Abstract
In this study, we have investigated the nucleophilicities of alcohols and related compounds toward highly reactive diarylmethyl cations in acetonitrile solution using a laser flash photolysis technique. For each nucleophile log kN increased linearly with decreasing electrophilicity of diarylmethyl cations. Using log k = s(N+E) proposed by Mayr, the nucleophilicity N values were determined. It was found that the N value decreases in the order of MeOH > EtOH > i-PrOH > t-BuOH in similar to the solvent nucleophilicty. Although this order is not consistent with the change in the basicity of alcohols, the N values for MeOH, n-PrNH2, and CF3CH2NH2 are linearly correlated with gas-phase basicity, suggesting that low nucleophilicities of i-PrOH and t-BuOH arise from steric effect.
