• Bulletin of the Korean Chemical Society
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• v.35 no.8
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• pp.2326-2330
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• 2014

A carbazole-based Schiff base CB2 was synthesized and applied as a highly selective and sensitive fluorescent probe for $Cu^{2+}$ in $H_2O$-DMSO (8/2, v/v, pH = 7.4) solution. CB2 exhibits an excellent selectivity to $Cu^{2+}$ over other examined metal ions with a prominent fluorescence "turn-on" at 475 nm. CB2 and $Cu^{2+}$ forms a 1:2 binding ratio complex with detection limit of $9.5{\mu}M$. In addition, the $Cu^{2+}$ recognition process is hardly interfered by other examined metal ions.

• Korean Journal of Pharmacognosy
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• v.42 no.1
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• pp.82-88
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• 2011

This study was carried out to investigate the optimum conditions for extraction of soluble acidic polysaccharides from ginseng marc. Method of carbazole-sulfuric acid was applied to determine the amount of acidic polysaccharides in ginseng marc. The amounts of soluble acidic polysaccharides in water extract of ginseng marc were increased with increasing extraction temperature. The contents of acidic polysaccharides were not significantly different despite the extraction time increasing from 0.5 hours to 6 hours. To estimate the rehydration rate of the freeze dried polysaccharide, the extracted acidic polysaccharide fraction powder was determined the amount of soluble acidic polysaccharides by carbazole-sulfuric acid method again. The rehydration rate of acidic polysaccharides from water-extract of red ginseng marc at room temperature was 100%. On the other hand, the rehydration rate of acidic polysaccharide of red ginseng marc at boiling temperature was about 50%. The rehydration rate of acidic polysaccharides from water-extract of white ginseng marc at room temperature was 50%. The rehydration rate of acidic polysaccharide of red ginseng marc at boiling temperature was about 40%. The rate of soluble acidic polysaccharide of Red Ginseng is higher than that of White Ginseng. We can find out the maximum extraction method of soluble acidic polysaccharide from ginseng marc.

• Applied Chemistry for Engineering
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• v.9 no.4
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• pp.548-553
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• 1998

The N-unsaturated alkylcarbazole derivatives were synthesized by the nucleophilic unimolucular substitution reaction ($S_N1$) of carbazole with unsaturated alkyl chloride. These reactions between carbazole and unsaturated alkyl chloride were conducted in dimethyl sulfoxide (DMSO) containing alkali (NaOH or KOH) at room temperature for 4 hrs under nitrogen atmosphere. The mole ratios of carbazole, alkali and unsaturated alkyl chloride were 1:6:1, respectively. All of the compounds of starting materials and reaction products were characterized by CHN analysis, $^1H$-NMR and FR-IR spectroscopy.

• Bulletin of the Korean Chemical Society
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• v.26 no.1
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• pp.77-84
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• 2005

We prepared the new nonlinear optical chromophores that show fairly high microscopic nonlinearity through intramolecular charge transfer. Phenothiazine and carbazole units played an important role to contribute high electron donability and connect the resonance pathway via conjugative effect in the cyclized ring beside the aromatic ring. Theoretical calculation, electrochemical analysis, and absorption spectroscopic study gave us useful information about the energy states and microscopic nonlinearities of two serial chromophores. We compared the microscopic nonlinearities of four chromophores with the conjugation length and electron donability in the push-pull type NLO chromophores. The effect of gradient donability and lengthening the conjugation were investigated on the electronic state and microscopic nonlinearity.

• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1429-1434
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• 2013

A synthesis and cation-induced fluorescent behavior of the carbazole-attached $NO_2S_2$-macrocycle (L) is described and structurally characterized by single crystal X-ray analysis. The photoluminescence spectrum of L in 80% $CH_3CN/CH_2Cl_2$ displays a peak maximum at 431 nm (blue emission). In the metal-induced fluorometric experiment, L showed a drastic chelation-enhanced fluorescence quenching (CHEQ) effect only with $Hg^{2+}$ and $Cu^{2+}$. In ESI-mass study, a 1:1 stoichiometry for complexation of L with $Hg^{2+}$ was confirmed, suggesting the unique sensing behavior of the proposed ligand L due to the selective complexation affinity for $Hg^{2+}$. The observed results indicate that L is a promising turn-off type fluoroionophore for $Hg^{2+}$ and $Cu^{2+}$ detections. Additionally, the $Ag^+$ complex of the precursor macrocycle was prepared and its solid structure was crystallographically characterized.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.514-516
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• 2003

