Water-scavenging ability

Both examples indicate that the water scavenging ability of some ionic liquids may influence the thermodynamics of a reaction, although in the light of more recent findings concerning the hydrolysis of hexafluorophosphate and tetrafluoro-borate to acidic HF [178], which in turn may act as catalyst, the scope of ionic liquid anions should be extended to verify the results. 

Tannin chemistry is complex and tannin blends (composed of singletree species tannins mixed together) offer a number of useful water treatment functions. Apart from oxygen-scavenging abilities, they act as passivating agents, film-formers, sequestrants, and polymeric sludge dispersants (for more details, see Section 10.3). 

Hu Z, Guan WC, Tang XY, Huang LZ, Xu H (2007) Synthesis of water-soluble cystine C derivative with catalyst and its active oxygen radical scavenging ability. Chin. Chem. Lett. 18 51-54. 

Novel water-dispersible lutein esters (115) and (116) have been prepared and showed potent, direct superoxide scavenging ability in an in vitro isolated human neutrophil assay... 

The ability of 2,2-dimethoxypropane to act as a water scavenger has resulted in its use (in conjunction with acetone and an acid catalyst) in the protection of the 2, 3 -hydroxy groups of purine and pyrimidine nucleosides. Here again, the formation of acetone and methanol serves to drive the equilibrium towards the product. 

The yields ranged from 55% for the mixture of enamines formed from morpholine and methylisopropyl ketone to 94% for the enamine formed from dimethylamine and methyl t-butyl ketone. The hindered ketone 2,5-dimethylcyclopentanone could be converted to an enamine, but the more hindered ketone, 2,6-di-t-butylcyclohexanone, was inert. White and Weingarten 43) attribute the effectiveness of titanium tetrachloride in this reaction to its ability to scavenge water and to polarize the carbonyl bond. 

The formation of Au nanoparticles can be easily monitored by following the appearance of a surface plasma resonance band around 520-540 nm (Fig. 6.1). Yeung et al. [33] observed that the efficiency of gold particle formation was different in different alcohols (n-pentanol > propan-2-ol > methanol). This is due to the air/water surface activity of the alcohols and the ability of the solute to scavenge the primary OH radicals at the bubble/liquid interface. 

The stability of the Cgg -cation can be increased by adding trifluoromethane-sulfonic acid CF3SO3H to the TCE/(TBA)PFg solutions [8]. Under these conditions the life-time of the cation is estimated to be at least some hours. Cgg" is probably stabilized by CF3SO3H because of acid s ability to scavenge water and nucleophiles that would react readily with the cation. The elevated lifetime of the cation made it... 

Sulfasalazine. Salicylazosulfapyridine or Azulfadine [599-79-1] (2-hydroxy-5-[[4[(2-pyridylamino)sulfonyl]-phenyl]azo] benzoic acid) (15) is a light brownish yellow-to-bright yellow fine powder that is practically tasteless and odorless. It melts at ca 255°C with decomposition, is very slightly soluble in ethanol, is practically insoluble in water, diethyl ether, chloroform, and benzene, and is soluble in aqueous solutions of alkali hydroxides. Sulfasalazine may be made by the synthesis described in Reference 13. It is not used as an antidiarrheal as such, but is indicated for the treatment of inflammatory bowel diseases such as ulcerative colitis and Crohn s disease. Its action is purported to result from the breakdown in the colon to 5-aminosalicylic acid [89-57-6] (5-AS A) and sulfapyridine [144-83-2]. It may cause infertility in males, as well as producing idiosyncratic reactions in some patients these reactions have been attributed to the sulfa component of the compound. The mechanism of 5-ASA is attributed to inhibition of the arachidonic acid cascade preventing leukotriene B4 production and the ability to scavenge oxygen free radicals. The active component appears to be 5-aminosalicylic acid. 

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