• Korean Journal of Materials Research
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• v.9 no.5
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• pp.473-477
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• 1999

Xerographic properties of double-layer photoconductor doped with 4-butyl-4'-methoxyazobenzene (BMAB) as charge-carrier transport material were investigated. BMAB can undergo reversible trans-cis isomerization by light with appropriate wavelength. In the results of measured surface voltage properties for photoconductor doped with BMAB, TNF: BMAB(4-wt%) sample with trans form showed the lowest dark decay, the lowest residual voltage, and the highest sensitivity among cis form. The trans isomer of BMAB has ordering orientation because the molecule possesses a rodlike shape, while the cis isomer has random orientation due to its bent shape. Therefore the molecular arrangement of trans form enhanced charge-carrier transport mobility.

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1681-1688
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• 2010

Density functional theory was adopted to study the various surface products and their reaction channels focusing on the on-dimer configuration which has not been suggested before. Energetic results show that the most stable on-dimer configuration is the 6,6-[2+2] structure which resembles the typical [2+2] cycloaddition product. The 6,6-[2+2] product is also more stable than any other possible surface structures of inter-dimer configuration further suggesting its existence. Potential energy surface scan along various possible initial surface reactions show that some of the possible on-dimer surface products require virtually no reaction barrier indicating that initial population of on-dimer surface products is thermodynamically determined. Various surface isomerization reaction channels exist further facilitating thermal redistribution of the initial surface products.

• Bulletin of the Korean Chemical Society
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• v.15 no.6
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• pp.469-473
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• 1994

The E-and Z-isomers of 1-methyl-l-phenyl-2-neopentylsilene, generated by the sealed tube thermolyses of their anthracene adducts are stereospecifically trapped by trimethylmethoxysilane to give diastereomeric adducts. The temperature dependence of the ratio of the two diastereomers obtained when the silene formed from the pure E-or Z-anthracene adduct was trapped at higher temperatures permitted the determination of an activation energy for the silene isomerization. The activation energies for the E-to Z-and Z-to E-silene isomerization are $45{\pm}$6 and $20{\pm}4$ kcal $mol^{-1}$, respectively. The significance of these values is discussed.

• Bulletin of the Korean Chemical Society
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• v.7 no.3
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• pp.201-204
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• 1986

Reduction of N-arylpyridinium compounds by $NaBH_4$ gave mixtures of the corresponding 1,2-dihydropyridine(major) and 1,4-dihydropyridine(minor), whereas similar reduction by $Na_2S_2O_4$ produced 1,4-dihydropyridines regioselectively. The proportion of 1,4-isomer in the product by $NaBH_4$ reduction appeared to increase with the electron-donating ability of N-aryl groups. When the N-aryl group is p-methylphenyl, p-ethylphenyl or p-methoxyphenyl, the 1,2-dihydropyridines in ethanol-water (4:1) solutions isomerized to the corresponding 1,4-dihydropyridines. N-(p-methylphenyl)-1,2-dihydropyridine and N-(p-ethylphenyl)-1,2-dihydropyridine in solid state also isomerized to the corresponding 1,4-dihydropyridines. The different behaviors of reduction among N-arylpyridiniums and isomerization of the reduction products depending on the substituent in N-aryl group were explained in terms of difference in the electronic effects of the substituents.

• Bulletin of the Korean Chemical Society
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• v.14 no.2
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• pp.287-291
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• 1993

Catalytic iminohydroacylation has been achieved by the reaction of aldimine 1 and 1,5-hexadiene (2a) with Wilkinson's complex as catalyst. Compounds 7a, 8a and 9a were obtained as final product after hydrolysis of the resulting iminohydroacylation products 4a, 5a and 6a. Depending on the reactant ratio (2/1), the ratio of products were changed dramatically : As the 2/1 ratio was increased, 7a is the major product after hydrolysis while 8a is the major with an 1/1 ratio of 2/1. The mechanism of the formation of 5a is determined by the reaction of 1 and 2b under the identical reaction conditions. Considering that 5a may not be formed from the hydroiminoacylation of 14a since 5b cannot be formed from that of conjugate diene 14b generated from isomerization of 2b, 5a must be formed from the reaction of 4a and 10 by addition-elimination mechanism.

• Bulletin of the Korean Chemical Society
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• v.29 no.6
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• pp.1259-1262
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• 2008

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.606-607
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• 2005

• Proceedings of the Microbiological Society of Korea Conference
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• 2007.05a
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• pp.32-33
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• 2007

• Bulletin of the Korean Chemical Society
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• v.26 no.8
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• pp.1274-1276
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• 2005

• Bulletin of the Korean Chemical Society
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• v.30 no.12
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• pp.2877-2878
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• 2009