Reversal behaviors of the enantiomer migration order and the stereo-selectivity of Cu(II) complex with amino acid enantiomers in ligand exchange-micellar electrokinetic chromatography
Zl. Chen et al., Reversal behaviors of the enantiomer migration order and the stereo-selectivity of Cu(II) complex with amino acid enantiomers in ligand exchange-micellar electrokinetic chromatography, ANAL SCI, 16(2), 2000, pp. 131-137
The dependence of the enantioselectivity and enantiomer migration order (EM
O) on the chirality and stereo-conformation of ligands used for the chiral
selectors of Cu(II) complexes was investigated. It was interestingly observ
ed that EMOs were reversed not only by a change of the ligand chirality of
selector, but also by the trans- or cis-conformation of a 4-hydroxy substit
uent in 4-hydroxyproline. In the presence of the sodium dodecyl sulfate (SD
S) micellar phase, the EMOs were reversed when both the bidentate and tride
ntate ligands of the proline family were used. The resolution (Rs) of enant
iomers decreases when the cis-hydroxy substituent exists in D- or L-hydroxy
proline. SDS micellar phase improves the resolution of amino acid enantiome
rs. The relationships among the EMO, ligand chirality, complex stability an
d stereo-selectivity are discussed.