• Title/Summary/Keyword: benzimidazole

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Effect of Ancillary Ligand, Phenyl group, on the Emission Spectrum of Pt(II) Complex Useful for Organic Light-Emitting Device (유기전기발광소자에 사용될 수 있는 백금 착물에 대해 보조리간드 phenyl 기가 발광스펙트럼에 미치는 영향)

  • Lee, Seung-Hee;Lee, Ho-Joon
    • Journal of the Korean Applied Science and Technology
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    • v.25 no.2
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    • pp.265-268
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    • 2008
  • Among the efforts to increase the efficiency of organic light-emitting device (OLED), there is a way: doping phosphorescent materials. As a phosphorescent material, complexes of heavy transition metal, platinum, were synthesized. $Cl^-$ ion and phenyl group were used as ancillary ligands with 2-(2-pyridyl)benzimidazole (pbi) as a chromophore. The complexes were analysed by FAB-mass spectrometer and absorption and emission spectra were obtained. A phenyl group was able to shift the emission band of the complex even if it's not a chromorphore.

음이온교환수지를 이용한 백금족 금속의 분리 및 정제 연구(I) - 상용 강염기성 음이온 교환수지의 흡착연구 -

  • 김유선;이성호;안도희;김광락;백승우;강희석;이한수;정흥석
    • Proceedings of the Korean Nuclear Society Conference
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    • 1997.05b
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    • pp.345-349
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    • 1997
  • 고준위 방사성 액체폐기물에서 얻어지는 백금족 금속(Pd, Rh, Ru) 들의 분리 및 정제방법으로 강염기성 음이온교환수지를 사용하여본 결과 상용 수지중에서 Dowex 1 $\times$ 8 이 IRN-78 에 비하여 저 농도의 질산 농도에서 Pd(II) 의 분리 및 정제시 우수한 흡착성을 보여 주었으며 Rh(III) 의 흡착은 Pd(II) 의 것보다 훨씬 낮은 값을 보여 주었다. 이 수지들의 백금족 금속에 대한 흡착성을 문헌에 보고된 실험 결과들과 비교 검토하여 본 바 이온 그룹으로 3급 및 4급 Benzimidazole을 가지는 수지에 비하여 훨씬 낮은 값을 나타내었다. 따라서 실용성이 큰 강염기성 음이온수지로서는 Benzimidazole과 같은 혼합 아민 그룹을 지닌 수지가 가장 접합할 것으로 전망되었다.

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Synthesis and Characterization of H3PO4 Doped Poly(benzimidazole-co-benzoxazole) Membranes for High Temperature Polymer Electrolyte Fuel Cells

  • Lee, Hye-Jin;Lee, Dong-Hoon;Henkensmeier, Dirk;Jang, Jong-Hyun;Cho, Eun-Ae;Kim, Hyoung-Juhn;Kim, Hwa-Yong
    • Bulletin of the Korean Chemical Society
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    • v.33 no.10
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    • pp.3279-3284
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    • 2012
  • Poly(benzimidazole-co-benzoxazole)s (PBI-co-PBO) are synthesized by polycondensation reaction with 3,3'-diaminobenzidine, terephthalic acid and 3,3'-dihydroxybenzidine or 4,6-diaminoresorcinol in polyphosphoric acid (PPA). All polymer membranes are prepared by the direct casting method (in-situ fabrication). The introduction of benzoxazole units (BO units) into a polymer backbone lowers the basic property and $H_3PO_4$ doping level of the copolymer membranes, resulting in the improvement of mechanical strength. The proton conductivity of $H_3PO_4$ doped PBI-co-PBO membranes decrease as a result of adding amounts of BO units. The maximum tensile strength reaches 4.1 MPa with a 10% molar ratio of BO units in the copolymer. As a result, the $H_3PO_4$ doped PBI-co-PBO membranes could be utilized as alternative proton exchange membranes in high temperature polymer electrolyte fuel cells.

