No abstract

The rate constants for the reactions of the 2‐azaallenium ion 1b+, the 2‐azaallylium ion 2a+ and the iminium ion 3+ with different nucleophiles were determined by 1H NMR spectroscopy. By correlation with the Linear Free Enthalpy Relationship (LFER) lg k20°C = s (E + N), developed by Mayr and Patz, the electrophilicity parameters E(1b+) = ‐3.7, E(2a+) ≈︁ ‐16 and E(3+) = ‐10.43 were obtained. They show that the relative reactivities of these ions are approximately 1012:1:106. Quantum chemical calculations (ab initio, DFT) of the methyl anion affinities for the ions 1b+,2a+ and3+ are in agreement with the experimental E values. The X‐ray structure of 3+·CF3SO 3− is reported for the first time; it shows no strong interaction between the cation and the anion.