The Substituent Effect. XI. Solvolysis of 5-, 6-, and 7-Substituted 1-(1-Naphthylethyl) Chlorides

Abstract

Abstract Fourteen 5-, 6-, and 7-substituted 1-(1-naphthylethyl) chlorides were prepared and the solvolysis rates were determined in 80% (v/v) aqueous acetone at 45 °C. The effects of −R substituents at respective positions were treated on the basis of the equation, logk⁄k0=ρiσi+ρx+σx+=ρ(Cijσi+qrij+σπ+). The position dependency of the inductive effect was given by Cij(=ρi⁄ρi,4α); C3α=1.37, C4α=1.00, C5α=0.75, C6α=0.57, and C7α=0.72. The Cij values appear to be correlated with Dewar’s simplified field function 1/rij. The position dependency of Pi-electronic effect given by the ratio ρπ+⁄ρi,4α=qr·ij+ was consistent with the prediction from the MO indices, such as Forsyth’s Δqij(ArCH2+ parameters. The same treatment was applied also to three other naphthalene reactivities, detritiation, pKa of α-naphthoic acids and pKa of naphthylammonium ions. The linear ρi–ρi relation holds among these reactions, suggesting a reaction-independent scheme of the inductive transmission. The qr·ij+ values vary at conjugate positions with reaction but not at non-conjugate positions irrespective of reactions. The results are discussed in comparison with those of relevant treatments.