Organometallics

About Organometallics

Organometallics are compounds containing a direct bond between carbon and a metallic or metalloid element. Classes of organometallic materials are named based upon the metal or metalloid element that is bonded to the carbon; for example, organolithium compounds contain carbon-lithium bonds.

Metalorganics or metallo-organics are broader terms for complexes which contain both organic groups and a metal, but lack a direct metal-carbon bond. Metal alkoxides and dialkylamides are examples of metal organics.

Organometallic and metal-organic compounds bridge both fields of inorganic and organic chemistry. Organometallics are commonly found in polyethylene packaging, toys, pharmaceuticals and electronic devices. Being both highly reactive and sensitive to air and moisture, these compounds are typically kept in solution with organic solvents in an inert atmosphere. Common organic solvents include diethyl ether and tetrahydrofuran.

Organometallics can be found in applications ranging from catalysis, fluorescence, and coatings. A number of industries utilize the compounds in medical imaging, anti-corrosion coatings, solid state lighting, batteries, and renewable energy.

Organometallic and metal-organic compounds are widely used as both reagents and catalysts in industrial chemistry. Many are reagents used in organic synthesis; for example, Grignard reagents are alkyl, vinyl or aryl-magnesium halides used in synthesis of complex organic molecules such as pharmaceutical compounds. Organometallics are also used in the production of simpler organic compounds, as in the industrial production of acetic acid using metal carbonyl catalysts, and in producing polymers such as polyethylene and poly propylene.

Other exemplary uses of organometallics include esterification and curing of polyester-based coating resins, adhesives, and anti-corrosion electrodeposition coatings (EDC) for the automotive and other industries. Fluorescent dyes for medical imaging and dye-sensitized solar cells, phosphor materials for light-emitting diodes (LEDs) and organic light emitting diodes (OLEDs). OLEDS have been developed using rhenium-based, osmium-based, and iridium-based, phosphorescent dyes.

Organometallic compounds are also used as precursors for coatings and thin film deposition via metalorganic chemical vapor deposition (MOCVD). Common coatings include optical coatings, glass coatings, transparent electrical conductive oxide layers (TCO) for such as indium tin oxide (ITO), and metallization of microelectronic components.

Deposition of semiconductor materials for use in electronics and solar cells requires ultra-high purity precursor compounds. Organometallic precursors are used in the production of silicon- and germanium-based semiconductors as well as in III-IV, II-VI, and IV-VI compound semiconductors. Precursors such as trimethylgallium (TMG or TMGa) , trimethylaluminum (TMA), and trimethylindium (TMI or TMIA) are used for the deposition common compound semiconductors such as GaAs, GaN, InGaAs, InGaN, Indium Gallium Phosphide and AlGaAs. Additionally, organometallics may be used in the deposition of dielectric materials. Dopant precursors such as dimethylzinc or bis(η5-cyclopentadienyl)magnesium may be used used to dope gallium arsenide semiconductors. In addition, a host of other organometallic compounds are used as semiconductor n-type or p-type dopants including rhodocene and diethyltellurium.

Organometallics can additionally serve as precursors for advanced ceramics, metal-oxide superconductors via sol-gel processes, and precursors for the synthesis of nanomaterials and quantum dots. For example, gallium acetylacetonate is used in growing high purity gallium nitride nanowires.

In battery and fuel cell applications, organometallics are commonly used as catalysts, electrolytes, electrode materials, and solid oxide fuel (SOFC) materials. Organometallic polymers such as ferrocene containing polymers poly(vinylferrocene), poly(ethynylferrocene), and poly(ferrocene) are being used as cathode active energy storage materials. Other polymeric organometallic compounds such as ethyl aluminum alkoxides and poly(ethylene oxide) provide corrosion protection as electrolytes and as lithium insertion compounds for electrodes in lithium ion batteries. Solid oxide fuel cells (SOFCs) are driven by a solid oxide or ceramic electrolyte materials. Metal organic vapor deposition is used in producing the electrolyte layers for solid oxide fuel cells at lower temperatures.

Health, Safety & Transportation Information

Organometallics are often highly reactive compounds, and as such must be handled with great care. Many of these compounds or their solutions are pyrophoric: they may ignite spontaneously when exposed to air. Others are highly flammable, but not as prone to spontaneous combustion. Additionally, some react explosively with water, and many are poisonous. Users of any organometallic materials should take care to learn about proper handling for any particular compound or formulation before handling. American Elements engineers can provide guidance on safe handling and usage and supply safety data sheets (SDSs) for all materials we manufacture.

Example Safety Data Table

Click on the labels for definitions

Safety Data
Safety Data Sheet	SDS
Signal Word	Danger
Hazard Statements	H228-H302-H312-H315-H319-H332-H335
Hazard Codes	F,Xn
Risk Codes	11-20/21/22
Safety Precautions	16-33-36
RTECS Number	ZG1925000
Transport Information	UN 3089 4.1/PG 2
WGK Germany	3
Globally Harmonized System of Classification and Labelling (GHS)