Correlation of the rates of solvolysis of n-octyl fluoroformate and a comparison with n-octyl chloroformate solvolysis

摘要

The specific rates of solvolysis of n-octyl fluoroformate have been measured at 24.2 degreesC in 28 pure and binary solvents. For the 23 solvents for which both N-T (solvent nucleophilicity) and Y-Cl (solvent ionizing power) values are known, a correlation using the two-term Grunwald-Winstein equation leads to sensitivities towards changes in the two scales of 1.80 +/- 0.13 (l value) and 0.79 +/- 0.06 (m value), respectively. For seven solvents, a parallel study was made of n-octyl chloroformate solvolysis and F : Cl specific rate ratios were, in most instances, above unity, consistent with the association step of an association-dissociation (addition-elimination) pathway being rate-determining. [References: 36]