Tunable Ultralong Organic Room-Temperature Phosphorescence of Dinaphthylamine Skeleton via Molecular Modification and Conformational Change in a Flexible Cross-Linked Polymer Network

作者：Jiaxin Ma, Xingda Zhang, Tianya Zhang, Maosheng Yu, Jingjuan Bai, Han Lin, Lijuan Bu, Mingxing Chen, Zhimin Ma, Zhiyong Ma, Zhiyong Ma, Zhiyong Ma · 发表于：ACS Applied Materials & Interfaces · 年份：2025 · DOI：10.1021/acsami.5c08470 · 被引用次数：8 · 研究领域：Luminescence and Fluorescent Materials、Organic Light-Emitting Diodes Research、Conducting polymers and applications

Herein, we developed a simple cross-linking strategy to fabricate a flexible PETA/MA polymer network featuring tunable ultralong organic room-temperature phosphorescence (UORTP). Three dinaphthylamine-structured phosphorescence molecules (NQA-1, NQA-2, and NQA-3), modified with an (iso)quinoline ring, were synthesized, and the tiny structural change made a great difference to their UORTP properties by controlling T 1 excited states and intersystem crossing (ISC) efficiency. We thoroughly studied the UORTP performance in toluene solution, in PMMA film, in non-cross-linked copolymerized films, and in cross-linked films with three different cross-linkers. In particular, the PETA/MA films can be prepared via 30-s photopolymerization, which greatly reduces possible photobleaching. When the weight ratio of pentaerythritol tetraacrylate (PETA) increased from 0 to 0.06, the phosphorescence lifetime of NQA-1 was prolonged from 120 ms to 1.07 s, and the optimal ratio was determined to be 0.04. As the cross-linking density increased gradually, the glass-transition temperature ( T g ) rose, and the free volume reduced, which significantly prohibited nonradiative relaxation and led to high-performance UORTP. Moreover, the 0.04PETA/MA film possessed high flexibility. In the 0.04PETA/MA film, NQA-1 and NQA-3 showed remarkable phosphorescence redshift, while NQA-2 displayed a unique phosphorescence blueshift, suggesting that the cross-linked network significantly influences the molecular con...