Silyl ligands electronic properties

Quite a number of silylnickel and silylenenickel compounds have been reported, and only a few can be cited here2305-2309 Bis(silyl)nickel complexes have been implicated as important intermediates in Ni-catalyzed double silylation of various organic substrates. Using an o-bis(dimethylsilyl)carborane ligand, complex (930) could be isolated and structurally characterized 2310 Its unusual thermal stability is attributed to the advantageous steric and electronic properties of the carboranyl unit. (930) undergoes... 

Similar octahedral facial silyl methyl hydride complexes of the type IrL3H(SiR3)Me have been shown to induce competitive C—H/Si—C reductive elimination depending on the electronic properties of the silyl ligand, thus affording a novel example of a metallation of silyl ligands or the metallation of the sp3C—H bond of the ethyl moiety when R = OEt. For the complex with R = Et, mixtures of different complexes are formed by the thermolysis with benzene (Scheme 32)198,199. 

Figure 4.29. Summary of several of the electronic properties of silyl ligands and silyl complexes.

---