Structural and energetic investigations based on semiempirical PM5 and ab initio HF and MP2 calculations suggested that the self-assembled monolayer of an atropisomeric compound, (R)- or (S)-1,1'-binaphthalene-2,2'-dithiol (BNSH), on a gold (1 1 1) surface selectively adsorbs one enantiomer of phenylalanine (Phe), resulting in chiral discrimination, through hydrophobic, cation(-NH3+)-pi and NH(Phe)-pi (BNSH) interactions in a nanometer-sized screw-hole-like pocket composed of three BNSH molecules in the monolayer. (c) 2006 Elsevier B.V. All rights reserved.