CHIRAL MOLECULAR LAMINATES - CRYSTAL-STRUCTURES OF BIS(N-2-N-ALKYL-(S)-PHENYLALANINAMIDATO)COPPER(II) COMPLEXES

N-2-n-octyl-(S)-phenylalaninamide and N-2-n-dodecyl-(S)-phenylalaninam ide were synthesized by reductive alkylation from the corresponding (S )-phenylalaninamide and n-octanal and n-dodecanal, respectively. Both ligands coordinate to copper(II) as amidates, giving rise to two trans -bis(phenylalaninamidato)copper(II) complexes CuL(2)H(-2) (1) and (2), respectively. The crystal structures of both complexes (1) and (2) we re determined by X-ray crystallography. The striking feature is that i n bis[N-2-alkyl-(S)-phenylalaninamidato]cop complexes both alkyl group s are on the axial positions and on the same side of the coordination plane. The hydrocarbon chains produce a bilayer structure with polar a nd apolar alternating zones. The knowledge of the crystal structures o f these complexes, which are used successfully as chiral selectors in HPLC (reversed phase), provides very useful information on the stereoc hemical features of the enantioselective selector and on the adsorptio n mode on a reversed phase C-18 chromatographic column.