Synergistic Intra ‐ and Intermolecular Noncovalent Interactions for Ultralong Organic Phosphorescence

Highly efficient ultralong organic phosphorescence luminogens are developed by the synergistic effect of intermolecular π–π stacking, intermolecular electronic coupling, and intramolecular hydrogen bonding. The pyrimidine‐based luminogens exhibit the longest phosphorescence lifetime of 1.37 s and the highest absolute phosphorescence quantum efficiency of 23.6%, respectively, which are rarely reported. AbstractMetal ‐free ultralong organic phosphorescence (UOP) materials have attracted significant attention owing to their anomalous photophysical properties and potential applications in various fields. Here, three pyrimidine‐based organic luminogens, 9‐(pyrimidin‐2‐yl)‐9H‐carbazole, 9‐(4,6‐dimethylpyrimidin‐2‐yl)‐9H‐carbazole, and 9‐(5‐bromopyrimidin‐2‐yl)‐9H‐carbazole are designed and synthesized, which show efficient yellow UOP with the longest lifetimes up to 1.37 s and the highest absolute phosphorescence quantum yields up to 23.6% under ambient conditions. Theoretical calculations, crystal structures, and photophysical properties of these compoun ds reveal that intramolecular hydrogen bonding, intermolecular π–π interactions, and intermolecular electronic coupling are responsible for forming dimers and generating highly efficient UOP. Their efficacy as solid materials for data encryption is demonstrated.

Source: Small - September 18, 2019 Category: Nanotechnology Authors: Xiao ‐Ning Li, Mingxue Yang, Xu‐Lin Chen, Ji‐Hui Jia, Wan‐Wan Zhao, Xiao‐Yuan Wu, Sa‐Sa Wang, Lingyi Meng, Can‐Zhong Lu Tags: Communication Source Type: research