KINETIC OF NUCLEOPHILIC ATTACK ON COORDINATED ORGANIC MOIETIES. XIV. THE SIGNIFICANCE OF AMINE BASICITY IN DETERMINING THE NUCLEOPHILICITIES OF PYRIDINES AND ANILINES TOWARDS + CATIONS

Article abstract of DOI:10.1016/S0022-328X(00)83705-5

The second-order rate constants, k₁, for addition of pyridines and anilines to the cations <(1-5-η-C6H7)Fe(CO)3>⁺ (I), <(1-5-η-2-MeOC6H6)Fe(CO)3>⁺ (II), and <(1-5-η-C7H9)Fe(CO)3>⁺> (III) in CH3CN decrease along the series I > II > III.The Broensted relationship, log k₁ = αpK_a + constant, is obeyed for the addition of substituted pyridines to I and of substituted anilines to II.The slopes, α, of about 1.0 in each case indicate a strong dependence of k₁ on amine basicity.These results, together with previous data on related phosphine additions, sugest a hard character for the dienyl ligands in these organometallic cations.