Showing papers on "Nitrobenzene published in 1971"
323 citations
48 citations
TL;DR: In this article, the rates of hydrogenation of nitrobenzene in n-butanol have been measured over catalysts of the palladium-silver alloy system, and the experimental activation energy from low (about 5 kcal mole−1) values on palladium rich alloys, to much higher values on silver-rich alloys (about 25 kcal moles−1), is consistent with the electronic band theory of catalysis.
21 citations
TL;DR: In this paper, the authors investigated the equilibria in and between the aqueous and organic phases and showed that the larger the association between the two phases, the more stable the association.
Abstract: Alkali metal picrates in an aqueous solution are extractable by nitrobenzene. The investigations of the equilibria in and between the aqueous and organic phases show that the larger the association...
17 citations
TL;DR: In this article, the reaction between hydrated lanthanide perchlorates and diphenylphosphinamide (DPPA) was studied and the X-ray powder patterns of the substances were obtained.
16 citations
TL;DR: In this article, the specific interaction of Silochrom with molecules of groups B and D consist in reversible formation of hydrogen bonds, which has a hydroxylated surface and is a specific adsorbent.
Abstract: Macroporous silica, Silochrom C80, with a specific surface area of about 80 m2/g and pore diameter of about 550 A is suggested for use in gas-adsorption chromatography. Silochrom C80 is characterized by high geometrical surface homogeneity. Silochrom, which has a hydroxylated surface, is a specific adsorbent. The specific interaction of Silochrom with molecules of groups B and D consist in reversible formation of hydrogen bonds. Saturated and aromatic hydrocarbons, ethers, esters, aldehydes, alcohols, acetophenone, nitrobenzene and aniline energe rapidly from a chromatographic column of Silochrom C80 at temperatures 100–200°C with symmetrical peaks.
15 citations
TL;DR: A number of substituted 6,13-dihalogenotriphenodioxazines have been synthesised by condensing halogeno-p-benzoquinones with arylamines as discussed by the authors.
Abstract: A number of substituted 6,13-dihalogenotriphenodioxazines have been synthesised (a) by condensing halogeno-p-benzoquinones with arylamines followed by cyclisation of the resulting bisarylamino-quinones with benzoyl chloride in nitrobenzene and (b) by condensing halogeno-p-benzoquinones with o-aminophenols in the presence of anhydrous sodium acetate in an alcoholic medium. A few triphenodithiazines have been prepared by condensing zinc o-aminobenzenethiolates with halogeno-p-benzoquinones.
14 citations
TL;DR: In this paper, the effect of geometrical structure of silica gels on retention volumes, band broadening and separation has been investigated, and it has been shown that, for analytical purposes and taking into account the analysis time, it is preferable to use temperature programming of the column.
14 citations
TL;DR: In this paper, a new flow method of measuring optical absorption spectra of radical ions is described, which consists in generation of flowing solutions of free radical anions by electrolysis on a porous electrode; the flowing solution then passes through a flow spectrophotometric cell.
12 citations
TL;DR: In this article, the reaction between hydrated lanthanide nitrates with N,N-dimethyl-diphenylphosphinamide was studied and the I.r. spectra, the molar conductance in nitrobenzene and the X-ray powder patterns of the substances were obtained.
12 citations
TL;DR: The partition coefficients of 8-quinolinol between water and benzene, nitrobenzene, toluene and chloroform have been determined as a function of temperature, and values of DeltaH and DeltaS determined for each.
TL;DR: Rates of decomposition of m-nitrobenzenesulfonyl peroxide in chloroform, nitrobenzene, chlorobenzene, and benzene were determined, and activation parameters were calculated.
Abstract: Rates of decomposition of m-nitrobenzenesulfonyl peroxide in chloroform, nitrobenzene, chlorobenzene, and benzene were determined, and activation parameters were calculated Products of decomposition in nitrobenzene were m-nitrophenyl m-nitrobenzenesulfonate and m-nitrobenzenesulfonic acid, whereas those in chloroform were m-nitrobenzenesulfonic acid, hexachloroethane, and phosgene (when air is present) Activation parameters and reaction products indicate that the reaction in chloroform involves homolytic cleavage of the O–O bond, whereas that in nitrobenzene involves electrophilic attack of the peroxide on aromatic nuclei When sulfonyl-18O labeled m-nitrobenzenesulfonyl peroxide was decomposed in benzene, about 35–36% of the label was found in the phenolic oxygen of m-nitrophenyl m-nitrobenzenesulfonate This finding could be accounted for by a mechanism which involves a loose π-complex prior to the formation of a σ-complex
TL;DR: The stability of the complex of arsenic acid with catechol (1:3) has been studied by the analysis of potentiometric neutralization curves and it is found that arsenic(V) in micro amounts can be extracted either into chloroform in the presence of tetraphenyl-arsonium chloride andcatechol, or into nitrobenzene in the absence of only catechols.
