Correlation, effects heterolytic bond

In view of the described effects of substitution on heterolytic bond cleavage rate and on the scissile bond length, it is not surprising that this bond distance is correlated with reactivity and that the correlation holds for variation at both ends of the bond. Indeed, Jones and Kirby point out that there are excellent linear correlations of log with intercepts and slopes of the corresponding bond length-pAfa plots for the series a-glucosides, methoxymethyl acetals, and axial tetrahydropyranyl... 

The cr-substituent effects and solvent effects (extended Grunwald-Winstein equation) for solvolyses of / -X-substituted benzoyl chlorides (X = OMe, Me, H, and Cl) in 97% wt/wt hexafluoroisopropanol/water was explained by two competing pathways. Plots of log k versus a were consistent with a cationic path and explained by an 5 n2-5n1 spectrum of mechanism. Electron-donating groups favoured the reaction and values of p increased in the order AcOH < HCO2H < TEE < HFIP. A benzoyl cation intermediate was trapped in hexafluoroisopropanol. Ab initio calculations of heterolytic bond dissociation energies of various chloro- and fluoro-substituted and other benzoyl chlorides were correlated with log k for solvolyses... 

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