Methanesulfonic special

A method suitable for analysis of sulfur dioxide in ambient air and sensitive to 0.003—5 ppm involves aspirating a measured air sample through a solution of potassium or sodium tetrachloromercurate, with the resultant formation of a dichlorosulfitomercurate. Ethylenediaminetetraacetic acid (EDTA) disodium salt is added to this solution to complex heavy metals which can interfere by oxidation of the sulfur dioxide. The sample is also treated with 0.6 wt % sulfamic acid to destroy any nitrite anions. Then the sample is treated with formaldehyde and specially purified acid-bleached rosaniline containing phosphoric acid to control pH. This reacts with the dichlorosulfitomercurate to form an intensely colored rosaniline—methanesulfonic acid. The pH of the solution is adjusted to 1.6 0.1 with phosphoric acid, and the absorbance is read spectrophotometricaHy at 548 nm (273). 

Removal of analogs from the training set was first performed on the highly active A s by Ken Pauli, then with Starks C. P., the acquisitions contractor. He presented Table IV, which classifies analogs among the 846 A s with defined structure. Familiar alkylating agents, which include mustards, methanesulfonates, epoxides, aziridines and nitrosoureas, make up 52% of the 846. Other, more specialized classes reduced the A s further until they were cut by 87%. 

Esters at C4 are formed as intermediates in acylations at C3 (69JHC13), although they can be isolated (see Section V,A,l,a). Special esters are the methanesulfonates (85JHC433) and the 4-toluenesulfonates (7111043 85S699). Hydrolysis of an acetate has also been described (85JMC1828). 

The interest in functionalized ionic liquids is growing because ionic liquids bearing ether, amino or alcohol functionalities have been shown to display special properties, including the ability to dissolve a larger amoimt of metal halide salts and to extract heavy metal ions from aqueous solutions. Imidazolium-based ionic liquids with ether and hydroxyl (see Section 2.2.1), thiourea, thioether and urea (see Section 2.2.8) " have been prepared following the standard quatemization procedure. A straightforward approach has been described for the preparation of imidazolium (as well as pyridinium) cations with ester, ketone or cyanide functionalities 1-methylimidazole reacts with methanesulfonic acid to provide the imidazolium salt 11, which undergoes a Michael-type reaction with methyl vinyl ketone as a ,j8-unsaturated compound to produce the ionic liquid 12 (Scheme 5). ... 

The special selectivity of lonPac CS15 with its crown ether functional groups is suitable for the isocratic separation of standard cations and monoethanol-amine, which has already been shown in Figure 4.15. Di- and triethanolamine, however, would be difficult to separate from sodium under these chromatographic conditions. If a purely aqueous methanesulfonic acid gradient is applied, the separation of all three ethanolamines can be carried out without any problem (Figure 4.81). 

As discussed in Section 10.5D, a special value of p-toluenesulfonic (tosylate) and meth-anesulfonic (mesylate) esters is that in forming them, an —OH is converted from a poor leaving group (hydroxide ion) in nucleophilic displacement to an excellent leaving group, the p-toluenesulfonate (tosylate) or methanesulfonate (mesylate) anions. 

Investigation of electrochemical characteristics of Cr(III) methanesulfonate complexes draws a special attention in view of ecological and technical benefits concerning production of metal electrodeposits [32, 33], The electrochemical systems comprising methanesulfonic acid (MSA) and its salts are known to have many advantages [34]. However, kinetics of Cr(III) electroreduction in MSA containing electrolytes has yet been studied insufficiently. 

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