Nitromethane conductances

THE STATE OF NITRIC ACID IN INERT ORGANIC SOLVENTS The absence of ions in mixtures of acetic acid and nitric acid is shown by their poor electrical conductivity and the Raman spectra of solutions in acetic acid, nitromethane, and chloroform show only the absorptions of the solvent and molecular nitric acid the bands corresponding to the nitronium and nitrate ions cannot be detected. -... 

Fractional crystn was more effective than fractional distn from Drierite in purifying nitromethane for conductivity measurements. [Coetzee and Cunningham J Am Chem Soc 87 2529 7965.] Specific conductivities around 5 x 10 ohm em were obtained. 

As noted above, there is no physical evidence for this equilibrium in pure N2O4, but the electrical conductivity is considerably enhanced when the liquid is mixed with a solvent of high dielectric constant such as nitromethane (e 37), or with donor solvents (D) such as MeC02Et, Et20, Mc2SO, or Et2NNO (diethylnitrosamdne) ... 

Besides complexes of thiosemicarbazones prepared from nitrogen heterocycles, iron(III) complexes of both 2-formylthiophene thiosemicarbazone, 26, and 2-acetylthiophene thiosemicarbazone, 27, have been isolated [155]. Low spin, distorted octahedral complexes of stoichiometry [Fe(26)2A2]A (A = Cl, Br, SCN) were found to be 1 1 electrolytes in nitromethane. Low spin Fe(27)3A3 (A = Cl, Br, SCN) complexes were also isolated, but their insolubility in organic solvents did not allow molar conductivity measurements. Infrared speetra indicate coordination of both via the azomethine nitrogen and thione sulfur, but not the thiophene sulfur. The thiocyanate complexes have spectral bands at 2065, 770 and 470 cm consistent with N-bonded thiocyanato ligands, but v(FeCl) and v(FeBr) were not assigned due to the large number of bands found in the spectra of the two ligands. 

The infrared spectra suggest bidentate dithiocarbamate coordination, the magnetic susceptibility is markedly field-dependent. Although the compound is monomeric in CHCI3, a molar conductance in nitromethane is found, which increases sharply on dilution, attributed to a weak electrolytic character. Accordingly, the authors formulate this compound as [Nb2(Et2r/tc)sBr2]Br. 

The reaction of a carboxylic acid with N,Af -carbonyldiimidazolellH33 (abbreviated as CDI), forming an imidazolide as the first step followed by alcoholysis or phenolysis of the imidazolide (second step), constitutes a synthesis of esters that differs from most other methods by virtue of its particularly mild reaction conditions.t41,[5] It may be conducted in two separate steps with isolation of the carboxylic acid imidazolide, but more frequently the synthesis is carried out as a one-pot reaction without isolation of the intermediate. Equimolar amounts of carboxylic acid, alcohol, and CDI are allowed to react in anhydrous tetrahydrofuran, benzene, trichloromethane, dichloromethane, dimethylformamide, or nitromethane to give the ester in high yield. The solvents should be anhydrous because of the moisture sensitivity of CDI (see Chapter 2). Even such unusual solvent as supercritical carbon dioxide at a pressure of 3000 psi and a temperature of 36-68 °C has been used for esterification with azolides.[6]... 

Relatively few attempts have been made to demonstrate the presence of ions in the polymerization of styrene, the most extensively studied of all monomers. Pepper [11] made conductivity studies on stannic chloride solutions in various solvents with and without monomer and added water, using open systems. He concluded that his results shed little light on the question of whether chain-carrying cations were present (which, indeed, he presumed) or on their concentration. Brown and Mathieson [12] found that for the polymerization of styrene by chloroacetic acids in nitromethane, the conductivity was indistinguishable from zero when no water was added, although the reaction rate was appreciable, and with increasing amounts of added water the conductivity increased, but the polymerization rate decreased. Therefore their results gave no useful information on the question of the participation of carbonium ions. 

Conductance studies of Li+ and Na+ in Acetonitrile and Nitromethane binary mixtures at 298.15 K... 

To minimize the effects of viscosity for purposes of comparing data between solvents, plots areoften made using the product of the ion mobility and the viscosity (Walden product) in place of mobility alone. A plot of the Walden product against the reciprocal of the crystallographic radii for several solvents is shown in Fig. 6. Arbitrary curves have been drawn to indicate general trends. Values in solvents for which precise transference numbers and conductance data are available, such as acetonitrile and nitromethane, give smooth curves. 

The conductivities of thorium (III) and uranium (IV) halides in nitromethane are increased in the presence of a donor molecule from chloride to iodide and they also increase with increasing donicity of the neutral donor 49-53)... 

Electric conductance measurements have been widely used in the study of lanthanide complexes to determine the nature of the anions in the complexes and hence to indicate the possible coordination number of the lanthanide ion. Water is a strong donor toward the lanthanides and is seldom used for the purpose of measuring electric conductance, since the complex is completely dissociated on dissolution in water. The complete dissociation of lanthanide complexes in water has been shown by molecular weight determinations in water as in the case of the complexes of DMSO (246,249, 250), PyO (147,157,158), and DMF (41, 43). Most useful data are obtained in non-aqueous solvents like nitromethane, acetonitrile, nitrobenzene, and acetone (317). 

