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.

Photodissociation dynamics of nitrobenzene and o-nitrotoluene

Abstract: Photodissociation of nitrobenzene at 193, 248, and 266nm and o-nitrotoluene at 193 and 248nm was investigated separately using multimass ion imaging techniques. Fragments corresponding to NO and NO2 elimination from both nitrobenzene and o-nitrotoluene were observed. The translational energy distributions for the NO elimination channel show bimodal distributions, indicating two dissociation mechanisms involved in the dissociation process. The branching ratios between NO and NO2 elimination channels were determined to be NO∕NO2=0.32±0.12(193nm), 0.26±0.12(248nm), and 0.4±0.12(266nm) for nitrobenzene and 0.42±0.12(193nm) and 0.3±0.12(248nm) for o-nitrotoluene. Additional dissociation channels, O atom elimination from nitrobenzene, and OH elimination from o-nitrotoluene, were observed. New dissociation mechanisms were proposed, and the results are compared with potential energy surfaces obtained from ab initio calculations. Observed absorption bands of photodissociation are assigned by the assistance of the ...

Formation and characterization of clay complexes with bitumen from athabasca oil sand

Abstract: Montmorillonite, kaolinite, illite, and chlorite were found to adsorb bitumen and its pentane- soluble and pentane-insoluble fractions. The formation of clay-bitumen complexes is influenced by the nature of the exchangeable cation on the clay and by the solvent carrier which stabilizes the bituminous compounds. Ca-clays adsorb organic compounds more strongly than sodium forms except in the presence of nitrobenzene. Solvents of high dielectric constant, such as nitrobenzene, promote ionization so that the ion-exchange mechanism of adsorption is favored, whereas solvents of lower dielectric constant, such as chloroform, tend to solvate rather than to dissociate bitumens. The behavior of the montmorillonite-bi- tumen complex in variable relative humidity indicates that organic molecules adsorb primarily on external surfaces and cause the clay to become less hydrophilic than prior to treatment. Clay-organic complexes are sufficiently stable to resist powerful organic solvents. The clay-organic complex separated from the Athabasca oil sand behaves similarly during chemical treatment to complexes formed between bitumen and the four reference clay minerals.

Stoichiometric production of aminobenzenes and ketones by photocatalytic reduction of nitrobenzenes in secondary alcoholic suspension of titanium(IV) oxide under metal-free conditions

Abstract: Photocatalytic conversion of nitrobenzenes in 2-propanol suspensions of bare titanium(IV) oxide (TiO 2 ) under various conditions was examined. Aniline and acetone were simultaneously produced almost stoichiometrically from a 2-propanol suspension of TiO 2 containing nitrobenzene under deaerated conditions without the use of a precious metal. Nitrobenzenes having another reducible group such as vinyl, chloro and bromo were chemoselectively reduced to corresponding aminobenzenes in 2-propanol suspensions of a TiO 2 photocatalyst with an almost stoichiometric amount of acetone. Photocatalytic reduction of nitrobenzene and oxidation of 2-propanol occurred even in the presence of oxygen, and no re-oxidation of anilines occurred.

The roles of pyrite for enhancing reductive removal of nitrobenzene by zero-valent iron

Abstract: Zero-valent iron (ZVI) is a popular reductant that has been successfully applied for remediation of groundwater contaminated with various pollutants, but it still suffers from surface passivation and pH increase in the reaction media. In this study, pyrite, a ubiquitous sulfide mineral in anaerobic environment, was adopted to enhance the reactivity of ZVI for removal of nitrobenzene. The synergetic effect between pyrite and ZVI was observed for nitrobenzene reduction, and the rate constant kobs at the initial pH (pH0) 6.0 was enhanced by 8.55–23.1 folds due to the presence of pyrite with pyrite/ZVI mass ratio ranging from 1.0 to 6.0. Moreover, nitrobenzene could be removed effectively at pH0 ranging from 5.0 to 10.0 in the presence of pyrite, while negligible removal of nitrobenzene by ZVI (0.5 g/L) alone was observed at pH0 ≥7.0. ZVI sample recovered from the reacted ZVI/pyrite mixture was also more effective for nitrobenzene degradation than pristine ZVI. The mechanism study revealed that pyrite could suppress the pH increase in reaction media, boost the production of reactive Fe2+, and activate the ZVI surface through replacing partially the passive oxide film with iron sulfide (FeS). In particular, the formation of highly reactive FeS@Fe in the reaction system of ZVI/pyrite mixture was proved by XRD, Mossbauer, XANES, XPS and SEM-EDS analyses, which provides a facile way for in-situ sulfidation of ZVI and for enhancing the removal of contaminants with ZVI technology.