Organometallics are compounds that contain a metal-carbon bond in which carbon is part of an organic group. Commonly represented as R-M, this bond can be either a direct carbon to metal σ or sigma bond (as in the Grignard reagents R-MgX), or a metal to multiple-carbon atoms π or pi bond (as in allyl palladium complexes and the metallocenes).
Organometallic compounds are widely used in both research and industry. Some common uses of organometallic compounds are:
- As catalysts and reagents in the synthesis of organic compounds, including pharmaceuticals and fragrances
- In industrial processes such as alkene polymerization and oligomerization, hydrogenation, hydrocyanation, and hydrosilylation
- In the industrial production of some alcohols
- In the preparation of semiconducting films
Organometallic compounds typically contain alkaline, alkaline earth, or transition metals. Thus, organolithium (e.g., n-butyllithium), organomagnesium (e.g., methylmagnesium bromide), and organocopper (e.g., lithium dimethylcuprate) reagents are some of the more common and important organometallic reagents. However, lanthanides, actinides, and semimetals such as boron, silicon, arsenic and selenium are also known to form organometallic bonds. Aside from forming bonds with organic fragments or molecules, these metals can bond with inorganic carbon, such as carbon monoxide, cyanide, or carbide.
Organometallic compounds typically have low melting points and are insoluble in water. Such compounds are soluble in ether and related solvents and have varying degrees of toxicity, oxidizability, and reactivity. They are usually kept in organic solvent solutions due to their high reactivity.