X-Ray crystallographic studies of enantiomerically pure dimethylphenazino-18-crown-6 ligand (R,R)-1 and its complexes with the enantiomers of α-(1-naphthyl)ethylammonium perchlorate NapEt were carried out. These studies clearly show that the heterochiral complex (R,R)-1-(S)- NapEt is more stable than the homochiral one (R,R)-1-(R)-NapEt. It was pointed out that besides the hydrogen bonding, mainly the π-π interaction between the aromatic systems of the host and guest, and the difference in steric repulsions were responsible for enantioselectivity. Molecular mechanical calculations using the LMOD/MINTA method also predicted the heterochiral complex to be more stable than the homochiral one in the gas phase.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry