Carbazolyl-contained phenol-pyridyl boron complexes: syntheses, structures, photoluminescent and electroluminescent properties

Abstract

A series of phenol-pyridyl boron complexes 1-4 bearing carbazolyl-containing groups on boron centres have been designed and synthesized. The single crystals of complexes 1, 2 and 4 were grown, and the crystal structures were determined by X-ray diffraction analysis. All complexes possess very high melting points (346-385 °C) and decomposition temperatures (Td5: 397-423 °C), indicative of their high thermal stabilities. The electrochemical and photophysical properties as well as theoretical calculations were also investigated. Typical three-layer electroluminescent (EL) devices based on these organoboron complexes exhibited white electroluminescence.

Synthesis of cationic iridium(III) complexes with high quantum yield via enhancing the steric hindrance of ligands

“…Additionally, their related parent complexes (1e4b) were also prepared for comparative studies (Scheme 1). Here, the carbazole group was chosen as hindrance unit due to their high stability and hole-transporting properties [47,48]. The functionalized Ir(III) complexes exhibited better photophysical, film-forming as well as thermal stability properties in comparison with their parent complexes.…”

Novel concept of polymers preparation with high photoluminescent quantum yield

“…Tetrahydrofuran (15 cm 3 ), potassium hydride (0.08 g), 18-crown-6 (0.528 g, 0.002 mol), and carbazole (0.33 g, 0.002 mol) were introduced into a glass reactor (50 cm 3 ) equipped with Teflon valve and magnetic stirrer and mixed during 1 h. A stoichiometric amount of hydrogen (44.7 cm 3 ) was evolved in the reaction resulting in the formation of the white powder of the product. The reaction course was shown on Scheme 1.…”

“…After total conversion of the monomer, obtained by chromatography method, methyl iodide (0.2 cm 3 ) was introduced to the system to transform active centers of chain growth to methoxy or methyl groups. Next, the precipitate of KI/18C6 was decanted, and the solvent was evaporated under reduced N N 3 and an upper containing water and the potassium salt residue. After evaporation of CHCl 3, the polymer was diluted in n-pentane.…”

“…However, new organic light-emitting materials (OLED) with high luminescence efficiency, little self-quenching, good carrier transporting property, and high stability are still desirable. Carbazole-based materials, both low molecular weight compounds and polymers, have been used as good electroand optical-active materials due to their holetransporting capabilities and strong fluorescence [2][3][4][5][6][7][8][9][10][11][12][13]. For example, luminescent properties of carbazyl-containing quinacridone derivatives [5] and phenol-pyridyl boron complexes [3] of tolan derivatives [3] have been noted.…”

“…Carbazole-based materials, both low molecular weight compounds and polymers, have been used as good electroand optical-active materials due to their holetransporting capabilities and strong fluorescence [2][3][4][5][6][7][8][9][10][11][12][13]. For example, luminescent properties of carbazyl-containing quinacridone derivatives [5] and phenol-pyridyl boron complexes [3] of tolan derivatives [3] have been noted. Moreover, several new efficient luminescent materials with a carbazole unit have been reported [6][7][8][9][10][11][12][13], e.g., materials containing benzothiadiazole and two carbazole units showed a significant increase in the emission intensity and quantum efficiency (75 %) [6], a group of fluorene derivatives with carbazole units was utilized as emitters for the construction of blue organic light emitting diodes (OLEDs) [12] and light-emitting spirobifluorene materials containing two carbazole moieties demonstrated efficient and stable bright red or green phosphorescence OLEDs [13].…”