Ammonium bromide tetraethylammonium salts

The data in Tables I-XVI (see Appendix for all tables) show the isobaric vapor-liquid equilibrium results at the boiling point for potassium, ammonium, tetramethylammonium, tetraethylammonium, tetra-n-propylammonium, and tetra-n-butylammonium bromides in various ethanol-water mixtures at fixed liquid composition ratios. The temperature, t, is the boiling temperature for all solutions in these tables. In all cases, the ethanol-water composition was held constant between 0.20 and 0.35 mole fraction ethanol since it is in this range that the most dramatic salt effects on vapor-liquid equilibrium in this particular system should be observed. That is, previous data (12-15,38) have demonstrated that a maximum displacement of the vapor-liquid equilibrium curve by salts frequently occurs in this region. In the results presented here, it should be noted that Equation 1 has been modified to... 

Quaternary ammonium salts exhibit high catalytic activity in radical-chain reactions of hydrocarbons liquid phase oxidation by [1, 2]. Tetraalkylammonium halides accelerate radical decomposition of hydroperoxides [3,4] that are primary molecular products of hydrocarbons oxidation reaction. Reaction rate of the hydroperoxides decomposition in the presence of quaternary ammonium salts is determined by the nature of the salt anion [4] as well as cation [5]. The highest reaction rate of the tert-butyl hydroperoxide and cumene hydroperoxide decomposition has been observed in the case of iodide anions as compared with bromide and chloride ones [4]. tetraalkylammonium bromides tetraethylammonium... 

An examination of Figures 1-6 indicates that Equation 1 is valid under conditions of constant x for potassium, ammonium, and tetramethylammonium bromides in ethanol-water mixtures. All three salts show an ability to salt out ethanol from these mixtures (i.e., increase its concentration in the equilibrium vapor) which is verified by their k values shown in Table XVIII. Also, the results for tetra-n-propylammonium bromide and tetra-n-butylammonium bromide in ethanol-water mixtures reveal that Equation 1 can be used to predict the salt effects of these systems however, these two salts demonstrate a propensity to salt in ethanol (i.e., decrease its vapor concentration) in ethanol-water mixtures. On the other hand, Figures 7-9 and the data in Table XVIII reveal that Equation 1 cannot be used to correlate the salt effects of tetraethylammonium bromide in ethanol-water. For this system, a linear dependence of log aja vs. z is observed initially however, a gradual levelling off occurs at higher concentrations. 

Tetraethylammonium bromide Reactions of oxido compounds catalyzed by quaternary ammonium salts 1,3-Dioxolanes from aldehydes... 

Thus, the elucidation of the reaction pathways requires taking into account many parameters and makes the investigation of other peroxide compounds reactivity a justified task. To get more information on the reaction scope and limitations, we studied aralkyl hydroperoxides reactivity in the presence of quaternary ammonium salt. The analysis of the data obtained earlier enabled us to eonsider tetraethylammonium bromide the appropriate eatalyst to study aralkyl hydroperoxides reactivity. 

In the case of complex formation peroxide geometry and electron structure changes bring it to the configm-ation close to that of transition state. Complex decomposition proceeds through oxyradical formation and ammonium salt regeneration. Assumed mechanism of cyclohexanone peroxides decomposition in the presence of tetraethylammonium bromide can be regarded as one of the supramolecular reactions [21]. 

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