Structural Analysis of Complexes 4, 5, and 7 S3 Computational Details S5 Energies of Optimized Structures S5 UV-vis Spectra of Complexes 4-7 (Observed and Calculated) S9 Analysis of Computed UV/Vis Data for 4-7 S10 Cyclic Voltammograms of Complexes 4-7 S15 Theoretical Analysis of Molecular Orbitals of Complexes 4-7 S16 Normalized Excitation and Emission Spectra of Complexes 4-7 S25 NMR Spectra of Complexes 2-7 S29 References S42 S3 Experimental Section: General Information. All reactions were carried out with rigorous exclusion of air using Schlenk-tube techniques. Solvents were dried by the usual procedures and distilled under argon prior to use or obtained oxygen-and water-free from an MBraun solvent purification apparatus. C, H, and N analyses were carried out in a Perkin-Elmer 2400B SeriesII-Analyzer. High-resolution (HRMS) were acquired using a MicroTOF-Q hybrid quadrupole time-of-flight spectrometer (Bruker Daltonics, Bremen, Germany). MALDI-TOF mass spectra were acquired using a Bruker Autoflex III, MALDI-TOF/TOF equipped with a DCTB matrix. IR spectra were measured using a PerkinElmer Spectrum 100 FT-IR spectrometer, equipped with an ATR accessory, as pure solids. 1 H and 13 C{ 1 H} NMR spectra were recorded on a Bruker Avance 300 or 400 MHz instrument. Chemical shifts (expressed in parts per million) are referenced to residual solvent peaks. Coupling constants J are given in hertz. UV-visible spectra were registered on an Evolution 600 spectrophotomer. Steady-state photoluminescence spectra were recorded on a Jobin-Yvon Horiba Fluorolog FL-3-11 spectrofluorimeter. Lifetimes were measured using an IBH 5000F coaxial nanosecond flash lamp. Quantum yields were measured using the Hamamatsu Absolute PL Quantum Yield Measurement System C11347-11. Cyclic voltammetry measurements were performed using a Voltalab PST050 potentiostat with Pt wire as working electrode, Pt wire as counter electrode, and saturated calomel (SCE) as reference electrode. The experiments were carried out under argon in dichloromethane or acetonitrile solutions (10-3 M), with Bu 4 NPF 6 as supporting electrolyte (0.1 M). Scan rate was 100 mV s-1. The potentials were referenced to the ferrocene/ferrocenium (Fc/Fc +) couple. Preparation of [Ir(μ-Cl)(κ 2-C,N-C 6 H 4-isoqui) 2 (1). A suspension of [Ir(μ-Cl)(η 2-COE) 2 ] 2 (500 mg, 0.56 mmol) in 10 mL of 2-ethoxyethanol was treated with 1phenylisoquinoline (470 mg, 2.30 mmol) and the mixture was refluxed for 12 h. The resulting suspension was filtered and the red solid was washed with diethyl ether (3 x 10 mL). Yield: 620 mg (87%). 1 H NMR (300 MHz, CD 2 Cl 2 , 298 K): δ 9.00 (m, 4H), 8.20 (d,
The way to prepare molecular emitters [5t + 4t'] of iridium(III) with a 5t ligand derived from the abstraction of the hydrogen atom at position 2 of the aryl group of 1,3-di(2pyridyl)benzene (dpybH) is shown. In addition, the photophysical properties of the new emitters are compared with those of their counterparts resulting from the deprotonation of 1,3-di(2pyridyl)-4,6-dimethylbenzene (dpyMebH), at the same position, which are also synthetized. Treatment of 0.5 equiv of the dimer [Ir(μ-Cl)( 2-COE)2]2 (COE = cyclooctene) with 1.0 equiv of Hg(dpyb)Cl leads to the iridium(III) derivative IrCl2{κ 3-N,C,N-(dpyb)}( 2-COE) (3), which reacts with 2-(1H-imidazol-2-yl)-6-phenylpyridine (HNImpyC6H5) and 2-(1H-benzimidazol-2yl)-6-phenylpyridine (HNBzimpyC6H5) in the presence of Na2CO3 to give Ir{κ 3-C,N,N-(NImpyC6H4)}{κ 3-N,C,N-(dpyb)} (4) and Ir{κ 3-C,N,N-(NBzimpyC6H4)}{κ 3-N,C,N-(dpyb)} (5), respectively. Similar reactions of the Williams' dimer [IrCl(μ-Cl){κ 3-N,C,N-(dpyMeb)}]2 with HNImpyC6H5 and HNBzimpyC6H5 in the presence of Na2CO3 afford the dimethylated counterparts Ir{κ 3-C,N,N-(NImpyC6H4)}{κ 3-N,C,N-(dpyMeb)} (6) and Ir{κ 3-C,N,N-(NBzimpyC6H4)}{κ 3-N,C,N-(dpyMeb)} (7), whereas 2-(6-phenylpyridine-2-yl)-1H-indole (HIndpyC6H5) initially gives IrH{κ 2-N,N-(IndpyC6H5)}{κ 3-N,C,N-(dpyMeb)} (8) and subsequently Ir{κ 3-C,N,N-(IndpyC6H4)}{κ 3-N,C,N-(dpyMeb)} (9). Complexes 4-7 are phosphorescent green emitters (em 490−550 nm), whereas 9 is greenish yellow emissive (em 547−624 nm). They display lifetimes in the range 0.5−9.7 μs and quantum yields in both doped poly(methyl)methacrylate films and in 2-methyltetrahydrofuran at room temperature depending upon the ligands: 0.5−0.7 for 6 and 7, about 0.4 for 4 and 5, and 0.3−0.2 for 9.
The synthesis of 3-alkyliden-2,3-dihydro-4-quinolones has been accomplished in a domino fashion through a three-step sequence that comprised an initial aza-Baylis-Hillman reaction, followed by a 1,3rearrangement and an intramolecular amination. Starting from readily available aryl vinyl ketones and Ntosyl imines, the reaction with PPh 3 , CsOAc and CuI in CH 3 CN gave rise, in good overall yields, to final 3alkyliden-4-quinolone derivatives, valuable scaffolds in medicinal chemistry. The simultaneous addition of two bases, PPh 3 and CsOAc, was found to be crucial for the success of the process. While PPh 3 promoted the reversible aza-Baylis-Hillman reaction, CsOAc triggered the subsequent 1,3-rearrangement, which shifted the initial equilibrium and allowed to complete the synthetic sequence upon the addition of CuI.
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