含發色或螢光基團之芳杯化學感應器的合成及其在金屬離子辨識之研究

Abstract

本論文報導了設計及合成含發色或螢光基團的芳杯衍生物作為金屬離子的化學感應器。 我們合成偶氮芳杯7，並以bistriazoles及azophenols作為金屬離子的辨識端，azo groups作為訊號傳遞的感應端。偶氮芳杯7對Ca2+及Pb2+離子具有很好的選擇性，並可直接由肉眼觀測顏色的變化。偶氮芳杯7與Ca2+及Pb2+離子是以1:1的模式錯合，錯合常數分別為7.06 x 104及8.57 x 103 M-1。 接著，我們合成具有兩種不同金屬離子錯合位置的螢光芳杯15作為光開關感應器的研究，分別在芳杯15的上緣修飾冠醚 (crown-5 ether ring)，作為金屬離子的第一個辨識端，而在芳杯的下緣利用即合化學 (Click Chemistry) 的方法獲得五員三唑雜環 (five-membered triazole) 作為金屬離子的第二個辨識端，並引入螢光基團蒽 (anthracene) 作為訊號傳遞的感應端。螢光芳杯15加入Hg2+、Cu2+、Cr3+及Pb2+離子後，螢光強度有很強烈地淬熄。而當錯合物15•Pb2+加入K+離子時，可以使其螢光強度恢復。從這樣的結果得知，我們成功地研發出可藉由金屬離子的交換過程來調控分子螢光的感應器。 另外，我們合成一系列的具有anthraceneisoxazolylmethyl 取代的螢光芳杯22-25作為Cu2+離子的化學計量器 (chemodosimeters)。藉由生命期的量測，可證明螢光芳杯對Cu2+離子的淬熄機制為static quenching。最後，經由循環伏安法 (CV)、電子順磁共振光譜 (EPR)、螢光光譜及氫核磁共振光譜等實驗，可證明螢光芳杯22-25與Cu2+會發生氧化還原反應，並作為Cu2+離子的化學計量器。 最後， 我們期望將具有功能性的芳杯鍵結在二氧化矽的表面作為金屬離子的隔離材料。我們將具有疊氮的二氧化矽材料34與含有雙丙炔基醚化的偶氮芳杯3，以即合化學 (Click Chemistry) 的條件反應，可得到具有三唑雜環的芳杯材料36。然後我們將利用材料36對金屬離子進行主客化學的研究。

This thesis presents the design and synthesis of chromogenic and fluorogenic calix[4]arene derivatives as chemosensors for metal ions. A novel chromogenic calix[4]arene 7 which has within a molecule both the triazoles and hydroxyl azophenols as the metal-binding sites and the azophenol moiety as a coloration site was designed and synthesized. Calix[4]arene 7 is highly sensitive to Ca2+ and Pb2+ ions which can be detected by the naked eye. Furthermore, the association constants for the 1:1 complexes of 7•Ca2+ and 7•Pb2+ were determined to be 7.06 □ 104 M-1 and 8.57 □ 103 M-1, respectively. A novel fluorescent on-off switchable chemosensor 15 with two different types of cationic binding sites was synthesized, which composed of a triazole-modified calix[4]crown in the 1,3-alternate conformation. Among fifteen metal ions examined, the fluorescence of 15 was strongly quenched by Hg2+, Cu2+, Cr3+, and Pb2+, respectively; however, the revival of emission from these strongly quenched complexes was solely observed by addition of K+ ion to the 15•Pb2+ complex. Thus, metal ion exchange can trigger an on-off switchable fluorescent chemosensor. We have designed a series of lower-rim anthraceneisoxazolylmethyl substituted calix[4]arenes 22-25 as chemodosimeters for Cu2+ ion. Stern-Volmer plots from steady state fluorescence quenching and lifetime measurements revealed that a static quenching mechanism is operative in the molecular system. Cyclic Voltammetry (CV), EPR, fluorescence measurement and 1H NMR titration experiments supported that these fluoroionophores 22-25 are Cu2+ selective chemodosimeters. Finally, we plan to immobilize the potentially useful calix[4]arene sensors onto the silica gel surface for the sequestration of metal ions. Cu(I)-catalyzed 1,3-dipolar cycloaddition reaction of the N3-material 34 and dipropargyloxy-azocalix[4]arene 3 in the Click Chemistry condition afforded the 1,2,3-triazole modified calix[4]arene-material 36. Then, we will examine the abilities of the 1,2,3-triazole modified calix[4]arene-material to remove metal cations from aqueous solution.