Nitrobenzene

About: Nitrobenzene is a research topic. Over the lifetime, 5285 publications have been published within this topic receiving 83368 citations. The topic is also known as: essence of mirbane & nitrobenzol.

Chromosomal genotoxicity of nitrobenzene and benzonitrile

Abstract: In order to investigate the chromosomal genotoxicity of nitrobenzene and benzonitrile, we studied the induction of micronuclei (MN) by these test compounds in V79 cells, as well as effects on the formation and stability of microtubules and on motor protein functions. No cytotoxicity was seen in V79 cell cultures in terms of Neutral red uptake after 18 h treatment with up to 1 mM nitrobenzene or 1 mM benzonitrile. Subsequently, a concentration range up to 100 micro M was used in the experiments on induction of MN. Both test compounds exhibit a weak, but definitely positive test result compared to the solvent (DMSO) control. Minimal effect concentrations of nitrobenzene and benzonitrile appeared as low as 0.01 micro M, and no-effect-concentrations were between 0.001 and 0.005 micro M. Clearly enhanced MN rates were found at 0.1 micro M and higher. Both, nitrobenzene and benzonitrile, induced mostly kinetochor (CREST)-positive micronuclei, thus characterising the chromosomal effects as aneugenic. In cell-free assays, a slight effect on tubulin assembly was observed at 1 mM nitrobenzene without addition of DMSO. Higher concentrations (5 mM) led to secondary effects. In presence of 1% DMSO, nitrobenzene exerted no detectable effect on tubulin assembly up to the solubility limit in water of about 15 mM. For benzonitrile in presence of DMSO, a clear dose-response of inhibition of tubulin assembly at 37 degrees C was seen above the no-effect-concentration of 2 mM, with an IC(50) of 13 mM and protein denaturation starting above a level of about 20 mM. The nature of the effects of nitrobenzene and benzonitrile on the association of tubulin to form microtubules was confirmed by electron microscopy. Treatment by either 5 mM nitrobenzene or 13 mM benzonitrile plus 1% DMSO left the microtubular structure intact whereas 5 mM nitrobenzene, in absence of DMSO, led to irregular cluster formations. The experiments demonstrate that both nitrobenzene and benzonitrile, in millimolar concentration ranges, may lead to interference with tubulin assembly in a cell-free system. The functionality of the tubulin-kinesin motor protein system was assessed using the microtubule gliding assay. Nitrobenzene affected the gliding velocity in a concentration-dependent manner, starting at about 7.5 micro M and reaching complete inhibition of motility at 30 micro M, whereas benzonitrile up to 200 micro M did not affect the kinesin-driven gliding velocity. The micronucleus assay data demonstrate a chromosomal endpoint of genotoxicity of nitrobenzene and benzonitrile. Aneugenic effects of both compounds occur at remarkably low concentrations, with lowest-effect-concentrations being 0.1 micro M. This points to the relevance of interactions with the cellular spindle apparatus.

Selective reduction of nitrobenzene to nitrosobenzene over different kinds of trimanganese tetroxide catalysts

Abstract: Selective reduction of nitrobenzene has been measured on several kinds of Mn3O4 catalysts obtained by different methods of preparation. Attention is mainly given to the relationship between catalytic performance of different Mn3O4 materials and their redox behaviour. It was found that the catalyst having the most active redox behavior favoured the formation of highly reduced product (e.g. aniline etc) but, the catalyst having the least active redox behaviour showed poor catalytic activity. It seems that the catalytic as well as the redox behavior of Mn3O4 could be related to the Jahn-Teller effect.

Comparative study of solvents for the extraction of aromatics from naphtha

Abstract: An experimental investigation was carried out to evaluate the efficiencies of different selective solvents used for the extraction of aromatic hydrocarbons from naphtha (boiling range IBP-200°C) distilled from Saudi Arabian light crude oil. The solvents used were 3-methoxypropionitrile, ethylene glycol, dimethylsulfoxide, sulfolane, phenol, and nitrobenzene. The parameters studied were operating temperature (range 20°-125°C), solvent-to-oil ratio (range 1:1-3:1), selectivity, and solvent capacity. The results indicate that sulfolane exhibits excellent extraction properties in comparison with other solvents. In addition, sulfolane has the advantage of having good solvent properties such as high density, low heat capacity, and appropriate boiling point, which helps simplify separation of the solvent from extract. Sulfolane is also commercially feasible as a solvent for aromatic extraction.

Sensitive detection of hazardous explosives via highly fluorescent crystalline porous aromatic frameworks

Abstract: A three-dimensional (3D) porous aromatic framework (PAF-14) with high fluorescence quantum yield was synthesized from luminescent monomer of tetra(4-dihydroxyborylphenyl)germanium (TBPGe) building blocks. The powder X-ray diffraction (PXRD) analysis of the experimental and simulated patterns indicate that PAF-14 is highly crystalline with ctn topology. The Argon sorption measurement indicates that PAF-14 possesses high surface area (Brunauer Emmet Teller surface area: 1288 m2 g−1). Significantly, the introduction of germanium into PAF-14 skeletons may bring about a low-lying lowest unoccupied molecular orbital (LUMO) and the crystalline polymeric backbones enhance the sensitivity of electron delocalization. Therefore the designed PAF-14 exhibits high fluorescence quenching ability for hazardous explosives, such as nitrobenzene, 2,4-DNT (2,4-dinitrotoluene) and TNT (2,4,6-trinitrotoluene).