下緣三唑基取代芳杯對金屬陽離子及陰離子之化學感測

Abstract

本論文主題以芳杯為感應分子平台，下緣以三唑基為辨識基，訊號基分別以具變色效果的偶氮基或具螢光性質的芘基進行金屬離子辨識探討。完成不同光學的訊號基討論後，進而探討三唑基辨識陰離子及自身變色的可能性。 在第二章的計畫中，開發具偶氮變色基的感應分子4，並發現其在具質子的極性混溶劑中，對15種過氯酸鹽金屬離子中的Hg2+有專一性且比例性的辨識效果，以1:1錯合，結合常數為1.07(□0.32) □ 104 M-1，可由溶液顏色由黃色變淡橘色判斷之。再者，利用化合物4以及相關的衍生物完成化合物4結構中各個官能基在金屬離子辨識中的功能探討。 在第三章的計畫中，成功開發共軛「三唑-芘」官能基，同時具有辨識及發送訊號功能。將其以對位或鄰位兩種方位置於芳杯下緣，發現鄰位「三唑-芘」18對Ag+的訊號強度大於對位「三唑□芘」20，及傳統非共軛「三唑-亞甲基-芘」與芳杯組成的金屬離子感應分子。在極性質子溶劑中，具對位共軛「三唑-芘」芳杯20對Ag+以CHEF (chelation-enhanced fluorescence) 螢光機制產生辨識，雖是1:1錯合，結合常數為1.83(□0.33) □ 104 M-1，但訊號不具比例化特性。然而，具鄰位共軛「三唑-芘」芳杯18對Ag+以單體/激發雙體 (monomer/excimer) 螢光機制產生辨識，具訊號比例化地1:1錯合，結合常數為7.11(□0.80) □ 103 M-1；即使在10% 水的甲醇溶液中對Ag+仍保有單體/激發雙體的螢光偵測效果。 在第四章的計畫中，成功開發具不同電性之共軛「三唑-苯」基。當芳杯下緣對位具有拉電子性的「三唑□硝基苯」基 (化合物30) 時，三唑基在395 nm產生一新的微弱吸收峰。其可對9種陰離子中的F□、CH3COO□、H2PO4□及HO□產生辨識，在UV-vis 吸收光譜中502 nm產生新的吸收峰，溶液顏色從無色變淡粉紅。即使在具質子性的乙腈/甲醇 (v/v, 95:5) 混溶劑中，此效果仍存在，只是錯合物502 nm的吸收峰紅位移至545 nm。

In this thesis, chromogenic and fluorogenic calix[4]arenes bearing lower-rim triazoles as chemosensors for metal cations in polar protic cosolvents were synthesized and studied. Besides, the lower-rim distal triazoles of calix[4]arene as an anionic recognition site and chromogenic group were also explored. In chapter 2, a specific and ratiometric chemosensor for Hg2+ based on triazole coupled ortho-methoxyphenylazocalix[4]arene 4 was synthesized. The complex 4□Hg2+ was determined to be 1:1 stoichometry and its association constant was determined to be 1.07(□0.32) □ 104 M-1 in a MeOH/CHCl3 (v/v, 98:2) cosolvent. The functions of azo, hydroxyl, and triazole groups on ligand 4 for sensing Hg2+ were distinguished by the studies of ligands 4 and its derivatives. In chapter 3, a novel fluoroionophore, triazolylpyrene, was developed. Furthermore, a calix[4]arene with lower-rim proximal triazolylpyrenes 18 is a ratiometric fluorescent chemosensor for Ag+ with higher sensitivity compared to that of a calix[4]arene with lower-rim distal triazolylpyrenes 20, and the conventional fluoroionophore with “triazole-CH2-pyrene”. In a MeOH/CHCl3 (v/v, 98:2) cosolvent, the complex 20□Ag+ was determined to be 1:1 stoichometry and its association constant was determined to be 1.83(□0.33) □ 104 M-1; however, the complex 18□Ag+ was determined to be 1:1 stoichometry and its association constant was determined to be 7.11(□0.80) □ 103 M-1. Even the detection of Ag+ by ligand 18 works in 10% aqueous methanol solution. In chapter 4, calix[4]arenes bearing lower-rim distal p-substituted phenyltriazoles were developed where the electronegativity of triazoles are controlled by its conjugated p-substituted benzene. Especially, a calix[4]arene with lower-rim distal p-nitrophenyltriazoles 30 was explored to be a novel ratiometric and chromogenic chemosensor toward F□, CH3COO□, H2PO4□, and HO□ in polar solvent as well as in polar protic cosolvents.