Consideration of the Factors Influencing the Specific Rates of Solvolysis of p-Methoxyphenyl Chloroformate

A recent correlations analysis of the specific rates of solvolysis of p-methoxyphenyl chloroformate (1) in 31 solvents using the three-term Grunwald-Winsteinequation led to a sensitivity (h) towards changes in the aromatic ring parameter (I) of0.85 0.15. This value, suggesting an appreciable contribution from the hI term, is incontrast to the h value of 0.35 0.19 that was reported for the parent phenyl chloroformate(2). However, for 1, only two specific rate values were available for the importantfluoroalcohol containing solvents. Values are now reported for 13 additional solvents,12 of which have appreciable fluoroalcohol content. With all 44 solvents considered, it isfound that the solvolytic behavior indicated for 1 now parallels very closely that previouslyreported for 2