|
Links New Chemistry A transition metal borylene complex
stabilized by a non- carbonyl
ligand set: formation by
spontaneous halide loss to give an
extremely short metal- -boron
bond (video). (work by David
Addy) |
|
New sterically demanding ligand
systems In
recent work we have been examining the synthesis and application of novel,
highly sterically demanding amido ligands in both main group and transition
metal chemistry. Related aryl ligands have been utilized to great effect in
recent years in the stabilization of metal complexes containing low
coordinate, unsaturated metal centres. Such compounds are of great interest,
not only from a fundamental bonding perspective (e.g. quintuple bonds
involving Cr), but also because of the potential for useful reactivity
displayed, for example, by low coordinate transition metal cations. We
have been seeking to extend this approach to related N-donor systems,
initially focusing on the 1,8-disubstituted carbazolyl
ligand class, as easily synthesized alternatives to the very widely-used
terphenyl ligands. Initial studies using the dichlorogallium complexes as
probes of ligand bulk, imply that these systems offer an even more sterically
protected pocket than their more celebrated terphenyl counterparts. More
recently the bis- and tetra-tert-butylcarbazolyl
frameworks have been used to give access to M(I) species (M = Ga, In, Tl),
the structural and reaction chemistry of which are currently under
investigation.
|
|
Further Information Sterically
demanding ligands Figures (right) The polymeric structure of solid tetra-tert-butylcarbazolyl indium(I). (left) The
1,8-dimesitylcarbazolyl ligand is shown to have a wider cone angle (269o vs 185o)
than the corres- ponding 2,6-dimesitylphenyl ligand: New chemistry (video) A
mixed valence In(I)/In(II) system Stabilized by amido ligands. Click here. (work of Hassanatu Mansaray) |