Tunable Emission of Static Excimer in a Pyrene-Modified Polyamidoamine Dendrimer Aggregate through Positive Solvatochromism
作者:P. K. Lekha、Edamana Prasad
DOI:10.1002/chem.201100116
日期:2011.7.25
geometry in the ground state, and readily generate pyrene “static excimer” on photoexcitation. The static pyrene excimer emits with an unprecedented quantum yield of 0.62±0.01 in dichloromethane, and also exhibits remarkable positive solvatochromism from 498 to 638 nm, which leads to the highest bathochromic shift for pyrene excimer emission in solution reported so far. Lippert–Mataga analysis of the
在pyr改性的零和第一代聚酰胺酰胺(PAMAM)树枝状聚合物中,超过其临界聚集浓度(CAC,> 10 -6 M,)。units单元通过亚胺键连接到树枝状聚合物骨架,该亚胺键在增强PAMAM树枝状聚合物的聚集倾向中起关键作用。扫描电子显微镜研究表明,pyr修饰的PAMAM树枝状大分子聚集成甜甜圈状的组件。作为聚集的结果,the发色团在基态下以面对面的几何形状预先排列,并且在光激发下很容易生成pyr“静态受激准分子”。静态pyr准分子在二氯甲烷中的发射空前的量子产率为0.62±0.01,并且在498nm至638nm范围内还表现出显着的正溶剂变色现象,这是迄今为止报道的溶液中pyr准分子发射的最大红移。Lippert-Mataga对系统的分析表明,一般和特定的溶剂作用在系统显示的正溶剂变色中起着至关重要的作用。在各种金属离子的存在下,对单体和聚集体系统进行了荧光猝灭研究,结果表明pyr修饰的P