基于氢键作用的杯芳烃超分子识别乙醇的传感机理及分析应用

摘要

采用4种杯芳烃衍生物为吸附涂膜材料,考察了涂膜石英晶体微天平(QCM)传感器对环境大气中微量乙醇气体的识别性能,发现C-乙基杯[4]连苯三酚芳烃(3)是识别乙醇气体最有效的活性涂膜材料.制备了C-乙基杯[4]连苯三酚芳烃·2CH3CH2OH(5)单晶体并进行X射线衍射结构解析,发现其识别机制是基于超分子主体3与客体乙醇分子之间形成的C—H…π,O—H…π及O—H…O氢键作用.当涂膜质量为24.70 μg时,涂膜QCM传感器对乙醇的响应最灵敏,达到10.53 Hz/(mg·L-1).分析了乙醇气体的吸附和解吸附动力学过程,得到传感器对乙醇气体吸附和解吸附的初速度分别为-0.04600 Hz/s和0.03896 Hz/s.该方法响应快,具有选择性、可逆性、重现性和稳定性好的优点,对乙醇样品测定的回收率为94.8％～105.2％,与气相色谱法的测定结果一致,表明该方法可用于生活环境中乙醇气体的检测.%Four calixarenederivatives were employed as adsorptive coating materials of quartz crystal microbalance (QCM) for the detection of ethanol gas in environmental atmosphere,indicating that C-ethylcalix [4] pirogallarene (3) was the most effectively active material to ethanol.The single crystal of complex C-ethylcalix[4] pirogallarene · 2CH3CH2OH(5) was prepared and subjected to X-ray diffraction analysis,showing that the recognition mechanism was based on the formation of C-H…π,O—H…π and O—H…O hydrogen bonds interaction between the supramolecular host calixarene 3 and the guest ethanol molecule.When the coating mass of calixarene 3 was 24.70 μg,the coated QCM sensor possessed the highest sensitivity,which was 10.53 Hz/(mg · L-1).The kinetics processes for adsorption and desorption of ethanol on calixarene 3 have been examined,and the initial speeds of the adsorption and desorption processes for ethanol gas on calixarene 3 were obtained as-0.04600 Hz/s and 0.03896 Hz/s,respectively.With rapid test time,good selectivity,reversibility,reproducibility and stability,the calixarene 3 coated QCM sensor could be used for the detection of ethanol samples with a recovery of 94.8％-105.2％,which was in well consistent with those obtained by gas chromatography,showing its potential application on the determination of ethanol gas in living environment.