Chiral Recognition Based on Hydrophobic Entanglement of Enantiomers with Chiral Diamide Phases in Aqueous Media

Enantioselective correlation between retention factor and lipophilicity index in chiral separation on cellulose and amylose tris(3,5-dimethylphenylcarbamate) CSPs in reversed mode: A case study

“…Specific hydrophobic interactions between enantiomeric species and recognition sites of imprinted polymers have recently been found in aqueous solution. 5 Hydrophobic interactions have been scarcely involved in "brush" type CSPs 6,7 and are almost absent in the catalog of relevant interactions accounting for retention on cellulosic or amylosic CSPs, which are traditionally used in normal mode. Retention and chiral recognition on the latter phases are mostly explained by a combination of hydrogen-bonding, dipole-dipole, stacking, and Van der Waals interactions.…”

Chiral separation through

“…In the classical arrangement of EKCC, pioneered by Terabe and associates (5), the charged micelles provide the pseudo stationary phase that readily interacts with the analyte molecules. The use of optically active micelles (13-15), mixed-micellar aggregates (16)(17)(18), and other means of incorporating chiral selectivity into the micellar systems appears to be a logical extension of this generally powerful approach. Another variation of the EKCC approach is the use of microemulsions (19,20).…”

“…Many biological surfactants are chiral themselves; thus, the formed micellar pseudo stationary phase will naturally assume chiral recognition properties. In an even more complicated case, mixed micellar systems (16)(17)(18) can intentionally be formed to optimize chiral separations. Researchers often find it more profitable to optimize their separations empirically; not all chiral recognition mechanisms are completely understood.…”

“…) recognition mechanism relies on the hydrophobic entanglement within the micelle's inner core. Differential hydrogen bonding is thought to be responsible for stereochemical discrimination (16).…”