Computationally Guided Molecular Design to Minimize the LE/CT Gap in D‐π‐A Fluorinated Triarylboranes for Efficient TADF via D and π‐Bridge Tuning. (2nd June 2020)

• Record Type: Journal Article
• Authors: Narsaria, Ayush K.; Rauch, Florian; Krebs, Johannes; Endres, Peter; Friedrich, Alexandra; Krummenacher, Ivo; Braunschweig, Holger; Finze, Maik; Nitsch, Jörn; Bickelhaupt, F. Matthias; Marder, Todd B.
• Is Part Of: Advanced functional materials. Volume 30:Number 31(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-06-02
• Subjects: boron -- charge transfer -- delayed fluorescence -- organic light‐emitting diodes -- singlet–triplet gap quantum efficiency; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202002064
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: In this combined experimental and theoretical study, a computational protocol is reported to predict the excited states in D‐π‐A compounds containing the B( F Xyl)2 ( F Xyl = 2, 6‐bis(trifluoromethyl)phenyl) acceptor group for the design of new thermally activated delayed fluorescence (TADF) emitters. To this end, the effect of different donor and π‐bridge moieties on the energy gaps between local and charge‐transfer singlet and triplet states is examined. To prove this computationally aided design concept, the D‐π‐B( F Xyl)2 compounds 1 –5 were synthesized and fully characterized. The photophysical properties of these compounds in various solvents, polymeric film, and in a frozen matrix were investigated in detail and show excellent agreement with the computationally obtained data. Furthermore, a simple structure–property relationship is presented on the basis of the molecular fragment orbitals of the donor and the π‐bridge, which minimize the relevant singlet–triplet gaps to achieve efficient TADF emitters. Abstract : A combination of experiment and theory leads to new insights into accurately and cost‐efficiently predicting the phenomenon of thermally activated delayed fluorescence. The calculations guide syntheses in optimizing the energy gaps between the states of different multiplicity involved in order to develop new efficient emitter materials.