The Formation Constants of Chromium(III)-Glycinato and α-Alaninato Complexes

Abstract

Abstract The formation constants of chromium(III) glycinato and α-alaninato complexes have been determined by the pH method. The values Connected with these two complexes are so close to each other that no effect of the presence of a methyl group could be found. The values of the first formation constants of these complexes are smaller than the mean value of those of ethylenediamine and oxalato complexes. These facts have been explained in terms of the finding that the decrease in the entropies of the formation of α-amino acid complexes is larger than that of ethylenediamine or oxalato complexes because the symmetry of the amino acid complexes is lower than of the ethylenediamine or oxalato complexes.