Nitrobenzene solvent

When we previously investigated the potentiometric properties of carefully purified plasticizers of low polarity, no EMF responses were observed, whereas for a more polar solvent (nitrobenzene), transient EMF responses were obtained [55,59]. Because of this large difference, we were also interested in the combined SHG and EMF response of more polar ion-exchanger membranes. As previously, we used nitrobenzene for this purpose. 

The last experimental work was aimed at measuring the propagation rate-constant, kp, for various monomers under the ideal conditions which, it was hoped, would be provided by the solvent nitrobenzene. This was frustrated by the complexing of the propagating carbenium ions with the solvent but the mechanistic insight resulting from a detailed examination of the results provided useful new understanding of previously unexplained anomalies. 

Consider the extraction of K from aqueous solution into the organic solvent nitrobenzene by addition of NaPh4B. Abbreviating PlqB by K, the extracted complex is the ion pair K AL In an inert solvent this is a stable ion pair, but in a highly polar solvent tike nitrobenzene, the ion pair may dissociate. 

Similar but even more pronounced anionic effects were observed with liquid membranes based on ionophore 80 and exhaustively purified organic solvents (nitrobenzene or 1,2-dichloroethane) but no polymer matrix. The use of such membranes allows to minimize the concentration of ionic impurities that could take the role of anionic sites. For a membrane with ionophore 80, the SHG response... 

Fig. 8. Effect of photoirradiation on the polymerization of VCZ initiated by NaAuClj 2H20 at 30° C,in the presence of air. Solvent nitrobenzene. [VCZ] = 0.25 M, [AunlJ = 1.0 x 10- M. (1) (- -) time-conversion, polymerization in the dark (2) (-o-) time-conversion, a hard glass, cylindrical polymerization vessel was irradiated by a 300 W mercury lamp from a distance of 28 cm (3) (-O-) polymerization time-molecular weight, polymerization in dark...

Here the equilibrium would be expected to lie further to the right hand side since CIO is much less nucleophilic than I , and a faster polymerisation to higher molecular weight polymer should result. In a more polar solvent nitrobenzene, the effect is very much reduced presumably because the initial iodide equilibria are themselves pushed further towards the right hand side. 

Fig. I. Polymerization of DL-leucine carbonic anhydride, initiated by preformed polymer. , solvent, nitrobenzene, 45°C X, o-nitroanisole, 45° C O, nitrobenzene, 25.2° C A, o-nitroanisole, 25.0 C. [Reprinted from D. G. H. Ballard and C. H. Bamford Proc. Roy. See. A 223, 495 (1954) (Fig- 4)]...

Large discrepancies were found in applying the treatment to the Friedel-Crafts benzoylation of the methylbenzenes in nitrobenzene solution (Brown et al., 1958a). It was suggested that these difficulties arose from the formation of ternary complexes of aluminum chloride, the aromatic hydrocarbon, and the solvent nitrobenzene. This notion was tested by a study of the total and positional rates of acetylation... 

Solvent Nitrobenzene o-Nitroanisole Nitrobenzene Nitrobenzene Dioxan... 

Nitrobenzene has been used for electrolysis [402] it was found that certain radicals were rather stable in this solvent. Nitrobenzene has a liquid range from 5.7 to 210.9°C BU4NCIO4 may be used as supporting electrolyte. An aqueous SCE separated from the solution by a suitable bridge with porous glass has been used as reference electrode. Nitrobenzene may be purified by passing it through a column of alumina followed by a distillation in vacuo. 

Molecular motion in the polar organic solvent nitrobenzene, induced by both continuous and pulsed electronic fields, was studied by magnetic resonance imaging. The resultant image correlation spectra indicate that the time scale of motion in a 9.6 kV cm electric field is tens of milliseconds. The data were analyzed by the Fokker-Planck probability function for one-dimensional bounded diffusion. 

With increasing temperatures the value of equilibrium concentration must rise, a finding shown by the measurement of W - [M]0 dependence at different temperatures in two solvents nitrobenzene and chlorobenzene. From these data the heats of dissolved monomer - dissolved polymer transition were estimated in34, 36, 37 ... 

Table 7.11. Calculated concentration of monomers in equilibrium with polyoxymethylene solvent nitrobenzene, temp. = 25 °C...

Finally, Figure 5 shows values of the variation of Henry s constant for carbon monoxide in the mixed solvent nitrobenzene-benzene at 298 K. The binary parameters were chosen so that correct values were obtained for H12 when using H1Z and for H1Z when using H12 in the integrations of Equation 19. 

The PVC/polypyrrole blends have been realised by in situ growth of the polypyrrole in a PVC solution in an organic solvent (nitrobenzene, THF, or cyclopenta-... 

The kinetics of addition of nitrosyl chloride to a number of olefins have been examined. In chloroform, methyl and phenyl substituents enhance the rate while electron-withdrawing groups (e.g. chlorine) retard it. Such be-haviour would be consistent with electrophilic attack by the dipole NO-CP. The effect of changes in the solvent was not simple, although more polar solvents (nitrobenzene, chloroform) speeded the reaction (compared with toluene or carbon tetrachloride). Methanol appeared to be a remarkably poor reaction medium, perhaps due to interaction with the reactant the low reactivity of nitrosyl chloride in diethyl ether was attributed to strong bonding between the solvent and the incipient NO cation. 

Values of 4G°r,torr are given in Tables 6 and 7. It may be seen that 4G°r is overestimated by the truncated SL model and that the apparent correction G°r,corr vaHes with solvent. Thus, the unsymmetric term zlGl.unsym appears to depend on the solvent, which would intuitively follow if orientational effects are dominant. For a single solvent, nitrobenzene. Table 7 shows that the truncated SL model again overestimates AG°r for the alkali metal cations Na -Cs, but in this case 4G r.corr is approximately a constant, - 10 3 kj/mol. 

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