COMPLEXATION OF ALUMINUM(III) WITH SEVERAL BI-DENTATE AND TRI-DENTATEAMINO-ACIDS

Complex formation between Al-III and various bidentate and potentially tridentate amino acids (Gly, Ser, Thr, Gin, Asn, Glu and Asp) and som e model Compounds (N-acetylaspartic acid, succinic acid, and 2-sulfany lsuccinic acid) was studied in aqueous solution by pH-potentiometric a nd multinuclear (H-1, C-13 and Al-27) NMR techniques. A weak interacti on through the carboxylate function was unambiguously detected for all of these ligands. For Asp, however, which contains two carboxylates a nd a central amino donor, tridentate co-ordinatron is strongly suggest ed. Although its steric environment is similar to that of the amino fu nction in Asp, binding of the thiolate sulfur of 2-sulfanylsuccinic ac id could not be verified.