Molecular Design and Synthesis of Dicarbazolophane-Based Centrosymmetric Through-Space Donors for Solution-Processed Thermally Activated Delayed Fluorescence OLEDs

Zhen Zhang; Stefan Diesing; Ettore Crovini; Abhishek Kumar Gupta; Eduard Spuling; Xuemin Gan; Olaf Fuhr; Martin Nieger; Zahid Hassan; Ifor D W Samuel; Stefan Bräse; Eli Zysman-Colman

doi:10.1021/acs.orglett.1c02273

Molecular Design and Synthesis of Dicarbazolophane-Based Centrosymmetric Through-Space Donors for Solution-Processed Thermally Activated Delayed Fluorescence OLEDs

Org Lett. 2021 Sep 3;23(17):6697-6702. doi: 10.1021/acs.orglett.1c02273. Epub 2021 Aug 13.

Authors

Zhen Zhang¹, Stefan Diesing^{2

3}, Ettore Crovini², Abhishek Kumar Gupta^{2

3}, Eduard Spuling^{1

2}, Xuemin Gan¹, Olaf Fuhr⁴, Martin Nieger⁵, Zahid Hassan¹, Ifor D W Samuel³, Stefan Bräse^{1

6}, Eli Zysman-Colman²

Affiliations

¹ Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany.
² Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, Fife KY16 9ST, United Kingdom.
³ Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, KY16 9SS, United Kingdom.
⁴ Institute of Nanotechnology (INT) and Karlsruhe Nano-Micro Facility (KNMF), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
⁵ Department of Chemistry, University of Helsinki, P.O. Box 55, A.I. Virtasen aukio 1, 00014 Helsinki, Finland.
⁶ Institute of Biological and Chemical Systems - Functional Molecular Systems (IBCS-FMS), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany.

PMID: 34387488
DOI: 10.1021/acs.orglett.1c02273

Abstract

Conjugation-extended carbazolophane donors, dicarbazolophanes (DCzp), were designed and synthesized using a multifold stepwise Pd-catalyzed Buchwald-Hartwig amination/ring cyclization process. Furthermore, elaboration of the DCzp core is possible with the introduction of pendant carbazole derivative groups. This provides a way to tune the optoelectronic properties of the thermally activated delayed fluorescence (TADF) compounds DCzpTRZtBu, dtBuCzDCzpTRZtBu, and dMeOCzDCzpTRZtBu. Solution-processed organic light-emitting diodes (OLEDs) were fabricated and achieved a maximum external quantum efficiency (EQE_max) of 8.2% and an EQE of 7.9% at 100 cd/m².