Copper(II) complexes of diamino-diamido-type ligands as chiral eluents in the enantiomeric separation of D,L-dansylamino acids by reversed-phase high-performance liquid chromatography.
For purpose of studying the mechanism of chiral recognition in high-performance liquid chromatography (HPLC) (reversed phase), a model system is proposed, i.e., copper(II) complexes of diamino-diamido-type ligands containing L-amino acids (AA-NN-n) which added to the eluent are able to perform the enantiomeric resolution of dansylamino acids on C8 and C18 columns. Being potentially tetradentate, this system should be more liable to give an apical or outer-sphere interaction with the enantiomer rather than a simultaneous dechelation of two binding sites, as in the classical ligand-exchange mechanism. This model allows the variation of several parameters, such as the structural and electronic features of the initial complexes, their relative stabilities and lipophilicities and their correlation with enantioselectivity in HPLC.
Armani
E
E
Istituto di Chimica Organica dell'Università, Parma, Italy.
Dossena
A
A
Marchelli
R
R
Virgili
R
R
D000596:Amino Acids / Q000032:analysis*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002851:Chromatography, High Pressure Liquid; D003300:Copper; D003619:Dansyl Compounds / Q000032:analysis; D003959:Diamines; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D008024:Ligands; D008968:Molecular Conformation; D013237:Stereoisomerism
D000596:Amino Acids; D003619:Dansyl Compounds; D003959:Diamines; D007202:Indicators and Reagents; D008024:Ligands; D003300:Copper