具烷基鏈結基團之矽烷基高分子其光物理性質探討

The Role of Oligomethylene Linkage on the Photophysics of Alternating Dialkylsilylene-Spaced Donor-Acceptor Copolymers

廖偉智(Wei-Chih Liao)

指導教授 ： 陸天堯

國立臺灣大學/理學院/化學研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.02757

摘要

設計並合成以矽烷基為間隔之芳香基聚合物以研究烷基鏈結基團於其光物理性質影響。合成的方法是以銠金屬催化矽氫化反應得到聚合物。在此共聚高分子中，電子傳遞予體與受體有機發光團被矽烷基分隔並交錯排列。於末端修飾矽烷基取代之反芪(反-1,2-二苯乙烯)有機發光團為電子傳遞受體，電子予體為兩個乙烯苯胺基團並以不同烷基鏈連結。藉由改變矽上取代基的大小(甲基 vs 異丙基)引入Thorpe-Ingold 效應的概念在矽烷基間隔上，而於相異矽上取代基之聚合物中觀察到差異甚大的光物理表現。因不同烷基鏈結基團具有不同構形變化，使其聚合物具有不等程度的高分子摺疊性質，而其光物理表現受到不等程度之擾亂。由此可推論，此類矽烷基聚合物之光物理性質會受到矽上取代基大小(Thorpe-Ingold效應)及高分子摺疊性質改變有所影響，而改變烷基鏈結基團可進而影響高分子摺疊性質。

關鍵字

烷基鏈結基團 ； 矽烷基高分子 ； 光物理性質 ； 電子轉移 ； 高分子摺疊

並列摘要

Alternating dialkylsilylene-spaced donor-acceptor copolymers with two substituents (methyl vs isopropyl) on silicon and different oligomethylene linkages, piperazinyl, ethylene, tetramethylene, and 2,2-dimethylpropylene, have been designed and synthesized by Rh-catalyzed hydrosilylations. The donors were selected to be the oligomethylene-connecting bis-aminostyrene moieties, and the acceptors were chosen as the stilbene chromophores with dialkylsilyl substituents at both ends.
Thorpe-Ingold effect is introduced by changing the size of the substituents (methyl vs isopropyl) on silicon. Totally different photophysical properties of SiMe2-spaced (methyl substituents on silicon) copolymers from those of SiiPr2-spaced (isopropyl substituents on silicon) copolymers were observed.
Furthermore, different oligomethylene linkages provide different behaviors of rotations of sigma-bonds. Thus, different polymer folding natures would be exhibited in those polymers with similar degrees of polymerization. The photophysical behaviors in SiMe2- and SiiPr2-spaced copolymers (within a range of degrees of polymerization ca. 5~15) may be perturbed.
To sum up, the photophysics of the copolymers could be affected by the synchronization of the Thorpe-Ingold effect on silicon and the polymer folding nature. Besides, it seems that polymer folding natures may be perturbed via different conformational equilibrium in various oligomethylene moieties within a range of degrees of polymerization.

並列關鍵字

oligomethylene ； dialkylsilylene ； donor ； acceptor ； photophysical property ； charge transfer ； polymer folding

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