Showing papers on "Nitrobenzene published in 1990"
TL;DR: In this article, the effect of reaction time and temperature on the rate of reaction has been measured and the nature of the aldehyde and acid products determined by gas-liquid chromatography.
Abstract: The alkaline nitrobenzene procedure for determining lignin building units has been applied to wheat internodes. The effect of reaction time and temperature on the rate of reaction has been measured and the nature of the aldehyde and acid products determined by gas-liquid chromatography. Survival factors for individual phenolic compounds were determined and found to be in the range 0.85–4.99, and were constant for each compound under the reaction conditions (c 6 % nitrobenzene in 2 M NaOH, 170°C, 2 h in a stainless steel pressure vessel), optimised for maximum recovery of products using wood and wheat internode meals. The reaction products fiom 24 monomeric and dimeric lignin model compounds were quantitativety determined to provide information on the susceptibility of various lignin structures to alkaline nitrobenzene oxidation. The results of these and earlier studies by other authors suggest that at the higher temperature a heterolytic reaction mechanism is operating on nitrobenzene oxidation conditions. On nitrobenzene oxidation, ferulic and p-coumaric acids survived in amounts which allowed the procedure to be used, with appropriate correction factors, to determine the nature and amount of these cinnamic acids associated with walls of grasses.
107 citations
TL;DR: In this article, a condensation of appropriate diamines and aldehydes in nitrobenzene was used to synthesize compounds 5f-h, which are analogues of the DNA binding fluorochrome Hoechst 33258.
84 citations
TL;DR: In this article, the Damkiihler number was used to predict the product distribution of second-order reactions between three substances in a semi-batch reaction setting, and a mixing model was applied to predict yields when segregation is complete.
77 citations
TL;DR: In this article, eight species of plants were exposed to nitrobenzene in a hydroponic solution and the transpiration stream concentration factor (TSCF) was 0.72.
Abstract: Eight species of plants were exposed to nitrobenzene in a hydroponic solution. Four species experienced no depression of either transpiration or photosynthetic rates, while one was rapidly killed and the other three were temporarily affected but recovered from the treatment. Uptake of nitrobenzene was passive and was shown to be proportional to the rate of water flux in each species. The transpiration stream concentration factor (TSCF) was 0.72. The root concentration factor (RCF) was variable between the species and was higher than expected, presumably due to deposits of insoluble metabolic products. All of the species examined displayed a capacity to chemically alter nonpolar nitrobenzene into both polar and insoluble products. Volatilization of nitrobenzene from the leaves was a major route of chemical loss.
69 citations
TL;DR: In this article, the rate of ion transfer across the polarized nitrobenzene/water interface has been determined for twelve homologous alkylammonium ions by using phase-selective ac polarography.
60 citations
TL;DR: In this paper, the properties of poly(N-alkyl-3,6-carbazolediyl)s (PCZSs) were investigated in the presence of a catalytic Ni(0)-based system.
60 citations
TL;DR: In this paper, a thermodynamic approach to the practical characterization of solvent strength and selectivity of a wide range of molecular and ionic stationary phases for gas chromatography is discussed and the experimenal protocol is outlined in detail and the principal sources of error with their magnitude identified.
57 citations
TL;DR: In this paper, the preparative electrochemical reduction of nitrobenzene, phenylhydroxylamine and hydrazobenzene was studied under controlled potential conditions at Devarda copper and Raney nickel electrodes in neutral and basic aqueous methanolic solutions.
54 citations
TL;DR: In this paper, a kinetic model was developed of nitrobenzene hydrogenation to aniline over industrial copper catalyst, considering the effects of mass transfer and deactivation.
52 citations
TL;DR: The degree of dispersion of clays in organic solvents requires hydrophobization of the clay minerals, usually by reacting the bentonites with alkylammonium salts as discussed by the authors.
50 citations
TL;DR: In this paper, density and shear viscosity for the binaries of anisole with nitrobenzene, chlorobenzene, carbon tetrachloride, cyclohexane, and 1,2-dichloroethane have been used to estimate the excess volume, excess shear, excess free energy of activation of flow, partial molar volume, contact parameter, and density increment over the entire mixture composition.
