Zhou Ying, Li Yao, Zhang Rong, Zhao Dahui, Yan Qifan
Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, 200237, P. R. China.
Beijing National Laboratory for Molecular Sciences, 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, P. R. China.
Chem Asian J. 2021 Jul 19;16(14):1893-1896. doi: 10.1002/asia.202100397. Epub 2021 Jun 1.
Luminophores with tunable emission properties are appealing due to various applications. Among those properties, thermally activated delayed fluorescence (TADF) has been attracting enormous research interests. Herein, we synthesized a 9,9'-spirobifluorene based homo-conjugated molecule 1, which connects a diphenylamino moiety as electron donor and a naphthalimide group as electron acceptor via 2,2'-positions of spirofluorene. Compound 1 displays dual emission behaviour with both blue and orange fluorescence. The one orange fluorescence around 555 nmshows sensitivity to oxygen and a prolonged lifetime of 284 ns in degassed toluene. Such characteristics imply TADF nature for this emission from a charge-transfer excited state. The other emission at 440 nm with blue colour displayed resistance to oxygen quenching and a normal fluorescence lifetime of 1.5 ns. Compared with control molecule, this emission band is assigned as conventional fluorescence from a localized excited state. In addition, dual emission property allows molecule 1 to be modulated to emit white photoluminescence in thin film with a CIE color coordinate of (0.25, 0.33).
具有可调发射特性的发光体因其多种应用而备受关注。在这些特性中，热激活延迟荧光（TADF）一直吸引着大量的研究兴趣。在此，我们合成了一种基于9,9'-螺二芴的同共轭分子1，它通过螺芴的2,2'-位连接一个作为电子供体的二苯胺部分和一个作为电子受体的萘酰亚胺基团。化合物1表现出蓝色和橙色荧光的双重发射行为。在555 nm左右的橙色荧光对氧气敏感，在脱气甲苯中的寿命延长至284 ns。这些特性表明这种电荷转移激发态发射具有TADF性质。在440 nm处的蓝色发射对氧气猝灭具有抗性，正常荧光寿命为1.5 ns。与对照分子相比，该发射带被指定为来自局域激发态的传统荧光。此外，双重发射特性使分子1能够被调制为在薄膜中发射白色光致发光，其CIE色坐标为(0.25, 0.33)。
