Modulation of the Physicochemical Properties of Donor-Spiro-Acceptor Derivatives through Donor Unit Planarisation: Phenylacridine versus Indoloacridine-New Hosts for Green and Blue Phosphorescent Organic Light-Emitting Diodes (PhOLEDs).
This work reports a detailed structure-property relationship study of a series of efficient host materials based on the donor-spiro-acceptor (D-spiro-A) design for green and sky-blue phosphorescent organic light-emitting diodes (PhOLEDs). The electronic and physical effects of the indoloacridine (IA) fragment connected through a spiro bridge to different acceptor units, namely, fluorene, dioxothioxanthene or diazafluorene moiety, have been investigated in depth. The resulting host materials have been easily synthesised through short, efficient, low-cost, and highly adaptable synthetic routes by using common intermediates. The dyes possess a very high triplet energy (ET ) and tuneable HOMO/LUMO levels, depending on the strength of the donor/acceptor combination. The peculiar electrochemical and optical properties of the IA moiety have been investigated though a fine comparison with their phenylacridine counterparts to study the influence of planarisation. Finally, these molecules have been incorporated as hosts in green and sky-blue PhOLEDs. For the derivative SIA-TXO2 as a host, external quantum efficiencies as high as 23 and 14 % have been obtained for green and sky-blue PhOLEDs, respectively.
UMR CNRS 6226 "Institut des Sciences Chimiques de Rennes", Université de Rennes 1-Campus de Beaulieu, 35042, Rennes Cedex, France.
Sébastien
S
Thiery
LPCIM, CNRS, École Polytechnique, Université Paris-Saclay, 91128, Palaiseau, France.
Denis
D
Tondelier
LICSEN, NIMBE, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191, Gif Sur Yvette, France.|LPCIM, CNRS, École Polytechnique, Université Paris-Saclay, 91128, Palaiseau, France.
Bernard
B
Geffroy
UMR CNRS 6226 "Institut des Sciences Chimiques de Rennes", Université de Rennes 1-Campus de Beaulieu, 35042, Rennes Cedex, France.
Olivier
O
Jeannin
UMR CNRS 6226 "Institut des Sciences Chimiques de Rennes", Université de Rennes 1-Campus de Beaulieu, 35042, Rennes Cedex, France. Joelle.Rault-Berthelot@univ-rennes1.fr.
Joëlle
J
Rault-Berthelot
UMR CNRS 6226 "Institut des Sciences Chimiques de Rennes", Université de Rennes 1-Campus de Beaulieu, 35042, Rennes Cedex, France. cyril.poriel@univ-rennes1.fr.
Cyril
C
Poriel
donor-acceptor systems; electrochemistry; luminescence; spiro compounds; structure-activity relationships