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

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24.70μg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.

Sensing Mechanism and Application for Recognition of Ethanol by Calixarene Supramolecules Based on Hydrogen Bonds Interaction

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-ethylcalix4]pirogallarene(3) was the most effectively active material to ethanol. The single crystal of complex C-ethylcalix4]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 cali-xarene 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.