以芘衍生物為基底之螢光化學感測分子用於偵測鐵(III)離子及鎘(II)離子

Abstract

本論文使用pyrene 為發光基團，設計合成出螢光化學感測分子 (1、2、3、4、5、6)。化合物1 藉由螢光變化(由微弱變發強綠光)來 辨識Fe(III)離子，在其他金屬離子的存在下仍對Fe(III)具有高度選擇性。 當加入Fe(III)時，化合物1 與Fe3+錯合，促使pyrene 芳香環的靠近，而 造成激發複體(excimer)的放光，產生綠色螢光(507 nm)。由Job plot 可得知1－Fe(III)的錯合比例為1：1。由Benesi-Hildebrand plot 得到1 －Fe(III)之結合常數為1.27 × 10^4 M^-1。合成化合物2、5 及6 作為化合 物1 之比較，而其螢光感測的篩選能力均不及化合物1。 化合物3 藉由螢光變化(藍光變綠光)來辨識Fe(III)及Hg(II)離子。當 加入Fe(III)時，化合物3 與Fe(III)錯合，促使pyrene 芳香環靠近，而造成 由激發單體(monomer)轉變成激發複體的放光。由Job plot 可得3－ Fe(III)的錯合比例為2：1。3－Fe3+之結合常數為6.57 × 10^10 M^-2。3－ Hg(III)之結合常數Ka = 1.93 × 10^11 M^-2。 化合物4 藉由螢光變化(綠光變藍光)來辨識Cd2+離子。當加入 Cd(II)時，化合物4 與Cd(II)錯合，導致pyrene 堆疊的扭曲，而生成static excimer 放光(457 nm)，由Job plot 得知化合物4 與Cd2+之錯合比例為 1：1。由Benesi-Hildebrand plot 得知4－Cd2+之結合常數為3.29 × 10^4 M^-1。

In this thesis, pyrene was used as a signal unit for chemosensors 1, 2, 3, 4, 5 and 6. Chemosensor 1 can detect Fe(III) by Fe(III)-induced formation of pyrene excimer, which resulted in a green emission. Upon Fe(III) addition, 1 exhibited a significant emission centered at 507 nm, which is the formation of pyrene excimer. The binding ratio of 1—Fe(III) was determined as 1：1 according to Job plot. The association constant of 1—Fe(III) complexes was found to be 1.27 × 10^4 M^-1 according to Benesi-Hildebrand plot.Chemosensor 1 is better sensor for Fe(III) than chemosensors 2, 5, 6. Chemosensor 3 can detect Fe(III) and Hg(II) from other metal ions. Upon addition of Fe(III), 3 exhibited a green emission centered at 505 nm, which comes from the formation of pyrene excimer. The binding ratio of 3－Fe(III) was decided as 2：1 according to Job plot. The association constant of 3－Fe(III) complexes was decided as 6.57 × 10^10 M^-2. Chemsensor 4 can detect Cd(II) from other metal-ion. Upon addition of Cd(II), 4 exhibited a strong emission at 457 nm due to the formation of static pyrene excimer. The binding ratio of 4－Cd(II) was found to be 1：1 according to Job plot. The association constant was determined as 3.29 × 10^4 M^-1 according to Benesi-Hildebrand plot.