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Organometallic chemistry is the study of organometallic compounds,
chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...
s containing at least one chemical bond between a
carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon ma ...
atom of an
organic molecule In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The ...
and a
metal A metal (from ancient Greek, Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electrical resistivity and conductivity, e ...
, including
alkali In chemistry, an alkali (; from ar, القلوي, al-qaly, lit=ashes of the saltwort) is a basic, ionic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a ...
,
alkaline earth The alkaline earth metals are six chemical elements in group 2 of the periodic table. They are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).. The elements have very similar properties: they are all ...
, and
transition metals In chemistry, a transition metal (or transition element) is a chemical element in the d-block of the periodic table (groups 3 to 12), though the elements of group 12 (and less often group 3) are sometimes excluded. They are the elements that ca ...
, and sometimes broadened to include metalloids like boron, silicon, and selenium, as well. Aside from bonds to organyl fragments or molecules, bonds to 'inorganic' carbon, like
carbon monoxide Carbon monoxide ( chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simpl ...
(metal carbonyls),
cyanide Cyanide is a naturally occurring, rapidly acting, toxic chemical that can exist in many different forms. In chemistry, a cyanide () is a chemical compound that contains a functional group. This group, known as the cyano group, consists of ...
, or
carbide In chemistry, a carbide usually describes a compound composed of carbon and a metal. In metallurgy, carbiding or carburizing is the process for producing carbide coatings on a metal piece. Interstitial / Metallic carbides The carbides of t ...
, are generally considered to be organometallic as well. Some related compounds such as transition metal hydrides and metal phosphine complexes are often included in discussions of organometallic compounds, though strictly speaking, they are not necessarily organometallic. The related but distinct term " metalorganic compound" refers to metal-containing compounds lacking direct metal-carbon bonds but which contain organic ligands. Metal β-diketonates, alkoxides, dialkylamides, and metal phosphine complexes are representative members of this class. The field of organometallic chemistry combines aspects of traditional inorganic and
organic chemistry Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J ...
. Organometallic compounds are widely used both stoichiometrically in research and industrial chemical reactions, as well as in the role of catalysts to increase the rates of such reactions (e.g., as in uses of homogeneous catalysis), where target molecules include polymers, pharmaceuticals, and many other types of practical products.


