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

Abstract

We demonstrated in this work the use of affinity ionic liquids, AIL 1 and AIL 2, 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 AIL 1 thin-coated on quartz chips. Starting with inexpensive reagents, bicyclic imidazolium ionic liquids AIL 1 and AIL 2 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., ΔF = −10 Hz), the detectability using AIL 1 was 6.3 ppb. Our preliminary investigation on detection of the much less nucleophilic alcohol gas by AIL 1 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.

Structural Engineering and Optimization of Zwitterionic Salts for Expeditious Discovery of Thermoresponsive Materials

“…With thirteen final ionic products ( IL 2 , ZIL 3a–f and ZIL 4a–f ) synthesized in this work, only ZIL 3a is an ionic salt with m.p. at 100 °C; other twelve are supercooled ionic liquids at room temperature [ 15 , 16 ] and viscous colorless-to-pale yellow liquid when obtained. As unambiguously demonstrated in Figure 3 , we were pleased that IL 2 not only was found as a room-temperature ionic liquid exhibiting UCST phase transition in water but also carried much lower T c value than that of IL 1 : 13 °C and 72 °C at 1:1 mass ratio, respectively.…”

Group of Uniform Materials Based on Organic Salts (GUMBOS): A Review of Their Solid State Properties and Applications

“…Sensing strategies for a variety of systems, from biological targets [158], environmental and regulatory applications [159,160], mechanical integrity of structures [161][162][163], and more [60,164], are continuously under investigation in the scientific community. In general, recognition can be categorized into two different methodologies: targeted and non-targeted [165].…”

Ionic Liquid-Based Quartz Crystal Microbalance Sensors for Organic Vapors: A Tutorial Review

“…The ionic liquids that we discussed above show reversible response, meaning that the analytes can be easily desorbed by blowing an inert gas [37]. There are several attempts to develop QCM sensors using specific chemical reactions of ILs with analytes, which can significantly increase the sensitivity and selectivity for several organic vapors; and, this type of ILs has been referred to as 'sensing ionic liquids' (SILs) [87][88][89][90][91][92][93]. Tseng and Chu [87] synthesized three SILs and used them for highly sensitive and selective detection of aldehyde, ketones, and amines.…”

“…Hsu et al [92] reported the detection of alkenes gas through the use of Diels-Alder [4+2] cycloaddition reaction of alkenes with so-called functional ionic liquids, and the sensitivity of detection was reported to be 1.5 ppb for cyclopentadiene. Li and Chu [93] reported detection of alcohol and amine gases by utilizing triazine-based ILs and nucleophilic aromatic substitution reactions. These reaction-based IL systems provide high sensitivity, high selectivity, and no sensitivity to moisture as compared to the ILs discussed in Section 4.1.…”