Rodrigues Ana Clara B, Wetterling Dario, Scherf Ullrich, Seixas de Melo J Sérgio
Department of Chemistry, CQC, University of Coimbra, Rua Larga, 3004-535, Coimbra, Portugal.
Macromolecular Chemistry Group (buwmakro) and Institute for Polymer Technology, Bergische Universitat Wuppertal, Gauss-Str. 20, 42097, Wuppertal, Germany.
Chemistry. 2021 May 20;27(29):7826-7830. doi: 10.1002/chem.202100123. Epub 2021 May 1.
Enhancement of the luminescence efficiency of two new diazapentacenium salts (D1 and D2) of more than 55 for D1 and 22 times for D2) in poor solvents, acetonitrile and/or dichloromethane, was observed and rationalized as formation of emissive J-aggregates. Both compounds displaying 4-n-decylphenyl substituents at the 7,14-carbons and phenyl (D1) or 2,6-difluorophenyl (D2) substituents at the quaternary nitrogen atoms in 5,12-positions have been synthetized in a two-step procedure involving a two-fold Buchwald-Hartwig-type CN cross-coupling and an electrophilic Friedel-Crafts-type cyclization. The optical properties of the dicationic diazapentacenium salts in various solvents and in thin films have been investigated by steady-state and time-resolved absorption and photoluminescence spectroscopies. In thin films and in good solvents, isolated molecules coexist with aggregates. Nonetheless, D1 is seven times more emissive than D2, reflecting a higher J-aggregate contribution in the former.
在不良溶剂乙腈和/或二氯甲烷中，观察到两种新型二氮杂戊鎓盐（D1和D2）的发光效率提高（D1提高了55倍以上，D2提高了22倍），并合理地解释为形成了发光的J-聚集体。两种化合物在7,14位带有4-正癸基苯基取代基，在5,12位的季氮原子上带有苯基（D1）或2,6-二氟苯基（D2）取代基，它们是通过两步法合成的，该方法涉及两步Buchwald-Hartwig型碳氮交叉偶联和亲电Friedel-Crafts型环化反应。通过稳态和时间分辨吸收光谱以及光致发光光谱研究了二阳离子二氮杂戊鎓盐在各种溶剂和薄膜中的光学性质。在薄膜和良溶剂中，孤立分子与聚集体共存。尽管如此，D1的发光能力是D2的七倍，这反映出前者中J-聚集体的贡献更高。
