RESUMO
A pair of high-efficiency deep-red emissive ionic iridophosphors (Ira and Irb) showing high photoluminescence quantum yields (PLQYs) are rationally designed by using 1-(thiophen-2-yl)isoquinoline as the cyclometalating ligand. Two bulky tetraarylborate anions (tetraphenylborate and tetrakis(3,5-bis(trifluoromethyl)phenyl)borate) are selected to improve their PLQYs in both solution and aggregated states, which enables efficient electroluminescence via a solution-processed approach. The variation of the tetraarylborate anions also aims to tune the photophysical properties of these deep-red emissive iridophosphors. Both ionic iridophosphors emit intense deep-red room-temperature phosphorescence in both solution and aggregated states. The phosphorescence spectra of both complexes are similar (630 nm with a shoulder emission of 686 nm) in CH2Cl2, originating from the same cationic species of the complexes. Both complexes show high PLQYs in CH2Cl2 (0.41 for Ira, 0.43 for Irb) and neat films (0.27 for Ira, 0.34 for Irb). Moreover, they serve as triplet emitters to evaluate their performance in solution-processed deep-red electroluminescent devices. The maximum external quantum efficiencies for the deep-red electroluminescence are 7.3% with an emission maximum of 649 nm for Ira, and 10.2% with an emission maximum of 635 nm for Irb, respectively, implying that they are good candidates for high-performance electroluminescence.
RESUMO
A useful and convenient method for C-H bond arylation of 8-aminoquinoline motifs on the remote C4 position was developed. This method shows good functional group tolerance toward various Grignard reagents and aminoquinoline via a nickel catalysis, giving the desired arylated products in good yields. The present method affords an efficient access to construct multisubstituted aminoquinolines.