2-(2-羥基苯基)苯並咪唑之金屬錯合物之合成、結構鑑定、光物理性質以及其陰離子辨識行為探討

Synthesis, Structures, Photophysical Properties, and Anion Recognition of 2-(2-Hydroxyphenyl)benzimidazole-based Metal Complexes

吳湧原(Yung-Yuan Wu)

指導教授 ： 吳景雲

國立暨南國際大學/科技學院/應用化學學系/碩士(2016年)

摘要

我們成功設計並且合成出以苯並咪唑為主架構的兩個有機配子HL1和H2L2，也合成出一系列金屬錯合物M(L1)2 (M = Zn, Co, Cu) 和M(HL2)2 (M = Zn, Co, Cu)。透過再結晶的方式長出兩種不同顏色的有機配子HL1晶體，從X-ray單晶數據可得知其分別為直線型和交錯型的堆疊，但兩者還是具有共同點，都具有分子內氫鍵、分子間氫鍵、π−π作用力。
　　從HL1和H2L2的吸收圖譜與螢光圖譜可得知其激發態分子內質子轉移(ESIPT) 機制的存在與較大的Stokes’ shift，由此兩種現象也說明了明顯的電子躍遷存在和分別為keto和enol之雙重螢光訊號存在。
　　我們以鋅金屬錯合物為螢光感測器，進行一系列的陰離子辨識。在螢光定性實驗中發現到Zn(L1)2的DMSO溶液加入醋酸根離子 (OAc-)、三溴根離子　(Br3-)、亞硝酸根離子 (NO2-)、氟離子 (F-)、焦磷酸根離子 (PPi-)會產生螢光焠熄現象，其中Br3-和F-會產生螢光訊號位移；Zn(HL2)2對於醋酸根離子、三溴根離子、亞硝酸根離子、氟離子會產生螢光焠熄現象，其中Br3-和F-會產生螢光訊號位移。在UV燈照射之下，我們能夠清楚看出這些加入不同陰離子溶液的顏色變化。此外進一步透過螢光滴定實驗、Job's plot和NMR探討Zn(L1)2與Zn(HL2)2和陰離子之間的辨識行為。

關鍵字：苯並咪唑基；螢光化學感測器；陰離子辨識

關鍵字

苯並咪唑基 ； 螢光化學感測器 ； 陰離子辨識

並列摘要

Two benzimidazole-based ligands, 2-(1H-benzimidazol-2-yl)phenol (HL1) and 2-(1H-5-carboxyl-benzimidazol-2-yl)phenol (H2L2), were successfully synthesized, which were reacted with M(OAc)2 to afford corresponding metal complexes, M(L1)2 (M = Zn, Co, Cu) and M(HL2)2 (M = Zn, Co, Cu). HL1 forms two different crystal phases, HL1-1 (orange color) and HL1-2 (colorless), both of which form intramolecular O-H…N hydrogen bonds, intermolecular N-H…O hydrogen bonds, and π−π stacking interations. However, the two phases pack in a linear and a staggered mammer, respectively.
　UV-vis absorption and fluorescence spectra indicate that HL1 and H2L2 have shown excited-state intramolecular proton transfer (ESIPT) and a large Stokes’ shift, providing obvious electron trasition proccess and dual fluorescence emissions for keto and enol forms.
　Zinc complexes Zn(L1)2 and Zn(HL2)2 have been designed as fluorescence sensors for anion recognition. Upon addition of OAc-,Br3-,NO2-,F-, PPi-, the fluorescence of Zn(L1)2 in DMSO has been quenched. Moreover, Br3-,and F- anions further cause fluorescence signal shift. Similarly, complexes Zn(HL2)2 also exhibit signifincant anion recognition towards OAc-,Br3-, NO2-, F- via fluorescence quenching. Among the four anions, Br3-and F- also induce shift in fluorescence wavelength. The anion recognition of both zinc complexes toward Br3- and F-can be observed by naked eye due to obvious color change. Moreover, fluorescence titration, Job's plot, and 1H NMR studies have applied to determine advancend anion recognition behaviors including host -to -guest binding ratios and possible binding sites etc.

Key words：Benzimidazol；Fluorescence Chemosensors；Anion Recognition

並列關鍵字

Benzimidazol ； Fluorescence Chemosensors ； Anion Recognition

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