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 Ru–alkylidene complex [Ru(DMF)3(IMesH2)(—CH—2—(2—PrO)—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. The highly electrophilic dicationic Ru–alkylidene complex [Ru(DMF)3(1,3‐dimesitylimidazolin‐2‐ylidene)(=CH—2—(2—PrO)—C6H4)]2+(BF4−)2] was used in the ring‐opening metathesis polymerization as well as in the cyclopolymerization of 1,6‐heptadiynes. In the presence of ionic monomers containing coordinating anions, a rapid change in the nature of the propagating alkylidene from a dicationic to a neutral occurs.