Transition metal silyl complexes
In chemistry, transition metal silyl complexes describe
Synthesis
From silyl halides
The first examples were prepared by treatment of sodium cyclopentadienyliron dicarbonyl with trimethylsilyl chloride:[2]
- (C5H5)Fe(CO)2Na + Me3SiCl → (C5H5)Fe(CO)2SiMe3 + NaCl
A related reaction is the oxidative addition of silyl halides.
From hydrosilanes
![](http://upload.wikimedia.org/wikipedia/commons/thumb/b/bb/ArrestedOAofSiH.png/248px-ArrestedOAofSiH.png)
- 2 (C5H5)2TiMe2 + 2 Ph2SiH2 → [(C5H5)2TiSiPh2]2 + 4 MeH
Oxidative addition of Si-Si bonds
Low valent metals insert into the Si-Si bond of disilanes. The main limitation of this reaction is the paucity of disilanes as reagents.
Silyl complexes with Si-Si bonds
Beyond simple ligands like SiR3-, silyl ligands with Si-Si bonds are known. (C5H5)Fe(CO)2-SiMe2SiPh3 is one example (Me = CH3, Ph = C6H5).[3] Another example is the metalacycle derived from titanocene dichloride, (C5H5)2Ti(SiPh2)5.[4]
Silane complexes
Transition metal silane complexes are
The bonding in silane sigma complexes is similar to that invoked in agostic interactions. The metal center engages the Si-H entity via a 3-center, 2-electron bond. It is widely assumed that these sigma complexes are intermediates in the oxidative addition of hydrosilanes to give metal silyl hydrides. This transformation is invoked in hydrosilylation catalysis.
Evidence for sigma-silane complexes is provided by