聚丙烯腈
发色团
磷光
单独一对
聚集诱导发射
光化学
聚合物
材料科学
化学物理
分子
荧光
聚类分析
纳米技术
化学
物理
有机化学
计算机科学
复合材料
机器学习
量子力学
作者
Qing Zhou,Boyu Cao,Chenxuan Zhu,Si Xu,Yongyang Gong,Wang Zhang Yuan,Yongming Zhang
出处
期刊:Small
[Wiley]
日期:2016-09-08
卷期号:12 (47): 6586-6592
被引量:325
标识
DOI:10.1002/smll.201601545
摘要
Intrinsic emission from nonconjugated polymers has attracted considerable attention owing to its fundamental importance and intensive applications in diverse fields. The emission mechanism, however, is still in debate. Herein, nonconjugated polyacrylonitrile (PAN) molecules are found to be virtually nonluminescent in dilute solutions, while being highly emissive when concentrated or aggregated as nanosuspensions, solid powders, and films, exhibiting distinct aggregation‐induced emission (AIE) characteristics. Moreover, triplet emissions of delayed fluorescence and room temperature phosphorescence are detected from the solid powders. Such unique emission of nonconjugated PAN is ascribed to the formation of cyano clusters, which act as the exact chromophores. In these clusters, through space electronic interactions, namely overlap of π and lone pair (n) electrons among cyano groups extend the conjugation and meanwhile rigidify the molecular conformations, thus offering remarkable emission upon irradiation. The AIE phenomenon can also be well rationalized by the formation of cyano clusters together with conformation rigidification. And the triplet emissions shall be originated from the n–π* transition owing to the presence of lone pairs. It is believed that such clustering‐triggered emission mechanism is instructive for further development of unorthodox luminogens.
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