Ultralong Near Infrared Room Temperature Phosphorescence in Cu(I) Metal‐Organic Framework Based‐on D–π–A–π–D Linkers. (31st January 2023)

• Record Type: Journal Article
• Authors: Wang, Zheng; Liu, Jia‐Jia; Yin, Shao‐Yun; Li, Meng‐Yang; Hou, Ya‐Jun; Wang, Dan; Mo, Jun‐Ting; Chen, Guang
• Is Part Of: Advanced functional materials. Volume 33:Number 16(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-01-31
• Subjects: Cu(I) metal‐organic frameworks -- NIR room temperature phosphorescence -- long persistent luminescence -- ultralong lifetime; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202212985
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Materials taking abundant advantage of triplet states luminescence have risen lots of attention in decades. In this work, a Cu(I) metal‐organic framework (MOF) with synchronous metal‐to‐ligand charge transfer (MLCT) state and triplet emission of the ligand is synthesized from a D–π–A–π–D ligand with suitable energy gap. The Cu(I) MOF possessed MLCT emission in the range of 450–505 nm with microsecond lifetimes (1.07 to 5.38 µs) and a triplet state emission in near infrared (NIR) region ≈705 nm with lifetimes of 1.85 ms at 300 K and 25.16 ms at 77 K, much longer than those of reported Cu(I) MOFs. Moreover, a white light is obtained through adjusting the relative intensity of dual peaks. More importantly, NIR long persistent luminescence of Cu‐MOF is observed by naked eyes under cryogenic condition. Multiple factors such as the delicate design of the D–π–A–π–D structure of ligand, the enhanced spin‐orbital coupling by Cu(I) networks, and the tight packing mode of the framework promote the generation of MLCT emission and ultralong NIR room temperature phosphorescence. The combination of calculation and experiment to analyse the luminescence mechanism of Cu(I) MOFs provides ideas for the development of Cu(I)‐based intelligently responsive materials with RTP properties. Abstract : The D–π–A–π–D structure of Tz‐Nap ligand with appropriate ΔEST is cleverly designed, which further self‐assembly with copper(I) to enhance spin‐orbital coupling. The tight packing mode of the framework promoted the generation of metal‐to‐ligand charge transfer emission and ultralong near infrared (NIR) room temperature phosphorescence. This is the first time that considerable NIR long persistent luminescence has been achieved in copper(I) metal‐organic frameworks at low temperature.