• Title, Summary, Keyword: nitrobenzene

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Interaction of Gallium Bromide with Hydrogen Bromide and Methyl Bromide in Nitrobenzene and in 1,2,4-Trichlorobenzene (니트로 벤젠 溶液 및 1,2,4-트리클로로 벤젠 溶液內에서의 브롬化갤륨과 브롬化水素 또는 브롬化 메칠과의 相互作用)

  • Choi, Sang-Up
    • Journal of the Korean Chemical Society
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    • v.6 no.1
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    • pp.77-83
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    • 1962
  • The solubilities of hydrogen bromide and methyl bromide in nitrobenzene and in 1,2,4-trichlorobenzene have been measured in the presence and absence of gallium bromide. When gallium bromide does not exist in the system, the solubilities of HBr and MeBr in nitrobenzene are greater than in 1,2,4-trichlorobenzene, indicating the greater basicity of nitrobenzene than 1,2,4-trichlorobenzene. When there exists gallium bromide in the system, the addition compounds, GaBr3·HBr and GaBr3·CH3Br, have been found to exist in solution. The addition compound of GaBr3·HBr is stable in nitrobenzene but unstable in 1,2,4-trichlorobenzene. On the other hand the addition compound of $GaBr_3{\cdot}CH_3Br$ is unstable in both solvents. All of these unstable addition compounds dissociate into components to large extents according to one of the following equilibria or both: $$GaBr_3{\cdot}RBr{\leftrightarrows}GaBr_3+RBr\;GaBr_3{\cdot}RBr{\leftrightarrows}1}2\;Ga_2Br_6+RBr$.$ where R denotes either hydrogen atom or methyl group.

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Application of Nanoroll-Type Ag/g-C3N4 for Selective Conversion of Toxic Nitrobenzene to Industrially-Valuable Aminobenzene

  • Devaraji, Perumal;Jo, Wan-Kuen
    • Journal of Environmental Science International
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    • v.29 no.1
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    • pp.95-108
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    • 2020
  • Silver nanoparticles were loaded onto g-C3N4 (CN) with a nanoroll-type morphology (Ag/CN) synthesized using a co-polymerization method for highly selective conversion of toxic nitrobenzene to industrially-valuable aminobenzene. Scanning electron microscopy and high-resolution transmission electron microscopy (HRTEM) images of Ag/CN revealed the generation of the nanoroll-type morphology of CN. Additionally, HRTEM analysis provided direct evidence of the generation of a Schottky barrier between Ag and CN in the Ag/CN nanohybrid. Photoluminescence analysis and photocurrent measurements suggested that the introduction of Ag into CN could minimize charge recombination rates, enhancing the mobility of electrons and holes to the surface of the photocatalyst. Compared to pristine CN, Ag/CN displayed much higher ability in the photocatalytic reduction of nitrobenzene to aminobenzene, underscoring the importance of Ag deposition on CN. The enhanced photocatalytic performance and photocurrent generation were primarily ascribed to the Schottky junction formed at the Ag/CN interface, greater visible-light absorption efficiency, and improved charge separation associated with the nanoroll morphology of CN. Ag would act as an electron sink/trapping center, enhancing the charge separation, and also serve as a good co-catalyst. Overall, the synergistic effects of these features of Ag/CN improved the photocatalytic conversion of nitrobenzene to aminobenzene.

Electrochemical Reduction of Nitrobenzene and Substituted Nitrobenzenes on Lead Electrode

  • Chon, Jung-Kyoon;Paik, Woon-Kie
    • Bulletin of the Korean Chemical Society
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    • v.2 no.1
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    • pp.1-8
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    • 1981
  • Electrochemical reduction of nitrobenzene and substituted nitrobenzenes on lead electrode was studied by galvano-static measurements and cyclic voltammetry in basic ethanol-water solvents. Nitroso compounds or hydroxylamines were detected as the main reduction product depending on the potential. Mechanisms of production and further reduction of substituted and unsubstituted nitrosobenzenes are deduced from Tafel slope, pH dependence and reaction order. The reduction of most of the substituted nitrobenzenes to corresponding nitrosobenzene derivatives seemed to follow the reaction mechanism of nitrobenzene reduction with a few exceptions. A Hammett type relationship between the magnitude of the reduction current and the kinds of substituents was found with the ${\rho}$ value of 0.54.

