Stereocontrol by a Pair of Epimeric Sugar-Derived Ligands of the Coordination Sphere of Copper(Il) Complexes.

A pair of novel C3-epimeric sugar-derived ligands (glycoligands) with a neutral N40 donor set was synthesized. Copper(ll) complexes of both ligands were obtained and characterized by X-ray crystallography. Cyclic voltammetry, electron paramagnetic resonance, and UV-vis spectroscopies showed similar electronic properties. Mirror-image CD spectra were obtained for the Cu" d-d band, indicating an enantiomeric character of the coordination sphere, which has been rationalized structurally. This example shows the possible predetermination of stereochemistry for complexes by ligands based on a glycoscaffold. [ABSTRACT FROM AUTHOR]