Organometallic compounds

Organometallic compounds are distinguished by the prefix "organo-" (e.g., organopalladium compounds), and include all compounds which contain a bond between a metal atom and a carbon atom of an
organyl group In organic and organometallic chemistry, an organyl group is an organic substituent with one (sometimes more) free valence(-s) at a carbon atom.. The term is often used in chemical patent literature to protect claims over a broad scope. Example ...
. In addition to the traditional metals (
alkali metal The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K),The symbols Na and K for sodium and potassium are derived from their Latin names, ''natrium'' and ''kalium''; these are still the origins of the names ...
s, alkali earth metals,
transition metals In chemistry, a transition metal (or transition element) is a chemical element in the d-block of the periodic table (groups 3 to 12), though the elements of group 12 (and less often group 3) are sometimes excluded. They are the elements that ca ...
, and post transition metals),
lanthanide The lanthanide () or lanthanoid () series of chemical elements comprises the 15 metallic chemical elements with atomic numbers 57–71, from lanthanum through lutetium. These elements, along with the chemically similar elements scandium and yt ...
s,
actinide The actinide () or actinoid () series encompasses the 15 metallic chemical elements with atomic numbers from 89 to 103, actinium through lawrencium. The actinide series derives its name from the first element in the series, actinium. The info ...
s, semimetals, and the elements
boron Boron is a chemical element with the symbol B and atomic number 5. In its crystalline form it is a brittle, dark, lustrous metalloid; in its amorphous form it is a brown powder. As the lightest element of the '' boron group'' it has t ...
,
silicon Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic ...
,
arsenic Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, b ...
, and selenium are considered to form organometallic compounds. Examples of organometallic compounds include Gilman reagents, which contain
lithium Lithium (from el, λίθος, lithos, lit=stone) is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the least dense metal and the least dense soli ...
and
copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pink ...
, and
Grignard reagent A Grignard reagent or Grignard compound is a chemical compound with the general formula , where X is a halogen and R is an organic group, normally an alkyl or aryl. Two typical examples are methylmagnesium chloride and phenylmagnesium bromide . ...
s, which contain
magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ...
. Tetracarbonyl nickel and
ferrocene Ferrocene is an organometallic compound with the formula . The molecule is a complex consisting of two cyclopentadienyl rings bound to a central iron atom. It is an orange solid with a camphor-like odor, that sublimes above room temperature, ...
are examples of organometallic compounds containing
transition metal In chemistry, a transition metal (or transition element) is a chemical element in the d-block of the periodic table (groups 3 to 12), though the elements of group 12 (and less often group 3) are sometimes excluded. They are the elements that can ...
s. Other examples of organometallic compounds include organolithium compounds such as ''n''-butyllithium (n-BuLi),
organozinc Organozinc compounds in organic chemistry contain carbon (C) to zinc (Zn) chemical bonds. Organozinc chemistry is the science of organozinc compounds describing their physical properties, synthesis and reactions.The Chemistry of Organozinc Compou ...
compounds such as diethylzinc (Et2Zn),
organotin Organotin compounds or stannanes are chemical compounds based on tin with hydrocarbon substituents. Organotin chemistry is part of the wider field of organometallic chemistry. The first organotin compound was diethyltin diiodide (), discovered ...
compounds such as tributyltin hydride (Bu3SnH), organoborane compounds such as triethylborane (Et3B), and organoaluminium compounds such as
trimethylaluminium Trimethylaluminium is one of the simplest examples of an organoaluminium compound. Despite its name it has the formula Al2( CH3)6 (abbreviated as Al2Me6 or TMA), as it exists as a dimer. This colorless liquid is pyrophoric. It is an industriall ...
(Me3Al). A naturally occurring organometallic complex is methylcobalamin (a form of Vitamin B12), which contains a
cobalt Cobalt is a chemical element with the symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, p ...
-
methyl In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula . In formulas, the group is often abbreviated as Me. This hydrocarbon group occurs in ...
bond. This complex, along with other biologically relevant complexes are often discussed within the subfield of bioorganometallic chemistry. File:Ferrocene.svg,
Ferrocene Ferrocene is an organometallic compound with the formula . The molecule is a complex consisting of two cyclopentadienyl rings bound to a central iron atom. It is an orange solid with a camphor-like odor, that sublimes above room temperature, ...
is an archetypal organoiron complex. It is an air-stable, sublimable compound. File:Cobaltocene.svg, Cobaltocene is a structural analogue of ferrocene, but is highly reactive toward air. File:HRh(CO)P3again.png, Tris(triphenylphosphine)rhodium carbonyl hydride is used in the commercial production of many aldehyde-based
fragrance An aroma compound, also known as an odorant, aroma, fragrance or flavoring, is a chemical compound that has a smell or odor. For an individual chemical or class of chemical compounds to impart a smell or fragrance, it must be sufficiently v ...
s. File:Zeise'sSalt.png, Zeise's salt is an example of a
transition metal alkene complex In organometallic chemistry, a transition metal alkene complex is a coordination compound containing one or more alkene ligands. Such compounds are intermediates in many catalytic reactions that convert alkenes to other organic products.Elschenbro ...
. File:Trimethylaluminium-from-xtal-3D-bs-17.png,
Trimethylaluminium Trimethylaluminium is one of the simplest examples of an organoaluminium compound. Despite its name it has the formula Al2( CH3)6 (abbreviated as Al2Me6 or TMA), as it exists as a dimer. This colorless liquid is pyrophoric. It is an industriall ...
is an organometallic compound with a bridging methyl group. It is used in the industrial production of some alcohols. File:Dimethylzinc-3D-balls.png,
Dimethylzinc Dimethylzinc, also known as Zinc methyl, DMZ, or DMZn is a colorless volatile liquid Zn(CH3)2, formed by the action of methyl iodide on zinc at elevated temperature or on zinc sodium alloy. :2Zn + 2CH3I → Zn(CH3)2 + ZnI2 The sodium assists the ...
has a linear coordination. It is a volatile pyrophoric liquid that is used in the preparation of semiconducting films. File:Lithium-diphenylcuprate-etherate-dimer-from-xtal-2D-skeletal.png, Lithium diphenylcuprate bis(diethyl etherate) is an example of a Gilman reagent, a type of organocopper complex frequently employed in organic synthesis. File:AdoCbl-ColorCoded.png, Adenosylcobalamin is a cofactor required by several crucial enzymatic reactions that take place in the human body. It is a rare example of a metal (cobalt) alkyl in biology. File:IronPentacarbonylStructure.png, Iron(0) pentacarbonyl is a red-orange liquid prepared directly from the union of finely divided iron and carbon monoxide gas under pressure. File:Tc99 sestamibi 2D structure.svg, Technetium sup>99mTcsestamibi is used to image the heart muscle in nuclear medicine.


