The Use of Various Solvents

Physica.1 Properties. Carbonyl sulfide [463-58-1] (carbon oxysulfide), COS, is a colorless gas that is odorless when pure however, it has been described as having a foul odor. Physical constants and thermodynamic properties are Hsted ia Table 1 (17,18). The vapor pressure has been fitted to an equation, and a detailed study has been made of the phase equiUbria of the carbonyl sulfide—propane system, which is important ia the purification of propane fuel (19,20). Carbonyl sulfide can be adsorbed on molecular sieves (qv) as a means for removal from propane (21). This approach has been compared to the use of various solvents and reagents (22). 

Variations include the use of steam and the means of reducing interfacial tension by the use of various solvents. The solvent extraction approach has... 

The use of various solvents as reaction media for diverse reactions is summarized in Reichardt (1988), and Marcus (1998). The following is a partial list of organic reactions requiring solvents. In chapters 5 through 7 we will look at green solvents and provide some examples of more environmentally benign alternatives to some of the more toxic solvents. 

Thus, varying thermodynamic quality of the solvent (by the use of various solvents and their mixtures or varying the temperature) one may appreciably affect the extent of inter- and/or intramolecular aggregation of the side groups. This, in turn, may definitely influence the formation of supermolecular organization of the mesophase in bulk polymeric samples. 

There is, on occasion, and depending on the circumstances, the need to analyze the extracts that have been retrieved from coal by the use of various solvents. This assumes that sufficient material has been isolated to proceed with the analysis. The caveat is, of course, that all of the solvent used from the extraction procedure has been removed from the extracts. If not, it may be removed by the use of fractionation techniques applied to the extracts, and corrections will need to be applied to determine the correct yield of the extract fractions. To fractionate the extracts into a variety of subfractions, the nature of the coal must be taken into account as well as the nature of the chemicals extracted from the coal. 

The use of various solvents as reaction media for diverse reactions is summarized in Table 5.4 (after Reichardt 1988). 

Derivation (1) By salting out from crude anthracene oil and draining. The crude salts are purified by pressing and finally phenanthrene and carbazole are removed by the use of various solvents. (2) By distilling crude anthracene oil with alkali carbonate in iron retorts, the distillate contains only anthracene and phenanthrene. The latter is removed by carbon disulfide. 

Other authors did not observe catalysis of radical decomposition of AIBN in the presence of ZnCl. See, for example, ref. [57]. This discrepancy was explained by Barton it is due to the use of various solvents, forming complexes of differing stability with ZnCI, [34]. 

Desymmetrization of the prochiral diol 283 was attained, using vinyl acetate as an acetylating agent and several lipases (CAL, AK, AH, PS, LPL, PFL), of which only Pseudomonas fluorescens lipase proved efficient. It was found that the use of various solvents led to opposite enantiomers of the product 284 and substantially influenced the stereoselectivity of the process. For example, the replacement of chloroform by isopropyl ether led to the formation of the optical antipode of 284 [175, 176]. Wiktelius [177] reported that the Candida antarctica lipase B (Novozym 435) afforded better results in the desymmetrization of prochiral... 

This aspect was mentioned by de Gennes in his original paper. Comparison with values of h obtained for PS by others showed remarkable agreement, the use of various solvents and solid substrates notwithstanding. However, the... 

It is also important to keep the applied volumes constant and to respect the fact that the solvent in which the sample was dissolved, if not eliminated from the adsorbent, can impair its activity and appreciably influence the JRp values. In chromatography on thin layers of nonadhering alumina we have observed that the use of various solvents for the application of the sample on the same chromatogram, such as, for example, benzene, alcohol, or pyridine, results in appreciable differences in Rp values of the same substance. 

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