含異咢唑、三唑及萘啶之衍生物的合成及金屬離子辨識應用

Abstract

含異咢唑、三唑及萘啶之衍生物的合成及金屬離子辨識應用 (1) 含異咢唑和三唑之偶氮芳杯衍生物在金屬離子感測器上的應用 我們將Sparpless教授所提出的即合化學應用於芳杯衍生化，成功合成出雙偶氮雙異咢唑之芳杯32及具有雙偶氮及蒽三唑兩種基團的芳杯34。藉由紫外可見光光譜的量測，發現化合物32對Ca2+和Pb2+有辨識的能力，但是辨識靈敏度稍差。化合物34對Cu2+、Ca2+和Zn2+離子皆有螢光增強的現象，其中和Cu2+可能發生氧化還原反應。化合物34和Ca2+形成了錯合物，因而抑制分子內的能量轉移，使得吸收光譜紅位移，放射光譜和吸收光譜重疊處減少，所以錯合物的螢光增強。化合物34在Zn2+離子加入後，吸收光譜並不會產生紅位移，我們推測造成螢光增強的原因為三唑和金屬進行錯合，抑制光誘導電子轉移機制，使得錯合物的螢光增強。

(2) 含三唑的1,8-萘啶衍生物之合成及其在螢光離子感測器上的應用 在證實三唑雜環對金屬離子的錯合能力後，將本體為螢光基團且具離子螯合能力的1,8-萘啶當作主體，引入三唑當作螯合基。研究結果發現，化合物47在鹼性條件下，行親核基取代反應，得到1,8-萘啶的異構物1,8-萘啶-2酮 54a。在氧化銀為試劑下，對於47進行自由基反應，可以得到1,8-萘啶的系列化合物51b-d，但是得不到丙炔基-1,8-萘啶化合物51a，只有得到2,7-苯甲基三唑-1,8-萘啶-2-酮55及控制化合物51b和57。經由紫外可見光光譜及螢光光譜的量測，發現化合物55對金屬離子不如控制化合物51b及57對金屬離子具有選擇性。利用氫核磁共振光譜滴定實驗證實化合物55由於可以螯合的位置太多，所以會得到很紊亂的圖譜改變。化合物51b及化合物57可以由氫核磁共振光譜滴定證明沒有和Cu2+行氧化還原反應。化合物51b在低當量的Hg2+存在時，其比例為2:1，但在高當量的Hg2+存在時，其配位數則為1:1。

Synthesis of Isoxazole, Triazole and Naphthalidene Derivatives and Their Applications in Metal Ion Sensing (1) Application of isoxazole and triazole modified calix[4]arenes as metal ion sensing Using Click chemistry, which was promoted by professor K. B. Sharpless, we successfully synthesized p-nitrophenylazo-isoxazole- calix-[4]arene 32 and p-nitrophenylazo-anthryl-triazole-calix[4]-arene 34. Based on the results from UV-Vis spectroscopy, we found that compound 32 could recognize Ca2+ and Pb2+, however with a poor sensitivity. When compound 34 was complexed with Cu2+, Ca2+ and Zn2+, the intensity of fluorescence enhanced. We found that compound 34 might undergo redox reaction with Cu2+. The complexation of Ca2+ with compound 34 suppressed intramolecular energy transfer, which caused the red shift of UV-Vis spectrum, less overlapping of the absorption spectrum and emission spectrum, and the enhancement of the fluorescence. Upon the addition of Zn2+, the absorption spectrum of compound 34 didn’t suffer red shift. We speculated that the suppression of the PET mechanism by the complexation of Zn2+ with triazole groups accounted for the fluorescence enhancement.

(2) Synthesis and application of 1,8-naphyridine derivative as fluorogenic cation sensors After confirming the ability of triazole ring to chelate metal ions, we attempted to make use of the 1,8-naphyridine which is an intrinsically fluorescent for metal ion sensing. We found that the reaction of 1,8-naphyridine in basic condition underwent SN2 reaction, to give 1,8-naphyridin-2-one derivatives. Only when using Ag2O as reagents 1,8-naphyridine 51b-d were obtained as the major products, which was probably going through radical mechanism. We were unable to obtain the 2,7-bis(prop-2-ynyloxy)-1,8-naphthyridine 51a, so we synthesized compound 55, control compounds 51b and 57. Based on the results from UV-Vis spectroscopy and fluorescence spectrometry, we found that compound 55 recognized almost all kinds of metal ions with poor selectivity. 1H NMR titration experiments showed that the 1H NMR spectrum of compound 55 suffered complicated and unexplainable changes upon the addition of metal ions, which might be due to the overabundance of the binding sites on the compound 55. 1H NMR supported that compounds 51b and 57 didn’t undergo redox reaction with Cu2+ ion. At low concentration of Hg2+ ion, compound 51b complexed with it at a 2:1 ratio. However, at higher concentration of Hg2+, they formed a 1:1 complex.