带有咔唑支链的聚乙炔的发光特性研究

Origin of the blue emissions of polyacetylenes bearing carbazole side groups

在室温下,对单取代聚乙炔(PACz-1)和两种双取代聚乙炔[PACz-2(m=3)、PACz-2(m=9)]的荧光特性和电子结构进行了研究.每种聚乙炔的支链上有一个咔唑单元.虽然它们的分子结构不同,但它们的稀溶液却有相同的吸收峰和强的绿色荧光发射峰,并且它们的吸收谱和发射谱很相似.当溶液的浓度增大到～1×10^(-3)M时,发现有强的绿色荧光发射,峰位位于475 nm.运用Huckel扩展紧束缚计算方法,从理论上计算了带咔唑支链的聚乙炔的电子结构。结果表明单取代聚乙炔和两种双取代聚乙炔的吸收峰、低浓度下的360 nm紫外光发射峰与高浓度下的475 nm的绿色荧光峰都是由于聚乙炔支链上咔唑生色团引起的.

The optical properties and electronic structures of one mono-substituted polyacetylene and two di-substituted polyacetylenes have been investigated. Each of the substituted polyacetylenes bears a carbazole unit in the side chain. In spite of the differences in their molecular structures, the dilute solutions （- 1 ×10^-6 M） of these substituted polyacetylenes exhibit the same absorptions and the same deep-blue emissions （-360 nm）. Interestingly, the absorption and emission spectra of these substituted polyacetylenes are similar to those of the small molecule carbazole. As the concentration of the substituted polyacetylenes increases to about 1 × 10^-3 M, we have detected intense blue emissions at about 475 nm. Using Huckel tight binding programs, we have calculated the electronic structures of the carbazole-containing polyacetylenes. Our results indicate that the absorption, the deep-blue emission （-360 nm） and the intense blue emission （-475 nm） originate from the carbazole chromophores in the side chain.