Sterically Demanding Hetero‐Substituted [2]Borametallocenophanes of Group IV Metals: Synthesis, Structure and Reactivity

We report the synthesis and characterisation of unprecedented unstrained [2]diborametallocenophanes of zirconium and hafnium that bear the bulky octamethylfluorenyl (η5-C29H36) system, the proligands of which were pre-constructed by a two-step synthesis. The compounds were fully characterised by NMR spectroscopy, MALDI-TOF mass spectrometry and X-ray diffraction analysis. Typical reactivities relevant to olefin polymerisation such as methylation and chloride abstraction were also investigated. Finally, a sterically demanding bis(octamethylfluorenyl) metallocene was prepared.