Type 12 Lewis Acid/Base Complexation Chemistry
Few Onium Ion Lewis acid/pi-HOMO Lewis acid complexes are known because it is likely that a ligand will rapidly transfer from the Onium Ion to the pi-HOMO Lewis base.

The effect will be to alkylate or protonate the pi-System, depending upon the nature of the ligand.

For more information look in the Chemogenesis webbook sections on Lewis acids and Lewis bases and the Lewis acid/base interaction matrix.