Solvent modulation of metal-ion effects in nucleophilic displacement at a phosphorus center

The reaction of alkali-metal phenoxides with p-nitrophenyl diphenylphosphinate shows strikingly different behaviour in ethanol and tetraglyme solvents. The overall rate of reaction is approximately 100,000 times greater in tetraglyme and the effects of alkali-metal counterions on rate are different in their nature (catalysis or inhibition) as well as in their extent in the two solvents. These observations are discussed in terms of the effects of hydrogen-bonding interactions and other specific solvent interactions on the ground state and the transition state of the reaction