TY - JOUR
T1 - Balanced Energy Gaps as a Key Design Rule for Solution-Phase Organic Room Temperature Phosphorescence
AU - Paredis, Simon
AU - Cardeynaels, Tom
AU - Kuila, Suman
AU - Deckers, Jasper
AU - Van Landeghem, Melissa
AU - Vandewal, Koen
AU - Danos, Andrew
AU - Monkman, Andrew P.
AU - Champagne, Benoît
AU - Maes, Wouter
N1 - Funding Information:
The authors thank the Research Foundation – Flanders (FWO Vlaanderen) for financial support (projects G087718N, G0D1521N, I006320N, GOH3816NAUHL, the Scientific Research Community ‘Supramolecular Chemistry and Materials’ (W000620N), and Ph.D. 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 financial support from the FNRS‐FRFC, the Walloon Region, and the University of Namur (Conventions No. GEQ U.G006.15, U.G018.19, U.G011.22, RW/GEQ2016, RW1610468, and RW2110213). A.P. Monkman is supported by EPSRC grant EP/T02240X/1.
Funding Information:
The authors thank the Research Foundation – Flanders (FWO Vlaanderen) for financial support (projects G087718N, G0D1521N, I006320N, GOH3816NAUHL, the Scientific Research Community ‘Supramolecular Chemistry and Materials’ (W000620N), and Ph.D. 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 financial support from the FNRS-FRFC, the Walloon Region, and the University of Namur (Conventions No. GEQ U.G006.15, U.G018.19, U.G011.22, RW/GEQ2016, RW1610468, and RW2110213). A.P. Monkman is supported by EPSRC grant EP/T02240X/1.
Publisher Copyright:
© 2023 Wiley-VCH GmbH.
PY - 2023/7/26
Y1 - 2023/7/26
N2 - Metal-free organic emitters that display solution-phase room temperature phosphorescence (sRTP) remain exceedingly rare. Here, we investigate the structural and photophysical properties that support sRTP by comparing a recently reported sRTP compound (BTaz−Th−PXZ) to two novel analogous materials, replacing the donor group by either acridine or phenothiazine. The emissive triplet excited state remains fixed in all three cases, while the emissive charge-transfer singlet states (and the calculated paired charge-transfer T2 state) vary with the donor unit. While all three materials show dominant RTP in film, in solution different singlet-triplet and triplet-triplet energy gaps give rise to triplet-triplet annihilation followed by weak sRTP for the new compounds, compared to dominant sRTP throughout for the original PXZ material. Engineering both the sRTP state and higher charge-transfer states therefore emerges as a crucial element in designing emitters capable of sRTP.
AB - Metal-free organic emitters that display solution-phase room temperature phosphorescence (sRTP) remain exceedingly rare. Here, we investigate the structural and photophysical properties that support sRTP by comparing a recently reported sRTP compound (BTaz−Th−PXZ) to two novel analogous materials, replacing the donor group by either acridine or phenothiazine. The emissive triplet excited state remains fixed in all three cases, while the emissive charge-transfer singlet states (and the calculated paired charge-transfer T2 state) vary with the donor unit. While all three materials show dominant RTP in film, in solution different singlet-triplet and triplet-triplet energy gaps give rise to triplet-triplet annihilation followed by weak sRTP for the new compounds, compared to dominant sRTP throughout for the original PXZ material. Engineering both the sRTP state and higher charge-transfer states therefore emerges as a crucial element in designing emitters capable of sRTP.
KW - donor-acceptor fluorophores
KW - energy gap tuning
KW - room temperature phosphorescence
KW - time-resolved spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=85161669676&partnerID=8YFLogxK
U2 - 10.1002/chem.202301369
DO - 10.1002/chem.202301369
M3 - Article
AN - SCOPUS:85161669676
SN - 0947-6539
VL - 29
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 42
M1 - e202301369
ER -