Reactivity of the Dicationic Ruthenium-Alkylidene Complex [Ru(DMF)3(IMesH2)(=CH-2-(2-PrO)-C6H4)],2+(BF4-)2] in Ring-Opening Metathesis and Cyclopolymerization

The reactivity of the dicationic Rualkylidene complex [Ru(DMF)3(IMesH2)(CH2(2PrO)C6H4)]2+(BF4-)2] (1, IMesH2 = 1,3-dimesitylimidazolin-2-ylidene) in the ring-opening metathesis polymerization (ROMP) of various functional norborn-2-enes as well as in the cyclopolymerization of different 1,6-heptadiynes is reported. Due to its dicationic character, complex 1 is highly electrophilic and possesses high reactivity towards alkenes and 1,6-heptadiynes. Generally, a pronounced difference in reactivity between monomers bearing coordinating groups and those that lack such moieties is observed. In the presence of ionic monomers containing coordinating anions such as Br- and I-, a rapid change in the nature of the propagating alkylidene from a dicationic to a neutral one is observed.