We have fabricated an air stable blue emitting organic electroluminescent devices (OLEDs) with a carbazole based emitting molecule, Bis(3-N-ethylcarbazolyl)terephthalidene (BECP). Our device emits strong blue at 472 nm with the luminance efficiency of near 1 lm/W at a voltage and current density of 8 V and 5.7 mA/cm2, respectively, reaching the brightness up to 5000 cd/m2 at 270 mA/cm2. Finally, in order to tune the emission color from blue to green, we have used Bis(3-N-ethylcarbazolyl)cynoterephthalidene (BECCP), a derivative of BECP by adding cyno group in side chain, and compared the electroluminscence (EL) of OLEDS prepared by BECCP to that of BECP based OLEDs.

• Polymer(Korea)
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• v.35 no.4
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• pp.314-319
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• 2011

The syndiotactic and atactic poly (2-N-carbazoylrnethyl) styrenes were obtained by a half-titanocene catalyst and a radical initiator for the investigation of photophysical properties, especially excimer formation. The atactic polymer exhibited only monomer emission, but the syndiotactic polymer showed both excimer emission and monomer emission resulting from the partial overlapping arrangement of carbazole pendants, The emission band of syndiotactic polymer was considerably dependent on solution concentration and temperature, however atactic polymer was independent because the excimer formation of syndiotactic helical conformation was more favorable than that of the random coil conformation of atactic polymer.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.3 no.1
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• pp.14-21
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• 1993

N-Heterocyclic aromatics (NHA) are widely occurring environmental pollutants formed during the pyrolysis of nitrogen-containing organic chemicals. NAH are found in significant amounts in tobacco condensates, synthetic fuels, polluted river sediment, and effluents from the heating of coal. Following topical application 7H-dibenzo[c, g]carbazole (DBC) induces cancer in liver as well as skin, indicating that dermal exposure can lead to systemic effect. DBC and dibenz[a,j]acridine (DBA) are examples of NHA. The potency of many carcinogenic compounds is related, at least in part, to the efficiency of their biological activation. We undertook studies to determine which initial metabolites lead to the formation of high levels of carcinogen-DNA adducts in vivo. DBC and DBA's, DBA, trans-DBA-1,2-dihydrodiol (DBA-1,2-DHD), trans-DBA-3,4-dihydrodiol (DBA-3,4-DHD), and trans-DBA-5,6-dihydrodiol (DBA-5,6-DHD), were applied to the skin of mice. There were six adducts that were related to DBC application. These addusts were seen in the target organ, liver at high levels, but at very low levels in non-target organs, skin, lung and kidney. In skin, DBA produced two distinct adducts. The same two adducts were seen when DBA-3,4-DHD was applied. In addition the total adduct level elicited by DBA-3,4-DHD higher than that of parent compound. Two adducts were seen when DBA-5,6-DHD was applied, but these were very different from adducts seen with DBA. These results suggested that activation of DBA to DNA-binding compounds in skin includes initial formation of DBA-3,4-DHD.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.2073-2076
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• 2010

• ETRI Journal
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• v.33 no.1
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• pp.32-38
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• 2011

We investigated the light-emitting performances of blue phosphorescent organic light-emitting diodes, known as PHOLEDs, by incorporating an N,N'-dicarbazolyl-3,5-benzen interlayer between the hole transporting layer and emitting layer (EML). We found that the effects of the introduced interlayer for triplet exciton confinement and hole/electron balance in the EML were exceptionally dependent on the host materials: 9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole, 9-(4-tert-butylphenyl)-3,6-ditrityl-9H-carbazole, and 4,4'-bis-triphenylsilanyl-biphenyl. When an appropriate interlayer and host material were combined, the peak external quantum efficiency was greatly enhanced by over 21 times from 0.79% to 17.1%. Studies on the recombination zone using a series of host materials were also conducted.