Catalyst Deactivation Processes During 1-Hexene Polymerization

The catalyst [Cp 2 Zr( μ -Me) 2 AlMe 2 ] + [B(C 6 F 5 ) 4 ] − ( 1 ) has been studied by electrospray ionisation mass spectrometry (ESI-MS) in order to better understand the complexities of catalyst deactivation in the polymerisation of 1-hexene. Using offline, online and flow-based methods, we observe that zirconium π-allyl species are unstable in solution and previously unobserved dimethylalane complexes are more stable. The dimethylalane complexes are resistant to further 1-hexene additions and their formation represent a new pathway for catalyst deactivation.