Reaction-Based Amine and Alcohol Gases Detection with Triazine Ionic Liquid Materials

We demonstrated in this work the use of affinity ionic liquids, and , for chemoselective detection of amine and alcohol gases on a quartz crystal microbalance (QCM). These detections of gaseous amines and alcohols were achieved by nucleophilic aromatic substitution reactions with the electrophilic 1,3,5-triazine-based thin-coated on quartz chips. Starting with inexpensive reagents, bicyclic imidazolium ionic liquids and were readily synthesized in six and four synthetic steps with high isolated yields: 51% and 63%, respectively. The QCM platform developed in this work is readily applicable and highly sensitive to low molecular weight amine gases: for isobutylamine gas (a bacterial volatile) at 10 Hz decrease in resonance frequency (i.e., Δ = -10 Hz), the detectability using was 6.3 ppb. Our preliminary investigation on detection of the much less nucleophilic alcohol gas by was also promising. To our knowledge, no example to date of reports based on nucleophilic aromatic substitution reactions demonstrating sensitive gas detection in these triazine ionic liquids on a QCM has been reported.