Mixture of water and acetone

The global quantities for the water-acetone system are also included in figure 7.12. It is seen that both the excess Gibbs energies, and the excess volumes for this system are quite large relative to all the systems discussed in the previous subsections. 

The relevant local information is shown in figure 8.17. The results are qualitatively similar to the results of water-ethanol, only the magnitudes of the quantities such as Gww A WA, and A A G(v are much larger in this case. Recently, Perera et al. (2004, 2005) have done an extensive examination of the data for this system obtained by different methods and by different authors. They found large discrepancies in the data from the different sources. 

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When tert-butyl chloride with sodium hydroxide in a mixture of water and acetone, the rate of formation of tert-butyl alcohol is dependent on the concentration of tert- butyl chloride, but is independent of the concentration of hydroxide ion. 

The reaction of cephalosporanic acid (1598) and cyclopenteno(6)pyri-dine in a 3 1 mixture of water and acetone in the presence of potassium iodide and ascorbic acid at 66-68°C for 4 hr gave the pyridiniumceph-3-ene-4-carboxylate derivative (1599) in 14% yield (84GEP3316796). 

Further progress in the field of conformational phase transition in polymer gels, especially in polyelectrolyte gels, was achieved in the paper by Tanaka [4]. He investigated the swelling of polyacrylamide (PAA) networks, which were crosslinked by N,AT-methylenebisacrylamide (BAA), in the mixtures of water and acetone. When the quality of the solvent was made poorer (this happened when the concentration of acetone was increased or the temperature was lowered) shrinking of the samples was observed. Tanaka showed that at certain... 

This behaviour is that expected if the positive effect of the dipolar aprotic solvent on the activity of the hydroxide ion is superimposed on the normal negative effect of an organic solvent, and should be observed also for other dipolar aprotic solvents. In fact this type of behaviour is found for the alkaline hydrolysis of ethyl p-nitrobenzoate in mixtures of water and acetone, which is less polar than dimethyl sulphoxide. Other esters show intermediate behaviour in this solvent259 (Fig. 16). It should be stressed that this represents special... 

The reaction of Dewar pyrimidinone 220 with water in 1 9 mixture of water and acetone at 20°C for 1 hour afforded 4//-pyrido[ 1,2-a]pyrimidin-4-one 108 and enamine 107 in 34% and 64% yields, respectively [89JCS(P1)1231]. Enamine 107 was formed by the cleavage of bond a of 4-hydroxyazetidin-2-one 221, and ring closure of enamine 107 by elimination of water gave 4//-pyrido[l, 2-a]pyrimidin-4-one 108 (Scheme 15). When the solvent polarity was increased, the cleavage of bond b of 4-hydroxyazetidin-2-one 221 also occurred. The reaction in aqueous acetoni-trile-d3 at 35°C for 37 hours gave 4//-pyrido[ 1,2-a]pyrimidin-4-one 109 and lactam 222 in 85% and 10% yields, respectively. The reaction of Dewar... 

The aqueous solution was then decolourized with charcoal and filtered, and the filtrate was neutralized with acetic acid. The precipitated product was separated and purified by crystallization from a mixture of water and acetone. 

Definitive location of all guest molecules inside the cavity is somewhat ambiguous owing to inexact stoichiometry and disorder. However, the (+)-MALDI mass spectra of II indicate that each individual capsule encloses different mixtures of water and acetone. In particular, two peaks implicated the presence of 24 entrapped water molecules that occupy axial coordination sites orientated toward the center of the cavity. 

The compatibility of two components A and B can be influenced by the additicm of a third substance and the corresponding change of the concentraticms of the components. For example, when table salt is added to a homogeneous mixture of water and acetone, a demixing takes place (Experiment 13.5). The reason for this is the low compatibility of the components which increases with the salt content of the water. 

Vesicles can also be composed of inorganic building blocks. A recent report shows that polyoxometallates can form stable vesicles in a mixture of water and acetone." In this case, vesicles assembled from a hybrid of two anionic polyoxometallate clusters linked by a bifunctional organic hgand in the presence of tetra-n-butylammonium counterion. 

Let us now consider another mechanism for nucleophilic substitution the SnI reaction. When tert-butyl chloride reacts with sodium hydroxide in a mixture of water and acetone, the kinetic results are quite different than for the reaction of chloromethane with hydroxide. The rate of formation of tert-butyl alcohol is dependent on the concentration of tert-butyl chloride, but it is independent of the concentration of hydroxide ion. Doubling the tert-butyl chloride concentration doubles the rate of the substitution reaction, but changing the hydroxide ion concentta-tion (within limits) has no appreciable effect tert-Butyl chloride reacts by substitution at virtually the same rate in pure water (where the hydroxide ion is 10 M) as it does in 0.05M aqueous sodium hydroxide (where the hydroxide ion concentration is 500,000 times larger). (We shall see in Section 6.10 that the important nucleophile in this reaction is a molecule of water.)... 

It has already been noted that a Raman analyzer can be useful for studying liquid distillation products [30,32,83], The flexibility afforded by the use of fiber-optic sampling probes allows for composition measurement of either vapor-phase materials directly on the distillation tower or the distillation liquid as it is being removed from the tower. A proof of concept example of this type has been shown by Pelletier [107] for a test mixture of water and acetone. 

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