Hydrolysis of p-Nitrophenyl Carboxylic Ester in N,N-Dimethyl-N-dodecyl-N-(2-methylbenzimidazoyl) Ammonium Chloride Micellar Solution (N,N-Dimethyl-N-Dodecyl-N-(2-methylbenzimidazoyl) Ammonium Chloride 미셀 용액속에서 p-Nitrophenyl Carboxylic Ester의 가수분해)

  • Kim, Jeung-Bea;Kim, Hak-Yoon
    • Journal of Environmental Science International
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    • v.17 no.5
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    • pp.509-516
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    • 2008
  • New functional surfactant, N,N-dimethyl-N-dodecyl-N-(2-methyl benzimidazoyl) ammonium chloride(DDBAC) having benzimidazole(BI) functional group have been synthesized and the critical micellar concentration of DDBAC measured by surface tentiometry and electric conductivity method was $8.9{\times}10^{-4}M$. Micellar effects in DDBAC functional surfactant solution on the hydrolysis of p-nitrophenylacetate(p-NPA), p-nitro-phenylpropionate(p-NPP) and p-nitrophenylvalerate(p-NPV) were observed with change of various pH (Tris-buffer). The pseudo first rate constants of hydrolysis of p-NPA, p-NPP and p-NPV in optimum concentration of DDBAC solution increase to about 160, 280 and 600 times, respectively, as compared with those of aqueous solution at pH 8.00(Tris-buffer). It is considered that benzimidazole functional moiety accelerates the reaction rates of hydrolysis because they act as nucleophile or general base. In optimum concentration of DDBAC solution, the rate constants of hydrolysis of p-NPP and p-NPV increase to about 1.5 and 3.0 times, respectively, as compared with that of p-NPA. It means that the more the carbon numbers of alkyl group of substrates, the larger the binding constants between DDBAC micelle and substrates are. To know the hydrolysis mechanism of p-NPCE(p-NPA, p-NPP and p-NPV), the deuterium kinetic isotope effects were measured in $D_2O$ solutions. Consequently the pseudo first order rate constant ratios in $H_2O$ and $D_2O$ solution, $k_{H_2O}/k_{D_2O}$, were about $2.8{\sim}3.0$ range. It means that the mechanism of hydrolysis were proceeded by nucleophile and general base attack in approximately same value.

Synthesis and Characterization of Phosphoric Acid-doped Poly (2,5-benzimidazole) Membrane for High Temperature Polymer Electrolyte Membrane Fuel Cells (고온 고분자 연료전지용 인산 도핑 폴리(2,5-벤지이미다졸) 막의 제조 및 특성)

  • Nguyen, Thi Xuan Hien;Mishra, Ananta Kumar;Choi, Ji-Sun;Kim, Nam-Hoon;Lee, Joong-Hee
    • Transactions of the Korean hydrogen and new energy society
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    • v.23 no.1
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    • pp.26-33
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    • 2012
  • Phosphoric acid-doped poly (2,5-benzimidazole) (DABPBI) was prepared by condensation polymerization of 3,4-diaminobenzoic acid for high temperature proton electrolyte membrane fuel cells. The membranes were casted directly using a hot-press unit and characterized by fourier transform infrared spectroscopy, thermogravimetric analysis, conductivity measurement, scanning electron microscopy and tensile test. The proton conductivities of DABPBI are observed to be 0.062 and 0.018 $S{\cdot}cm^{-1}$ under 30 and 1% relative humidity, respectively at a temperature of $120^{\circ}C$ which is appreciably higher than that of Nafion 115 under similar conditions. The DABPBI membrane has demonstrated excellent thermo- mechanical properties and proton conductivity suggesting its suitability as a high temperature membrane.

Biochemical and Pharmacological Properties of a New Proton Pump Inhibitor, 2-Amino-4,5-dihydropyrido[1,2-a]thiazolo [5,4-g] benzimidazole (YJA20379-5)

