A stereodynamic chiroptical sensor based on three-component assembly of 3-(di-2-picolylaminoacetamido)-2-formyl-naphthalene (1), Zn II and amino acids was developed. The imine formed between 1 and an amino acid has six coordination sites to bind tightly Zn II ion. The crystal structure of the Zn II complex, 1-Zn-D-Phe, revealed that the naphthyl ring is tilted to one pyridine ring to generate axial chirality. The dihedral conformations observed in 1-Zn-D-Phe were herein arbitrarily designated as α 1 and α 2 . DFT calculation suggests that the D-Phe binding prefer the α 1 -conformer: the energy of D-Phe-α 1 is more stable than L-Phe-α 1 by 5.5 kcal/mol. This preference to one diastereomer generates amplification of CD signal with Cotton effect, which can be applied to the determination of ee values of the amino acid.
- Absolute configuration of amino acid
- Circular dichroism amplification
- Dihedral chirality
- Enantiomeric excess determination
- Stereodynamic imprinting