The monomeric complexes of OMPA, Ln(0MPA)2(N03)3, in nitromethane and methylene chloride, show conductance values in the range intermediate between that... 

Complexes of the type Ln(TMSO)3 Cl3 are nonelectrolytes in nitromethane, indicating the coordination of all the chloride ions to the lanthanide ion (262). In methanol, however, these complexes behave as 1 1 electrolytes. The variation of molar conductance values with concentration of the Dy(III) complex in methanol was studied. The data indicate that at higher concentrations the complex behaves as a nonelectrolyte while at lower concentrations dissociation sets in and the complex behaves as a 1 1 electrolyte. 

The first report of an enantioselective organocatalytic [3+2] cycloaddition between nitrones and a,P-nnsaturated aldehydes was reported by MacMillan and co-workers who showed that iminium ion activation was effective in this reaction (Scheme 8) [64], After a survey of seven catalysts the imidazolidinonium salt 12 HC10 emerged as the most efficient system. The reactions were conducted in a mixture of nitromethane and water at -20 °C in the presence of 20 mol% catalyst... 

Detonotion, Flash-Across, Heat Pulse and Hypervelocity Phenomena. According to Cook (Ref 3), the phenomenon of heat pulse was first recognized by Dr W.S. McKewan of NOTS, China Lake, Calif while viewing microsecond, color, framing photographs of Nitromethane (NM) detonated thru SPHF (shock-pass-heat-filter) glass plates in experiments conducted by D.H. Pack,... 

D. L. Chapman, for potassium tri-iodide. 0. Gropp measured the effect of temp, on the conductivity of solid and frozen soln. of sodium iodide. For the effect of press, on the electrical properties, vide alkali chlorides. A. Reis found the free energy for the separation of the ions of K1 to be 144 lrilogrm. cals, per mol. for iN al, 158 Lil, 153 and for HI, 305. S. W. Serkofi 35 measured the conductivity of lithium iodide in methyl alcohol P. Walden, of sodium iodide in acetonitrile P. Dutoit in acetone, benzonitrite, pyridine, acetophenone. J. C. Philip and H. R. Courtman, B. B. Turner, J. Fischler, and P. Walden of potassium iodide in methyl or ethyl alcohol J. C. Philip and H. P. Courtman in nitromethane P. Dutoit in acetone. H. C. Jones, of rubidium iodide in formamide. S. von Lasczynsky and S. von Gorsky, of potassium and sodium iodides in pyridine. A. Heydweiller found the dielectric constants of powdered and compact potassium iodide to be respectively 3 00 and 5 58. 

VISCOSITIES, ELECTRICAL CONDUCTIVITIES, REFRACTIVE INDEXES AND DENSITIES OF BINARY IIQUID SYSTEMS OF SULPHURIC ACID WITH NITROMETHANE, NITROBENZENE AND o-, m- AND //-NITROTOLUENE... 

Abstract—The viscosities, electrical conductivities, densities and refractive indexes of the binary systems of sulphuric acid with nitromethane, nitrobenzene and o-, m- and p-nitrotoluene have been investigated at 25° and 40°C. It has been shown that the forma tion of addition compounds according to the equation ... 

The investigation of viscosities, electrical conductivities, refractive indexes and densities of binary liquid systems of sulphuric acid with nitromethane, nitrobenzene and 0-, m and p-nitrotoluene was made in order to obtain a clearer picture of the behaviour of these binary mixtures, regarding the stability of the addition compounds formed between the components. The application of these methods of physicochemical analysis to a number of binary systems with sulphuric acid [1, 2, 3] has enabled us to get some idea of the way in which the formation and stability of addition compounds affects the liquid phase properties of these systems. The binary systems of sulphuric acid with mononitrocompounds are particularly suitable for comparison with each other, because of the close similarity of the liquid media in these systems, due to comparable values of dielectric constants and liquid phase properties of the mononitrocompounds. The stability of the addition compounds in these systems in the crystalline phase [4] has... 

The methods of measuring the liquid phase properties were described previously [1], It was observed that heat was evolved during the preparation of all these mixtures. It should be mentioned that the electrical conductivities of the sulphuric acid-nitromethane mixtures were not constant, but were found to increase with time. Reliable data could therefore not be obtained. This is due to the fact that nitromethane reacts with sulphuric acid in dilute solutions, as has been recently discussed by Gillespie and Solomons [6]. All other properties of these mixtures were constant at 25° and measurements were restricted to this temperature. For the other four systems the viscosity, electrical conductivity and density were investigated at two temperatures 25° and 40°), because of the importance of the temperature coefficients of viscosity and electrical conductivity. The refractive indexes were measured only at 25°. The investigation of the liquid phase properties of the system with p-nitro toluene at these temperatures was possible only up to 50 mole % of p-nitrotoluene, i.e. until the solutions became saturated with respect to p-nitrotoluene. The refractive indexes of these solutions were not measured. 

Tris(organoseleninate) complexes have been synthesized and, in DMF or nitromethane, are non-conducting.261 The ligands act as bidentate 0,0 -seleninate and the complexes have an octahedral configuration with Z>3 symmetry. 

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