¹ it was pointed out that the order of stability of a series of internal metal complexes is substantially the same whether the metals are combined with bidentate chelate molecules like salicylaldehyde, glycine or 8-hydroxyquinoline. There is evidence from the results of other workers^2,3 that the same order is to be found with complex cations and with internal complexes formed with quadridentate chelate molecules. Cations containing ethylenediamine have been studied by Bjerrum^2,4 and Carlson, MeReynolds and Verhoek³. From the accompanying table, which shows the overall stability constants for salicylaldehyde and ethylenediamine complexes, the similarity of order in the two cases is evident.