Effects of Medium on Substitution Reactions

Inorganic kineticists with an interest in solvent medium effects have not been generously supplied with reviews recently. Solvent paths and solvento-inter-mediates in substitution at square-planar centres have been discussed in a well referenced review. Unfortunately, another fully referenced and undoubtedly important review, on solvent properties of significance in determining reactivity in substitution at nickel(ii), has appeared in a periodical access to which may prove difficult for many readers. The contents of another, more general, review of solvent effects on kinetics, which includes discussion of appropriate physical models, may prove equally elusive.  

In the present Report we shall deal with solvent effects and with salt effects, including effects of polyelectrolytes and of micellar agents. The emphasis will be on substitution at inorganic centres, but related references of relevance will also be mentioned. 

Nitromethane has been used as a diluent in establishing the rate law for exchange of dimethyl sulphoxide at aluminium(iii), and the variation of rate 

Simpler uses of mixed solvents include the use of appropriate mixtures of methanol and water so that sufficiently low temperatures may be attained to obtain evidence for the intermediacy of B3H7OH2 in acid hydrolysis of the [BgHg]- anion, of glycerol and water so that sufficiently high temperatures may be reached for acceptably rapid formation of the [Ru(tptz)2] cation, and of ethanol and water so that both components of the chromium(iii)+2,2 -bipyridyl reaction may be dissolved.  

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