FT-ICR studies of the gas-phase reactions of W⁺ with alkanes, alkenes, benzene, water, ammonia and silane are reported. Most of these molecules are readily activated, accompanied by dehydrogenation, indicating that W⁺ selectively inserts into C-H rather than C-C bonds of hydrocarbons. Sequences of reactions with several molecules are observed in all cases, ending at widely different points. The longest sequence is observed with silane, corresponding to the final products WSi₁₀H₆⁺ and WSi₁₀ H₄⁺. In the case of NH₃, H₂O and benzene, association reactions are observed as the last steps. Collision induced dissociation spectra are used in order to help assigning structures and mechanisms.