The Boratacyclooctatetraene Ligand: An Isoelectronic Trianionic Analogue of the Cyclooctatetraene Dianion

摘要

The cyclooctatetraene dianion (COT~(2-)) and its derivatives are versatile ligands for transition metal atoms. When bound to metal centers, they are formally considered as dianionic 10π electron donors. Their use in actinide and lanthanide chemistry, in particular, has been well documented. Representative examples from the literature include uranocene, [(C_8H_8)_2U], and [(C_8H_8)_2Ce]. Catalytic species can also be designed, for instance [Ni_2(COT)_2] serves as an effective catalyst for acetylene tetramerization.