杯芳烃超分子对甲醇的识别机理分析及应用

Mechanism and Sensing Application for Recognition of Methanol Based on Calixarene Supramolecules

采用四种杯芳烃超分子化合物为吸附涂层物质,探讨了涂膜石英晶体微天平(QCM)传感方法对环境大气中微量甲醇气体的识别研究,发现RCT(Resorcinol cyclic tetramer)是对甲醇气体识别最有效的活性涂层材料.通过RCT-MeOH单晶体的制备并对其进行X-ray衍射结构解析,发现其识别机制是基于甲醇分子中的甲基与杯芳烃化合物的苯环之间形成了C—H…π键作用.当RCT涂层质量为28.16μg时,涂膜QCM传感器对甲醇的响应最灵敏,达到0.01245 Hz/ppm.该传感器对甲醇气体吸附和解吸附的初速度分别为-0.2110 Hz/s和0.09497 Hz/s.该方法具有响应快、重现性和稳定性好的优点,对甲醇测定的回收率在97.83%～103.66%之间,与气相色谱法测定结果一致,表明该方法可应用于环境大气中甲醇气体含量的检测.

Four calixarene supramolecular compounds were employed as adsorptive coating materials of quartz crystal microbalance （QCM） for detection of methanol gas in environmental atmosphere, indicating that resorcinol cyclic tetramer （RCT） was the most effectively active material to methanol. The single crystal of RCT-MeOH was prepared and subject to X-ray diffraction analysis, showing that the recognition mechanism was based on the formation of C-H…π bond interaction between the methyl group of the methanol molecule and the phenyl ring of the calixarene. When the coating mass of RCT was 28.16 μg, the coated QCM sensor possessed the highest sensitivity, that was 0.01245 Hz/ppm. The initial speeds of the adsorption and desorption processes for methanol gas on RCT were obtained as -0.2110 Hz/s and 0.09497 Hz/s, respectively. With rapid test time, good reproducibility and stability, the RCT coated QCM sensor could be used for the detection of methanol samples with a recovery of 97.83%-103.66%, which agreed well with those obtained by gas chromatography, showing its potential application on the determination of methanol gas in atmospheric environment.