Chiral Separations

Normal Phase Chiral Separation of Hexahelicene Isomers Using a Chiral Surface Confined Ionic Liquid Stationary Phase

“…In general, successful chiral recognition requires a primary docking mechanism (e.g., electrostatic, inclusion complexation) between the immobilized chiral selector and the chiral analyte. [22,23] The primary docking must place the stereogenic centers of the chiral selector and the chiral analyte in close proximity to each other. [24] The stereospecificity of the interactions between the chiral selector and chiral analyte are delineated by the secondary interactions (e.g., hydrogen bonding, dipole-dipole, dispersion, steric) emanating from the respective stereogenic centers.…”

Chiral Separation for Enantiomeric Determination in the Pharmaceutical Industry

“…Such requirement has important consequences for protein folding because the peptide carbonyl oxygen and N-H groups are regularly arranged along the polypeptide backbone. Extended arrangements having optimum hydrogen-bonded interactions among residues either within or between polypeptide chains reflect the periodic regularity and result in the formation of protein secondary structures [12]. In α-helix, the polypeptide backbone follows a path of a rigid right handed helical spring to form an arrangement in which each carbonyl group forms a hydrogen bond with the amide NH group.…”

“…The first successful chiral phases used under GC conditions were N-trifluoroacetyl (TFA)-L--amino acid esters. These phases separated racemates of the more volatile members of the same compounds [12]. The diamide stationary phase contained two hydrogen bonding sites, a C5 and a C7 site, where hydrogen bonding selector/selectand-associations could take place [7]:…”