Acetone solvent properties

Salts and Derivatives. Generally the vitamers are high melting crystalline soHds that are very soluble in water and insoluble in most other solvents. Properties of the common forms are Hsted in Table 1. The only commercially important form of vitamin B is pytidoxine hydrochloride (7). This odorless crystalline soHd is composed of colorless platelets melting at 204—206°C (with decomposition). In bulk, it appears white and has a density of - 0.4 kg/L. It is very soluble in water (ca 0.22 kg/L at 20°C), soluble in propylene glycol, slightly soluble in acetone and alcohol (ca 0.014 kg/L), and insoluble in most lipophilic solvents. A 10% water solution shows a pH of 3.2. Both the hydrochloride and corresponding free base sublime without decomposition (16). 

This preparation illustrates a general and convenient way of oxidizing secondary alcohols to ketones. The novel feature of the reaction is represented by acetone solvent which affects markedly the properties of the oxidizing agent. The reaction is very rapid (if not instantaneous), and the yields are high, the reagent rarely attacking unsaturated centers. The procedure is applicable to acetylenic carbinols, allyl and other unsaturated alcohols, and saturated carbinols. The main limitation is the low solvent power of acetone. 

The most useful solvents are diethyl ether and acetone, and pentane and cyclohexane are amongst the best precipitants, i.e. worst solvents. It is not widely known that amongst hydrocarbons the lower the molar mass, the worse are the solvent properties, and there is a distinct difference in this respect between, say, pentane and heptane. 

In a consumer sense, propanone is the most familiar ketone its common name is acetone. The flammability and odor associated with acetone are properties that are common among ketones. They are also generally good solvents—that is often their industrial purpose. 

However, the direct ionization of the analyte is generally characterized by a weak efficiency. This can be partially explained by the solvent property to absorb photons producing photoexcitation without ionization. This reduces the number of photons available for the direct ionization of the sample, thus reducing the ionization efficiency. Consequently, ionization using doping molecules has also been described. It has indeed been shown that dopant at relatively high concentrations in comparison with the sample allows generally an increase in the efficiency of ionization from 10 to 100 times. This indicates that the process is initiated by the photoionization of the dopant. The dopant must be photoionizable and able to act as intermediates to ionize the sample molecules. The most commonly used dopants are toluene and acetone. Thus, two distinct APPI sources have been described direct APPI and dopant APPI. 

Important solvent properties are volatility, viscosity, surface tension, and lipid solubility. The first three determine the area over which a given volume of solvent spreads the larger the area of contact between insecticide and outer cuticle layers, the larger its total penetration rate will be. Acetone does not spread very far from the site of application, because it is so volatile. Lipid solubility affects the dissolution of the wax components of the epicuticle. By disrupting this layer, e.g., depositing a drop of acetone, the insecticide could bypass the epicuticular barrier. All these effects together may explain why an optimal balance of solvent properties is necessary to obtain maximal penetration rates (Welling and Patterson, 1985). 

The systematic names of a/dehydes end in -al the systematic names of keto cs end in -one. The simplest ketone, propanone, known familiarly as acetone, has three carbon atoms. Because of its solvent properties, acetone is used in nail polish remover. The simplest aldehyde, methanal, also known as formaldehyde, is perhaps most familiar because it was formerly routinely used as a preservative for biological specimens. 

Ketones often have useful solvent properties (acetone is found in nail polish remover, for example) and are frequently used in industry for this purpose. Aldehydes typically have strong odors. Vanillin is responsible for the pleasant odor in vanilla beans cinnamaldehyde produces the characteristic odor of cinnamon. On the other hand, the unpleasant odor in rancid butter arises from the presence of butyraldehyde. 

Methyl ethyl ketone (bp 80°) has excellent solvent properties similar to acetone and has the advantage of a somewhat higher boiling point. The methods of purification applicable to acetone may be used with this ketone also. 

A study of the effect of solvent on the insertion reaction of (lb) with cis-1,2-dimethylcyclohexane shows that the reaction occurs faster in solvents with greater hydrogen bond donor capacity <94JCS(P2)45l>. The rates of the insertion reaction in several binary solvents (acetone plus a second solvent) were measured and treated with a multiparameter empirical solvent equation. This correlation indicated that, of the several solvent property parameters contained in the equation, solvent donor capacity was the most influential. 

