Department of Organic Chemistry, The University, Zernikelaan, Groningen, The Netherlands
Abstract:
The acid-catalyzed and water-catalyzed solvolysis ofbenzoylphenyldiazomethane (1) have been studied in water and in t-butanol-water mixtures, the mole fraction of water (nH2O) being varied from 0·75-1·00. Increasing t-butanol concentrations produce a pronounced decrease in both kH⊕ and kH2O. In the “water reaction” mutually compensatory changes of AH and AS are associated with the rate variations, with minima in AH and AS at about nH2O = 0·95. In addition it was found that the magnitude of the salt effect of (n-Bu)4NCl on the rate of hydrolysis of 1 in water at 25° is much larger than that of LiCl, NaCl and NaBr. Assuming that the rate of the “water reaction” is largely determined by water acidity, the data are suggestive for the existence of a relation between water acidity and solvent structural integrity in highly aqueous t-butanol-water solutions.
