• Bulletin of the Korean Chemical Society
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• 제30권8호
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• pp.1832-1834
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• 2009

A simple and safe method has been presented for conversion of olefins into bromohydrins using hydrogen bromide and hydrogen peroxide as bromide source by visible light induced within a very short time to get high yield bromohydrins along with a little mount dibromo-product. In this paper, cyclohexene is firstly carried out as the model substrate and investigated the bromination under HBr/$H_2O_2$ system using 150 W incandescent light irradiated in C$Cl_4$ within short time to get good yield of 2-bromocyclohexanol along with a little mount of 1,2-dibromocyclohexane; then, a series of alkenes are brominated to corresponding bromohydrins using the same protocol.

• Bulletin of the Korean Chemical Society
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• 제24권10호
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• pp.1444-1448
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• 2003

The microsurface adsorption - spectral correction (MSASC) technique has been applied to the interaction of indigo carmine (IC) with cetyltrimethylammonium bromide (CTAB). The aggregation of IC on CTAB obeys Langmuir isothermal adsorption. The results show that both the monomer complex $IC{\cdot}CTAB$ and the micellar complex $(IC{\cdot}CTAB)_{78}$ were formed. The binding constant of the monomer complex was calculated to be $K_{IC{\cdot}CTAB}$ = 2.20 ${\times}10^5L{\cdot}mol^{-1}$, and the molar absorptivity of the micellar complex was calculated to be ${\varepsilon}_{(IC{\cdot}CTAB)78}\;^{560nm}$ = 8.58 ${\times}10^5L{\cdot}mol^{-1}{\cdot}cm^{-1}$. The aggregation was applied to the determination of cationic surfactant in wastewater.

• Bulletin of the Korean Chemical Society
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• 제24권7호
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• pp.921-924
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• 2003

Homochiral (-)-pipecolaldehyde 6 from D-glucono- δ-lactone underwent a highly diastereoselective addition upon treatment with vinylmagnesium bromide. Treatment with vinylmagnesium bromide produced antiaminoalcohol 7a which was easily converted into the synthesis of 1,6-diepicastanospermine 2.

• Journal of Advanced Marine Engineering and Technology
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• 제24권4호
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• pp.478-485
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• 2000

An experimental study of the absorption process of water vapor into lithium bromide solution was performed. For the purpose of development of high performance absorption chiller-heater utilizing Lithium Bromide solution as working fluid, the absorber is the most effective to improve the performance of an absorber because it requires the largest heat transfer area in an absorption chiller-heater system. This paper introduces bare tube and inner ribbed notched fin tube for the absorber of absorption chiller-heaters. Inner ribbed notched fin tube has about 10∼20% higher heat and mass transfer performance than bare tube conventionally used in absorbers and the it is expected to perform high heat and mass transfer. This paper will provide important information on the selection of absorber tubes in commercial absorption chill-heaters.

• Bulletin of the Korean Chemical Society
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• 제3권2호
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• pp.55-60
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• 1982

The rate of the bromine-exchange reaction of antimony tribromide with benzyl bromide in nitrobenzene or 1,2,4-trichlorobenzene has been measured, using Br-82 labelled antimony tribromide. The result of the study indicates that the exchange reaction is first order with respect to benzyl bromide, and either second or first order with respect to antimony tribromide depending on its concentrations. The second-order kinetics with respect to antimony tribromide have been observed at relatively high $[SbBr_3]$ concentrations, and the first-order kinetics at lower $[SbBr_3]$ concentrations. Reaction mechanisms are proposed for the exchange reaction.

• Bulletin of the Korean Chemical Society
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• 제12권4호
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• pp.411-413
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• 1991

The effects of electrolyte on the critical micelle concentration (cmc) and bromide counterion binding in the micelles of cetylpyridinium bromide (CPB) have been investigated by UV spectroscopy and conductance measurements. Salts used in this study decreased cmc in the order $Cl^-\;<\;Br^-\;<\;NO3^-$ (which parallels the lyotropic series for the inorganic anions) and the effects on cmc followed the equation proposed by Shinoda: log cmc = A - B log (cmc + [NaX]). In the equation, constant B represents the counterion binding to the micelles at cmc and for the micelle of CPB at $25^{\circ}C$, B=80.76%. The association constant for the binding of counterions to long chain cations within micelles was also derived from the cmc values and counterion binding constant to the micelles.

