Organometallic compounds with metals

Organometallic compounds with metal-metal bonds... 

Reactivity of Organometallic Compounds with Metallic Surfaces... 

Figure 10-2. Although they are relatively rare in biology, organometallic compounds with metal-carbon bonds are important. An typical example is coenzyme B12. The cobalt is co-ordinated to a tetraazamacrocyclic ligand, and has one axial nitrogen donor heterocyclic ligand and one axial alkyl group. The figure illustrates only the core of the macrocycle and the axial groups.

Organometallic compounds with metal-carbon bonds are formed by nearly all metallic elements, but those of transition metals show a diversity without parallel in main groups. Carbonyl has cyanide ligands are not considered organic, although they may also be present in organometallic compounds along with... 

Regarding antimony and bismuth, only a few studies exist involving organometallic compounds with metal-carbon bonds. Hence in these cases inorganic and organic compounds with metal—O—C bonds are also described. 

The methodology of the addition of tin into supported platinum or rhodium seems to play an important role in the behaviour of the active phase obtained. Controlled surface reactions of organometallic compounds with metal surfaces result in the formation bimetallic systems with specific properties in the hydrogenation of different unsaturated compounds. ° However, the nature of the Sn-Pt or Sn-Rh bimetallic phase formed, and its influence on the final properties of the catalyst, have not been yet well determined and this is still a subject to be investigated. 

As with many other organometaiiic compounds, the exact structure of these reagents is more compiex than we imply here they are probably tetramers (four molecules of RjCuLi bound together), but for simplicity we will draw them as monomers. Organometallics (compounds with metal-carbon bonds) get a chapter to themselves (Chapter 40). 

Both organometallic compounds, with metal centers and multiple ligands bonded around them, and elemental hydrides have a distinct similarity. They are said to be isolobal to each other. 

Acetylenes may form various organometallic compounds with metal complexes [equations (8.38)-(8-40)]. 

Reactions of organometallic compounds with metal halides... 

Vyazankin, N. S., Razuvaev, G. A. and Kruglaya, 0. A., "Organometallic compounds with metal-metal bonds between different metals, Organometal. Chem. Rev., Sect. A i, 323- 23 (I968). 

ABSTRACT. Interactions of organometallic compounds with metal surfaces can be used to produce metal films and coatings as well as to modify the properties of metal catalysts for hydrocarbon conversion. The literature is reviewed, and results are evaluated characterizing the interaction of metal carbonyl clusters with surfaces of supported metals under mild conditions. The reactions lead to the preparation of highly dispersed bimetallic particles, which have homogeneous compositions and nonadditive properties in CO hydrogenation and hydrocarbon conversion. 

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