The molecular recognition ability of the molecular tweezers 5～8 for the aromatic amino acid have been investigated by means of UV～Visible spectrophotometric titrition. The titrition data are analyzed by using the BenesiHidebrandequation. The results showed that all these molecular tweezers can form 1∶1 supramolecular complexes with the aromatic amino acid and exhibited chiral recognition property. These receptors are favorable for complexation with Damino acid. The enantioselectivity K D/K L of receptor 8 for PheOMe reached to 3.18. The recognition ability of these molecular tweezers come mainly from hydrogen bonding, ππ Stacking between aromatic residues and Van der Waals interaction.The size/shepefit and micvoenvion ments complementary between receptor and substrate pley a pivotal role in the inclusion complexation of amino acid methyl esters with these receptors.