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A Study on the Solid-liquid Equilibria for Benzene+aniline, Benzene+nitrobenzene, p-xylene+cyclohexane (Benzene+aniline, benzene+nitrobenzene, p-xylene+cyclohexane계의 고액평형에 관한 연구)

  • Park, So-Jin;Paik, Seung-Kwan
    • Applied Chemistry for Engineering
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    • v.9 no.6
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    • pp.864-869
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    • 1998
  • In this work, the solid-liquid equilibria (SLE) of some aromatic organic mixtures including benzene, widely used as an industrial solvent, were measured by static method using our own made experimental apparatus. The accuracy and reproducibility of apparatus were tested by comparing experimental results with literature values for 1-dodecanol+cyclohxane and benzene + p-xylene systems. The SLE for new binary systems of benzene+aniline, benzene+nitrobenzene, p-xylene+cyclohexane were measured afterwards and compared with the calculated values by modified UNIFAC(Dortmund) equation.

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An Efficient Preparation of 4-Nitrosoaniline from the Reaction of Nitrobenzene with Alkali Metal Ureates

  • Park, Jaebum;Kim, Hyung Jin
    • Journal of the Korean Chemical Society
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    • v.60 no.4
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    • pp.251-256
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    • 2016
  • This paper describes the synthesis of alkali metal salts of urea (ureates) and their application to the direct preparation of 4-nitrosoaniline from nitrobenzene via nucleophilic aromatic substitution of hydrogen. Sodium and potassium ureates were readily prepared from the reaction of urea with sodium hydride, metal methoxides, and metal hydroxides. The effect of ureates as nucleophiles on the conversion of nitrobenzene to 4-nitrosoaniline was investigated and compared with that of a urea-metal hydroxide mixture. It was found that the ureates were superior for producing 4-nitrosoaniline owing to their higher thermal stability of the ureate. The ureate obtained from the treatment of urea with sodium hydride gave the highest yield for the preparation of 4-nitrosoaniline. The ureates generated from the reaction of urea with metal hydroxide also gave high yields of 4-nitrosoaniline. Catalytic hydrogenation of 4-nitrosoaniline afforded polymer-grade 1,4-benzenediamine in quantitative yield.

Nitrobenzene Functionalized Hexahomotrioxacalix[3]arene

  • Kang, Jong-Min;Cheong, Na-Young
    • Bulletin of the Korean Chemical Society
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    • v.23 no.7
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    • pp.995-997
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    • 2002
  • The synthesis and characterization of a nitrobenzene modified hexahomotrioxacalix[3]arene 1 are described.When calixarene 1 bound with ammonium ions carrying fluorescence group, the fluorescence of ammonium ions were effectively quenched and chang e of emission intensity provided the information of ammonium ion binding events to the calixarene 1.

The Interaction of Gallium Bromide with Ethyl Bromide in Nitrobenzene and in 1,2,4-Trichlorobenzene (니트로벤젠溶液 및 1,2,4-트리클로로벤젠 溶液內에서의 브롬化갤륨과 브롬化에칠과의 相互作用)

  • Sang Up Choi
    • Journal of the Korean Chemical Society
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    • v.7 no.1
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    • pp.65-68
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    • 1963
  • The solubility of ethyl bromide in nitrobenzene and in 1,2,4-trichlorobenzene has been measured at $19^{\circ}$ in the presence and absence of gallium bromide. When gallium bromide does not exist in the system, the solubility of ethyl bromide in nitrobenzene is greater than in 1,2,4-trichlorobenzene, indicating the stronger interaction of ethyl bromide with nitrobenzene than with 1,2,4-trichlorobenzene. When there exists gallium bromide in the system, an unstable 1: 1 complex, C2H5Br·GaBr3, of gallium bromide with ethyl bromide is formed in the solution. The 1: 1 complex in solution dissociates into the components to a large extent according to one of the following equilibria or both: $C_2H_5Br{\cdot}GaBr_3{\rightleftarrows}C_2H_5Br+GaBr_3$C_2H_5Br{\cdot}GaBr_3{\rightleftarrows}C_2H_5Br+1}2GaBr_3$$ The stability of the 1: 1 complex of ethyl bromide with gallium bromide is compared with that of the corresponding complex of methyl bromide.

