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.

Hydroxyl radical reactivity with nitrobenzene in subcritical and supercritical water.

Abstract: The bimolecular rate constants of the addition reaction between hydroxyl radical (*OH) and nitrobenzene (C(6)H(5)NO(2)) were measured in subcritical and supercritical water (SCW) at temperatures between ambient and 390 degrees C. The measured bimolecular rate constants showed distinctly non-Arrhenius behavior (i.e., essentially no increase with temperature) from ambient to 350 degrees C, but increased in the slightly subcritical and supercritical region between 350 and 390 degrees C. These data were modeled reasonably well over the entire temperature range with a three-step reaction mechanism, originally proposed by Ashton et al.(1) This model includes the formation of a pi-complex intermediate as the precursor of the nitrohydroxycyclohexadienyl radical.

Is Fullerene a Nonmetal Catalyst in the Hydrogenation of Nitrobenzene

Abstract: A recent report claimed that fullerene is a nonmetal catalyst for molecular activation of hydrogen, and that its catalytic activity is comparable to that of a noble metal catalyst. Li and Xu showed neutral fullerenes (C60 and C70) to activate molecular hydrogen under UV irradiation at room temperature and hydrogenation of aromatic nitro compounds to the corresponding aromatic amines took place with high yields and selectivities under 0.1 MPa of hydrogen. In control experiments in the absence of UV irradiation, the reduction of the nitro compounds did not proceed at 0.1 MPa H2. The mechanism of the molecular hydrogen activation in these systems is unclear at present. They also showed activated fullerene (fullerene anion) to effectively catalyze the hydrogenation of nitrobenzene to aniline, under dark conditions and at elevated temperature and pressure, with high selectivity. These findings could revolutionize catalysis, because fullerenes are environmentally friendly and their application would reduce costs. Nonmetal-catalyzed hydrogenation is an exciting prospect. We were interested in the mechanism of the molecular hydrogen activation under dark conditions and the subsequent transfer of hydrogen to the substrate, and thus reproduced the experiments. We did not address the hydrogenation of nitro compounds with neutral fullerene under UV irradiation and ambient conditions in this study. Herein, we demonstrate that C60 is not a nonmetal catalyst for hydrogenation. To produce the active catalyst, C60 was treated with solid NaOH and a Ni Al alloy in a nitrogen atmosphere. After adding THF and water, a reduction occurred and a red cloudlike fullerene monoanion (C60 ) product formed. The product diffused into the THF layer, the color of which became dark violet. After approximately 15 min, the violet THF phase was separated from the colorless aqueous solution. The THF phase was then used for the hydrogenation of nitrobenzene. In a typical reaction, C60 or C60 (0.019 mmol), nitrobenzene (3.25 mmol), mesitylene (0.50 mmol) as the internal standard, and THF (25 mL) as the solvent were placed into a stainless steel autoclave at 100 8C (or 150 8C) and 5 MPa H2 pressure. The control reaction without catalyst gave 2.3 % conversion at 100 8C (Table 1, entry 1). With 0.019 mmol C60 catalyst, the conversion was equally low (Table 1, entry 2), indicating that untreated C60 is inactive in hydrogenation reactions. [4] An increase in temperature to 150 8C led to an increase in conversion to

Inhibiting Radiolysis of BTP Molecules by Addition of Nitrobenzene

Abstract: Autoradiolysis of extraction systems sometimes occurs during reprocessing of spent fuel, which may result in a change in the extraction behaviour of the system. In the work reported here, an aromatic heterocyclic nitrogen bearing tridentate extraction agent, 2,6-di(5,6-diethyl-1,2,4-triazin-3-yl)pyridine (a BTP), was irradiated using a 60 Co source. The investigation focused on the effect of changing the organic diluent in the extraction system in order to protect the extracting agent from degradation. A relationship between the distribution ratio and extracting agent concentration was determined, and it was found that the extraction efficiency decreased with increasing irradiation dose. The effect on extraction of the degradation products from the organic diluents was also considered.

Catalytic oxidation and oxidative dehydrogenation using metal-compound-loaded, deboronated hams-1b crystalline borosilicate molecular sieve compositions

Abstract: Compositions comprising certain metal-containing materials distributed interactively on a deboronated HAMS-1B crystalline borosilicate molecular sieve which are useful for catalytically oxidizing or oxidatively dehydrogenating organic compounds such as alkanes, aromatics, and alkyl-substituted aromatics are described. Alkanes are oxidatively dehydrogenated to olefins, and an aromatic compound such as benzene can be oxidized by nitric and/or nitrous oxide to largely phenol or largely nitrobenzene depending upon the oxidation temperature. When the compound is a methylaromatic, oxidation produces an aromatic aldehyde. Alkyl groups larger than methyl oxidatively dehydrogenate to alkenyl groups. The compositions can be used in a process to separate p-xylene from a mixture of its isomers based upon the ability of the compositions, which preferably comprise a iron molybdenum material interactively distributed on a deboronated HAMS-1B crystalline borosilicate molecular sieve, to selectively oxidize the p-xylene to an aldehyde or dialdehyde while not substantially oxidizing the ortho and metaxylene isomers. Such partially oxidized mixtures of p-xylene are useful to make TPAA or as feeds to a water-based, further oxidation to make terephthalic acid. Carbon dioxide used as a carrier gas with a methylaromatic feed to the oxidation catalyst is shown to have a beneficial effect on yield and selectivity.