NOVEL ENANTIOSELECTIVE PHOTOCATALYSIS BY CHIRAL, HELICAL RUTHENIUM(II) COMPLEXES

The enantioselective photoreduction of the helical substrates of rac-[Co(acac)3] (acac- = acetylacetonato) and rac-[Co(edta)]- (edta4- = ethylenediaminetetraacetato) with the newly synthesized helical photocatalysts DELTA- (or rac)-[Ru[Menbpy)3(2)+ {Menbpy = 4,4'-bis[(1R,2S,5R)-(-)-menthoxycarbonyl]-2,2'-bipyridine}, and LAMBDA- (or DELTA)-[Ru{(S or R)-PhEtbpy}3]2+ {(S or R)-PhEtbpy = 4,4'-bis[(S)-(-) or (R)-(+)-1-phenylethylaminocarbonyl]-2,2'-bipyridine} was realized in the helical-shape recognition reaction with a maximum enantiomer rate ratio (k(DELTA)/k(LAMBDA)) of 14.7 in 90% v/v EtOH-H2O at 25-degrees-C.