Higashino Tomohiro, Kumagai Atsushi, Imahori Hiroshi
Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto, 615-8510, Japan.
Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Sakyo-ku, Kyoto, 606-8501, Japan.
Chem Asian J. 2018 Jun 19. doi: 10.1002/asia.201800856.
Fluoride (F ) ion sensing is an important topic due to its roles in health, medical, and environmental sciences. In this regard, colorimetric sensors with a near infrared (NIR) optical response are useful in biological systems because they can avoid interference from endogenous chromophores. Although calix[n]phyrins are highly attractive as sensors with the NIR optical response, studies on calix[n]phyrins are still limited owing to their intrinsic instability against ambient light and air. In this study, we report the synthesis and characterization of a new calix[5]phyrin bearing one sp -hybridized carbon atom as a π-expanded calix[n]phyrin. Upon addition of tetrabutylammonium fluoride, the calix[5]phyrin exhibited distinct NIR absorptions at 908 and 1064 nm as well as a visible color change. Importantly, it revealed an excellent selectivity for F ion. These results demonstrate that calix[5]phyrins are promising colorimetric and NIR sensors of F ion.
氟离子（F⁻）传感是一个重要的课题，因为它在健康、医学和环境科学中都发挥着作用。在这方面，具有近红外（NIR）光学响应的比色传感器在生物系统中很有用，因为它们可以避免内源性发色团的干扰。尽管杯[n]卟啉作为具有近红外光学响应的传感器极具吸引力，但由于其对环境光和空气的固有不稳定性，对杯[n]卟啉的研究仍然有限。在本研究中，我们报道了一种新型杯[5]卟啉的合成与表征，该杯[5]卟啉带有一个sp杂化碳原子，作为一种π扩展杯[n]卟啉。加入四丁基氟化铵后，杯[5]卟啉在908和1064 nm处表现出明显的近红外吸收以及可见颜色变化。重要的是，它对F⁻离子显示出优异的选择性。这些结果表明，杯[5]卟啉是很有前景的F⁻离子比色和近红外传感器。
