Polar Effects. Part 14. Inductive Charge Dispersal in Bicyclo[2.2.2]oct-1-yl Cations

The rate constants (log k) for solvolysis of 2-, 3-, and 4-substituted bicyclo2.2.2]octyl p-nitrobenzenesulfonates 10, 11 and 12 , respectively, correlate linearly with the corresponding inductive substituent constants s?. The formation of the ion pairs 9 is, therefore, controlled by the I effect of neighboring substituents. It follows from the corresponding reaction constants ρ₁ of ?1.54, ?1.12, and ?1.22 that inductivity is highest at the positions α to C(1). It is lower and practically equal at the β- and γ-positions. Therefore, charge dispersal is similar to that previously observed in the quinuclidinium ion 7 .