• 대한화학회지
• /
• 제20권1호
• /
• pp.15-18
• /
• 1976

염화벤젠술페닐의 바람직한 형태를 EHMO법으로 구하였다. 이 형태의 안정도는 황원자와 벤젠고리 사이의 n-${\pi}$ 콘쥬게이션에 따른다는 것을 알았다. 또 염화벤젠술페닐의 가에탄올 분해반응을 연구하여 얻은 반응속도상수를 치환기 효과와 황원자의 d-궤도함수 기여로 논의하였다. 비선형 Hammett 그래프로 부터 쌍뿔형의 중간체를 제안할 수 있었다.

• 한국환경보건학회지
• /
• 제23권2호
• /
• pp.106-114
• /
• 1997

When surfactants meet chlorine bleaches not only in the washing drums but also through the whole path from the stream to the river, it is not difficult to expect that they produce the harmful substances like DBPs. Furthermore considering wastewater that is contaminated by surfactants is used to discharge into drinking water sources via sewer system, it also can be imagined that residual surfactants would contribute to the some extent of DBPs' formation during chlorine disinfection in water treatment plants. Although the main behavior observed was the formation of chloroform during the reaction of LAS with free chlorine, the other manifest behaviors like the trends of pH, MBAS, free chlorine, the mole concentration of benzene ring and etc. were also investigated.

• 한국안전학회지
• /
• 제27권2호
• /
• pp.13-19
• /
• 2012

The effectiveness of treeing resistance in low density polyethylene containing azocompounds were investigated under radiation environments. 4-(4-nitrophenylazo)-1-naphthol and 4-(4-nitrophenylazo) resorcinol were selected for treeing inhibitors. LDPE containing the additives were crosslinked with dicumyl peroxide, irradiated by $Co^{60}$ ${\gamma}$-ray in the presence of air at room temperature. Treeing inception voltage, AC breakdown strength measurements were carried out for electrical insulation characteristics, thermoluminescence and gel contents were analyzed as various irradiation doses also. LDPE with treeing inhibitors showed much better insulation characteristics than pure LDPE. It is interpreted that molecular structures, polar groups and the type of radicals connected on the benzene ring of the additives affected electrical characteristics. From the results, 4-(4-nitrophenylazo) resorcinol was the most effective upon the best treeing and radiation resistance.

• 대한화학회지
• /
• 제24권1호
• /
• pp.64-72
• /
• 1980

새로운 acrylimide로서 N-acrylylpyrrolidone을 합성하였다. N-Acrylylpyrrolidone은 N-methacrylyl-lactam과는 다르게 homopolymerization을 열적으로도 함을 관찰하였다. Styrene과 N-acrylylpyrrolidone의 공중합시 각 monomer의 reactivity ratio를 구하였다. 그 결과 생성되는 copolymer는 pyrrolidone의 음이온 중합에 적절한 acyl-lactam function을 가지고 있음을 알았다.

• Bulletin of the Korean Chemical Society
• /
• 제23권11호
• /
• pp.1623-1628
• /
• 2002

Tetracyclic pyrido[2,3-b]azepine derivatives 4a-d and 4f as analogues of mirtazapine were synthesized via N-acyliminium ion cyclization by using aromatic rings such as benzene and thiophene ring as a ${\pi}-nucleophile$, and evaluated for the binding affinity for ${\alpha}2-adrenoceptor$. Among tested compounds, 2,3,9,13b-tetrahydro-1H-benzo[f]pyrrolo[2,1-a]pyrido[2,3-c]azepine (4a) was the most potent (Ki = 0.26 ${\mu}M)$ but showed about 3-fold less binding affinity than mirtazapine (Ki = 0.08 ${\mu}M)$ for a2-adrenoceptor.

