Showing papers on "Nitrobenzene published in 1977"
64 citations
TL;DR: In this article, the rate constants for Ps reactions with nitrobenzene and CuCl/sub 2/ in various micellar systems such as hexadecyltrimethylammonium bromide and chloride, hexadecylpyridinium chloride, and tergitol were measured.
Abstract: The rate constants for Ps reactions with nitrobenzene and CuCl/sub 2/ in various micellar systems such as sodium dodecyl sulfate, sodium octyl sulfate and sulfonate, hexadecyltrimethylammonium bromide and chloride, hexadecylpyridinium chloride, and tergitol were measured. The results show that in most cases the Ps reactivity toward nitrobenzene is significantly reduced when the latter is located in the micellar phase as compared to the homogeneous aqueous phase. On the other hand, the observed reaction constants do not coincide with the constants measured for Ps-nitrobenzene in the corresponding alkanes either, with the exception of sodium octyl sulfate and sulfonate. Since Ps-nitrobenzene reaction rate constants were found to be sensitive to the environment in which they occur, these results may suggest that the nitrobenzene probe molecule is located in the Stern layer where it forms complexes with the various head groups, in which form its reactivity toward Ps will be decreased. An exception could be the sodium octyl sulfate system, where nitrobenzene may be in an aqueous environment, or the sodium octyl sulfonate where the nitrobenzene may reside in a hydrocarbon-like environment. In micellar solutions containing Cu/sup 2 +/ ions, no change in the Ps rate constants is observed in the case ofmore » the neutral tergitol or the cationic hexadecylpyridinium chloride micellar systems, whereas in the presence of the anionic micelles, sodium dodecyl sulfate or sodium octyl sulfate or sulfonate, which easily adsorb Cu/sup 2 +/ ions, the rate constants drastically drop.« less
54 citations
TL;DR: A high-pressure liquid chromatographic method has been developed for the determination of nanomole quantities of aniline; its metabolites o- and p-aminophenol, phenylhydroxylamine, nitrosobenzene and nitrobenzane; and azobenzene and azoxybenzenes which form non-enzymatically by condensation of reactive metabolites.
50 citations
TL;DR: Using known values of the 14 N quandrupole coupling constant and asymmetry parameter and the 13 CH bond distances, this article determined the three reorientational correlation times and the orientation of 14 N quadrupoles coupling tensor.
30 citations
TL;DR: The number of water molecules attached to alkaline earth metal cations (M2+: Ca2+,Sr2+, and Ba2+), some crown ethers (L), and the 1:1 metal-crown complexes (ML2+) extracted into nitrobenzene with hexanitrodiphenylamine was determined by the Karl-Fischer method as discussed by the authors.
Abstract: The number of water molecules attached to alkaline earth metal cations (M2+: Ca2+,Sr2+, and Ba2+), some crown ethers (L), and the 1:1 metal-crown complexes (ML2+) extracted into nitrobenzene with hexanitrodiphenylamine was determined by the Karl-Fischer method. Ca2+, Sr2+, and Ba2+ have 13.0, 12.1, and 10.5 water molecules in nitrobenzene respectively, and 6 to 8 water molecules are released on complexation with the crown ethers.
30 citations
TL;DR: Deoxygenative reduction of nitrobenzene by tributylphosphine in the presence of primary or secondary alcohols gave 2-alkoxy-3H-azepines in good yields as discussed by the authors.
Abstract: Deoxygenative reduction of nitrobenzene by tributylphosphine in the presence of primary or secondary alcohols gave 2-alkoxy-3H-azepines in good yields. The use of acidic hydroxylic compounds, such as phenol or acetylacetone, in place of the alcohols did not lead to ring enlargement. Triphenylphosphine could be used as a reducing agent, but the yields of the azepines were relatively low. 2-Alkoxy-3H-azepines were converted into 2-amino-3H-azepine in good yields by the reaction with ammonium carbonate. 2,3-Dihydro-1H-azepin-2-one was prepared by the hydrolysis of 2-butoxy-3H-azepine or 2-amino-3H-azepine.
17 citations
16 citations
TL;DR: In this article, the photochemical reactions of nitrobenzene, o-nitrotoluene, m-nitro-luene and p-nitrophenols were described.
14 citations
TL;DR: In this paper, the solvent dependence of the NH 2 stretching frequencies of C 6 F 5 NH 2 was investigated and the value for pK a is −2.2± 0.5.
13 citations
TL;DR: In this paper, the rate constants for Ps reactions with nitrobenzene and CuCl/sub 2/ in various micellar systems such as hexadecyltrimethylammonium-bromide and -chloride, hexadecylpyridiniumchloride and tergital were measured.
