Methyl acetate dielectric constant

Colorless gas pungent suffocating odor gas density 2.927 g/L at 20°C heavier than air, vapor density 2.263 (air=l) condenses to a colorless liquid at -10°C density of liquid SO2 1.434 g/mL freezes at -72.7°C critical temperature 157.65°C critical pressure 77.78 atm critical volume 122 cc/g dielectric constant 17.27 at -16.5°C dissolves in water forming sulfurous acid, solubility 22.97 g and 11.58 g/lOOmL water at 0° and 20°C, respectively, under atmospheric pressure very soluble in acetone, methyl isobutyl ketone, acetic acid, and alcohol soluble in sulfuric acid liquid SO2 slightly miscible in water. 

The effect of the medium on the rates and routes of liquid-phase oxidation reactions was investigated. The rate constants for chain propagation and termination upon dilution of methyl ethyl ketone with a nonpolar solvent—benzene— were shown to be consistent with the Kirkwood equation relating the constants for bimolecular reactions with the dielectric constant of the medium. The effect of solvents capable of forming hydrogen bonds with peroxy radicals appears to be more complicated. The rate constants for chain propagation and termination in aqueous methyl ethyl ketone solutions appear to be lower because of the lower reactivity of solvated R02. .. HOH radicals than of free RO radicals. The routes of oxidation reactions are a function of the competition between two R02 reaction routes. In the presence of water the reaction selectivity markedly increases, and acetic acid becomes the only oxidation product. 

When C4H80 is diluted by water to 80 volume %, the only product of C4H80 oxidation is acetic acid (99% per methyl ethyl ketone reacted) formed by ketone hydroperoxide conversion. The reason for this increase in the reaction selectivity is that the rate of decomposition of the radical complex R02. . . HOH is lower than that of free R02, while the decrease in the rate of reaction of R02. . . HOH with methyl ethyl ketone is somewhat offset by the higher dielectric constant of the medium. 

Activity Coefficient of a Dipolar Molecule. Our first application will be to the activity coefficients of a dipolar molecule as a function of the dielectric constant of the solvent. Harned and Ross (14) have determined the activity coefficient of methyl acetate in dioxane-water mixtures of various compositions at 25°C. Equation 32 can be applied to this data, and since the particles have no ionic charges, the first term can be omitted. For the difference between the activity coefficients of methyl acetate in dioxane-water mixtures and those in water we have from Equation 32... 

FIGURE 10. Relative quantum yields for exciplex fluorescence (filled symbols) and addition product formation (open symbols) versus solvent dielectric constant for trans-stilbene with di isopropyl methyl amine (0)> ethyldiisopropylamine (A), and triethylamine ( ) in hexane-ethyl acetate and ethyl acetate-acetonitrile mixed solvents. From ref. (114) with permission of the American Chemical Society. 

Catalytic supercritical water oxidation is an important class of solid-catalyzed reaction that utilizes advantageous solution properties of supercritical water (dielectric constant, electrolytic conductance, dissociation constant, hydrogen bonding) as well as the superior transport properties of the supercritical medium (viscosity, heat capacity, diffusion coefficient, and density). The most commonly encountered oxidation reaction carried out in supercritical water is the oxidation of alcohols, acetic acid, ammonia, benzene, benzoic acid, butanol, chlorophenol, dichlorobenzene, phenol, 2-propanol (catalyzed by metal oxide catalysts such as CuO/ZnO, Ti02, MnOz, KMn04, V2O5, and Cr203), 2,4-dichlorophenol, methyl ethyl ketone, and pyridine (catalyzed by supported noble metal catalysts such as supported platinum). ... 

Extraction of micro-amounts of Ga" by a number of reagents (butyl acetate, isobutyl methyl ketone, etc.) is suppressed by the addition of macro-amounts of Sb or Sb. The extent of the suppression increases with increasing dielectric constant of the organic solvent. ... 

The rates increase with increasing dielectric constant, and H20+Br is the reactive oxidant species. The oxidation of [2-(2- 4-[(4-chlorophenyl)(phenyl)methyl]-l-piperazino ethoxy) acetic acid dihydrochloride (CTZ) by BAT in HCl has a negative fractional dependence in H+ ion, and the rates decrease with increasing dielectric constant of the solvent. CH3C6H5S02NHBr is the reactive BAT species. " The oxidation of cetrizine dihydrochloride (CTZH) with BAT has been investigated both in acid and alkaline medium. A negative fractional order in H+ ion and positive fractional order in HO ion are reported, accompanied by a fractional order in CTZH in both acidic and alkaline media. The rate increases with increasing dielectric constant of the solvent. The reaction in alkaline medium has fractional order in p-toluenesulfonamide (PTS). The oxidation rate of CTZH is faster in acid medium and 4-chlorobenzophenone and (2-piperazine-l-yl-ethoxy)-acetic acid are the oxidation products. ... 

The deaminations of fra 5-2-phenyl- and frans-2-methyl-cyclopropylamine hydrochlorides in acetic acid solution have been examined. The relative amounts of the various products are shown in (26)-(29) and (30)-(33), respectively. The most remarkable feature of these results is the formation of considerable quantities of ring-opened chlorides, which are scarcely formed in deaminations of related open-chain compounds. The addition of chloride ion led to a marked increase in the amount of chloride product. These and other results are interpreted in terms of the formation of a cyclopropyl-diazonium-chloride tight ion pair. The reactions were successfully modelled by ab initio calculations at the B3LYP/6-31G level, including a reaction-field solvent-effect calculation using the dielectric constant of acetic acid. 

Even if these early observations are now explained differently, a high transient plume density is expected, as described above. The model runs into difficulty mainly in that plume properties are not sufficiently polar for extensive ion separation. Liquid, substituted aromatics somewhat similar to MALDI matrices typically have dielectric constants around or below 10 at room temperature (phenol 9.8, methyl salicylate 9.4, acetic acid 6.1). " In addition, at least a factor-of-two decrease could be expected at MALDI plume temperatures. For example, 1-butanol has a dielectric constant of 15 at room temperature, but 7 at 400°C. " Assuming the MALDI plume is a similarly solvating fluid, separation of ionic substances (including matrix itself) will be extremely limited. 

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