• 자연과학논문집
• /
• 제16권1호
• /
• pp.129-141
• /
• 2005

The equilibrium geometry, adiabatic electron affinity, harmonic vibrational frequencies, and infrared intensities of 1,4,6,9-Tetra chlorinated dibenzo-$\rho$-dioxin anion have been studied using B3LYP method. The local minimum conformation is found to be twisted form with $D_2$ symmetry. The predicted adiabatic electron affinity is 0.54 eV. The predicted inversion barrier between twisted and planar conformers was 0.9 kcal/mol, thus we expect that experimentally observed structure seems to be planar. the characteristic IR band of 1,4,6,9-TCDD anion appears at 1510 $cm^4$, which is a benzene ring skeleton vibration mode related with CaCb and C2C3 bond. this characteristic band could be sued for identication of 1,4,6,9-TCDD anion.

• 대한화학회지
• /
• 제12권1호
• /
• pp.35-38
• /
• 1968

Radio iodination of various aromatic derivatives (aniline, toluene, iodobenzene, acetanilide, benzene, benzoic acid) were achieved at low temperature by a chloroamine-T procedures in presence of polar solvent(dioxane). Organic base (piperidine) was used as the catalyst. Iodine replacement reaction had occured on the aromatic or alicyclic ring by this reaction, and the kind and ratio of iodinated products were proved to be different from those of usual iodide reaction in organic solvent at low temperature. The reactivity of various aromatic or alicyclic compounds towards the present iodination system was evaluated and the scope and limitation of the present procedures in the preparation of radio pharmaceuticals were discussed.

• Bulletin of the Korean Chemical Society
• /
• 제35권3호
• /
• pp.737-742
• /
• 2014

The vibronic emission spectra of isomeric trimethylbenzyl radicals were reassigned based on substituent effect on electronic transition energy as well as ab initio calculation of the benzyl radical. The electronic transition energy of three isomeric jet-cooled trimethylbenzyl radicals produced by corona discharge of 1,2,3,5-tetramethylbenzene were analyzed using the empirical data of three isomeric methylbenzyl radicals. Calculated data were obtained by summing up the shifts measured from methylbenzyl radicals as well as taking the position and alignment of substituents on the benzene ring into account. The revised assignments show better agreement with observation, and rationalize the validity of the model developed to explain the substituent effect on electronic transition energy of benzyl radicals.

• Food Science and Biotechnology
• /
• 제15권2호
• /
• pp.220-226
• /
• 2006

Component having antioxidant activity on lard during heating was separated from hexane extract of spinach, and its characteristic chemical structure was speculated through nuclear magnetic resonance spectroscopy, liquid chromatography-mass spectrometry, and Fourier transform infrared spectrophotometry. Lard was heated with hexane-, ethyl ether-, ethyl acetate-, or ethanol extract of spinach at $180^{\circ}C$ for 20 hr. Hexane extract of spinach, having highest antioxidant activity on lard during heating, was fractionated by silicic acid column chromatography (SACC), and SACC fractions having higher antioxidant activity on lard during heating were further separated by thin layer chromatography (TLC). Isolated compound from SACC fractions of hexane extract of spinach by TLC had sugar moieties and benzene ring along with hydroxy, carbonyl, and alkyl groups in the structure.

• 대한화학회지
• /
• 제7권4호
• /
• pp.225-229
• /
• 1963

The nature of the two isomers of 4-nitroazoxybenzenes in strongly acidic solution have been analyzed by U.V. spectrophotometry. Oxygen atom in the azoxy-group of $\alpha$-and $\beta$-4-nitroazoxybenzene in strong acid solution migrates neither to para position nor ortho position of the unsubstituted benzene ring of the compound in contrast with the cases of methyl-and bromo-substituted azoxybenzene, and shown no Wallach rearrangement. Since the $^1A{\rightarrow}^1H$ bands of the spectra shown hyperchromic effect whereas the ${\pi}{\rightarrow}{\pi}^*$ bands of them exhibit extream hypochromic effect, it appears most likely that trans ${\rightarrow}$cis isomerization take place in the media. A mechanism of a triangular transition state by which the transformation might be proceeded, is proposed.