From phosphorescence to delayed fluorescence in one step: tuning photophysical properties by quaternisation of an sp²-hybridised nitrogen atom

Klimash, A. , Prlj, A., Yufit, D. S., Mallick, A., Curchod, B. F. E., McGonigal, P. R., Skabara, P. J. and Etherington, M. K. (2022) From phosphorescence to delayed fluorescence in one step: tuning photophysical properties by quaternisation of an sp²-hybridised nitrogen atom. Journal of Materials Chemistry C, 10(25), pp. 9484-9491. (doi: 10.1039/D2TC01737G)

Abstract

Control of the delayed emission of organic compounds is an important factor in the development of new display technology and for the emerging use of organic emitters in sensing and fluorescence microscopy. In particular, there is a need to understand how the phenomena of room-temperature phosphorescence and thermally activated delayed fluorescence intersect. Here, we show that delayed fluorescence can be activated in room temperature phosphorescence emitters by quaternising the sp2-hybridised heterocyclic nitrogens. Furthermore by judicious positioning of a carbazole donor in the meta- or para-position with respect to the ring nitrogen atom, structural and sterical influences combine to tune the origins of the delayed fluorescence from triplet–triplet annihilation to thermally activated delayed fluorescence. Crucially, the quaternisation of nitrogen provides us with the means to fine-tune singlet and triplet states in a predictable manner, uncover the intersection between phosphorescence and delayed fluorescence and tip the balance in favour of delayed fluorescence.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Skabara, Professor Peter and Klimash, Ms Anastasiia

Creator Roles

Klimash, A.: Conceptualization, Formal analysis, Investigation, Methodology, Project administration, Resources, Visualization, Writing – original draft, Writing – review and editing
Skabara, P.: Conceptualization, Supervision, Funding acquisition, Writing – review and editing

• Authors: Klimash, A., Prlj, A., Yufit, D. S., Mallick, A., Curchod, B. F. E., McGonigal, P. R., Skabara, P. J., and Etherington, M. K.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Journal of Materials Chemistry C
• Publisher: Royal Society of Chemistry
• ISSN: 2050-7526
• ISSN (Online): 2050-7534
• Published Online: 25 May 2022
• Copyright Holders: Copyright © 2022 The Royal Society of Chemistry
• First Published: First published in Journal of Materials Chemistry C 10(25): 9484-9491
• Publisher Policy: Reproduced under a Creative Commons License

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
308120		Ultra-fast, ultra-small and ultra-dilute: an integrated understanding of conjugated polymers in solution across temporal and spatial scales	Peter Skabara	Engineering and Physical Sciences Research Council (EPSRC)	EP/T013710/1	Chemistry