Determination of the absolute configuration and identity of chiral carboxylic acids using a Cu(II) complex of pyridine–benzimidazole-based ligand

We report a new achiral Cu host [Cu(bmb–bpy)(H2O)(OTf)2] (bmb–bpy = 6,6′-bis[((1-methylbenzimidazol-2-yl)thio)methyl]-2,2′-bipyridine) for the enantioselective and chemoselective recognition of chiral carboxylic acids. The binding of chiral carboxylic acids to [Cu(bmb–bpy)(H2O)(OTf)2] produced an exciton-coupled circular dichroism signal; the linear discriminant analysis allowed the assignment of the absolute configuration, enantiomeric excess, and identity of chiral carboxylic acids.