• 대한화학회지
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• 제25권2호
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• pp.110-118
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• 1981

치환 브롬화페나실과 치환 피리딘과의 반응속도를 메탄올과 DMF 용매중, 25∼$45^{\circ}C$의 온도범위에서 전기전도도법으로 측정하였다. 그 결과 두 용매 다 같이 치환 피리딘에서는 전자를 주는 기가 치환되었을 경우 반응속도 상수는 컸으며, 반대로 전자를 끄는 치환기일 경우는 반응속도 상수가 작았다. 기질에서의 치환기 효과는 핵에 전자를 끄는기가 치환되었을 경우 반응속도는 증가하였다. 이 사실들은 탄소원자에 아민이 친핵적으로 공격한다는 것을 알 수 있다. 브롬화페나실과 피리딘의 반응에서 보여준 등속온도는 메탄올과 DMF에서 각각 614와 $202^{\circ}K$였고 $Br{\phi}nsted {\beta}$값은 0.29와 0.36이었다. 치환 브롬화페나실과 피리딘과의 반응의 경우는 등속온도는 전자를 끄는 치환기일 수록 감소하였으며, ${\beta}$값은 그 반대였다. 위의 결과로부터 p-Cl에서 p-MeO 브롬화페니실로 감에 따라 N…C 결합형성이 점차적으로 줄어들고 있으며 결합 형성은 DMF가 메탄올보다 우세하게 진전함을 추측할 수 있다. 치환 피리딘의 경우 Hammett식의 ${\rho}$값은 양 용매에서 모두 부(-)의 값을 가졌다. 핵 치환 브롬화페나실에서의 ${\rho}$값은 0.3의 적은 값이었으며 이는 메틸렌탄소에 피리딘의 질소 원자가 직접적으로 $S_N2$공격을 한다고 생각된다.

• 자원리싸이클링
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• 제12권1호
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• pp.48-54
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• 2003

연간 250,000 톤 정도 생산되는 패각을 이용하여 악취제거기능을 갖는 폴리에틸렌 필름을 제조하기 위해, 패각 표면의 탄산이온을 바탕으로 양이온 또는 양이온성 계면활성제의 이온교환에 의한 표면흡착 및 이에 따른 표면 극성 변화를 통해서 악취제거능을 부여하였다. 패각 표면의 개질은 앙이온성 계면활성제로서 DTAB(n-dodecyltrimethylammonium bromide), CTAB(n-cetyltrimethy-lammonium bromide), 그리고 DHAB(n-dihexadecyldimethylammonium bromide)를 사용하였다. 또한 앙이온의 금속으로는 $Ce^{3+}$ , $Mg^{2+}$ , $Al^{3+}$ 를 이용하여 계면활성제의 이온교환방법으로 표면을 개질하였다. 표면 개질된 패각 분말을 이용하여 LDPE라 패각 기준 20 wt% 마스터배치(masterbatch, MB)를 제조한 후 다시 LDPE와 섞어서 패각 기준 3, 5, 10 wt%의 폴리에틸렌필름을 제조하였다. 생산된 필름의 규격은 폭 40 cm, 두께 40 $mu extrm{m}$ 이었다. 제조된 패각 필름에 대한 기계적 물성 측정 결과 패각의 첨가로 인한 기계적 물성의 큰 저하는 관찰되지 않았으며, 순수 폴리에틸렌 필름 대비 80% 이상의 물성을 유지하였다. 악취제거능은 양이온성 계면활성제로 개질된 패각 필름이 시험된 모든 종류의 악취에 대하여 가장 우수한 악취 흡착 제거능을 보여주었으며, 개질되지 않은 패각 필름도 비교적 우수한 악취제거능을 보여주었다.

• 대한화학회지
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• 제60권2호
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• pp.107-110
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• 2016

A new series of hydrazino thiazolyl-2-azetidinone 4(a-i) derivatives were synthesized efficiently using benzylidene hydrazinyl thiazole derivatives 3(a-i). The precursors, benzylidene hydrazinyl thiazoles were prepared by reacting 4-fluoro phenacyl bromide with thiosemicarbazones 2(a-i). All the structures of the synthesized compounds were ascertained by IR, NMR and mass spectral analysis.

• Archives of Pharmacal Research
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• 제17권4호
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• pp.249-255
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• 1994

An efficient synthetic method for 11-deoxyanthracycline AB synthons is described. A verstile key intemediate vinyl bromide 3 was prepared from 5- methodxy-1-tetralone in three steps, and then was converted to the allylic alcohols 4 and 8 which, in tum, fumished highly fuctionalized AB synthons 7 and 12, respectively, via sequential epoxidation-reduction-protection processes.