Use of simultaneous face to face and face to edge π-π interactions to facilitate chiral recognition

Could linear solvation energy relationships give insights into chiral recognition mechanisms?

“…The s coefficients are three to four times higher than in RPLC keeping the same positive sign (except for the R-CSP whose s coefficient was high in RPLC, Table 3) and there is no e coefficient in the normal phase mode (e = 0). It was observed in NPLC chiral separations that π-π interactions could play a significant role in solute retention and enantiomer discrimination [21]. If the LSER analysis returns a nil value for the polarizability e coefficient in normal phase mode, it means that the π-π interaction contribution to solute retention is not encoded in this coefficient or that these interactions are insignificant in this apolar mode or that these interactions between the solute and the stationary phase and between the solute and the heptane mobile phase are exactly the same.…”

Chloroperoxidase Catalyzed Enantioselective Epoxidation of Selected Olefins and Regiospecific Degradation of Dimethylsulfoniopropionate

“…55 The basic selective mechanism of Whelk-O 1 is the "three point rule": three simultaneous interactions are required between the analyte and the CSP, and these interactions may be attractive or repulsive and they may be single point (e.g., hydrogen bonding) or multipoint (e.g., π-π and dipole-dipole interactions). According to the rule, there should be at minimum three interaction sites required between the chiral selector and one enantiomer in a racemic mixture.…”

“…55 The broad versatility of Whelk-O 1 columns compares favorably with other chiral stationary phases. Moreover, the selector is covalently bonded to the support, so this CSP can readily tolerate the usual range of solvents, both organic and aqueous.…”

A QSPR Study of Association Constants of Macrocycles toward Sodium Cation

“…[1][2][3][4][5] The characterizing feature of the supramolecular chemistry is that carefully designed synthetic structures (hosts) recognize target molecules (guests) forming a supramolecular complex through non-covalent complexes. Supramolecular chemistry and the quantification of non-covalent interactions offer the basis for new approaches in medicine, host-guest chemistry, [6] chromatography, [7] and biocatalysis. [8] A host-guest relationship involves a complementary stereoelectronic arrangement of binding sites in host and guest, the host component is defined as an organic molecule or ion whose binding sites converge in the complex the guest component is defined as any molecule or ion whose binding sites diverge in the complex.…”

“…Cram and coworkers and Reinhoudt and coworkers have extensively investigated the complexation behavior of hemispherand molecules with various binding sites. [9][10][11][12][13][14][15][16] Hemispherands are very efficient hosts for alkali metals and ammonium ions. They form mainly 1:1 complexes, and solid-state structural analyses show the ion perching above the macrocyclic cavity of the host.…”