Conductances of Some Quaternary Ammonium Bromides and Iodides in Dimethylformamide at 25°

Abstract

The conductances of several quaternary ammonium bromides and iodides in dimethylformamide have been measured at 25°. In each case, the observed slope of the plot of the equivalent conductance versus the square root of the concentration was more negative than that predicted by the Onsager equation. Limiting equivalent conductances and dissociation constants have been determined by the Shedlovsky extrapolation method. The quaternary ammonium halides being dissociated to a lesser extent than some potassium and sodium halides is strong evidence that the latter cations are rather highly solvated in dimethylformamide. Bromides were found to be 1.6 ± 0.1 ohm-1 cm.2 more conducting than the corresponding iodides. Data are presented showing that the ratio of the conductance in acetone to that in dimethylformamide is 2.32 ± 0.09 for each of seventeen salts.

Hydrogen reduction of .mu.3-oxo-triruthenium(III) acetate in dimethylformamide

“…Further evidence for the formation of a hydride species during the first stage of reduction was obtained from experiments in which the addition of protons (i.e., HC104) in the absence of air caused re-formation of the starting oxotriruthenium(III) complex and quantitative evolution of bonds by reaction with dissociated acids is well documented.12 Such reactions with acid usually result in complete displacement of the hydride ligand by the anion of the acid or by another complexing agent present in solution. For example, the hydridochlororuthenium(II) carbonyl complex, HRuCl-(CO)(Me2PPh)3, reacts with nitric acid in ethanol as shown in reaction 6.13 In the present system, the oxotrirutheni-HRuC1(CO)((CH3)2P(C6H5))3 + hno3 -RuC1(N03)(C0)((CH3)2P(C6H5))3 + H2 (6) um(III) complex probably re-forms via the nonbridging acetate becoming a bridging ligand and the perchlorate species functioning as the anion for the oxotriruthenium species. Addition of perchloric acid to the initial oxdtriruthenium(III) acetate compound results in formation of [Ru30-(OCOCH3)6(DMF)3] [C104] as does such addition for the analogous oxotrirhodium(III) acetate.…”

“…TableIII. Products of the Hydrogen Reduction of Mj-Oxo-trirutheniumflll) Acetate in DMF at 80 mol of H2/mol of Ru3 6. mol of CH3COOH/mol of Ru3.…”

Octahedral cobalt(III) complexes in dipolar aprotic solvents. XII. Ion association studies in N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide by conductance measurements

“…That the present set of constants are extraordinarily high is more clearly shown by comparison of these results with KlP values determined for other salts in these solvents. 26 Sears, Lester, and Dawson26 have studied a wide range of simple 1:1 electrolytes in DMSO and find all salts "to be completely dissociated." Sears, et association constants were 37 and 16 in DMF and that AfIP for Et4N+Br~in DMA was 20.…”

Conductance of tetraalkylammonium halides in ethylene glycol

“…These salts (Eastman Kodak) had been recrystallized from mixtures of methanol and ether, or acetone and ether, and then dried for 12 hr in a vacuum oven at 65°. We dried the salts in a vacuum oven for an additional 12 hr at 65°before we used them.…”