Separation of Chiral Molecules Using Mixed Matrix Membranes Incorporating Chiral Metal Organic Frameworks

Exciting new porous coordinated materials have recently been synthesised that incorporate chiral pore structures, which opens up the opportunity to use these materials as sorbents for the selective adsorption of enatiomerically distinct molecules from racemic mixtures. The significance of this development to the pharmaceutical and fine chemical industries is enormous, since a significant proportion of their products are chiral molecules which are usually separated using low-throughput, highly expensive elution columns (or must be synthesised using challenging chemistry which is directed towards producing enantiomerically pure products).

In this presentation, we will outline our recent results synthesising chiral metal organic framework materials using two distinct approaches; the use of chiral ligands to impart chirality to the resulting metal organic framework, and an emerging and lower-cost approach with is to post-synthetically modify non-chiral (but usually easily synthesised) subtrate materials, to impart a degree of chirality to them. These materials are tested as batch liquid-phase sorbents to screen their potential for selective sorption of a library of low molecular weight chiral molecules (primarily sugars, alcohols and amino acids). The most promising candidates, are incorporated into mixed matrix membranes and tested as membranes, with a specially- configured gas chomatograph with chiral columns used to resolve the components in the feed and permeate, to quantify the selectivity.