Type 14 complexes are often generated as reactive intermediates with the Complex anion Lewis base acting as a non-nucleophilic counter ion to reactive electrophilic Lobe-LUMO Lewis acid. Friedel-Crafts reactions, for example, employ Type 14 Lewis acid/base complexes. For more information look in the Chemogenesis
webbook sections on Lewis
acids and Lewis bases and the Lewis
acid/base interaction matrix.