鐵(III)離子、汞(II)離子及鋅(II)離子螢光感測分子之合成與應用

Abstract

本論文分別以menadione、coumarin及pyrene為基底，設計合成出螢光化學感測分子1、2、3。化合物1藉由顏色變化(由黃色變無色)及藍色螢光turn-on的方式來辨識Hg2+，在其他金屬離子的存在下，仍對Hg2+具有高度選擇性。由核磁共振氫譜得知，化合物1以炔基及胺基與Hg2+鍵結。由Job plot可得1 – Hg2+的錯合比例為1 : 1。由Benesi-Hildebrand plot 得知1 – Hg2+之結合常數為1.07 × 104 M-1。化合物1最佳pH值範圍是pH = 4.5 – 7.5。 化合物2藉由藍色螢光turn-on的方式來辨識Zn2+，在其他金屬離子的存在下仍對Zn2+具有高度選擇性。由核磁共振氫譜得知，化合物2以羥基和亞胺上的氮與Zn2+鍵結。由Job plot可得2 – Zn2+的錯合比例為1 : 1。由Benesi-Hildebrand plot 得知2 – Zn2+之結合常數為2.36× 104 M-1。化合物2最佳pH值範圍為pH 7左右。 化合物3藉由螢光轉變(由橘紅光變綠光)的方式來辨識Fe3+，在其他金屬離子的存在下仍對Fe3+具有選擇性。由核磁共振氫譜得知，化合物3上的羥基和亞胺上的氮與鐵離子鍵結。由Job plot可得3 – Fe3+的錯合比例為2: 1。由鐵離子的滴定實驗中可得知3 – Fe3+之結合常數為1.67× 109 M-2。

In this thesis, menadione, coumarin and pyrene were used as signal units for chemosensors 1, 2 and 3, respectively. Chemosensor 1 indicated the presence of Hg2+ among other metal ions with high selectivity by color change from yellow to colorless and a remarkable blue emission. According to 1H NMR studies, addition of Hg2+ caused the disappearance of amine (NH) hydrogen signal and shifting of alkane (CH2) and alkyne (CH). These observations indicate that Hg2+ binding with chemosensor 1 is mainly through the amine (NH) group and the alkyne (C≡C) group. The binding ratio of 1–Hg2+ complexes was determined as 1 : 1 according to Job plot. According to Benesi-Hildebrand plot, the association constant of 1–Hg2+ complexes was decided as 1.07 × 104 M-1. The best pH range for detecting Hg2+ by 1 was from pH 4.5 to 7.5. Chemosensor 2 indicated the presence of Zn2+ among other metal ions with high selectivity by remarkable blue emission. According to 1H NMR studies, addition of Zn2+ caused the disappearance of hydroxy (OH) hydrogen signal and shifting of hydroxy (OH). These results indicate that Zn2+ binding with chemosensor 2 is mainly through hydroxyl group (OH) and nitrongen of imine (C=N). The binding ratio of 2–Zn2+ complexes was determined as 1:1 according to Job plot. According to Benesi-Hildebrand plot, the association constant of 2–Zn2+ complexes was decided as 2.36× 104 M-1. The best pH range for detecting Zn2+ by 2 was around pH 7 . Chemosensor 3 indicated the presence of Fe3+ among other metal ions with selectivity by fluorescent emission change from orange-red to green. According to 1H NMR titration studies, the disappearance of hydroxy (OH) indicates that Fe3+ binding with chemosensor 3 is mainly through hydroxyl group (OH) and nitrongen of imine (C=N). The binding ratio of 3–Fe3+ complexes was determined as 2 : 1 according to Job plot. According to Fe3+ titration, the association constant of 3–Fe3+ complexes was decided as1.67× 109 M-2.