Yan Qifan, Cai Kang, Zhao Dahui
Beijing National Laboratory for Molecular Sciences, Department of Applied Chemistry, Centre for Soft Matter Science and Engineering, Key Lab of Polymer Chemistry & Physics of the Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China.
Phys Chem Chem Phys. 2016 Jan 21;18(3):1905-10. doi: 10.1039/c5cp05561j. Epub 2015 Dec 21.
The self-assembly behaviors of two series of monodispersed oligomers consisting of perylenediimide (PDI) linked by ethynylene and butadiynylene spacers are investigated in solutions. In spite of the very similar chemical structures, the two sets of oligomers manifest completely different optical properties upon self-aggregation, implying differed aggregate structures. While the oligomers containing butadiynylene spacers form H-aggregates, those featuring ethynylene linkers display J-aggregation characteristics. Thermodynamic analysis revealed that the self-association constants of both series of oligomers increase with the number of PDI units in the backbones. Oligomers containing the same number of PDI units but different spacers display nearly identical enthalpy changes. According to the molecular exciton theory, the observed H- and J-aggregates are suggested to comprise similar packing motifs with slightly varied slipping angles, giving rise to greatly disparate optical properties.
研究了由亚乙炔基和丁二炔基间隔基连接的苝二酰亚胺（PDI）组成的两个系列单分散低聚物在溶液中的自组装行为。尽管化学结构非常相似，但这两组低聚物在自聚集时表现出完全不同的光学性质，这意味着聚集结构不同。含有丁二炔基间隔基的低聚物形成H-聚集体，而具有亚乙炔基连接基的低聚物表现出J-聚集特征。热力学分析表明，两个系列低聚物的自缔合常数均随着主链中PDI单元数量的增加而增大。含有相同数量PDI单元但间隔基不同的低聚物表现出几乎相同的焓变。根据分子激子理论，观察到的H-和J-聚集体被认为包含相似的堆积基序，但滑动角略有不同，从而导致光学性质有很大差异。
