Lanthanidocene Catalysts for the Homo‐ and Copolymerization of Ethylene with Butadiene

Alkylation of lanthanidocene chloride complexes was performed with BuLi, Mg(Bu)(Oct), or an equimolar mixture of BuLi and AlH( i Bu) 2 . In the case of the latter, chain transfer reactions were observed between neodymium and aluminium, and higher activities were obtained. The use of the silylene‐bridged complex, [Me 2 Si(3‐Me 3 SiC 5 H 3 ) 2 ]NdCl, in combination with BuLi and AlH( i Bu) 2 provided an efficient and unique catalyst for the copolymerization of ethylene with butadiene. Copolymers with high butadiene contents (up to 62 mol‐%) were synthesized. The microstructure of butadiene units was mostly trans ‐1,4, and copolymers exhibited a strong alternating character. The influence of butadiene content on the thermal properties of the copolymers was also investigated.Copolymerization of ethylene with butadiene using 4 /BuLi/AlH( i Bu) 2 (▪) and 2 /BuLi/AlH( i Bu) 2 (▴).