含五苯荑金(I)炔基錯合物之刺激響應放光性質之研究

Stimuli-Responsive Photoluminescent Properties of Pentiptycene-Containing Gold(I) Acetylide Complexes

吳庭緯(Ting-Wei Wu)

指導教授 ： 楊吉水

國立臺灣大學/理學院/化學研究所/碩士(2020年)

https://doi.org/10.6342/NTU202003002

摘要

金(I)錯合物獨有的”親金作用力”，可受外界刺激，如機械力、有機物蒸氣、熱及光等的影響而改變。親金作用力為金(I)離子與金(I)離子之間彼此透過非共價鍵所形成的作用力，距離大約為2.5~3.8埃。親金作用力的變化，往往可使放光有顏色上的變化，因此使金(I)錯合物被廣泛應用於刺激響應材料當中。
本實驗室過去發表了一系列以五苯荑為主體的刺激響應材料，主要可歸因於剛硬且H型結構的五苯荑基團。首先，其可有效阻止分子間的π-π堆疊，使分子於固態下有著良好的放光效率；此外，特殊的U型凹槽及V型凹槽，可於固態下提供各種不同的排列模式以及與客體分子發生超分子作用力，使放光顏色有許多變化。
在這篇論文中，我們合成一系列含五苯荑的金(I)-炔基錯合物，並修飾上不同的苯乙炔基配體。其中以最簡單的苯乙炔原型被命名為Ph；以及延伸共軛長度的Naph及An；修飾不同對位取代的苯乙炔，命名為OMe、CN及CF3。我們觀察其受刺激後之放光行為，並透過光譜、晶體結構以及拉曼光譜提出合理機制。
我們的結果顯示全部的錯合物都具有力致放光變色的響應，主要歸因於研磨可使親金作用力增強，進一步使放光紅移；又或者開啟/減少激發雙體放光，使得光譜紅移/藍移。
我們還發現對位取代系列的錯合物對苯胺小分子具放光響應，形成激發複合體放光，且隨著錯合物的缺電子性增加，紅位移的程度會隨之提升；透過與晶體結構的連結，我們歸納出孔洞結構為一重要的因素。
此外，對位取代系列錯合物的晶體，通過紫外光的照射可使放光紅移至橘紅色，然而整體的放光效率變差；由於循序漸進的紅移，會經過一白色放光的過渡狀態。經光照後，親金作用力增強，生成以四核金原子團簇為主導的消光團，導致單體形式放光經由能量轉移淬滅為可能的機制。

關鍵字

金(I)-炔基錯合物 ； 親金作用力 ； 力致放光變色 ； 薰致放光變色 ； 光致放光變色 ； 激發複合體 ； 孔洞型晶體結構

並列摘要

The luminescence properties of many gold(I) complexes are sensitive to their molecular arrangements and intermolecular interactions. In general, the aurophilic interactions (AuI… AuI ,ca. 2.5 ~3.8 Å ) of gold(I) complexes strongly affect the emission properties in the solid state. In addition, the aurophilic interaction could be easily regulated by external stimuli, such as mechanical force, volatile organic vapor, heat, and light, thereby making gold(I) complexes an intriguing type of luminescent materials.
Our group has been interested in stimuli-responsive materials that contain the rigid H-shaped pentiptycene skeleton. Pentiptycene group has been incorporated into π-conjugated organic or organometallic systems to diminish intermolecular π-stacking and thus improve photoluminescence quantum efficiency in solid state. Moreover, the unique U- and V-cavities created by the two iptycenyl units could lead to different packing modes and supramolecular interactions.
Here we report a novel class of pentiptycene-gold(I) hybrid systems bearing different arylacetylene moiety. The phenylacetylene as prototype is named Ph; Complex Naph and An have extended the π-conjugation length, those with substitued at the para position are named OMe, CN and CF3. We study there emission properties with various stimulation and propose a reasonable mechanism through the emission spectrum, single crystal structure and Raman spectroscopy.
Our results reveal that all the complexes exhibit emission color change upon treatment of mechanical grinding due to enhanced of aurophilic interactions or the variation of exmeric emission.
To our surprise, we found that Ph and its para analouges showed a unique vapochromic luminescent response to the electron-rich aniline vapors, forming red-shifted exciplex emission. As the electron deficiency of the complex increases, the degree of red shift will increase. We conclude that the porous structure is an important factor.
In addition, Ph and its para analouges display interesting luminescence response in the crystalline form to UV illumination. Upon photoirradiation, the blue emissive crystals gradually change the emission colors to orangish-red with reduced intensity via a white light emitting intermediate state. It is attributed to photoinduced enhancement of the aurophilic interactions for the tetranuclear cluster that is responsible for the red emission and quenching as a energy trap.

並列關鍵字

Gold(I) Acetylide complex ； Aurophilic interactions ； Mechanochromic Luminescence ； Vapochromic Luminescence ； Photoochromic Luminescence ； Exciplex ； Porous Crystal Structures

參考文獻

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