Enantiodiscrimination by a quinine-based chiral stationary phase: A computational study

Schefzick, Sabine; Lindner, Wolfgang; Lipkowitz, Kenny B.; Jalaie, Mehran

doi:10.1002/(sici)1520-636x(2000)12:1<7::aid-chir3>3.0.co;2-q

Cited by 38 publications

(11 citation statements)

References 22 publications

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“…Previous work in this area is limited to fundamental studies attempting to predict the separation factor from considerations of statistical thermodynamics 21 or quantum mechanics. 22 Because the properties of the two types of sites could be identified separately, the properties of CBH I-bonded silica could be used to prove experimentally that heterogenous mass transfer kinetics is a cause of peak tailing. 13 This study provided also the explanation of an unusual temperature effect previously reported.…”

mentioning

confidence: 99%

Apparent and true enantioselectivity in enantioseparations

2000

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The separation factor of two compounds in chromatography is the ratio of their equilibrium constants or retention factors. This parameter is universally employed to investigate their resolution and to optimize the experimental conditions of their analysis. In enantioseparations, the situation is more complex because there is a mixed retention mechanism. The retention factor is the sum of two contributions, one enantioselective, the other nonselective. Although both contribute to retention, the latter being identical for the two enantiomers and does not contribute to their separation. We show how these two contributions can be measured and how it becomes necessary to distinguish between the apparent, alpha(app), and the true, alpha(true), separation factors. The existence of nonselective sites is responsible for alpha(app) being less than alpha(true). Depending on the difference between these two factors, the more effective approach to improve a separation is either to increase the enantioselectivity or to reduce the nonselective interactions. Practical applications to separations of different beta-blockers on cellobiohydrolase are discussed. The apparent enantioselectivity of alprenolol is larger and increases faster with increasing pH than that of the more hydrophobic propranolol, in spite of the importance of hydrophobic interactions in the enantioselective mechanism. These two unexpected properties are discussed and explained.

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confidence: 99%

Apparent and true enantioselectivity in enantioseparations

2000

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“…Under reversed phase conditions, they operate through an ion pairing interaction with acidic enantiomeric analytes. Under normal phase conditions, they operate through  interactions as well as ion pairing [128,129].…”

Section: Chiral Separation Through a Combination Of Charge Transfer mentioning

confidence: 99%

“…The basis of the interactions in the complex consists of electrostatic interactions between the quinuclidin of the amine ion and the carboxylate of the selectand, the  interactions between the quinoline ring of the selector and the dinitrobenzoyl of the selectand and the steric repulsion between the leucine side chain and the carbamate moiety [129]. Table 6.6 lists some successful separation on the commercial Chiral AX ® column based on quinine CSP.…”

Section: Chiral Separation Through a Combination Of Charge Transfer mentioning

confidence: 99%

Chiral Separation for Enantiomeric Determination in the Pharmaceutical Industry

Grinberg¹,

Pan²

2012

Physico-Chemical Methods in Drug Discovery and Development

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“…The basis of the interactions in the complex consists of electrostatic interactions between the quinuclidin's ammonium ion and the selectand's carboxylate, the π-π interactions between the quinoline ring of the selector and the dinitrobenzoyl of the selectand, and the steric repulsion between the leucine side chain and the carbamate moiety [102]. …”

Section: Chiral Separation Through Combination Of Charge Transfer Andmentioning

confidence: 99%