Abstract: Results of density and shear viscosity for the binaries of anisole with nitrobenzene, chlorobenzene, carbon tetrachloride, cyclohexane, and 1,2-dichloroethane have been used to estimate the excess volume, excess shear viscosity, excess free energy of activation of flow, partial molar volume, contact parameter, and density increment over the entire mixture composition
TL;DR: In this article, the barrier and associated one-dimensional torsional potential were derived for two conjugated molecules, nitroethylene and nitrobenzene, using the second-order Moller-Plesset perturbation theory.
TL;DR: In this article, a large deviation was observed between the observed value of the equivalent conductivity (Λ obsd ) and the calculated value (λ calcd ) only with ion-pair formation constant (K 1 ) for tributylammonium chloride (n-Bu 3 NHCl, (0.4-6.0)×10 -3 M) in nitrobenzene and benzonitrile.
Abstract: A large deviation was observed between the observed value of the equivalent conductivity (Λ obsd ) and the calculated value (Λ calcd ) only with ion-pair formation constant (K 1 ) for tributylammonium chloride (n-Bu 3 NHCl, (0.4-6.0)×10 -3 M) in nitrobenzene and benzonitrile
TL;DR: Copper(I) iodide dissolves in methylene chloride and nitrobenzene solutions of equimolar diamine ligands L=N,N, N',N'-tetramethylethylenediamine as mentioned in this paper.
Abstract: Copper(I) iodide dissolves in methylene chloride and nitrobenzene solutions of equimolar diamine ligands L=N,N,N',N'-tetramethylethylenediamine N,N,N',N'-tetraethylethylenediamine, N,N,N',N'-tetrapropylethylenediamine and N,N,N',N'-tetramethyl-1,3-propanediamine under dinitrogen to give neutral dimeric copper(I) molecules (LCuI] 2
TL;DR: In this paper, the reaction of acetanilide with nitrobenzene in the presence of a base in DMSO yielded p -nitrosodiphenylamine (3) as the major product.
TL;DR: Several nitrobenzene derivatives were submitted to reaction with carbon monoxide in alkene solvents in the presence of catalytic amounts of Ru3(CO)12 as discussed by the authors.
TL;DR: In this article, the thermodynamic and kinetic properties of ion transfer facilitated by crown ethers from water to nitrobenzene were studied by means of cyclic voltammetry and impedance measurement.
TL;DR: In this paper, the authors used cyclic voltammetry and equilibrium faradaic impedance measurements to study the transfer of tetra-alkylammonium, choline, perchlorate and picrate ions across the water/polyvinylchloride (PVC)+nitrobenzene gel or agar+water gel/nitrophenzene boundaries as a function of the polymer concentration.
TL;DR: In this paper, a reaction kinetic study was performed for the reduction of nitrobenzene on a rotating disc electrode for which the current-potential data were supplemented with product-concentration measurements.
Abstract: A reaction kinetic study has been performed for the reduction of nitrobenzene on a Cu electrode in 1m H2SO4 in a 50∶50 (Vol%) mixture of water and 1-propanol at 27°C. The study was carried out on a rotating disc electrode for which the current-potential data were supplemented with product-concentration measurements. The resulting rate expressions represent a reaction mechanism for the reduction of nitrobenzene to aniline and p-aminophenol through the common intermediate phenylhydroxylamine, and incorporate the dependence on reactant concentration and potential for the three predominant reaction pathways. The three major reaction steps were studied independently by performing experiments in which phenylhydroxylamine only was used as the reactant to complement those experiments in which nitrobenzene was used. The kinetic expressions found from measuring the rates of the individual reactions were consistent with the results of experiments in which all the reactions were carried out simultaneously. The expressions obtained are suitable for use in reactor design, modelling and control, and of equal importance, the methodology outlined to extract kinetic parameters from the current and concentration data serves as a model for application to other reaction systems.
TL;DR: In this article, the electronic absorption (UV) spectrum, 59Co, and 13C NMR of potassium hexacyanocobaltate(III), K3[Co(CN)6], were measured in water and a variety of organic solvents: ethylene glycol, methanol, formamide, ethanol, chloroform, nitromethane, dichloromethane, dimethyl sulfoxide, acetonitrile, N,N-dimethylformamide, benzonitrile and nitrobenzene.
