Chiral molecular imprinting in liquid-crystalline network.

A cholesteric imprinted elastomer was obtained by cross-linking a nematic side-chain polysiloxane around a chiral template. The template was first linked to some functionalised groups of the polymer via hydrogen-bound interactions, then was removed by washing. The sample was macroscopically oriented during the synthesis; so, both a molecular chirality and a supramolecular phase chirality were topologically imprinted inside the network. Batch rebinding experiments, performed in the presence of the template or of the other enantiomer, showed that the imprinted polymer has a pronounced stereo-selectivity towards the template enantiomer. The rebinding capacity appeared to be greater than an unimprinted mesogenic network as well as than an imprinted non mesogenic one.