om6b00688_si_001.pdf (2.66 MB)
Zwitterionic d0 Metal Complexes [(Cy2N)3M]+[(μ-Me)B(C6F5)3]− (M = Ti, Zr, Hf) Derived from Tris(dicyclohexylamido)methyl Metal Precursors
journal contribution
posted on 2016-10-21, 22:29 authored by Christian Adler, Nils Frerichs, Marc Schmidtmann, Rüdiger BeckhausThe synthesis and
characterization of tris(dicyclohexyl)amido hafnium
complexes ClHf(NCy2)3 (1-Hf) and
MeHf(NCy2)3 (2-Hf) are presented.
The reactions of the group 4 derivatives of this compound class (MeM(NCy2)3; M = Ti (2-Ti), Zr (2-Zr), Hf (2-Hf)) with B(C6F5)3 are investigated. Their reactions with strong Lewis acids
lead to the first examples of zwitterionic group 4 complexes employing
three amido ligands at the electrophilic metal center ([(Cy2N)3M]+[(μ-Me)B(C6F5)3]−). The solid-state structures of
all of the betaines (3-Ti, 3-Zr, 3-Hf) are presented and compared. In all homologues the methyl group
is abstracted by the Lewis acid but remains in interaction with the
electron-deficient metal center, resulting in a linearly bridging
methyl group. The M···C distances of 3-M are elongated by 0.25 Å (av) in comparison to 2-M.