- Synthesis and photophysical properties of a new carbazole-based acidochromic molecular switch
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A reversible color–changing and fluorescence molecular switch was designed and synthesized based on carbazole fluorophores and amino group receptors. The crab shape molecule 1 is not soluble in most organic solvents and showslow solubility in acetic acid and DMSO (1 mg/ml in DMSO). The solution of 1 in DMSO performed as single on/off switch triggered by acidic protons. The colorless solution in basic and neutral conditions turned to yellow upon addition of a small amount of acid together with quench in fluorescence emission. The solid state of 1 has a dual-mode fluorescence switching property. The creamy white powder of 1has an emission λmax at 398 nm but when exposed to acidic vapors or suspended into acidic mediathe color of the powder changed to yellow and its emission λmax appeared at 516 nm. Monte-Carlo simulation has been performed to search the conformational space of the neutral and acidic forms. The frontier molecular orbitals of the most stable conformers has been calculated using DFT/B3LYP method using 6–31 g (d) basis set in attempt to explain the difference in electronic transition of 1 and its porotonated form.
- Heydari, Zahra,Rashidi-Ranjbar, Parviz
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- Hydrogen-bonded cyclic tetramers based on ureidopyrimidinones attached to a 3,6-carbazolyl spacer
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Direct attachment of two 2-ureido-4-[1H]-pyrimidinone (UPy) subunits to a 3,6-carbazolyl core gives rise to a highly viscous, supramolecular polymer. However, insertion of a methylene spacer between the UPy's and the carbazole leads to a well-defined, cyclic tetramer, in a belt-shaped arrangement, as evidenced by MALDI-TOF, DOSY, and NOESY spectra.
- Yang, Yong,Xue, Min,Marshall, Laura J.,De Mendoza, Javier
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- A nitrophenyl-carbazole based push-pull linker as a building block for non-linear optical active coordination polymers: A structural and photophysical study
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Non-linear optical effects (NLO) such as multi-photon absorption, second harmonic generation (SHG) etc. have a wide range of applications. Nevertheless, the performance of many NLO-active organic dyes is limited by their thermal stability and photobleaching. These problems can be overcome by integrating the dyes into coordination polymers or metal-organic frameworks. Here, we present a structural and photophysical study of dipropyl-9-(4-nitrophenyl)-carbazole-3,6-dicarboxylate, a new “push-pull” organic dye molecule designed as a chromophore linker for NLO-active coordination polymers. Structure determination of a single-crystal showed that it crystallizes in a monoclinic crystal system P 21/c. The solvated chromophore exhibits two aromatic absorption bands at 250 nm and 275 nm as well as broad long wavelength band at 350 nm, which we assign to an intramolecular charge transfer state. Photoluminescence measurements in solvents of different polarities revealed two main effects: In nonpolar solvents, the spectrum shows an emission band at 360 nm, whereas in solvents with a higher polarity, the emission maximum broadens and redshifts. Solid-state emission measurement of sample powder exhibits an emission band at 520 nm which is redshifted compared to the measurements in solution, due to excimer formation in the solid-state. The optical as well as solvation-related properties of the investigated pigment render it to be a versatile ligand in coordination polymers.
- Fischer, Roland A.,Hauer, Jürgen,Mayer, David C.,P?thig, Alexander,Thyrhaug, Erling,Weish?upl, Sebastian J.