Distinction from coordination compounds with organic ligands

Many complexes feature coordination bonds between a metal and organic
ligands In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electr ...
. Complexes where the organic ligands bind the metal through a
heteroatom In chemistry, a heteroatom () is, strictly, any atom that is not carbon or hydrogen. Organic chemistry In practice, the term is usually used more specifically to indicate that non-carbon atoms have replaced carbon in the backbone of the molecula ...
such as oxygen or nitrogen are considered coordination compounds (e.g., heme A and Fe(acac)3). However, if any of the ligands form a direct metal-carbon (M-C) bond, then the complex is considered to be organometallic. Although the IUPAC has not formally defined the term, some chemists use the term "metalorganic" to describe any coordination compound containing an organic ligand regardless of the presence of a direct M-C bond. The status of compounds in which the canonical anion has a negative charge that is shared between ( delocalized) a carbon atom and an atom more
electronegative Electronegativity, symbolized as , is the tendency for an atom of a given chemical element to attract shared electrons (or electron density) when forming a chemical bond. An atom's electronegativity is affected by both its atomic number and the ...
than carbon (e.g. enolates) may vary with the nature of the anionic moiety, the metal ion, and possibly the medium. In the absence of direct structural evidence for a carbon–metal bond, such compounds are not considered to be organometallic. For instance, lithium enolates often contain only Li-O bonds and are not organometallic, while zinc enolates ( Reformatsky reagents) contain both Zn-O and Zn-C bonds, and are organometallic in nature.


Structure and properties

The metal-carbon bond in organometallic compounds is generally highly
covalent A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs. The stable balance of attractive and repulsive forces between atom ...
. For highly electropositive elements, such as lithium and sodium, the carbon ligand exhibits carbanionic character, but free carbon-based anions are extremely rare, an example being
cyanide Cyanide is a naturally occurring, rapidly acting, toxic chemical that can exist in many different forms. In chemistry, a cyanide () is a chemical compound that contains a functional group. This group, known as the cyano group, consists of ...
. Most organometallic compounds are solids at room temperature, however some are liquids such as methylcyclopentadienyl manganese tricarbonyl, or even volatile liquids such as nickel tetracarbonyl. Many organometallic compounds are air sensitive (reactive towards oxygen and moisture), and thus they must be handled under an
inert atmosphere An inert gas is a gas that does not readily undergo chemical reactions with other chemical substances and therefore does not readily form chemical compounds. The noble gases often do not react with many substances and were historically referred to ...
. Some organometallic compounds such as
triethylaluminium Triethylaluminium is one of the simplest examples of an organoaluminium compound. Despite its name it has the formula Al2( C2H5)6 (abbreviated as Al2Et6 or TEA), as it exists as a dimer. This colorless liquid is pyrophoric. It is an industrially ...
are
pyrophoric A substance is pyrophoric (from grc-gre, πυροφόρος, , 'fire-bearing') if it ignites spontaneously in air at or below (for gases) or within 5 minutes after coming into contact with air (for liquids and solids). Examples are organolith ...
and will
ignite To ignite is the first step of firelighting. Ignite may also refer to: Music *Ignite (band), a melodic hardcore band from Orange County, California * ''Ignite'' (Econoline Crush album), 2007 * ''Ignite'' (Shihad album), 2010 * "Ignite" (Eir Aoi s ...
on contact with air.


