Stabilization of Organosilicenium Ions by means of Intramolecular Coordination of O, S, or P Ligands

For the intramolecular stabilization of silicenium ions (R3Si+), O, S, and P donors as well as the known nitrogen‐containing systems (as in 1 a) are suitable. The silyl cations in 1 a–d show a trigonal‐bipyramidal structure; dynamic processes can be proved by NMR spectroscopy for 1 c, d. Calculations on model compounds document substantial differences in the bonding relationships and support the structural findings. Furthermore, preliminary experiments with 1 b–d indicate significant differences in reactivity.