M. Bochmann et al., ANIONIC AND ZWITTERIONIC METALLOCENE COMPLEXES DERIVED FROM NOVEL BORATOCYCLOPENTADIENYL LIGANDS, Journal of the Chemical Society, Chemical Communications, (20), 1995, pp. 2081-2082
Berate-substituted di- and tri-anionic cyclopentadienyl ligands [X(3)B
-C5H4](2-) and [X(2)B(C5H4)(2)](3-) (X = C6F5) give anionic group 4 me
tallocene complexes which provide a facile route to zwitterionic 'sing
le-component' alkene polymerisation catalysts.