TL;DR: In this article, the trans-ozonium ion combines rapidly with methoxide ion to form cis-p-nitrophenylazo methyl ether, which then further reacts to form nitrobenzene and trans-azo-ether in approximately equal amounts.
Abstract: p-Nitrobenzenediazonium ion combines rapidly with methoxide ion to form cis-p-nitrophenylazo methyl ether, which then further reacts to form nitrobenzene (by a radical mechanism) and the trans-azo-ether in approximately equal amounts.
TL;DR: In this paper, the excited singlet state of the chloro-compound is implicated in the mechanism of these reactions, and is measured for the photochemical phenylation of anisole with chloro-, bromo-, and iodo-benzenes.
Abstract: U.v. irradiation of a variety of substituted chlorobenzenes in benzene gives the corresponding biphenyls, accompanied in some cases by products of reductive dechlorination. m-Chlorofluorobenzene and p-bromochlorobenzene react with selective replacement of the heavier halogen. Isomer ratios have been measured for the photochemical phenylation of anisole with chloro-, bromo-, and iodo-benzenes. The excited singlet state of the chloro-compound is implicated in the mechanism of these reactions. Chloronitrobenzenes, which are photostable in benzene, are slowly reduced to nitrobenzene on irradiation in ethanol.
TL;DR: Iodide was extracted from the aqueous phase into nitrobenzene in a wide pH range of 3-9 by use of tris(1,10-phenanthroline)iron(II) chelate cations and then determined spectrophotometrically at 516 mμ as mentioned in this paper.
Abstract: Iodide was extracted from the aqueous phase into nitrobenzene in a wide pH range of 3–9 by use of tris(1,10-phenanthroline)iron(II) chelate cations and then determined spectrophotometrically at 516 mμ. Beer’s law was effective up to 8.0×105 M of iodide in the aqueous phase. Standard deviation of the determination was 1.1% at 15°C. The color intensity of the extracted species in nitrobenzene was constant for at least 3 hr. The distribution ratio was 1.02 at 15°C and 0.83 at 26°C. No serious interferences by foreign anions were observed except for perchlorate, chlorate, and thiocyanate. Cations did not essentially interfere with the determination.
TL;DR: In this article, a mechanistic approach was proposed to rationalize the effect of added nitrobenzene on the nature of the products from the thermal decomposition of benzoyl peroxide in benzene.
Abstract: A mechanistic scheme is suggested which rationalises the effect of added nitrobenzene on the nature of the products from the thermal decomposition of benzoyl peroxide in benzene. A small fraction of the nitro-compound is reduced to nitrosobenzene, which scavenges phenyl radicals to form diphenyl nitroxide. The nitroxide radicals efficiently oxidise phenylcyclohexadienyl radicals to biphenyl, and thus prevent side-reactions (e.g., dimerisation), which would give high molecular weight products. The nitroxide is regenerated by oxidation of diphenylhydroxylamine by molecular benzoyl peroxide. Evidence in support of this scheme is evaluated, and several complicating features are discussed.
TL;DR: In this paper, the reduction of nitrobenzene, nitrosobenzenes, and azoxybenenzene by potassium borohydride is catalysed by hydroxocobalamin.
Abstract: The reduction of nitrobenzene, nitrosobenzene, and azoxybenzene by potassium borohydride is catalysed by hydroxocobalamin. The products of the reaction with nitrobenzene include aniline and azobenzene. The cobalt(I) cobalamin, vitamin B12s, reacts with nitrobenzene, nitrosobenzene, azoxybenzene, and azobenzene but not with phenylhydroxylamine or hydrazobenzene. A mechanism for the reduction is proposed.
