Origin of chiral discrimination by a two-dimensionally chiral self-assembled monolayer: A quantum chemical study

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+)-π and NH(Phe)-π (BNSH) interactions in a nanometer-sized screw-hole-like pocket composed of three BNSH molecules in the monolayer.

Graphical abstractSemiempirical 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) through hydrophobic, cation(−NH3+)-π (BNSH) and NH(Phe)-π (BNSH) interactions in a nanometer-sized screw-hole-like pocket composed of three BNSH molecules.Download full-size image