Search results for "carbazole"
showing 10 items of 98 documents
Conducting Polymer with Orthogonal Catechol and Disulfide Anchor Groups for the Assembly of Inorganic Nanostructures
2017
To combine several inorganic components with organic material in a controlled special and permanent manner still remains a difficult issue. Two specifically functionalized block copolymers were synthesized separately and combined in a second step. A heterofunctional poly(ethylene glycol) (PEG) block copolymer bearing a single amino unit, a short PEG spacer, and multiple catechol functionalities was obtained via anionic ring-opening polymerization (AROP). Using the reversible addition–fragmentation chain transfer (RAFT) radical polymerization technique, a semiconducting block copolymer with carbazole side groups was obtained. The second polyacrylate block contained reactive ester groups and …
Influences of histone deacetylase inhibitors and resveratrol on DNA repair and chromatin compaction
2013
Accessibility of DNA is a prerequisite for both DNA damage and repair. Therefore, the chromatin structure is expected to have major impact on both processes, with opposite consequences for the stability of the genome. To analyse the influence of chromatin compaction on the generation and repair of various types of DNA modifications, we modulated the global chromatin structure of AS52 Chinese hamster ovary cells and HeLa cells by treatment with either histone deacetylase inhibitors or resveratrol and measured the repair kinetics of (i) pyrimidine dimers induced by ultraviolet B, (ii) oxidised purines generated by photosensitisation and (iii) single-strand breaks induced by H2O2, using an alk…
Eu3+ ternary and tetrakis complexes with carbazole and methyl group substituted dibenzoylmethane derivatives: Induction of aggregation enhanced emiss…
2019
Abstract Two dibenzoylmethane (DBM) derivatives with methyl (Me-DBM) or carbazole (CBZ-DBM) substituents at the para-position of the phenyl ring and their four novel ternary and tetrakis Eu3+ complexes with 1,10-phenanthroline (PHEN) as a secondary ligand or tetraethylamonium ion (N+(Et)4) as the counter-cation were synthesized and characterized. The investigation of the optical properties of the complexes revealed that Me-DBM based compounds exhibit aggregation enhanced emission (AEE), while in the case of CBZ-DBM this effect is not observed. At the same time, the introduction of a carbazole substituent reduces the emission quantum yield of the complexes. The decrease in luminescence effic…
ChemInform Abstract: Carbazole Synthesis via an in situ Trapping Strategy with Indolyl Enol Ethers.
2010
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
ChemInform Abstract: Reaction of 2,2′-Bis(N-methylindolyl) with Dimethyl Acetylenedicarboxylate and Thermally and Photochemically Induced Cyclization…
2010
2,2′-Bis(N-methylindolyl) 1 reacts with dimethyl acetylenedicarboxylate to furnish the 3-dimethyl maleoyl-substituted 2,2′-bisindolyl 2. Compound 2 cyclizes under aluminum trichloride catalysis according to a polar process to give a cyclopenta[2,1-b:3,4-b′]diindole derivative 4. Reaction of compound 4 with benzyl-amine yields the spiro derivative 5. Photochemically-induced 1,6-electrocyclization of compound 2 gives rise to the indolo[2,3-a]carbazole 6 directly, which is readily transformed to the pyrrolo-annelated carbazole 7 by treatment with benzylamine.
Reaction of 2,2′-bis(N-methylindolyl) with dimethyl acetylenedicarboxylate and thermally- and photochemically-induced cyclizations of the product
1995
2,2′-Bis(N-methylindolyl) 1 reacts with dimethyl acetylenedicarboxylate to furnish the 3-dimethyl maleoyl-substituted 2,2′-bisindolyl 2. Compound 2 cyclizes under aluminum trichloride catalysis according to a polar process to give a cyclopenta[2,1-b:3,4-b′]diindole derivative 4. Reaction of compound 4 with benzyl-amine yields the spiro derivative 5. Photochemically-induced 1,6-electrocyclization of compound 2 gives rise to the indolo[2,3-a]carbazole 6 directly, which is readily transformed to the pyrrolo-annelated carbazole 7 by treatment with benzylamine.
Differently substituted benzonitriles for non-doped OLEDs
2020
DG acknowledges to the ERDF PostDoc grant No. 1.1.1.2/VIAA/1/16/177 . This research was funded by the European Regional Development Fund according to the supported activity ‘Research Projects Implemented by World-class Researcher Groups’ under Measure No. 01.2.2-LMT-K-718 .
Carbene-metal complexes as molecular scaffolds for construction of through-space TADF emitters
2021
Through-space charge transfer (CT) process is observed in Cu(I) carbene-metal-amide complexes, where conventional imidazole or imidazoline N-heterocyclic (NHC) carbene fragments act as inert linkers and CT proceeds between a metal-bound carbazole donor and a distantly situated carbene-bound phenylsulfonyl acceptor. The resulting electron transfer gives a rise to efficient thermally activated delayed fluorescence (TADF), characterized with high photoluminescence quantum yields (ΦPL up to 90 %) and radiative rates (kr) up to 3.32×105 s-1. TADF process is aided by fast reverse intersystem crossing (rISC) rates of up to 2.56×107 s-1. Such emitters can be considered as hybrids of two existing TA…
Understanding the domino reaction between 3-chloroindoles and methyl coumalate yielding carbazoles. A DFT study.
2014
The molecular mechanism of the reaction between N-methyl-3-chloroindole and methyl coumalate yielding carbazole has been studied using DFT methods at the MPWB1K/6-311G(d,p) level in toluene. This reaction is a domino process that comprises three consecutive reactions: (i) a polar Diels-Alder (P-DA) reaction between indole and methyl coumalate yielding two stereoisomeric [2 + 4] cycloadducts (CAs); (ii) the elimination of HCl from these CAs affording two stereoisomeric intermediates; and (iii) the extrusion of CO2 in these intermediates, finally yielding the carbazole. This P-DA reaction proceeds in a completely regioselective and slightly exo selective fashion. In spite of the highly polar …
Phenothiazine-based dyes for efficient dye-sensitized solar cells
2016
As an emerging photovoltaic technology, dye-sensitized solar cells (DSSCs) have attracted a great deal of academic and industrial interest due to their reasonably high power conversion efficiency, low material cost and facile fabrication process. Metal-free organic dyes, as one of the key components of DSSCs, play a pivotal role in light harvesting and electron injection. Among the various species of organic dyes, easily tunable 10H-phenothiazine-based dyes hold a large proportion. The electron-rich nitrogen and sulfur atoms render 10H-phenothiazine a stronger donor character than other amines, even better than triphenylamine, tetrahydroquinoline, carbazole and iminodibenzyl. On the other h…