Prof. Aihua Yuan and her collaborator made important progress on phosphorescentiridium complexes
Title: B-andN-embeddedcolor-tunablephosphorescentiridium complexesand B−N lewisadductswithintriguingstructuraland optical changes
Recently, Prof. Yuan’s group report a novel family of B- and N-embedded phosphorescent iridium complexes(Fig. 1 and Fig. 2). Single crystal structures indicate that the B-embedded polycyclic unit exhibits better planarity than N-embedded polycyclic unit, which leads to the different π-π-stacking and electrical characteristics. More importantly, by controlling the number of boron or nitrogen atoms embedded, solution-processed OLED devices incorporating these emitters as emitting layers can achievephosphorescence color variation from green to deep red (638 nm) and show low-efficiency roll-off and turn-on voltage. Especially for B-embedded complex Ir-BB, it shows good color purity with a narrow full width at half maximum (1211 cm-1) and CIE coordinates (0.67, 0.31) in the deep red light region. Notably, B-embedded iridium complexes can also react with two different Lewis bases (pyridine and DMAP) to form intriguing B−N Lewis adducts through different coordination modes. During this process, significantly different structural and optical changes are triggered by the structure and electronic property of Lewis bases, as confirmed by X-ray crystallographic, 1H NMR and spectral analysis.This work has been published in Chemical Science, 2019, 10, 3257-3263.