When the substrate and oxidized product tolerate hydrolytic conditions, the oxidation can be performed in situ. For this purpose we have found it advantageous to employ 2-butanone [5] instead of acetone as source of the dioxirane. Because of its partial solubility in water and excellent solvent properties no cosolvents such as CH2C12 or C6H6 are required. For convenience, in Table 2, we have summarized the reaction conditions and variables used for the dioxirane oxidations in the isolated and in situ modes. 

The rise of the synthetic organic chemical industry has required an ever increasing share of solvents for use as chemical intermediates where solvency and other traditional solvent properties are immaterial. Examples include use of acetone for... 

Render in an address before the Division of Industrial and Engineering Chemistry at the 64th meeting of the American Chemical Society at Pittsburgh, Sept., 1922, said, The excellent solvent properties of acetone have established its useful application in many industries notwithstanding the fact that data relative to its value as a solvent are widely disseminated in the literature and are also sometimes indefinite. The large quantities of this solvent used during the World... 

War, in the manufacture of cordite and airplane dope exceeded the production from calcium acetate, with the result that new methods for its manufacture were developed. At the present time the supply of the chemical is greater than the demand, and consequently there has been a drop in price. The availability of acetone in any quantity at a reasonable cost, together with its technically important solvent properties, has suggested consideration to the extension of its present applications and to finding new uses for it in industry. ... 

The extreme solvent sensitivity of the exciplex fluorescence is very interesting. Fullerene-amine exciplex emissions observed in saturated hydrocarbon solvents are absent in solvents such as benzene and toluene (27,84,88,101), which has been explained in terms of solvent polarizability effects [101]. However, there has also been an explanation [84] that the formation of exciplexes in a solvent such as benzene is hindered by specific solute-solvent interactions that result in complexation between the fullerene and solvent molecules. The two explanations are fundamentally different. In the former, the exciplex state is effectively quenched through a radiationless decay pathway facilitated by a stronger dielectric field of the solvent. However, the latter assumes that the ground state fiillerene-solvent complexation prevents the formation of fullerene-donor exciplexes. In order to understand whether the extreme solvent sensitivity is solvent specific (limited to benzene, toluene, and other aromatic solvents) or solvent property specific (solvent polarity and polarizability), fluorescence spectra of C70-DEA were measured systematically in mixtures of hexane and a polar solvent (acetone, THF, or ethanol) with volume fraction up to 10% [101]. The results are consistent with the explanation of solvent polarity and polarizability effects. 

The polar nature of water largely determines its solvent properties. Ionic compounds with full charges, such as potassium chloride (KGl, and Cl in solution), and/)o/arcompounds with partial charges (i.e., dipoles), such as ethyl alcohol (GgHgOH) or acetone [(GH3)2G=0], tend to dissolve in water (Figures 2.2 and 2.3). The underlying physical principle is electrostatic attraction... 

The properties of solvents has been studied extensively by Snyder (5), who created a dassification of the solvent properties of common solvents. It has been found (7) that (excluding proton donors such as alcohols) the maximum difference in mobile-phase selectivity is obtained if the polar solvents have a large difference in basidty. Thus, for maximum selectivity differences, one solvent should have a low basidty. Solvents of this type are acetonitrile, ethyl acetate or other esters, and acetone or other ketones. The other solvent should have a high basidty examples are ethers such as tert-butyl methyl ether, diethyl ether or tetrahydrofuran, or amines such as triethylamine. Between these groups and alcohols, large differences in chromatographic selectivity can be obtained in normal-phase chromatography (10). 

The nature of the solvent influenced the equilibrium formation constant and subsequent rate-determining conversion to products for an intermediate complex, formed between the substrates and PDA these constants were reported for reactions in acetone and benzene. Equations correlating the rates of Py oxidation with the solvent properties are reported the rates are affected by the basicity and polarity, unaffected by polarizability and electrophilicity, and appreciably retarded by added AcOH.234... 

---