Abstract: The rate constants for Ps reactions with nitrobenzene and CuCl/sub 2/ in various micellar systems such as sodium dodecylsulfate, sodium octylsulfate and -sulfonate, hexadecyltrimethylammonium-bromide and -chloride, hexadecylpyridiniumchloride and tergital were measured. The results show that in most cases the Ps reactivity toward nitrobenzene is significantly reduced when the latter is located in the micellar phase as compared to the homogeneous aqueous phase. On the other hand the observed reaction constants do not coincide with the constants measured for Ps-nitrobenzene in the corresponding alkanes either, with the exception of sodiumoctylsulfate and -sulfonate. Since Ps-nitrobenzene reaction rate constants were found to be sensitive to the environment in which they occur, these results may suggest that the nitrobenzene probe molecule is located in the Stern layer where it forms complexes with the various head groups, in which form its reactivity toward Ps will be decreased. An exception could be the sodiumoctylsulfate system, where nitrobenzene may be in an aqueous environment, or the sodiumoctylsulfonate where the nitrobenzene may reside in the hydrocarbon-like environment.In micellar solutions containing Cu/sup + +/ ions, no change in the Ps rate constants is observed in the case of the neutral tergital or the cationic hexadecylpyridiniumchloride micellar systems, whereas inmore » the presence of the anionic micelles, sodium dodecylsulfate or sodiumoctylsulfate or -sulfonate which easily adsorb Cu/sup + +/ ions, the rate constants drastically drop.« less
12 citations
TL;DR: In this article, a method for the determination of nitrate in water by gas chromatography (GC) and mass spectrometry (MS) with a multiple ion detector (MID) was developed.
TL;DR: In this article, the authors investigated the thermal effect of polycyclotrimerization of 2,2-bis-(4-cyanatophenyl) propane in the presence of chromium acetylacetonate.
Abstract: The solvent nature was found to have a marked effect on the reaction rate and the thermal effect in the polycyclotrimerization of 2,2-bis-(4-cyanatophenyl) propane in the presence of chromium acetylacetonate. Placing the solvents in order according to the polycyclotrimerization rate we have: ditolylmethane > nitrobenzene > anisole > diglyme. The thermal effect for the polycyclotrimerization in nitrobenzene anisole and diglyme is 5–10 kcal/mole lower than in ditolymethane.
TL;DR: In this paper, the forward and backward rate constants for the reaction OH−+HA−\oversetkf\undersetkr\ightleftharpoonsH2O+A2− are evaluated to be in the range of 9.2×105−1.3×105 mol−1 dm3 s−1 and 5.5×103−1, respectively.
Abstract: Kinetics of proton-transfer reactions in 4 to 50%(v/v) dioxane–water media between hydroxide ion and 4-(2,4-dihydroxyphenylazo)nitrobenzene (Magneson; MAG) having a strong OH···N intramolecular hydrogen-bond are studied by means of the temperature-jump method. The forward and the backward rate constants kf and kr[H2O] for the reaction OH−+HA−\oversetkf\undersetkr\ightleftharpoonsH2O+A2− are evaluated to be in the range of 9.2×105–1.3×105 mol−1 dm3 s−1 and 5.5×103–1.8×103 s−1, respectively. The dependence of the kf and the acid dissociation constant Kac on the dioxane contents of the medium is interpreted on the basis of solute-solvent interactions.
TL;DR: The excess volumes of 18 binary solutions containing nitrobenzene as a weak electron acceptor and various mono-and polysubstituted aromatic donors were evaluated at 25 °C as mentioned in this paper.
Abstract: The excess volumes of 18 binary solutions containing nitrobenzene as a weak electron acceptor and various mono- and polysubstituted aromatic donors were evaluated at 25 °C. The partial molal volume of nitrobenzene in these solvents was also evaluated. There is no quantitative correlation between the volumetric behavior of the solutions and the electron donor acceptor abilities of the solution constituents. The results, however, clearly prove that isomers of higher cohesive energy affect the volumetric behavior of solutions less than their lower cohesive energy counterparts. An attempt is made to interpret this observation in terms of the steric effect and the cohesive energy of donors.
TL;DR: Nitrites and nitrates in meat and meat products are determined by nitration of benzene in the presence of sulfuric acid and peak height quantitation is both accurate and reproducible.
Abstract: Nitrites and nitrates in meat and meat products are determined by nitration of benzene in the presence of sulfuric acid. Nitrites are converted to nitrates by permanganate oxidation prior to nitration. The heat of dilution originating from the sulfuric acid is sufficient to complete the reaction. The final product, nitrobenzene, is determined by gas-liquid chromatography and electron capture detection. Peak height quantitation is both accurate and reproducible. Interferences from impurities are rarely encountered, and may be differentiated easily. The method also has potential application to samples other than meat.
TL;DR: In this article, the polymerization of pMeSt and pClSt copolymers with styrene (St) in benzene, methylene chloride, and nitrobenzene solvents was compared.
