Aqueous Solvents Miscellaneous

Mixed Aqueous Solvents Miscellaneous.—Solvolysis. A dissociative mechanism operates for the solvolyses of [CoCl(NH3)5] + in aqueous ethanol and in aqueous DMSO and of cw-[CoCl(OH)(en)2]+ in a wide range of mixed solvents. Kinetics of aquation of [CrI(OH2)6l in aqueous methanol and in aqueous DMSO can be interpreted as indicating a D or, less convincingly, an /a mechanism. Now the establishment of A V values indicates the h mechanism, though a D mechanism for the conjugate base [CrI(OH)(OH2) J+. Some kinetic observations have been made relating to platinblau, the intensely coloured product from [PtCy - in aqueous acetonitrile. Rates of hydrolysis of phosphonium ylides and salts in THF-water mixtures are very sensitive to solvent composition.  

Formation. The dependence of rate on solvent composition for formation reactions of nickel(n) has been established for ethylenediamine in acetone-water, for acetate in methanol-w ater and dioxan-water, and for pada in acetonitrile-water. For the last system it is suggested that the mechanism of the reaction may change as the solvent composition changes. 

Some kinetic data are available for reactions of chromium(m) in methanol-water and in DMSO-water mixtures, and for (dissociative) replacement of water by DMSO in [Cr(N03)(0H2)5l + in water-DMSO mixtures. Kinetic results for reaction of /ra 5-[Co(dmgH)2(OaSC6H4Me)(solvent)] with pyridine or with triphenylphosphine in water, methanol, ethanol, and water-methanol mixtures are more easily accommodated by a Z than by an /d mechanism.  

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The single largest use of ammonia is its direct apphcation as fertdizer, and in the manufacture of ammonium fertilizers that have increased world food production dramatically. Such ammonia-based fertilizers are now the primary source of nitrogen in farm soils. Ammonia also is used in the manufacture of nitric acid, synthetic fibers, plastics, explosives and miscellaneous ammonium salts. Liquid ammonia is used as a solvent for many inorganic reactions in non-aqueous phase. Other apphcations include synthesis of amines and imines as a fluid for supercritical fluid extraction and chromatography and as a reference standard in i N-NMR. 

Miscellaneous. Tetramethylphosphonium salts have been generated from methylenetrimethylphosphorane by treatment with acid in inert solvent, or with ammonium salts in inert solvents or in aqueous ethanol. Details have appeared of the preparation of ]8y-unsaturated ketones using lithiated phen-acylidenetriphenylphosphorane. Alkylation of the metallated ylide (32) has... 

No Name temp, X I Id T C Cone (C)and solvent Aqueous phenol Collidine- Lutidine Butanol Ac acid Toluene sulfonyl Benzoyl Dinitro benzoyl Picrate Miscellaneous... 

Miscellaneous Compounds. The rate of the alkaline decomposition of [PPh4]+Cl in aqueous acetone increases rapidly with the acetone content of the solvent, a result similar to that observed previously with aqueous dioxan. Qualitatively similar results are found for [PhsPCHaPhl+Cl" in aqueous THF. A virtually identical rate... 

Miscellaneous kinetic studies of solvolysis in binary aqueous mixtures have included those of the [Co(NH3)5(dmso)] + cation in seventy-one such mixtures, of the /rans-[Co(dmgH)2Cl(N02)] anion and its methylglyoximate analogue in ethanol- and propan-2-ol-water, of [Cr(sal)3] and of ajffy5-tetra-(p-sulphonato-phenyl)porphineiron(m) in ethanol-water, of the 5,6-dimethylbenzimidazoIe derivative of methylcobalamin, of the acid-catalysed hydrolysis of (BHJ- in acetonitrile containing small amounts of water, and of the rate-determining aquation prior to redox of the [Mn(ox)2(OH2)a] anion in aqueous dimethylformamide. A kinetic study of the reaction of thallium(m) with dimethylformamide indicates caution in the use of this co-solvent in binary aqueous mixtures at elevated temperatures or in the presence of oxidants. ... 

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