1420904-84-2Relevant academic research and scientific papers
Asymmetric thermal excitation delay fluorescent diphenyl ether aromatic phosphine oxygen material, synthetic method and its application
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Paragraph 00197; 00198; 0199; 0200, (2017/07/04)
The invention provides an asymmetric thermal-excitation delayed fluorescence diphenyl ether aromatic phosphine oxide material and a synthetic method and application thereof and aims at solving the technical problem that the thermal-excitation delayed fluorescence diphenyl ether aromatic phosphine oxide material is large in polarity, is easily quenched and is strong in intermolecular effect. The asymmetric thermal-excitation delayed fluorescence diphenyl ether aromatic phosphine oxide material is formed by introducing 2, 3 or 4 diphenylphosphine oxygen groups to 2, 2', 4 and 4' positions of diphenyl ether. The synthetic method comprises the steps of mixing bromo-diphenyl phosphine oxide phenylate, diphenylphosphine, anhydrous sodium acetate, palladium acetate and DMF, pouring a mixture into icy water to perform extraction, obtaining an organic layer for oxidation and performing extraction, drying and purification. The asymmetric thermal-excitation delayed fluorescence diphenyl ether aromatic phosphine oxide material can effectively inhibit mutual intermolecular effect and accordingly inhibit quenching effect. The asymmetric thermal-excitation delayed fluorescence diphenyl ether aromatic phosphine oxide material serves as a light-emitting layer and used for preparing electro-phosphorescence devices.
Convergent modulation of singlet and triplet excited states of phosphine-oxide hosts through the management of molecular structure and functional-group linkages for low-voltage-driven electrophosphorescence
Han, Chunmiao,Zhang, Zhensong,Xu, Hui,Xie, Guohua,Li, Jing,Zhao, Yi,Deng, Zhaopeng,Liu, Shiyong,Yan, Pengfei
, p. 141 - 154 (2013/03/13)
The controllable tuning of the excited states in a series of phosphine-oxide hosts (DPExPOCzn) was realized through introducing carbazolyl and diphenylphosphine-oxide (DPPO) moieties to adjust the frontier molecular orbitals, molecular rigidity, and the location of the triplet excited states by suppressing the intramolecular interplay of the combined multi-insulating and meso linkage. On increasing the number of substituents, simultaneous lowering of the first singlet energy levels (S1) and raising of the first triplet energy levels (T1, about 3.0 eV) were achieved. The former change was mainly due to the contribution of the carbazolyl group to the HOMOs and the extended conjugation. The latter change was due to an enhanced molecular rigidity and the shift of the T1 states from the diphenylether group to the carbazolyl moieties. This kind of convergent modulation of excited states not only facilitates the exothermic energy transfer to the dopants in phosphorescent organic light-emitting diodes (PHOLEDs), but also realizes the fine-tuning of electrical properties to achieve the balanced carrier injection and transportation in the emitting layers. As the result, the favorable performance of blue-light-emitting PHOLEDs was demonstrated, including much-lower driving voltages of 2.6 V for onset and 3.0 V at 100 cd m -2, as well as a remarkably improved E.Q.E. of 12.6 %.
