Enantiomer Recognition by the Difference in Adsorption Rates on the Surfaces of Chiral Crystals

• Published in: Chirality (New York, N.Y.) Vol. 36; no. 9; pp. e23717 - n/a
• Main Authors: Belonogov, Eduard, Ermolaeva, Ekaterina, Zinoviev, Ilya, Zhang, Zhi‐hui, Guskov, Vladimir
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.09.2024
• Subjects: Adsorption; Biopolymers; Catalysis; Chemical perception; Chemoreception; chiral crystal; Chirality; Crystals; Enantiomers; enantioselectivity; Equilibrium; Equilibrium conditions; Glycine; kinetic curve; Menthol; Nonequilibrium conditions; Object recognition; supramolecular chirality; enantioselectivity; adsorption; kinetic curve; chiral crystal; supramolecular chirality
• DOI: 10.1002/chir.23717
• ISSN: 0899-0042; 1520-636X

ABSTRACT The chirality of biopolymers remains one of the mysteries of Life. For such objects, the phenomenon of supramolecular chirality (SMC) is vital. Enantiomers can be recognized by the adsorption on surfaces with SMC. However, the mechanisms of such chiral recognition are still unknown. In this work, the adsorption kinetics of menthol test enantiomers on the surfaces of γ‐glycine and NiSO4•6H2O chiral crystals was studied. It was found that the difference in adsorption was observed in nonequilibrium state more often than in equilibrium. If the enantioselectivity in equilibrium state was observed, the enantioselectivity coefficient α at nonequilibrium conditions was higher. The maximum α in nonequilibrium state was 2.44 for γ‐glycine crystals and 2.12 for NiSO4•6H2O crystals. Even if no differences in adsorption were observed under adsorption–desorption equilibrium conditions, a significant enantioselectivity at nonequilibrium conditions was found. This has proved the possibility of chiral recognition on surfaces with SMC by the differences in adsorption rates. Such novel chiral recognition mechanism can provide enhanced enantioselectivity in adsorption, catalysis, chromatographic separation, and chemical sensing. A nontrivial phenomenon was discovered: enantioselectivity of menthol enantiomer adsorption on the surfaces of NiSO4•6H2O and γ‐glycine was determined both by differences in thermodynamics and by the different adsorption rates. Even in the absence of enantioselectivity in equilibrium state, the non‐equal rates of enantiomer adsorption have observed.