Abstract: p-Methyl- and p-chlorostyrenes (pMeSt and pClSt) were polymerized by CF3SO3H in methylene chloride at 0°C and gave polymers with a bimodal molecular weight distribution (MWD). This indicates that the polymerizations involve two independent propagating species: a dissociated and a non-dissociated species. Their selectivities toward monomers were compared in the copolymerizations of pMeSt and pClSt with styrene (St) by CF3SO3H in benzene, methylene chloride, and nitrobenzene solvents. Decreasing solvent polarity and the presence of a common-ion salt ((n-C4H9)4N+SO3CF−3) greatly increased the reactivity difference between the monomers. Thus the non-dissociated species is more selective than the dissociated species. In contrast, the composition of pMeSt-St copolymers produced by BF3O(C2H5)2 did not change with the solvent polarity. The difference in nature between the propagating species generated by CF3SO3H and by BF3O(C2H5)2 is discussed.
TL;DR: In this article, excited nitrobenzene derivatives were shown to be efficient to hydroxylate electron-rich aromatic substrates at the benzylic position, and they were applied to a variety of applications.
Abstract: Photoexcited nitrobenzene derivatives are shown efficiently to hydroxylate electron-rich aromatic substrates at the benzylic position.
TL;DR: The scarlet precipitate formed by the interaction of ferroin and antimony(V) in strong hydrochloric acid medium is soluble in nitrobenzene as mentioned in this paper, and its composition is [Fe(phen) 3 ] [SbCl 6 ] 2.
TL;DR: In this article, the conductivities of mixtures of 2,2′-bipyridyl with MeEtSnCl 2 or BuPrNCl 2 in nitromethane are interpreted in terms of formation of (i) RR′snCl 2 · bipy, (ii) [RR′snclbipy] + Cl −, and (iii) (RR′SnCl 3 ) −.
TL;DR: In this paper, a new sulfonating agent, bis(trimethylsilyl) sulfate, was found, which easily sulfonates benzene derivatives that contain substituents of the first type, and also thiophene.
Abstract: A new sulfonating agent, namely bis(trimethylsilyl) sulfate, was found, which easily sulfonates benzene derivatives that contain substituents of the first type, and also thiophene. Benzene and nitrobenzene do not react with bis (trimethylsilyl) sulfate.
Patent•
28 Mar 1977
TL;DR: In this article, a method for the nitration of benzene by the use of nitrogen dioxide under irradiation of visible ray or ultraviolet ray in the presence of oxygen was proposed. But this method was not suitable for the case of carbon monoxide.
Abstract: A method for the nitration of benzene by the use of nitrogen dioxide under irradiation of visible ray or ultraviolet ray in the presence of oxygen.
TL;DR: In this paper, photoexcited nitrobenzene was used for benzylic hydroxylation, and 17β-acetoxy-9α-hydroxy-3-methoxy-estra-1,3,5(10)-triene (IIIa) was obtained.
Patent•
31 Mar 1977
TL;DR: In this paper, a copper phthalocyanine pigments by reaction of phthalic anhydride, urea and CuCl were reacted in tert. amyl benzene for 4h at 180-185 degrees C. After treatment with boiling dil. Noah and dil. HCl, the pigment was obtd in clearer shades than from usual solvents.
Abstract: Prepn. of copper phthalocyanine pigments by reaction of phthalic anhydride or deriv., urea and a Cu salt, or of phthalodinitrile or deriv. and a Cu salt, employs as solvent >=1 alkyl benzene of formula (in which R is 1-4C alkyl). In contrast to methyl, ethyl or isopropyl benzene, the solvents even when heated in presence of oxygen, produce very little peroxide, which gives tarry products by decomposn. and recombination and dull pigment shades. They are less toxic and harmful than nitrobenzene or trichlorbenzene solvents. In an example, phthalic anhydride, urea and CuCl were reacted in tert. amyl benzene for 4h. at 180-185 degrees C. After treatment with boiling dil. Noah and dil. HCl, the pigment was obtd. in clearer shades than from usual solvents.
TL;DR: Cationic polymerization of styrene (St) initiated by phosphorus oxychloride was carried out at 30° in dichloromethane and nitrobenzene as discussed by the authors.
TL;DR: The activity of PdCl2 as a catalyst for the carbonylation of nitrobenzene to phenyl isocyanate at 190° and an initial CO pressure of 100 atm increases by 6-9 times when either pyridine or quinoline is added to the reaction system as mentioned in this paper.
Abstract: The activity of PdCl2 as a catalyst for the carbonylation of nitrobenzene to phenyl isocyanate at 190° and an initial CO pressure of 100 atm increases by 6–9 times when either pyridine or quinoline is added to the reaction system.
Patent•
09 Feb 1977
TL;DR: In this article, the reaction of an aliphatic alcohol with carbon monoxide and oxygen under pressure in the presence of a catalyst, a reaction accelerator and a side reaction inhibitor such as nitrobenzene is described.
Abstract: PURPOSE:Oxalic acid diester, useful as analytical reagents, solvents, raw materials of oxamide or orotic acid, is prepared in high yield and high selectively by the reaction of an aliphatic alcohol with carbon monoxide and oxygen under pressure in the presence of a catalyst, a reaction accelerator and a side reaction inhibitor such as nitrobenzene.