Etude spectroscopique des complexes cuivre-l-arginine

Abstract Cu 2+ - l -argine complexes having 1:1 and 1:2 metal to ligand molar ratios have been investigated by means of visible, u.v. and i.r. absorption spectra, as well as circular dichroism. This study shows that the d - d transitions of the 1:1 complex are optically inactive. On the other hand, in both complexes the charge transfer transition σ( Cu  N ) → σ ∗ (3d x 2 −y 2 ) occurs at 255 nm, and is optically active while the σ( Cu  O ) → σ ∗ (3d x 2 −y 2 ) transition at 230 nm is inactive.