Enhancing enantioselectivity in chiral metal organic framework fluorescent sensors

Abstract

The straightforward identification of enantiomers is of large importance to applications in the pharmaceutical, food and agricultural industries. We report the incorporation of two ligands containing the 1,1′-binaphthyl (BINOL) core with axial chirality and D-camphoric acid containing point chirality into Zn(II) metal–organic framework (MOF) chiral fluorescence sensors. The Zn(II) MOFs displayed outstanding enantioselectivity as chiral fluorescent sensors with an exceptional enantiomeric ratio (ER) of 3.92 which is amongst the highest values reported, along with excellent accuracy for the determination of enantiomeric excess in unknown samples. The role of complementary void shapes, a chiral co-ligand and hydrogen bonding interactions between the guest and sensors are explored.