A new triphenylsilyl-containing gelator for visual sensing of fluoride ion

Abstract

We report the rational design and synthesis of a new triphenylsilyl group–containing small-molecule gelator for visual sensing of fluoride ion. Fluoride-mediated conversion of this gelator (gel state) into a nongelator (gel degradation) was crucial to the success of this approach. Two different detection techniques were developed. In the first, a pre-formed gel made from the gelator was rapidly degraded at elevated temperatures in the presence of fluoride ion but not in its absence. Fluoride ion could be quantitatively estimated by correlating gel-degradation times with fluoride ion concentrations. In the second, a differential gel-formation inhibition was observed in the presence of varying amounts of fluoride ion but not in its absence which led to a semi-quantitative estimation of fluoride ion concentrations. The performance of the small-molecule gelator described here is significantly better than many of the previously reported gelation-based visual detection techniques for fluoride ion.