芳香環異咢唑取代雙芳杯之合成及膠體性質探討

Abstract

本論文成功在芳杯下緣利用1,3-偶極環化加成反應將異咢唑取代之芳香環做為橋聯合成出一系列單橋聯雙芳杯化合物50、51、52、56和57，其合成策略利用雙腈氧基取代之芳香化合物和單取代丙炔基芳杯，以1:2比例進行1,3-偶極環化加成反應，經過四個步驟的合成後產率約22-35%。另外利用即合反應得到三唑取代之單橋聯雙芳杯化合物55，產率約為50%。化合物50和51經丙炔化後再一次利用1,3-偶極環化加成反應，我們可合成出雙橋聯雙芳杯化合物58和63，兩步驟之產率約為32%。這些化合物之結構皆經由1H-, 13C 核磁共振光譜和質譜確認。 意外的，我們發現化合物59是以異咢唑雙芳杯為主體結構的有機凝膠物質，文獻上大多在有機凝膠物質的結構中，需要有長烷鏈的協助才易於形成膠體，而化合物59結構中並不具有長烷鏈，即可於醇類溶劑下可形成一穩定膠體，目前在文獻上，雙芳杯結構尚未出現具有膠體性質的例子。我們利用掃描式電子顯微鏡與變溫核磁共振光譜來探討化合物59形成膠體的原因。此外，化合物59在膠體態加入17種金屬離子，結果顯示銀、銅和汞離子對膠體會產生崩解與螢光淬熄的現象，鐵離子則只會造成螢光淬熄，不會使膠體崩解，因此我們可以利用此簡便方法對金屬離子進行篩選。

Biscalixarene is an important member of calixarene family, composed of two calixarene moieties linked at their lower rim through various spacers with more complicated structures and colourful properties as compared to monocalixarene. We have developed a method of attaching aryl isoxazole units onto the lower rims of calix[4]arenes by 1,3-dipolar cycloadditions to obtain a series of biscalix[4]arenes (50, 51, 52, 56 and 57) and our synthetic strategy for linking two calix[4]arenes involves a double cycloaddition between aryl dinitrile oxides and propargyl groups, yielded 22-35 % in four steps.The structures of all products were confirmed by spectral data including 1H-, 13C NMR, and MS. Organogels are usually assembled through self-aggregation of the small gelator molecules to form entangled supramolecular fibril networks via a combination of noncovalent interactions such as hydrogen bonding, □-□ stacking, and van der Waals interactions. Serendipitously, we have observed the first example of thermoreversible organogel with biscalix[4]arene in the gelator framework. We have prepared a new fluorescence organogelator 59 with isoxazole based biscalix[4]arene framework without the assistance of long alkyl chain. Furthermore, we have explored their molecular assembly properties during the sol-to-gel phase transition by variable-temperature 1H-NMR. Moreover, we found that the gel suprastructure is sensitive to added metal ions which are known to coordinate with triple bonds like Ag+, Cu2+ and Hg2+. The gel matrix will collapse into a solution phase and quench its fluorescence in the presence of Ag+, Cu2+ and Hg2+. The organogel-based approach becomes quite attractive comparing to conventional metal ion sensors.