808142-68-9Relevant articles and documents
Impact of the use of sterically congested Ir(iii) complexes on the performance of light-emitting electrochemical cells
Hierlinger, Claus,Trzop, Elzbieta,Toupet, Lo?c,ávila, Jorge,La-Placa, Maria-Grazia,Bolink, Henk J.,Guerchais, Véronique,Zysman-Colman, Eli
, p. 6385 - 6397 (2018)
The synthesis, structural and optoelectronic characterization of a family of sterically congested cyclometalated cationic Ir(iii) complexes of the form [Ir(C^N)2(dtBubpy)]PF6 (with dtBubpy = 4,4′-di-tert-butyl-2,2′-bipyridine and C^N = a cyclometalating ligand decorated at the 4-position of the pyridine ring and/or the 3-position of the phenyl ring with a range of sterically bulky substituents) are reported. This family of complexes is compared to the unsubstituted analogue complex R1 bearing 2-phenylpyridinato as cyclometalating ligand. The impact of sterically bulky substituents on the C^N ligands on both the solid state photophysics and light-emitting electrochemical cell (LEEC) device performance is investigated. X-ray diffraction analysis of complexes 1a, R2, 2a, and 1b show an increasing internuclear distance in the solid state, within these four complexes. Emission studies in solution and neat film show that the chosen substituents essentially do not impact the emission energy. The photoluminescence quantum yields (ΦPL) are in the same range (ΦPL ～ 25-31%), except for 1b, which shows a lower ΦPL of 12%. All complexes exhibit similar monoexponential emission lifetimes in the submicrosecond regime. LEECs based on R1, 1a, 1b and R2 were fabricated, showing yellow luminescence and moderate efficiencies and lifetimes. The arguably best performing LEEC device, showing the highest luminance (737 cd m-2), current efficiency (7.4 cd A-1) and EQE (2.6%), employed emitter 1a.
Iron-catalyzed direct C-H arylation of heterocycles and quinones with arylboronic acids
Deb, Arghya,Manna, Srimanta,Maji, Arun,Dutta, Uttam,Maiti, Debabrata
supporting information, p. 5251 - 5256 (2013/09/02)
The arylation of C-H bonds to generate heteroaryl-aryl (Het-Ar) and arylated quinone (Quin-Ar) compounds has received great attention to achieve sustainable goals in synthetic chemistry. Despite significant advances, arylation of a broad range of Het-Ar and Quin-Ar derivatives remains a challenging task. Herein, a variety of heterocycles are arylated by using arylboronic acids in the presence of catalytic amounts of inexpensive Fe(NO 3)3. The C-arylated quinone compounds can be prepared by reacting arylboronic acids with either quinone or hydroquinone. The present method is operationally simple, scalable, does not require prefunctionalization of the heterocycle or quinone, and can tolerate a wide variety of functional groups in the coupling partners. These qualities are expected to render this method attractive for academic and industrial use. Direct C-H arylation of a variety of heterocycles and quinones with arylboronic acids has been developed. An inexpensive iron catalyst, Fe(NO3)3, and a co-oxidant, persulfate, were used in air. The protocol is applicable for large-scale synthesis and is expected to find application as a result of its operational simplicity. Copyright
