Mechanistic insights on Zn(II)−Co(III) double metal cyanide-catalyzed ring-opening polymerization of epoxides

•The effect of complexing agents on double metal cyanide (DMC) catalysis is investigated.•The β-, and γ-dicarbonyl compounds are highly effective complexing agents.•The adsorption of complexing agents in keto form is favorable for high activity.•The fragmentation of catalyst occurs at the early period of polymerization.•Plausible mechanistic pathways of DMC-catalyzed polymerizations are proposed.