Aggregation-Enhanced Emissions of Intramolecular Excimers in Disubstituted Polyacetylenes

详细信息    查看全文

• 作者：Anjun Qin ; Cathy K. W. Jim ; Youhong Tang ; Jacky W. Y. Lam ; Jianzhao Liu ; Faisal Mahtab ; Ping Gao ; Ben Zhong Tang
• 刊名：Journal of Physical Chemistry B
• 出版年：2008
• 出版时间：August 7, 2008
• 年：2008
• 卷：112
• 期：31
• 页码：9281-9288
• 全文大小：425K
• 年卷期：v.112,no.31(August 7, 2008)
• ISSN：1520-5207

文摘

Whereas chain aggregation commonly quenches light emission of conjugated polymers, we here report a phenomenon of aggregation-induced emission enhancement (AIEE): luminescence of polyacetylenes is dramatically boosted by aggregate formation. Upon photoexcitation, poly(1-phenyl-1-alkyne)s and poly(diphenylacetylene)s emit blue and green lights, respectively, in dilute THF solutions. The polymers become more emissive when their chains are induced to aggregate by adding water into their THF solutions. The polymer emissions are also enhanced by increasing concentration and decreasing temperature. Lifetime measurements reveal that the excited species of the polymers become longer-lived in the aggregates. Conformational simulations suggest that the polymer chains contain n = 3 repeat units that facilitate the formation of intramolecular excimers. The AIEE effects of the polymers are rationalized to be caused by the restrictions of their intramolecular rotations by the aggregate formation.