6592-18-3

Upstream product

• 1448-87-9 2-chloroquinoxaline 
• 133730-34-4 2,4-dimethoxyphenylboronic acid 
• 829-20-9 2',4'-dimethoxyacetophenone 
• 95-54-5 1,2-diamino-benzene 

Relevant academic research and scientific papers

Highly efficient red emissive heteroleptic cyclometalated iridium(III) complexes bearing two substituted 2-phenylquinoxaline and one 2-pyrazinecarboxylic acid nallathambi sengottuvelan1

A series of highly efficient red phosphorescent heteroleptic iridium(III) complexes 1-6 containing two cyclometalating 2-(2,4-substitued phenyl)quinoxaline ligands and one chromophoric ancillary ligand were synthesized: (pqx)2Ir(mprz) (1), (dmpqx)2Ir(mprz) (2), (dfpqx)2Ir(mprz) (3), (pqx)2Ir(prz) (4), (dmpqx)2Ir(prz) (5), (dfpqx)2Ir(prz) (6), where pqx = 2-phenylquinoxaline, dfpqx = 2-(2,4-diflourophenyl)quinoxaline, dmpqx = 2-(2,4-dimethoxyphenyl)quinoxaline, prz = 2-pyrazinecarboxylate and mprz = 5-methyl-2-pyrazinecarboxylate. The absorption, emission, electrochemical and thermal properties of the complexes were evaluated for potential applications to organic light-emitting diodes (OLEDs). The structure of complex 2 was also determined by single-crystal X-ray diffraction analysis. Complex 2 exhibited distorted octahedral geometry around the iridium metal ion, for which 2-(2,4-dimethoxyphenyl)quinoxaline N atoms and C atoms of orthometalated phenyl groups are located at the mutual trans and cis-positions, respectively. The emission spectra of the complexes are governed largely by the nature of the cyclometalating ligand, and the phosphorescent peak wavelengths can be tuned from 588 to 630 nm with high quantum efficiencies of 0.64 to 0.86. Cyclic voltammetry revealed irreversible metal-centered oxidation with potentials in the range of 1.16 to 1.89 V as well as two quasi-reversible reduction waves with potentials ranging from -0.94 to -1.54 V due to the sequential addition of two electrons to the more electron-accepting heterocyclic portion of two distinctive cyclometalated C^N ligands.

Logic design and synthesis of quinoxalines via the integration of iodination/oxidation/cyclization sequences from ketones and 1,2-diamines

A novel protocol for the synthesis of quinoxalines has been developed from simple ketones and 1,2-diamines. This process underwent a logic approach to bis-substituted quinoxalines via a consecutive iodination/Kornblum oxidation/cyclization in the presence of I2/CuO/DMSO and to mono-substituted quinoxalines via an iodination/cyclization/aromatization in the presence of I2/CuO/K3PO4·3H 2O.

Tuning photophysical and electrochemical properties of heteroleptic cationic iridium(III) complexes containing substituted 2-phenylquinoxaline and biimidazole

Design and syntheses of four red phosphorescent heteroleptic cationic iridium(III) complexes containing two substituted phenylquinoxaline (pqx) or benzo[b]thiophen-2-yl-pyridin (btp) main ligands and one 2,2′-biimidazole (H2biim) ancillary ligand are reported: [(pqx)2Ir(biim)]Cl (1), [(dmpqx)2Ir(biim)]Cl (2), [(dfpqx)2Ir(biim)]Cl (3), [(btp)2Ir(biim)]Cl (4). Complex 1 showed a distorted octahedral geometry around the iridium(III) metal ion with cis metallated carbons and trans nitrogen atoms. The absorption, emission and electrochemical properties were systematically evaluated. The complexes exhibited red phosphorescence in the spectral range of 580 to 620 nm with high quantum efficiencies of 0.58 - 0.78 in both solution and solid-state at room temperature depending on the cyclometalated main ligands. The cyclic voltammetry of the complexes (1-3) showed a metal-centered irreversible oxidation in the range of 1.40 to 1.90 V as well as two quasi reversible reduction waves from -1.15 to -1.45 V attributed to the sequential addition of two electrons to the more electron accepting heterocyclic portion of two distinctive cyclometalated main ligands, whereas complex 4 showed a reversible oxidation potential at 1.24 V and irreversible reduction waves at -1.80 V.