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A Convenient Method for the Catalytic Hydrogenation of Aromatic Nitro Compounds to Aromatic Primary Amines (수소첨가 촉매 반응에 의한 니트로 화합물에서 방향족 1차 아민을 제조하는 편리한 방법)

  • Kim, Misoo;Lee, Hagyoung
    • Transactions of the Korean hydrogen and new energy society
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    • v.8 no.3
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    • pp.131-135
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    • 1997
  • Aromatic primary amines were prepared by the catalytic hydrogenation of aromatic nitro compounds in a benzene solution over 50 mg of 10 % palladium on charcoal at a room temperature under 45 psi. This paper describes a study on the catalytic hydrogenation of nitrobenzene-$d_5$, $^{15}N$-labelled nitrobenzene, and 4'-nitrobenzo-15-crown-5, respectively. The infrared absorption spectra exhibited a characteristic N-H stretching vibrations at 3450 and $3350cm^{-1}$. The results suggest that the non-readily available aromatic amines would be commercially produced by catalytic hydrogenation because of its good yield and little by-product formation.

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Characteristics of Nitrobenzene Degradation by Mycobacterium chelonae Strain NB01

  • Oh, Young-Sook;Lee, Youn-Hee;Lee, Jung-Hyun;Choi, Sung-Chan
    • Journal of Microbiology and Biotechnology
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    • v.13 no.2
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    • pp.309-312
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    • 2003
  • A bacterial strain NB01, isolated from wastewater, was found to utilize nitrobenzene (NB) as the sole source of nitrogen, carbon, and energy. The strain was classified as a member of a high G+C Gram-positive group and identified as Mycobacterium chelonae based on an analysis of its 16S rRNA gene sequence. The strain grew on NB with a concomitant release of about 63% of the total available nitrogen as ammonia, suggesting a reductive degradation mechanism. The optimal pH and temperature for degradation were PH 7.0-8.0 and $30^{\circ}C$, respectively. The cell growth was retarded at NB concentrations above 1.8 mM. The degradation of NB followed Michaelis-Menten kinetics within the tolerance range, and the $K_m$ and maximum specific removal rate for NB were 0.33 mM and $11.04\;h^{-1}$, respectively.

Kinetics of the Bromine-Exchange Reaction of Gallium Bromide with n-Propyl Bromide in 1,2,4-Trichlorobenzene and in Nitrobenzene

  • Kwun, Oh-Cheun;Kim, Young-Cheul;Choi ,Sang-Up
    • Bulletin of the Korean Chemical Society
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    • v.2 no.3
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    • pp.86-89
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    • 1981
  • The rate of the bromine-exchange reaction between gallium bromide and n-propyl bromide in 1,2,4-trichlorobenzene and in nitrobenzene was measured at 19, 25 and $40^{\circ}C$, using n-propyl bromide labelled with Br-82. The results indicated that the exchange reaction was second order with respect to gallium bromide and first order with respect to n-propyl bromide. The third-order rate constant determined at $19^{\circ}C$ is $2.9{\times} 10^{-2}l^2{\cdot}mole^{-2}{\cdot}sec^{-1}$ in 1,2,4-trichlorobenzene and $4.5{\times}10^{-3}l^2{\cdot}mole^{-2}{\cdot}sec^{-1}$. in nitrobenzene. The activation energy, the enthalpy of activation and the entropy of activation for the exchange reaction were also determined. Reaction mechanism for the bromine exchange of n-propyl bromide seemed to be similar to those observed in earlier studies with other alkyl bromides.

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