Homochiral Tetraphenylethene-Based Metal-Organic Frameworks with Circularly Polarized Luminescence for Enantioselective Recognition.

A pair of water-stable and highly porous homochiral fluorescent silver-organic framework enantiomers, namely, R -Ag-BPA-TPyPE ( R - 1 ) and S -Ag-BPA-TPyPE ( S - 1 ), had been prepared as enantioselective fluorescence sensors. Combining homochiral 1,1'-binaphthyl-2,2'-diyl hydrogen phosphate (BPA) with an AIE-based ligand tetrakis[4-(pyridin-4-yl)phenyl]ethene (TPyPE) in complexes R - 1 and S - 1 made them possess favorable circularly polarized luminescence (CPL) properties, and their CPL spectra were almost mirror images of each other. The luminescence dissymmetry factors ( g lum ) are ±2.2 × 10 -3 for R - 1 and S - 1, and the absolute fluorescence quantum yields (Φ Fs ) are 32.0% for R - 1 and S - 1 , respectively. Complex R - 1 could enantioselectively recognize two enantiomers of amino acids in water or DMF with high Stern-Volmer constants of 236-573 M -1 and enantioselectivity ratios of 1.40-1.78.