Chiral Discrimination by.

Chiral hold promise in many asymmetric applications. This study explores the impact of ionic solutes on the chiral discrimination of five amino acid methyl ester-based , including L- and D-alanine methyl ester, L-proline methyl ester, L-leucine methyl ester, and L-valine methyl ester cations combined with bis(trifluoromethanesulfonimide) anion. Circularly polarized luminescence spectroscopy was used to study the chiral discrimination by measuring the equilibrium of a dissymmetric europium complex, Eu(dpa)₃³⁻ (where dpa = 2,6-pyridinedicarboxylate). The chiral discrimination measured was dependent on the concentration of Eu(dpa)₃³⁻ and this concentration-dependence was different in each of the . with L-leucine methyl ester and L-valine methyl ester even switched enantiomeric preference based on the solute concentration. Changing the cation of the Eu(dpa)₃³⁻ salt from tetrabutylammonium to tetramethylammonium ion also affected the chiral discrimination demonstrated by the . Chirality 27:320-325, 2015. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]