  • Sohn, Sang-Kwon;Chang, Man-Sik;Chung, Young-Kuk;Kim, Kyu-Bong;Woo, Tae-Wook;Kim, Sung-Gyu;Choi, Wahn-Soo
    • Archives of Pharmacal Research
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    • v.21 no.3
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    • pp.241-247
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    • 1998
  • This study was designed to determine biochemical and pharmacological properties of a newly synthesized benzimidazole derivative, 2-amino-4, 5-dihydropyrido [1, 2-a] thiazolo [5, 4-g] benzimidazole (YJA20379-5) in vitro and in vivo. In the leaky membrane vesicles of pig gastric mucosa, YJA20379-5 inhibited the $K^+$-stimulated $H^+$, $K^+$-ATPase activity in a concentration- and time-dependent manner, with $IC_{50}$ values being $43{\mu}\textrm{M}$ and $43{\mu}\textrm{M}$ at pH 6.4 and 7.4, respectively. YJA20379-5, given intraduodenally, had a potent inhibitory effect on the gastric acid secretion in pylorus-ligated rats. The $ED_{50}$ value for acid secretion was 15.4 mg/kg. YJA20379-5, administered orally, also suppressed gastric damages induced by water-immersion stress, indomethacin and ethanol, and duodenal damage induced by mepirizole in rats; the $ED_{50}$ values were 17.6, 4.7, 3.0 and 18.7 mg/kg, respectively. Furthermore, repeated oral administration of YJA20379-5 accelerated the spontaneous healing of acetic acid-induced gastric ulcers in rats. It is concluded that the a-ntisecretory activity of YJA20379-5 appears to be associated with inhibition of $H^+$, $K^+$-ATPase, while its antigastric and antiduodenal lesion activities are primarily related to the antisecretory effect.

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Synthesis and Photovoltaic Properties of Polymers Based on Cyclopentadithiophene and Benzimidazole Units

  • Song, Su-Hee;Park, Sei-Jung;Kwon, Soon-Cheol;Shim, Joo-Young;Jin, Young-Eup;Park, Sung-Heum;Kim, Il;Lee, Kwang-Hee;Suh, Hong-Suk
    • Bulletin of the Korean Chemical Society
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    • v.33 no.6
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    • pp.1861-1866
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    • 2012
  • The new semiconducting copolymers with 4,4-dialkyl-$4H$-cyclopenta[2,1-$b$:3,4-$b^{\prime}$]dithiophene and 2,2-dimethyl-$2H$-benzimidazole units were synthesized. The fused aromatic rings, such as cyclopentadithiophene (CPDT) unit, can make the polymer backbone more rigid and coplanar, which induces long conjugation length, narrow band gap, and strong intermolecular ${\pi}-{\pi}$ interaction. The stacking ability was controlled through attaching of linear or branched alkyl side chains. The spectra of PEHCPDTMBI and PHCPDTMBI in the solid films show absorption bands with maximum peaks at 401, 759 and 407, 768 nm, and the absorption onsets at 925 and 954 nm, corresponding to band gaps of 1.34 and 1.30 eV, respectively. The devices comprising PHCPDTMBI with $TiO_X$ showed a $V_{OC}$ of 0.39 V, a $J_{SC}$ of 1.14 $mA/cm^2$, and a $FF$ of 0.34, giving a power conversion efficiency of 0.15%. The PHCPDTMBI with linear alkyl chain on CPDT shows good solubility in organic solvent with higher PCE value than that of PEHCPDTMBI.

Preparation and Characterization of the $H_3PO_4$-doped Sulfonated Poly(aryl ether benzimidazole) Membrane for Polymer Electrolyte Membrane Fuel Cell (고분자전해질 연료전지용 인산 도핑 술폰화 폴리아릴에테르벤즈이미다졸 고분자전해질 막의 제조 및 특성)

  • Hong, Young-Taik;Jeong, Jin-Ju;Yoon, Kyung-Sock;Choi, Jun-Kyu;Kim, Young-Jun
    • Membrane Journal
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    • v.16 no.4
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    • pp.276-285
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    • 2006
  • Acid-doped sulfonated poly(aryl ether benzimidazole) (S-PAEBI) copolymers were synthesized by a direct polymerization technique and a doping with phosphoric acid as a dopant, and the polymer electrolyte membranes were fabricated from them by a solution casting method. To optimize the reaction condition, the degree of sulfonation and doping level were varied in the ranges of $0{\sim}60%\;and\;0.7{\sim}5.7$, respectively. Physiochemical properties of the doped membranes were investigated by AFM, TGA and the measurement of proton conductivity. It was found that proton conductivities depend on doping levels of membranes. Conductivity determined at the condition of $130^{\circ}C$ and no humidity was $7.3{\times}10^{-2}S/cm$ for the $H_3PO_4$-doped PAEBI membrane with a doping level of 5.7.