Studies on the Composition and Stability of Chromium Complexes of Amino-acids

Composition and stability of a number of complexes of Cr(III) with amino-acids have been studied by spectrophotometric and pH-metric methods. The combining ratio of 1:2, Cr (III): amino-acid, which might vary to 1:2, depending on the concentration of the reactants, has been found to exist in most asses. For meth­ionine end asparagine, the ratios ere 1:2 for aspartic acid, and 1:1. ß-.Alaniae forms no violet complex. The results have been explained in the light of the influence of different side groups on the relative position of NH2 and-COOH groups. Stability constants of the different complexes point towards the similarity in the composition of the Cr(III)-amino acid complexes