Synthesis, X-ray crystal structures and characterization of copper(II)-2, 2'-bipyridyl derivatives of (4-amino)-hippuric acid and of L-proline

摘要

In this paper the synthesis and the characterization of two complexes of copper and 2, 2'-bipyridyl with amino acids 4-aminohippuric acid and L-proline are reported. The X-ray structure reveals for the first complex, [Cu_2(OH)(OH_2)(bipy)_2(Am-hip)](NO_3)_2 centre dot 4H_2O, dinuclear copper(II) cations with nitrate counterions and lattice water molecules. The two metal centres are linked together by a water molecule, a hydroxyl group and the carboxylic moiety of the 4-amino-hippuric acid, the remaining two positions on both metal centres are occupied by bipyridyl molecules. The second compound consists of monomeric [Cu(OH_2)(bipy)(L-pro)]~+ cations and prechlorate anions. Also in this case copper is five-coordinated in a distorted square pyramidal geometry with the bipyridine nitrogens, one carboxylate oxygen atom and the amino nitrogen of the L-proline ion on the basal plane.