Search results for "carbazole"
showing 10 items of 98 documents
Diphenylsulfone-based hosts for electroluminescent devices: Effect of donor substituents
2020
DG acknowledges to the ERDF PostDoc project No. 1.1.1.2/VIAA/1/16/177. This work was supported by the project of scientific co-operation program between Latvia, Lithuania and Taiwan ?Polymeric Emitters with Controllable Thermally Activated Delayed Fluorescence for Solution-processable OLEDs? (grant No. S-LLT-19-4). Support of the Lithuanian Academy of Sciences is gratefully acknowledged; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²
Reaktionen von elektronenreichen Heterocyclen mit Orthocarbonsäure-Derivaten, 10. Formylierungs- und Alkylierungsreaktionen von Carbazolen mit ambide…
1987
Carbazole werden durch Diethoxycarbenium-tetrafluoroborat mit hoher Regioselektivitat formyliert, wahrend die thermodynamisch stabileren Diethoxymethylcarbenium- und Trimethoxycarbenium-Ionen infolge ausgepragter ambidenter Elektrophilie Carbazole bevorzugt alkylieren. Reactions of Electron-Rich Heterocycles with Orthocarboxylic Acid Derivatives, 10. – Formylation and Alkylation of Carbazoles with Ambident Dialkoxycarbenium Tetrafluoroborates Carbazole and some derivatives were formylated regioselectively with diethoxycarbenium tetrafluoroborate. The thermodynamically more stable diethoxymethylcarbenium and trimethoxycarbenium ions exhibit ambident electrophilic reactivity as predominant al…
Synthesis and Photoelectrical Properties of 3-(Diphenylamino)Carbazolyl-Functionalized DMABI Derivatives
2019
A modular approach was used in the synthesis of the 3-(diphenylamino)carbazolyl- functionalized 2-(4-(dimethylamino)benzylidene)-1H-indene-1,3(2H)-dione (DMABI) derivatives. For this purpose, carboxyl functional group was introduced into the framework of DMABI molecule. Additionally, a regioselective method for substitution of carbonyl group of DMABI with dicyanomethylene group was investigated and verified using the heteronuclear multiple bond correlation NMR spectra. Steglich esterification method was used to connect the 3‑(diphenylamino)carbazolyl moiety via an unconjugated spacer. The UV-Vis absorption spectra and molecular energy level data were obtained for the evaluation of the synth…
Protein kinase C promotes angiogenic activity of human endothelial cells via induction of vascular endothelial growth factor
2008
Aims Protein kinase C (PKC) plays an important role in the regulation of angiogenesis. However, downstream targets of PKC in endothelial cells are poorly defined. Methods and results mRNA expression of vascular endothelial growth factor (VEGF) was analysed by quantitative real-time RT-PCR in human umbilical vein endothelial cells (HUVEC) and HUVEC-derived EA.hy 926 cells. siRNA was used to knockdown PKC isoforms and VEGF. Matrigel tube formation assay was used to analyse the angiogenic activity of endothelial cells. Phorbol-12-myristate-13-acetate (PMA) enhanced the ability of HUVEC to organize into tubular networks when plated on Matrigel, a phenomenon that could be prevented by PKC inhibi…
CCDC 2106018: Experimental Crystal Structure Determination
2021
Related Article: Essi Taipale, Marcel Siepmann, Khai-Nghi Truong, Kari Rissanen|2021|Chem.-Eur.J.|27|17412|doi:10.1002/chem.202103152
Performance of dye-sensitized solar cells based on novel sensitizers bearing asymmetric double D−π−A chains with arylamines as donors
2012
Abstract Three novel, metal-free organic sensitizers bearing two asymmetric double donor-π-acceptor (D-π-A) chains ( DC1 - 3 ), each, and a reference dye containing single D-π-A chain ( SC ) with cyanoacrylic acid as electron acceptor are synthesized. Their photophysical, electrochemical properties and the performances of the corresponding dye-sensitized solar cells (DSSCs) are further investigated. The dyes, DC1, DC2 and DC3 contain one chain with diphenylamine and another chain with carbazole or phenothiazine as electron donor, while diphenylamine is only employed as electron donor in SC . Compared to the inferior solar energy to electricity conversion efficiency ( η ) of 2.82%, 4.66% and…
The Role of Emission Layer Morphology on the Enhanced Performance of Light-Emitting Diodes Based on Quantum Dot-Semiconducting Polymer Hybrids
2016
The influence of the morphology of quantum dot (QD)-semiconducting polymer hybrid emission layers on the performance of quantum dot-based light emitting diodes (QLEDs) is systematically investigated. Chemically grafted QD-semiconducting polymer hybrids are fabricated by the ligand exchange procedure between CdSe/CdxZn1−xS QDs and a new block copolymer consisting of a carbazole-based electroactive block with a low highest occupied molecular orbital level and a disulfide-based anchor block. The performance of QLEDs with hybrid emission layers is compared with QLEDs utilizing QD-only and physically mixed QD/polymer emission layers. It is shown that only in the emission layers formed by chemica…
Carbazole synthesisviaanin situtrapping strategy with indolyl enol ethers
1994
Indolyl enol ethers, generated from the alkoxy(indolyl)carbenium tetra- fluoroborates (1) by treatment with sodium hydride, can be trapped with dimethyl acetylenedicarboxylate or N-phenylmaleimide to furnish the se- lectively functionalized carbazoles (3), (4), (5), (9), (10), and (13). In addition, the biaryl derivatives (6) and (11) are produced by a ring- opening reaction of the primarily formed Diels-Alder adduct. In the case of the biaryl derivative (6), an X-ray crystal structure analysis yields valuable information on constitutions and configurations in the biaryl series. The phenomenon of atropisomerism is discussed for this compound
Side-chain conjugated polymers for use in the active layers of hybrid semiconducting polymer/quantum dot light emitting diodes
2016
Three monomers, M1–M3, with modified carbazole cores and styrene functionality were prepared for use in the active layers of hybrid polymer/quantum dot light emitting diodes. Utilizing reversible addition fragmentation chain transfer polymerization, side-chain conjugated polymers, P1–P3, with narrow polydispersities and disulfide end groups were obtained. The thermal, optical, and electrochemical properties of the polymers varied depending on the substituents of the carbazole cores. Through the disulfide end groups the polymers were chemically blended with quantum dots to obtain QD/polymer hybrids, which were further used as active layers in light emitting diodes. The fabricated devices ret…
ChemInform Abstract: Advances in Indolo[2,3-a]carbazole Chemistry: Design and Synthesis of Protein Kinase C and Topoisomerase I Inhibitors
2010
Indolo[2,3-a]carbazoles, their pyrrolo[3,4-c]anellated variants and structurally closely related bisindolylmaleimides represent a biologically highly interesting class of natural compounds which are potential anticancer agents. According to the ongoing literature new and efficient synthetic methods yield a great variety of these compounds which have been reported in detail. The biological activities and the inhibitory activities against the target enzymes protein kinase C and topoisomerase I are also discussed including structure activity relationships. A molecular binding model of the protein kinase C inhibitors with the target enzyme at the atomic level is presented and supported by X-ray…