Jonathan S. Ward
Roberto S. Nobuyasu
Mark A. Fox
Juan A. Aguilar
David Hall
Andrei S. Batsanov
Zhongjie Ren
Fernando B. Dias
Martin R. Bryce
2019-03-26
<p>Thermally activated delayed fluorescence (TADF) and room-temperature phosphorescence (RTP) are known to occur in organic D–A–D and D–A systems where the donor group contains the phenothiazine unit and the acceptor is dibenzothiophene-<em>S</em>,<em>S</em>-dioxide. This study reports the synthesis and characterization of one new D–A and four new D–A–D systems with methoxy groups on the phenothiazine to examine their effect on emission properties in the zeonex matrix. X-ray analysis and highly specialized NMR techniques were used to characterize asymmetric methoxy-substituted derivative <strong>3b</strong>, which is chiral at N because of an extremely high flipping barrier at the phenothiazine N atom. Based on hybrid-density functional theory computations, the methoxy substituents tune the relative stabilities of the axial conformers with respect to equatorial conformers of the phenothiazine units, depending on their substitution position. This conformational effect significantly influences both TADF and RTP contributions compared to the parent D–A–D system. It is also demonstrated that the equatorial forms of D–A–D and D–A systems in zeonex exhibit TADF. Additionally, the methoxy groups promote luminescence in D–A–D systems where only axial conformers exist. This work reveals further design opportunities for more efficient TADF and RTP molecules.</p>
https://doi.org/10.1021/acs.joc.8b02848
oai:zenodo.org:3677103
Zenodo
info:eu-repo/semantics/openAccess
Creative Commons Attribution 4.0 International
https://creativecommons.org/licenses/by/4.0/legalcode
Impact of Methoxy Substituents on Thermally Activated Delayed Fluorescence and Room-Temperature Phosphorescence in All- Organic Donor−Acceptor Systems
info:eu-repo/semantics/article