Concepts and techniques

As in other areas of chemistry,
electron counting Electron counting is a formalism used for classifying compounds and for explaining or predicting electronic structure and bonding. Many rules in chemistry rely on electron-counting: * Octet rule is used with Lewis structures for main group eleme ...
is useful for organizing organometallic chemistry. The 18-electron rule is helpful in predicting the stabilities of organometallic complexes, for example metal carbonyls and metal hydrides. The 18e rule has two representative electron counting models, ionic and neutral (also known as covalent) ligand models, respectively. The hapticity of a metal-ligand complex, can influence the electron count. Hapticity (η, lowercase Greek eta), describes the number of contiguous ligands coordinated to a metal. For example,
ferrocene Ferrocene is an organometallic compound with the formula . The molecule is a complex consisting of two cyclopentadienyl rings bound to a central iron atom. It is an orange solid with a camphor-like odor, that sublimes above room temperature, ...
, η5-C5H5)2Fe has two cyclopentadienyl ligands giving a hapticity of 5, where all five carbon atoms of the C5H5 ligand bond equally and contribute one electron to the iron center. Ligands that bind non-contiguous atoms are denoted the Greek letter kappa, κ. Chelating κ2-acetate is an example. The covalent bond classification method identifies three classes of ligands, X,L, and Z; which are based on the electron donating interactions of the ligand. Many organometallic compounds do not follow the 18e rule. The metal atoms in organometallic compounds are frequently described by their d electron count and
oxidation state In chemistry, the oxidation state, or oxidation number, is the hypothetical charge of an atom if all of its bonds to different atoms were fully ionic. It describes the degree of oxidation (loss of electrons) of an atom in a chemical compound. C ...
. These concepts can be used to help predict their reactivity and preferred
geometry Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is c ...
. Chemical bonding and reactivity in organometallic compounds is often discussed from the perspective of the isolobal principle. A wide variety of physical techniques are used to determine the structure, composition, and properties of organometallic compounds.
X-ray diffraction X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angles ...
is a particularly important technique that can locate the positions of atoms within a solid compound, providing a detailed description of its structure. Other techniques like
infrared spectroscopy Infrared spectroscopy (IR spectroscopy or vibrational spectroscopy) is the measurement of the interaction of infrared radiation with matter by absorption, emission, or reflection. It is used to study and identify chemical substances or functi ...
and nuclear magnetic resonance spectroscopy are also frequently used to obtain information on the structure and bonding of organometallic compounds. Ultraviolet-visible spectroscopy is a common technique used to obtain information on the electronic structure of organometallic compounds. It is also used monitor the progress of organometallic reactions, as well as determine their
kinetics Kinetics ( grc, κίνησις, , kinesis, ''movement'' or ''to move'') may refer to: Science and medicine * Kinetics (physics), the study of motion and its causes ** Rigid body kinetics, the study of the motion of rigid bodies * Chemical kin ...
. The dynamics of organometallic compounds can be studied using dynamic NMR spectroscopy. Other notable techniques include X-ray absorption spectroscopy, electron paramagnetic resonance spectroscopy, and
elemental analysis Elemental analysis is a process where a sample of some material (e.g., soil, waste or drinking water, bodily fluids, minerals, chemical compounds) is analyzed for its elemental and sometimes isotopic composition. Elemental analysis can be qualit ...
. Due to their high reactivity towards oxygen and moisture, organometallic compounds often must be handled using air-free techniques. Air-free handling of organometallic compounds typically requires the use of laboratory apparatuses such as a glovebox or
Schlenk line The Schlenk line (also vacuum gas manifold) is a commonly used chemistry apparatus developed by Wilhelm Schlenk. It consists of a dual manifold with several ports. One manifold is connected to a source of purified inert gas, while the other is co ...
.