Abstract: The electronic absorption (UV) spectrum, 59Co, and 13C NMR of potassium hexacyanocobaltate(III), K3[Co(CN)6], were measured in water and a variety of organic solvents: ethylene glycol, methanol, formamide, ethanol, chloroform, nitromethane, dichloromethane, dimethyl sulfoxide, acetonitrile, N,N-dimethylformamide, benzonitrile, and nitrobenzene. The complex salt was dissolved in organic solvents by macrobicyclic polyether, cryptand 222. It was found that the spectra are influenced by the solvent, and vary according to the electrophilic ability (Gutmann’s acceptor number) of solvents. Especially, the 13C NMR chemical shifts of coordinated cyano carbons (octet) have shifted downfield as the acceptor number becomes larger. This means that the solvent influence is caused by direct interaction between the ligand CN− and solvent molecules as electron acceptors. The result concerning the linear correlation between the solvent influence on the peak position (nm) of the first d–d transition band and on the chemical...
TL;DR: In this article, the reaction rate constants of positronium with nitrobenzene have been determined in hexane and benzene solutions as a function of external pressure up to 1000 kg/cm 2.
TL;DR: The Keggin-type heteropoly anions which contain Mo and V as addenda atoms showed a noticeable promoting effect on the catalysis of Pd in the reductive carbonylation of nitrobenzene to form N-phenyl carbamate in the presence of alcohol in dimethoxyethane solvent as discussed by the authors.
Abstract: The Keggin-type heteropoly anions which contain Mo and V as addenda atoms showed a noticeable promoting effect on the catalysis of Pd in the reductive carbonylation of nitrobenzene to form N-phenylcarbamate in the presence of alcohol in dimethoxyethane solvent.
Patent•
03 Jan 1990TL;DR: In this paper, a process for preparing para-aminophenol from nitrobenzene by utilizing electrochemical synthesizing method in high yield for dissolution or dispersion of nitrogen in electrolytic bath in which working electrodes are constituted with multi-rotating disk electrode having a plurality of disk electrode and solid polymer electrolyte electrode.
Abstract: A process for preparing para-aminophenol from nitrobenzene by utilizing electrochemical synthesizing method in high yield for dissolution or dispersion of nitrobenzene in electrolytic bath in which working electrodes are constituted with multi-rotating disk electrode having a plurality of disk electrode and solid polymer electrolyte electrode.
TL;DR: In this article, the interaction of trichloromethylarnes with areneamidoximes was studied in the presence of a solvent at 140-150 °C, leading to the formation of 3,5-diaryl-1,2,4-oxadiazoles.
TL;DR: The first example of a platinum organosol stable to air and aqueous acidic conditions is described in this paper, and the exploitation of its high activity as a practical hydrogenation catalyst is illustrated in the reduction of nitrobenzene.
Abstract: The first example of the synthesis of a platinum organosol stable to air and aqueous acidic conditions is described and the exploitation of its high activity as a practical hydrogenation catalyst is illustrated in the reduction of nitrobenzene.
TL;DR: In this article, the reductive carbonylation of nitrobenzene in ethanol to one exclusive product, phenylurethane, was investigated at mild conditions of 15 atm CO and 160 °C with a turnover rate of 80 mol product per mol catalyst per hour.
TL;DR: In this paper, the copper centers of the heteropolymetallic target family (μ 4 -O)(N,py) 4 Cu 4−x M x X 6 are specifically replaced with M' from M'(NS) n transmetalators by monotransmetalation in nitrobenzene.
Abstract: The copper(II) centers of the heteropolymetallic target family (μ 4 -O)(N,py) 4 Cu 4−x M x X 6 are specifically replaced with M' from M'(NS) n transmetalators by monotransmetalation in nitrobenzene. Here, N is N,N-diethylnicotinamide, py is pyridine, x=1−3, M is Co or Ni(H 2 O), X is Cl or Br, M' is Co, Ni, or Zn, NS is monoanionic S-methyl isopropropylidenehydrazinecarbodithioate, and n=2
TL;DR: In this paper, equilibrium constants were determined at 25°C for the formation of the proton transfer complex between 2,4-dinitrophenol and diethylamine in mixed solvents of benzene and small amounts of the following electron-donating Solvents: nitrobenzene, n -propyl ether, 1,2-dimethoxyethane, tetrahydropyran, and 1,3-dioxalane.