TY - JOUR
T1 - Benzo[1,2-b:4,5-b']dithiophene as a weak donor component for push-pull materials displaying thermally activated delayed fluorescence or room temperature phosphorescence
AU - Cardeynaels, Tom
AU - Paredis, Simon
AU - Danos, Andrew
AU - Vanderzande, Dirk
AU - Monkman, Andrew P.
AU - Champagne, Benoît
AU - Maes, Wouter
N1 - Funding Information:
This work is supported by the University of Namur and Hasselt University [PhD BILA scholarship T. Cardeynaels]. The authors also thank the Research Foundation – Flanders (FWO Vlaanderen) for financial support [project G.0877.18 N, Hercules project GOH3816NAUHL, and SB PhD scholarship S. Paredis]. The calculations were performed on the computers of the « Consortium des équipements de Calcul Intensif (CÉCI) » ( http://www.ceci-hpc.be ), including those of the « UNamur Technological Platform of High-Performance Computing (PTCI) » ( http://www.ptci.unamur.be ), for which we gratefully acknowledge the financial support from the FNRS-FRFC, the Walloon Region , and the University of Namur [Conventions No. 2.5020.11, GEQ U.G006.15, U.G018.19, 1610468, and RW/GEQ2016]. A. Danos and A.P. Monkman are supported by EU Horizon 2020 Grant Agreement No. 732013 (HyperOLED). We thank Alastair Harrison for assistance in collecting spectroscopic data for TXO2-DMAC.
Publisher Copyright:
© 2020 Elsevier Ltd
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2021/2
Y1 - 2021/2
N2 - In the search for high-performance donor-acceptor type organic compounds displaying thermally activated delayed fluorescence (TADF), triisopropylsilyl-protected benzo[1,2-b:4,5-b']dithiophene (BDT-TIPS) is presented as a novel donor component in combination with two known acceptors: dimethyl-9H-thioxanthenedioxide (TXO2) and dibenzo[a,c]phenazinedicarbonitrile (CNQxP). For a broader comparison, the same acceptors are also combined with the well-studied 9,9-dimethyl-9,10-dihydroacridine (DMAC) donor. Optimized BDT-TIPS-containing structures show calculated dihedral angles of around 50° and well-separated highest occupied and lowest unoccupied molecular orbitals, although varying singlet-triplet energy gaps are observed experimentally. By changing the acceptor moiety and the resulting ordering of excited states, room temperature phosphorescence (RTP) attributed to localized BDT-TIPS emission is observed for TXO2-BDT-TIPS, whereas CNQxP-BDT-TIPS affords a combination of TADF and triplet-triplet annihilation (TTA) delayed emission. In contrast, strong and pure TADF is well-known for TXO2-DMAC, whereas CNQxP-DMAC shows a mixture of TADF and TTA at very long timescales. Overall, BDT-TIPS represents an alternative low-strength donor component for push-pull type TADF emitters that is also able to induce RTP properties.
AB - In the search for high-performance donor-acceptor type organic compounds displaying thermally activated delayed fluorescence (TADF), triisopropylsilyl-protected benzo[1,2-b:4,5-b']dithiophene (BDT-TIPS) is presented as a novel donor component in combination with two known acceptors: dimethyl-9H-thioxanthenedioxide (TXO2) and dibenzo[a,c]phenazinedicarbonitrile (CNQxP). For a broader comparison, the same acceptors are also combined with the well-studied 9,9-dimethyl-9,10-dihydroacridine (DMAC) donor. Optimized BDT-TIPS-containing structures show calculated dihedral angles of around 50° and well-separated highest occupied and lowest unoccupied molecular orbitals, although varying singlet-triplet energy gaps are observed experimentally. By changing the acceptor moiety and the resulting ordering of excited states, room temperature phosphorescence (RTP) attributed to localized BDT-TIPS emission is observed for TXO2-BDT-TIPS, whereas CNQxP-BDT-TIPS affords a combination of TADF and triplet-triplet annihilation (TTA) delayed emission. In contrast, strong and pure TADF is well-known for TXO2-DMAC, whereas CNQxP-DMAC shows a mixture of TADF and TTA at very long timescales. Overall, BDT-TIPS represents an alternative low-strength donor component for push-pull type TADF emitters that is also able to induce RTP properties.
KW - Benzo[1,2-b:4,5-b']dithiophene
KW - Organic light-emitting diodes
KW - Photophysical and quantum-chemical characterizations
KW - Room temperature phosphorescence
KW - Thermally activated delayed fluorescence
UR - http://www.scopus.com/inward/record.url?scp=85097450889&partnerID=8YFLogxK
U2 - 10.1016/j.dyepig.2020.109022
DO - 10.1016/j.dyepig.2020.109022
M3 - Article
AN - SCOPUS:85097450889
VL - 186
JO - Dyes and pigments
JF - Dyes and pigments
SN - 0143-7208
M1 - 109022
ER -