History

Early developments in organometallic chemistry include Louis Claude Cadet's synthesis of methyl arsenic compounds related to cacodyl, William Christopher Zeise's platinum-ethylene complex,
Edward Frankland Sir Edward Frankland, (18 January 18259 August 1899) was an English chemist. He was one of the originators of organometallic chemistry and introduced the concept of combining power or valence. An expert in water quality and analysis, he was ...
's discovery of diethyl- and
dimethylzinc Dimethylzinc, also known as Zinc methyl, DMZ, or DMZn is a colorless volatile liquid Zn(CH3)2, formed by the action of methyl iodide on zinc at elevated temperature or on zinc sodium alloy. :2Zn + 2CH3I → Zn(CH3)2 + ZnI2 The sodium assists the ...
, Ludwig Mond's discovery of Ni(CO)4, and Victor Grignard's organomagnesium compounds. (Though not always acknowledged as an organometallic compound, Prussian blue, a mixed-valence iron-cyanide complex, was first prepared in 1706 by paint maker
Johann Jacob Diesbach Johann Jacob Diesbach () (born around 1670 – died in 1748), also written as Johann Jacob von Diesbach, was a Swiss pigment and dye producer known for first synthesizing a blue pigment known as Prussian blue (i.e. iron blue or Berlin blue). ...
as the first
coordination polymer A coordination polymer is an inorganic or organometallic polymer structure containing metal cation centers linked by ligands. More formally a coordination polymer is a coordination compound with repeating coordination entities extending in 1, 2 ...
and synthetic material containing a metal-carbon bond.) The abundant and diverse products from coal and petroleum led to Ziegler–Natta, Fischer–Tropsch,
hydroformylation Hydroformylation, also known as oxo synthesis or oxo process, is an industrial process for the production of aldehydes from alkenes. This chemical reaction entails the net addition of a formyl group (CHO) and a hydrogen atom to a carbon-carbon ...
catalysis which employ CO, H2, and alkenes as feedstocks and ligands. Recognition of organometallic chemistry as a distinct subfield culminated in the Nobel Prizes to Ernst Fischer and Geoffrey Wilkinson for work on metallocenes. In 2005, Yves Chauvin,
Robert H. Grubbs Robert Howard Grubbs ForMemRS (February 27, 1942 – December 19, 2021) was an American chemist and the Victor and Elizabeth Atkins Professor of Chemistry at the California Institute of Technology in Pasadena, California. He was a co-recipient ...
and Richard R. Schrock shared the Nobel Prize for metal-catalyzed olefin metathesis.


