Unsymmetrical 2,4,6-Triarylpyridines as Versatile Scaffolds for Deep-Blue and Dual-Emission Fluorophores

authors	Fontes, LFB; da Silva, RN; Silva, AMS; Guieu, S
nationality	International
journal	CHEMPHOTOCHEM
author keywords	triphenylpyridine; fluorescence; deep blue; dual emission; excited state intramolecular proton transfer
keywords	AGGREGATION-INDUCED EMISSION; ACTIVATED DELAYED FLUORESCENCE; ENHANCEMENT; SYSTEMS; DESIGN
abstract	Pyridines substituted with different aromatic groups at C-2, C-4 and C-6 were prepared following a Krohnke synthetic route. Introducing ortho-anisole at C-2 resulted in deep blue emitters in solution, with quantum yields up to 74%. On the other hand, when ortho-phenol was introduced, forming a strong hydrogen bond with the pyridine nitrogen, excited-state intramolecular proton transfer was witnessed by the dual emission of the fluorophores, which is sensitive to the dye environment. The phenyl ring at C-4 was used to introduce electron-donating or withdrawing groups, to fine-tune the photophysical properties of the dyes. Crystal structures of the fluorophores, together with theoretical studies using DFT/TD-DFT calculations, were used to rationalize the experimental photophysical properties of the two families of dyes. Unsymmetrical 2,4,6-triarylpyridines are therefore versatile scaffolds for the preparation of deep-blue and dual emission fluorophores, and are promising building blocks for luminescent devices and sensors.
publisher	WILEY-V C H VERLAG GMBH
issn	2367-0932
year published	2020
volume	4
issue	11
beginning page	5312
ending page	5317
digital object identifier (doi)	10.1002/cptc.202000134
web of science category	Chemistry, Physical
subject category	Chemistry
unique article identifier	WOS:000548280000001