Anthracene-Resorcinol Derived Covalent Organic Framework as Flexible White Light Emitter

• Published in: Journal of the American Chemical Society 2018-10, Vol.140 (41), p.13367-13374
• Main Authors: Haldar, Sattwick, Chakraborty, Debanjan, Roy, Bibhisan, Banappanavar, Gangadhar, Rinku, Kushwaha, Mullangi, Dinesh, Hazra, Partha, Kabra, Dinesh, Vaidhyanathan, Ramanathan
• Format: Article
• Language: English
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.8b08312

The ordered modular structure of a covalent organic framework (COF) facilitates the selective incorporation of electronically active segments that can be tuned to function cooperatively. This designability inspires developing COF-based single-source white light emitters, required in next-generation solid-state lighting. Here, we present a new anthracene-resorcinol-based COF exhibiting white light emission. The keto–enol tautomers present in the COF give rise to dual emission, which can be tuned by the O-donor and N-donor solvents. Importantly, when suspended in a solid polymer matrix, this dual emission is retained as both tautomers coexist. A mere 0.32 wt % loading of the COF in poly­(methyl methacrylate) (PMMA) gives a solvent-free film with intense white light emission (CIE coordinates (0.35, 0.36)). From steady-state and time-resolved studies, the mechanism of the white light emission has been unambiguously assigned to fluorescence, with the blue emission originating from the π-stacked columns of anthracene, and the mixture of red and green from the keto–enol tautomerized resorcinol units. The study introduces the COF as a new class of readily processable, single-source white light emitter.