4-氮杂芴-9-酮衍生物的合成及发光性质

以4-氮杂芴-9-酮(IP)为电子受体,咔唑(Cz)为电子供体,通过调节Cz在IP上的取代位置合成了4例荧光染料,即IP-6-Ph Cz、IP-7-PhCz、IP-8-PhCz和IP-9-PhCz。利用紫外吸收光谱、荧光发射光谱、电化学分析等对所得4例荧光染料的光致发光、电致发光以及电化学性质进行了测试。结果表明,IP-6-Ph Cz和IP-9-PhCz分别实现了45.3°和51.8°的大扭曲角,其单重态-三重态能级差(ΔEST)分别为0.32和0.28eV,表现出热活化延迟荧光(TADF)特征,而IP-7-PhCz和IP-8-PhCz仅是普通的荧光染料。其中,IP-7-PhCz的光致发光量子产率(PLQY)为29%,电致发光的最大外量子效率为2.8%。

Synthesis and Luminescent Properties of 4-azafluoren-9-one Derivatives

A series of novel fluorescent isomers were designed and synthesized by using 4-azafluoren-9-one (IP) as electron acceptor and carbazole as electron donor. The substitution position of carbazole on IP was adjusted to form IP-6-PhCz, IP-7-PhCz, IP-8-PhCz and IP-9-PhCz. The photoluminescent, electroluminescent and electrochemical properties of the four fluorescent dyes were characterized by UV absorption spectroscopy, fluorescence emission spectroscopy, electrochemical analysis. Experiment result shows that the substitution position of Cz on IP leads to different molecular conformation and determines the luminescent behavior of these isomers. The isomers IP-6-PhCz and IP-9-PhCz with larger torsion angles due to strong steric hindrance exhibited thermally activated delayed fluorescence (TADF) feature, while IP-7-PhCz and IP-8-PhCz emit only normal fluorescence. IP-7-PhCz showed higher photoluminescent quantum yields of 29% and realized the best performance with a maximum external quantum efficiency of 2.8% in organic light-emitting diode.