Isophthalamide bearing 1-pyrenylethynyl group as a highly fluorescent hydrogen bond motif for anion receptors

Abstract

Isophthalamide-based receptor 2 bearing 1-pyrenylethynyl group as a fluorophore was prepared for a ratiometric fluorescence sensor for anions. Receptor 2 showed small hypsochromic shift by UV–vis titrations and ratiometric fluorescence changes upon the addition of anions, in particular biologically important anions such as AcO−, H2PO4−, and Cl− with high association constants. The high quantum yield of receptor 2 (ΦF = 0.88) implies that 5-(1-pyrenyl)isophthaloyl amide spacer is a versatile component for various fluorescence receptors.