Chromium(III) complexes with DL-methionine and L-cysteine

Chromium(III) complexes with DL-methionine and L-cysteine have beon investigated by pH-metric and spectrophotometric methods. In both investigated systems, three complexes of the composition H : L = 1 : 1; 1 : 2; 1 : 3, have been found, stability constants for the resultant complexes have been determined by the method of Bjerrum. Crystalline complexes with the investigated ligands of the type: [Cr(Met)₃]. 2H₂O and Na[Cr(Cys)₂]. 2H₂O were also obtained. The made combination of Cr(III) with the investigated aminoacid and structures of the complexes reported have been proposed on the basis of their spectra. A method for precipitation pure complexes from solutions has been devised using the ion-exchange procese on the resin Sephadex A-25.