Solvent-induced enantioselectivity reversal in a chiral metal organic framework

(a) Solvent-dependent enantioselectivity from chiral gas chromatography. (b) Loading of ZnBLD with racemic 1-phenylethanol, limonene, and 2-butanol in the presence of other solvents from NMR spectroscopy after digestion

Abstract

Solvent-induced enantioselectivity reversal is a rarely reported phenomenon in porous homochiral materials. Similar behavior has been studied in chiral high performance liquid chromatography, where minor modifications to the mobile phase can induce elution order reversal of two enantiomers on a chiral stationary phase column. We report the first instance of solvent-induced enantioselectivity reversal in a homochiral metal organic framework. Further, we highlight the complex enantioselectivity behavior of homochiral metal organic frameworks toward racemic mixtures in the presence of solvents through racemate-solvent enantioselectivity and loading experiments as well as enantiopure-solvent loading experiments. We hypothesize that this interesting selectivity reversal behavior is likely to be observed in other competitive adsorption, nonchiral selective processes involving a solvent.

Publication
Journal of Separation Science

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