Abby R. O'Connor and Maurice Brookhart
The polymerizations of butadiene, isoprene, 2,3-dimethylbutadiene, the functionalized diene, 2,3-bis(4-trifluoroethoxy-4-oxobutyl)-1,3-butadiene, and styrene catalyzed by cationic complexes (2-R-allyl)Ni(mes)+ (R = H, 13, or CH3, 14) and [(2-R-allyl)Ni] [B(ArF)4] (R = H, 5, or CH3, 6) are described. Highly cis-enchained polymers with moderate molecular weights are observed for the poly-1,3-dienes. Styrene polymerization is achieved with (2-methallyl)Ni(mes)+, 14, as catalyst, yielding polystyrene with Mn = 4–5 K and a MWD of ∼2. NMR studies have been used to identify intermediates during the polymerization reaction.