Characterization of β-B-Agostic Isomers in Zirconocene Amidoborane Complexes
Forster, T., Tuononen, H., Parvez, M., & Roesler, R. (2009). Characterization of β-B-Agostic Isomers in Zirconocene Amidoborane Complexes. Journal of the American Chemical Society, 131 (19), 6689-6691. doi:10.1021/ja901460y
Published inJournal of the American Chemical Society
DisciplineEpäorgaaninen ja analyyttinen kemia
© 2009 American Chemical Society. This is a final draft version of an article whose final and definitive form has been published by ACS. Published in this repository with the kind permission of the publisher.
The reaction of Cpx2ZrCl2 (Cpx = Cp, Cp*) with ammonia borane in presence of n-butyllithium yielded Cp2Zr(Cl)NH2BH3 and Cpx2Zr(H)NH2BH3. These derivatives are isoelectronic with the ethyl zirconocene chloride and hydride, respectively, and feature a chelating amidoborane ligand coordinating through a Zr−N bond and a Zr−H−B bridge. In solution, each of the complexes consists of an equilibrium mixture of two isomers differing in the orientation of the amidoborane ligand with respect to the Zr−X bond (X = H, Cl), while in the solid state, only one isomer was observed. Such isomers have not been characterized for any metal complexes containing the isoelectronic β-agostic ethyl ligand or any other agostic alkyl group.