Isomeric chiral pyrrole diamides and their efficacy in enantioselective sensing of tartrate in sol–gel medium

Abstract Pyridinium motif-based chiral pyrrole diamide clefts 1 and 2 have been designed and synthesized for chiral recognition of hydroxycarboxylates in sol–gel medium. Of the two isomeric chiral receptors, receptor 1 shows selective sensing of d -tetrabutylammonium tartrate over its mirror image isomer in CH 3 CN. The isomeric receptor 2 did not show any enantioselectivity in the recognition. Moreover, the receptor 1 validates prompt visual sensing of d -tartrate through gelation. The recognition properties of the receptors have been studied by fluorescence, UV–vis, 1 H NMR and CD spectroscopic methods.