Spectroscopic Studies of Aminoacids Complexes with Biometals

The [Cu(L)2]·H2O, [Co(L)2]·2H2O, [Zn(L)2]·H2O complexes with methionine (L) as ligand, were synthesized in water solution and analyzed by means of: elemental analysis, atomic absorption spectroscopy, thermogravimetry, FT-IR, UV-VIS and EPR spectroscopies. The atomic absorption spectroscopy and elemental measurements confi rm the ratio 1:2 metal ion: methionine composition for the synthesised compounds.The IR spectra show that amino acids act as bidentate ligands with coordination involving the carboxylic oxygen and the nitrogen atom of the amino group. Spectral UV-VIS data confi rmed the covalent metal-ligand bonds, the pseudotetrahedral symmetry around the copper and zinc ions and the octahedral environment for the cobalt ion. Powder ESR spectra at room temperature are typically for monomeric species.