Density functional theory (DFT)/IGLO 29Si NMR study of trialkylsilylated arenium, bromonium, oxonium and nitrilium ions, comparison with experimental data and the question of persistent trialkylsilicenium ions in solution

Abstract

Density functional theory (DFT)/IGLO 29Si NMR studies show that there is no significant silicenium ion nature in trialkylsilyl substituted arenium, bromonium, oxonium and nitrilium ions. High electrophilicity of trivalent silicon and its affinity for π-donor arene solvents, as well as for oxygen, halogen and nitrogen heteroatoms of solvents or counter ions, is responsible for the inability to observe long-lived trisubstituted silyl cations.