The invention is a process for the preferential removal of a variable amount of alkynes and multiunsaturates from a gas stream containing at least hydrogen, olefins, alkynes, and multiunsaturates by contacting a gas stream containing H.sub.2, olefins, alkynes and multiunsaturates with a metal complex-containing stream selected from the group consisting of liquids and slurries, at conditions sufficient to form multiunsaturate adducts of the metal complex, by introducing the metal complex stream at a rate sufficient to form stoichiometric adducts of the alkynes and multiunsaturates to be removed, and removing the alkyne and multiunsaturate adducts of the metal complex. The invention has utility for removal of multiunsaturates from multicomponent syngas streams.