TL;DR: In this article, the rate equation r for the vapor phase reduction of nitrobenzene to aniline on copper-magnesia catalyst in the temperature range from 175°C to 220°C was obtained as follows;r=kPH/1+KNPN+KAPA+KWPW where k; rate constantPH, PN, PA and PW; partial pressure of hydrogen, Nitrobenzinzene, anilines, and waterKN, KA and KW; adsorption equilibrium constant of n-bensene,
Abstract: The kinetics of the catalytic vapor phase reduction of nitrobenzene to aniline over copper-magnesia catalyst in the temperature range from 175°C to 220°C was studied using a differential reactor. The rate of reaction was measured at atmospheric pressure with a high mole ratio of hydrogen to nitrobenzene. From the analysis of the experimental data, it was concluded that the rate-controlling step was the adsorption process of hydrogen on the copper-magnesia catalyst surface. According to the Langmuir-Hinshelwood mechanism, the final rate equation r for the vapor phase reduction of nitrobenzene on copper-magnesia catalyst in the temperature range from 175°C to 220°C was obtained as follows;r=kPH/1+KNPN+KAPA+KWPWwhere k; rate constantPH, PN, PA and PW; partial pressure of hydrogen, nitrobenzene, aniline and waterKN, KA and KW; adsorption equilibrium constant of nitrobenzene, aniline and waterThis equation will be useful if it can be used to predict the rate over a wide range of reactions and hence, be suitable for reactor design.
TL;DR: In this paper, the rate constants of the reaction of benzoyl peroxide with typical secondary amines, namely, diphenylamine, N-methylaniline, and piperidine, were measured in benzene-nitrobenzene binary mixed solvents.
Abstract: The rate constants of the reaction of benzoyl peroxide with some typical secondary amines, namely, diphenylamine, N-methylaniline, and piperidine, were measured in benzene-nitrobenzene binary mixed solvents. The reaction rates of diphenylamine and N-methylaniline are little influenced by the compositions of the solvents, while the reaction of piperidine proceeds more rapidly in nitrobenzene than in benzene. The isokinetic relationship holds for the reaction of piperidine in the binary mixed solvents. The isokinetic temperature is calculated to be 265°K. The analysis of the behavior of these reactions in the mixed solvents leads to the conclusion that, in the cases of diphenylamine and N-methylaniline, there are no specific interactions between the activated complexes and solvent molecules, whereas in the case of piperidine the activated complex is weakly solvated with the polar nitrobenzene. The reaction of benzoyl peroxide with N-methylaniline and N-n-butylaniline was also studied in benzene. These amine...
TL;DR: Aromatic compounds with an acidic group, such as -OH, -SH, -COOH, -SO3H, >NH, and (Remark: Graphics omitted)B− (tetraphenylborate) were tested as extracting agents for potassium as mentioned in this paper.
Abstract: Aromatic compounds with an acidic group, such as –OH, –SH, –COOH, –SO3H, >NH, (Remark: Graphics omitted)CH, and (Remark: Graphics omitted)B− (tetraphenylborate) were tested as extracting agents for potassium The first four acids showed an extractability lower by far than that of the last three Most inorganic acids exhibited no signs of extraction Bulky and electronattracting substituents, such as nitro or halogen group, were proved to be effective in enhancing the extractability The addition of iodine was also effective A few kinds of surfactants showed considerably high extractability Some factors influencing the extraction were speculated upon
TL;DR: In this article, the effect of steric characters and pK values on the distribution equilibrid of alkali-metal nitrophenolates was studied by using nitrobenzene as the extracting solvent.
Abstract: The liquid-liquid extraction of alkali-metal nitrophenolates was studied by using nitrobenzene as the extracting solvent. Nitrophenol derivatives such as o-, m-, p-nitrophenols, α-dinitrophenol, and picric acid were chosen here in order to examine the effect of their steric characters and pK values on the distribution equilibrid. It was concluded that: 1) all the cesium nitrophenolates extracted into nitrobenzene were mainly in the dissociated form; 2) the extraction of m- and p-nitrophenolates proceeds by the stepwise adduct formation with free phenols, whereas little tendency of adduct formation was observed with the pier ate system; 3) α-dinitrophenolate has a character between the other two; 4) the distribution of o-nitrophenolate is negligible. A detailed discussion is given of the phenomena in terms of ionic equilibria in both the aqueous and organic phases.
Patent•
29 Sep 1971
TL;DR: In this paper, Borzesti et al. presented a method to produce chloronitrobenzene in the presence of a catalyst comprising a mixture of 0A1-0A8% iodine and 2-8% anhydrous ferric chloride.
Abstract: 1,247,660. m-Chloronitrobenzene. GRUPUL INDUSTRIAL DE PETROCHIMIE BORZESTI. 7 May, 1970, No. 21971/70. Heading C2C. m-Chloronitrobenzene is prepared by chlorinating nitrobenzene in the presence of a catalyst comprising a mixture of 0A1-0A8% iodine and 2-8% anhydrous ferric chloride, the percentage being relative to the weight of the nitrobenzene subjected to chlorination.