Copolymerization of ethylene with isoprene promoted by titanium complexes containing a tetradentate [OSSO]-type bis(phenolato) ligand

Copolymerization of ethylene with isoprene (IP) catalyzed by 1,4-dithabutanediyl-linked bis(phenolato) titanium complexes 1 and 2 and methylaluminoxane (MAO) produced exclusively ethylene-IP copolymers with good activity. The copolymer microstructure can be varied by changing the ratio between the monomers in the copolymerization feed, affording copolymers with IP content 60%. The copolymer microstructure was fully elucidated by 13C-NMR spectroscopy of the copolymers with various IP content revealing a strong tendency to the alternating microstructure