ChemInform Abstract: Coordination Behavior of L-Glutamic Acid: Spectroscopic and Structural Properties of (L-Glutamato)(imidazole)copper(II), (L-Glutamato)(2,2′-bipyridine)copper(II), and Aqua(L-glutamato)(1,10-phenanthroline)copper(II) Trihydrate Complexes.

ChemInform Abstract

All the complexes (I)-(III) were prepared by dissolving Cu-glutamate and the amine in a 1:1 or 1:1.5 molar ratio in hot water or water/methanol. The complex (I) (space group: P2₁2₁2₁; Z=4) has a one-dimensional polymeric structure, due to the bridging by the glutamate ligand between square-planar copper ions. The same polymeric structure and the same metal binding by the glutamate ion occur in (II) (space group: P2₁2₁2₁; Z=8), but in a square-pyramidal geometry. The structure of (III) (space group: P2₁; Z=4) is made up of discrete mononuclear units, in which the glutamate ion acts as a simple bidentate ligand toward a square-pyramidal Cu atom. IR-, VIS- and EPR-spectroscopic properties of the complexes are interpreted in the light of the known structures.