Complexes silyl

Very recently, even examples of donor-stabilized bissilylene complexes have been introduced. For instance, the two cyclic systems 13 and 14 are prepared by an aminolysis reaction of the respective bis(chloro)silyl complexes. The x-ray structure analysis of 13 has been performed [39]. 

Basically the same methods known from the synthesis of classical metal-silyl complexes can also be applied to the preparation of low valent Si compounds. The procedures given here are summarized with the focus on silylene complexes These are a) reactions of appropriate metal anions with halosilanes, which are the most important methods for the formation of M-Si bonds. Alternatively, silyl... 

Finally, the reaction of silyl anions with dichlorides of Zr and Hf, which provides the silyl complexes 28 and 29, should be mentioned [116]. 

This synthetic approach is known from the synthesis of L M(alkene)H compounds from LnM(CO)alkane precursors and can easily be applied to the analogous silyl complexes. The Si—H bond even shows an increased activity for oxidative addition reactions [42, 43]. 

Excess of the olefin is desirable so that the formation of Si—Co complexes [Eq. (112) and Section II,B,7] is suppressed 54, 57). These silyl complexes are not hydrosilylation catalysts. 

A plausible mechanism proposed for this reaction involves migratory insertion of an olefin into the Pd-Si bond of a paUadium-silyl intermediate I followed by migratory insertion of the pendant olefin into the resulting Pd-C bond of II forming palladium-alkyl intermediate III. Reaction of Iff with hydrosilane releases the carbocy-cle to regenerate the palladium-silyl complex I (Scheme 3-21) [61]. 

The Ir1 silyl complex Ir(PMe3)2(CO)2(SiMe2Ph), (313), is formed by reaction Scheme 29 and is characterized by X-ray crystallography.507 This result shows that metalation of silyl ligands can be a facile, reversible process. 

Complex (dippe = 1,2-bis(diisopropylphosphino)ethane)Pd(SiH2Ph)2 is a very rare example164-168 of an isolated Pd11 czj-bis(silyl) complex.169... 

The preparation of various platinum-silyl complexes, including a platinum(II), platinum(IV), and mixed-valence platinum(II)-(IV) species, has been described.59 The treatment of one equivalent of 1,2-disilylbenzene with [Pt(PEt3)3] in toluene solution at 0°C affords [Pt(C6H4Si2H4)-(PEt3)2] (25) as a white powder the use of excess 1,2-disilylbenzene in the reaction leads to the formation of various platinum(IV) derivatives. 

Anionic Transition Metal Silyl Complexes New Building Blocks in Coordination Chemistry... 

Preparative Applications of Anionic Silyl Complexes 3.1 Reactions with Organic Dihalides... 

The preparative potential of silyl- or stannyl-substituted polynuclear complexes is currently far from being exploited. Due to the reactivity of silyl ligands, selective cleavage of metal-silicon bonds is possible. In some cases this was observed during the reaction of an anionic silyl complex with metal... 

These new silyl complexes are monomeric in benzene solution, but are dimeric in the solid state. The crystal structure of the samarium analogue (Figure 1) shows that dimers form via intermolecular Sm-CH3-Si interactions. The Sm-Si distance, 3.052 (8) A, is to our knowledge the longest metal-silicon distance known. As with other complexes that display Ln-CH3-Si interactions in the solid state, evidence for these interactions in solution is not observed in NMR spectra. The [H NMR chemical shifts for the neodymium... 

Given the ability of 14 electron fragments [(dtbpm)Pt(O)] and [(dcpm)Pt(O)] to activate C-H and C-Si bonds of inert organosilanes under very mild reaction conditions, it was of course no big surprise that Si-H activation reactions of silanes are possible as well. Hydrido-silyl complexes were formed in practically quantitative reactions if 14 or IS were used as precursors for the [(dtbpm)Pt(O)] fragment. Examples of Si-H insertion products, all stable, isolable compounds which could be fully characterized, are 25 - 27, and others have been made. 

Most of this section is devoted to derivatives containing CO and Cp-type ligands. An exception is a family of coordinatively unsaturated, silyl complexes LFeSiR2R involving the tripodal ligand [PhB(CH2PPr 3)3]-.170... 

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