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- ORGANIC COMPOUNDS, ORGANIC LIGHT EMITTING DIODE AND ORGNIC LIGHT EMITTING DEVICE HAVING THE COMPOUNDS
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The present invention relates to an organic compound having at least one aromatic ring connected to an indolocarbazole moiety directly or through a linker in the indolocarbazole moiety. According to the present invention, the organic compound has a firm structure by having an indolocarbazole moiety composed of five rings having a large steric hindrance with adjacent moieties. In addition, the organic compound of the present invention has a cyano group having excellent electron withdrawing characteristics in an indolocarbazole moiety and/or an adjacent aromatic ring, thereby having a wide band gap, no degradation in triplet energy, and high purity blueshift. The organic compound of the present invention can reduce a driving voltage of the light emitting element by applying the organic compound as a host to the light emitting element, and can improve luminous efficiency. In addition, the organic compound of the present invention can be applied to an organic light emitting diode capable of emitting blue light with high purity, an organic light emitting device, and the like.COPYRIGHT KIPO 2019
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Paragraph 0148; 0149-0151
(2019/06/13)
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- Facile preparation of dibenzoheterocycle-functional nanoporous polymeric networks with high gas uptake capacities7
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A consolidated ionothermal strategy was developed for the polymerization of thermally unstable nitriles to construct high performance materials with permanent porosity, and carbazole, dibenzofuran, and dibenzothiophene were separately introduced into covalent triazine-based networks to investigate the effects of heterocycles on the gas adsorption performance. Three nitriles, namely 3,6-dicyanocarbazole, 3,6-dicyanodibenzofuran, and 3,6- dicyanodibenzothiophene, were designed and synthesized, which were readily converted to heat-resistant intermediates at a moderate temperature and then polymerized to create highly porous poly(triazine) networks instead of the traditional one-step procedure. This documents an improved strategy for the successful construction of heterocyclic-functional triazine-based materials. The chemical structures of monomers and polymers were confirmed by 1H NMR, FTIR, and elemental analysis. Such polymers with high physical-chemical stability and comparable BET surface areas can uptake 1.44 wt % H2 at 77 K/1 bar and 14.0 wt % CO2 at 273 K/1 bar and present a high selectivity for gas adsorption of CO2 (CO2/N2 ideal selectivity up to 45 at 273K/1.0 bar). The nitrogen- and oxygen-rich characteristics of carbazole and dibenzofuran feature the networks strong affinity for CO2 and thereby high CO2 adsorption capacity. This also helps to thoroughly understand the influence of pore structure and chemical composition on the adsorption properties of small gas molecules.
- Wu, Shaofei,Liu, Yao,Yu, Guipeng,Guan, Jianguo,Pan, Chunyue,Du, Yong,Xiong, Xiang,Wang, Zhonggang
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p. 2875 - 2882
(2014/06/09)
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- A convenient preparation of 9 H -carbazole-3,6-dicarbonitrile and 9 H -carbazole-3,6-dicarboxylic acid
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A catalytic, high yielding and scalable procedure for the synthesis of 9H-carbazole-3,6-dicarbonitrile has been developed. Subsequent hydrolysis of the dinitrile in the presence of a catalytic copper species (i.e., CuI) yields 9H-carbazole-3,6-dicarboxylic acid. Both compounds are versatile and fine-tunable organic building blocks and therefore offer potential in material science, medicinal and supramolecular chemistry. Georg Thieme Verlag Stuttgart New York.
- Weseliński, ?ukasz J.,Luebke, Ryan,Eddaoudi, Mohamed
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p. 596 - 599
(2014/03/21)
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- Anti-Pneumocystis carinii pneumonia activity of dicationic carbazoles
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A series of 2,7- and 3,6-bis cationic carbazoles was synthesized and evaluated for activity against a rat model of Pneumocystis carinii pneumonia (PCP). The compounds were also tested for inhibition of topoisomerase II and binding to DNA. Several of the compounds proved to be more potent and less toxic than a standard anti-PCP drug (pentamidine). While no quantitative correlation was seen between anti-PCP activity, topoisomerase inhibition and DNA binding, a minimal level of DNA binding was found to be necessary for antimicrobial activity.
- Patrick,Boykin,Wilson,Tanious,Spychala,Bender,Hall,Dykstra,Ohemeng,Tidwell
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p. 781 - 793
(2007/10/03)
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- 3,6-Dicarboximidamidecarbazoles
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Compounds having the formula STR1 wherein R1 is aryl and R2 is alkyl or arylalkyl, have useful antiinflammatory activity.
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