Making chiral zeolites in bulk

Abstract

Composed of a network of molecule-sized channels and pores, zeolites have been used for decades in catalysis, separations, ion exchange, and adsorption. Researchers would like to make chiral versions of these molecular sieves for separating mixtures of stereoisomers and carrying out chiral reactions. Yet making bulk samples of chiral zeolite crystals that are made entirely of one enantiomer has remained an elusive goal. A team of researchers led by Mark E. Davis of California Institute of Technology has now synthesized enantio-enriched batches of germanosilicate molecular sieves exhibiting R and S chirality. The team has used these materials to separate chiral molecules and as heterogeneous catalysts to mediate chiral reactions (Proc. Natl. Acad. Sci. USA 2017, DOI: 10.1073/pnas.1704638114). To make the materials, Davis and coworkers used computational methods to design and evaluate organic structure-directing agents (OSDAs), which are used to guide the three-dimensional assembly of zeolite components. Th...