Acetone

About: Acetone is a research topic. Over the lifetime, 9458 publications have been published within this topic receiving 120867 citations. The topic is also known as: propanone & dimethylketone.

Solubility of carbon dioxide in acetone and propionic acid at temperatures between 298 K and 333 K

Abstract: The solubility of carbon dioxide in organic solvents acetone and propionic acid has been measured with an analytical method. The composition and the density of the liquid phase in the binary vapor−liquid equilibrium have been investigated at (313 and 333) K (for the system carbon dioxide + acetone) and at (298, 313, and 333) K (for the system carbon dioxide + propionic acid) at pressures up the binary critical pressure. The experimental results for the phase equilibrium have been correlated with the Peng−Robinson EOS applying several mixing rules.

Switch-over in photochemical reaction mechanism from hydrogen abstraction to exciplex-induced quenching: interaction of triplet-excited versus singlet-excited acetone versus cumyloxyl radicals with amines.

Abstract: The fluorescence and phosphorescence quenching of acetone by 13 aliphatic amines has been investigated. The bimolecular rate constants lie in the range of 108−109 M-1 s-1 for singlet-excited acetone and 106−108 M-1 s-1 for the triplet case. The rate data indicate that a direct hydrogen abstraction process dominates for triplet acetone, while a charge-transfer mechanism, namely, exciplex-induced quenching, becomes important for singlet-excited acetone. Pronounced stereoelectronic effects toward H abstraction, e.g., for 1,4-diazabicyclo[2.2.2]octane (DABCO), and significant steric hindrance effects, e.g., for N,N-diisopropyl-3-pentylamine, are observed. A negative activation energy (Ea = −0.9 ± 0.2 kcal mol-1 for triethylamine and DABCO) and the absence of a significant solvent effect on the fluorescence quenching of acetone are indicative of the involvement of exciplexes. Full electron transfer can be ruled out on the basis of the low reduction potential of acetone, which was found to lie below −3.0 V vers...

Aldol-condensation of furfural by activated dolomite catalyst

Abstract: Aldol-condensation of furfural with acetone catalysed by activated dolomite was investigated at temperatures from 306 to 413 K. The process of activation by calcination and hydration produced catalytically active calcium and magnesium hydroxides with improved surface area and surface basicity. The aldol-condensation mechanism began with a deprotonation of acetone forming a carbanion intermediate by hydroxyl ions, which then reacted with the carbonyl group of furfural to form a water soluble C8 monomer (4-(furan-2-yl)-4-hydroxybutan-2-one). This C8 monomer readily dehydrated to form selectively α,β-unsaturated ketone (4-(2-furyl)-3-buten-2-one), which in turn, reacted with furfural forming a C13 dimer (1,4-pentadien-3-one,1,5-di-2-furanyl). Compared with conventional sodium hydroxide catalyst, activated dolomite was less selective towards lumped C8 monomers and C13 dimers owing to carbon losses and deactivation, particularly at high temperatures. Activated dolomite was more selective to C13 dimer owing to higher adsorption enthalpy of C8 monomer compared with acetone competitor. Activated dolomite is therefore a promising catalyst to produce C13 dimers which can be transformed upon hydrogenation and deep hydrodeoxygenation in high-quality diesel fuels. The first-order kinetic model with respect to furfural and acetone fitted well with actual experimental results with an average normalised standard deviation of 6.2%.