Structure-lock induced phosphorescence lifetime enhancing of (9H-carbazol-9-yl)(phenyl)methanone: An organic phosphorescent materials
Structure-lock induced phosphorescence lifetime enhancing of (9H-carbazol-9-yl)(phenyl)methanone: An organic phosphorescent materials
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DOI：
10.1016/j.jlumin.2020.117587
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发表时间：
2020-08
影响因子：
3.6
通讯作者：
Yonggang Yang;Yang Liu;Yufang Liu;Kai Jiang
中科院分区：
文献类型：
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作者：
Yonggang Yang;Yang Liu;Yufang Liu;Kai Jiang
不同的分子设计策略已经被用来研究纯有机材料的室温磷光（RTP），通过抑制非辐射失活和促进系统间的交叉。在这项工作中，CPM（（9 H-carbazol-9-yl）（phenyl）methanone）的基础上的合成策略已被执行，以实现长寿命RTP通过固定扭转的二苯甲酮部分，并形成一个六元杂环含氮元素。合成的具有较高刚性的锁定CPM（8H-indolo[3，2，1-de]phenanthridin-8-one）在单重态和三重态均具有平面构型，其锁定构型有效抑制了CPM的扭曲分子内电荷转移（TICT），并将单重态和三重态之间的能隙显著减小至0.89 ev.这种变化有利于系统间的交叉和三重态激子的泛化。通过对磷光衰减曲线的拟合，我们发现锁定CPM的磷光寿命比CPM的磷光寿命提高了近40倍，这表明所提出的策略将为开发长寿命RTP材料带来新的见解。指出抑制分子的振动和扭转，减小单-三重态之间的能隙，将有利于长的磷光寿命。
Different molecular design strategies have been performed to study purely organic materials with room-temperature phosphorescence (RTP) by suppressing nonradiative deactivation and facilitating intersystem crossing. In this work, a synthetic strategy based on CPM ((9H-carbazol-9-yl)(phenyl)methanone) has been performed to achieve long lived RTP by immobilizing the torsion of benzophenone moiety and forming a six-membered heterocyclic ring containing nitrogen element. This synthesized locked-CPM (8H-indolo[3,2,1-de]phenanthridin-8-one) with higher rigidity has planar configuration both in the singlet state and the triplet state, whose locking configuration effectively inhibits the twist intramolecular charge transfer (TICT) of CPM and significantly reduces the energy gap between the singlet and triplet states to 0.89 ev. This change facilitates intersystem crossing and the generalization of triplet excitons. By fitting the phosphorescence decay curves, we demonstrate that the phosphorescence lifetime of the locked-CPM has increased by nearly forty times compared with that of the CPM, indicating that the presented strategy will bring insight into the developing long lived RTP materials. It is noted that suppress the vibration and torsion of molecular and reduce the energy gap between single-triplet states will favors of long phosphorescence lifetime.