Kinetics of nucleophilic attack on co-ordinated organic moieties. Part 8. Addition of NN-dimethylaniline to the tricarbonyl(dienyl)-iron, -ruthenium, and -osmium cations and related complexes

Abstract

The complexes [M(C₆H₇)(CO)₃][BF₄](1; M = Fe, Ru, or Os) have been shown to act as electrophiles towards NN-dimethylaniline (RH) according to equation (I). A similar reaction occurs with [Cr(C₆H₇)(CO)₃][BF₄]. For [M(C₆H₇)(CO)₃][BF₄]+ RH →[M(C₆H₇R)(CO)₃]+ HBF₄(I)(1; M = Fe) and [Fe(C₆H₆OMe-2)(CO)₃][BF₄] the rate law, Rate =k[complex][RH] is observed. Preliminary kinetic investigations of the related reactions with (1; M = Ru or Os) provide the first quantitative comparison of the reactivity of cyclohexadienyl rings when co-ordinated to each of the iron triad metals, namely Fe > Os > Ru (41 : 3.6 : 1).