New Heteropolycyclic Structures for Fluoride Anion Sensing by Naked‐Eye Visualization

Abstract

AbstractFluoride anion (F−) plays an important and fundamental role in chemical, biological, pathological, and environmental processes. It is highly desired to develop new methods for facial and efficient F− detection. Herein we present the synthesis and characterization of two effective fluoride ion probes and their selective F− sensing by naked‐eye visualization. A N‐heteroannelated anthraquinone derivative, compound I, was prepared by a cyclocondensation reaction of 1,2‐diaminoanthraquinone with 1,6‐bis(triisopropylsilyl)‐hexa‐l,5‐diyne‐3,4‐dione. Compound I was treated with malononitrile in the presence of Lehnert reagent to afford an HCl adduct, compound II, and an aza‐polycyclic aromatic compound III. All three compounds were characterized crystallographically and were studied photochemically. Similarly, 2,3‐diamino‐1,4‐anthraquinone reacted with 1,6‐bis(triisopropylsilyl)‐hexa‐l,5‐diyne‐3,4‐dione to afford compound IV, which reacted with malononitrile in the presence of Lehnert reagent to yield compound V. Compounds III and V are sensitive and selective probes for the detection of F− with significant color changes. The detection by naked eye visualization is rapid and facile, showing both compounds are potential probes for fluoride ion sensing.