Organometallic chemistry timeline

* 1760 Louis Claude Cadet de Gassicourt investigates inks based on
cobalt Cobalt is a chemical element with the symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, p ...
salts and isolates cacodyl from cobalt mineral containing
arsenic Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, b ...
* 1827 William Christopher Zeise produces Zeise's salt; the first
platinum Platinum is a chemical element with the symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish , a diminutive of "silver". Pla ...
/
olefin In organic chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond. Alkene is often used as synonym of olefin, that is, any hydrocarbon containing one or more double bonds.H. Stephen Stoker (2015): General, Organic, a ...
complex * 1848
Edward Frankland Sir Edward Frankland, (18 January 18259 August 1899) was an English chemist. He was one of the originators of organometallic chemistry and introduced the concept of combining power or valence. An expert in water quality and analysis, he was ...
discovers diethylzinc * 1863
Charles Friedel Charles Friedel (; 12 March 1832 – 20 April 1899) was a French chemist and mineralogist. Life A native of Strasbourg, France, he was a student of Louis Pasteur at the Sorbonne. In 1876, he became a professor of chemistry and mineralogy at ...
and
James Crafts James Mason Crafts (March 8, 1839 – June 20, 1917) was an American chemist, mostly known for developing the Friedel–Crafts alkylation and acylation reactions with Charles Friedel in 1876. Biography James Crafts, the son of Royal Altamo ...
prepare organochlorosilanes * 1890 Ludwig Mond discovers nickel carbonyl * 1899 Introduction of Grignard reaction * 1899 John Ulric Nef discovers
alkynylation In organic chemistry, alkynylation is an addition reaction in which a terminal alkyne () is added to a carbonyl group () to form an α-alkynyl alcohol (). When the acetylide is formed from acetylene (), the reaction gives an α-ethynyl alcohol. ...
using sodium acetylides. * 1900
Paul Sabatier Paul Sabatier may refer to: *Paul Sabatier (chemist) (1854–1941), French chemist and Nobel Prize winner *Paul Sabatier (theologian) (1858–1928), French clergyman and historian See also *Paul Sabatier University Paul Sabatier University (''U ...
works on
hydrogenation Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organic ...
organic compounds with metal catalysts. Hydrogenation of fats kicks off advances in
food industry The food industry is a complex, global network of diverse businesses that supplies most of the food consumed by the world's population. The food industry today has become highly diversified, with manufacturing ranging from small, traditional, ...
, see margarine * 1909 Paul Ehrlich introduces Salvarsan for the treatment of syphilis, an early arsenic based organometallic compound * 1912
Nobel Prize The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfr ...
Victor Grignard and
Paul Sabatier Paul Sabatier may refer to: *Paul Sabatier (chemist) (1854–1941), French chemist and Nobel Prize winner *Paul Sabatier (theologian) (1858–1928), French clergyman and historian See also *Paul Sabatier University Paul Sabatier University (''U ...
* 1930
Henry Gilman Henry Gilman (May 9, 1893 – November 7, 1986) was an American organic chemist known as the father of organometallic chemistry, the field within which his most notable work was done. He discovered the Gilman reagent, which bears his name. Earl ...
works on lithium cuprates, see Gilman reagent * 1951 Walter Hieber was awarded the Alfred Stock prize for his work with metal carbonyl chemistry. * 1951
Ferrocene Ferrocene is an organometallic compound with the formula . The molecule is a complex consisting of two cyclopentadienyl rings bound to a central iron atom. It is an orange solid with a camphor-like odor, that sublimes above room temperature, ...
is discovered * 1956 Dorothy Crawfoot Hodgkin determines the structure of vitamin B12, the first biomolecule found to contain a metal-carbon bond, see bioorganometallic chemistry * 1963
Nobel prize The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfr ...
for
Karl Ziegler Karl Waldemar Ziegler (26 November 1898 – 12 August 1973) was a German chemist who won the Nobel Prize in Chemistry in 1963, with Giulio Natta, for work on polymers. The Nobel Committee recognized his "excellent work on organometallic compound ...
and Giulio Natta on Ziegler–Natta catalyst * 1965 Discovery of cyclobutadieneiron tricarbonyl * 1968
Heck reaction The Heck reaction (also called the Mizoroki–Heck reaction) is the chemical reaction of an unsaturated halide (or triflate) with an alkene in the presence of a base and a palladium catalyst (or palladium nanomaterial-based catalyst) to form a s ...
is developed * 1973
Nobel prize The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfr ...
Geoffrey Wilkinson and Ernst Otto Fischer on sandwich compounds * 1981
Nobel prize The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfr ...
Roald Hoffmann and Kenichi Fukui for creation of the Woodward-Hoffman Rules * 2001
Nobel prize The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfr ...
W. S. Knowles,
R. Noyori R. or r. may refer to: * '' Reign'', the period of time during which an Emperor, king, queen, etc., is ruler. * '' Rex'', abbreviated as R., the Latin word meaning King * ''Regina'', abbreviated as R., the Latin word meaning Queen * or , abbrevia ...
and Karl Barry Sharpless for asymmetric hydrogenation * 2005
Nobel prize The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfr ...
Yves Chauvin,
Robert Grubbs Robert Howard Grubbs ForMemRS (February 27, 1942 – December 19, 2021) was an American chemist and the Victor and Elizabeth Atkins Professor of Chemistry at the California Institute of Technology in Pasadena, California. He was a co-recipient o ...
, and
Richard Schrock Richard Royce Schrock (born January 4, 1945) is an American chemist and Nobel laureate recognized for his contributions to the olefin metathesis reaction used in organic chemistry. Education Born in Berne, Indiana, Schrock went to Mission Bay H ...
on metal-catalyzed alkene metathesis * 2010
Nobel prize The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfr ...
Richard F. Heck Richard Frederick Heck (August 15, 1931 – October 9, 2015) was an American chemist noted for the discovery and development of the Heck reaction, which uses palladium to catalyze organic chemical reactions that couple aryl halides with alkenes ...
, Ei-ichi Negishi, Akira Suzuki for palladium catalyzed cross coupling reactions


Scope

Subspecialty areas of organometallic chemistry include: *
Period 2 element A period 2 element is one of the chemical elements in the second row (or period) of the periodic table of the chemical elements. The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behavior of th ...
s: organolithium chemistry, organoberyllium chemistry, organoborane chemistry * Period 3 elements: organosodium chemistry, organomagnesium chemistry,
organoaluminium chemistry Organoaluminium chemistry is the study of compounds containing bonds between carbon and aluminium. It is one of the major themes within organometallic chemistry. Illustrative organoaluminium compounds are the dimer trimethylaluminium, the monom ...
, organosilicon chemistry *
Period 4 element A period 4 element is one of the chemical elements in the fourth row (or ''period'') of the periodic table of the elements. The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behaviour of the element ...
s: organocalcium chemistry, organoscandium chemistry, organotitanium chemistry, organovanadium chemistry,
organochromium chemistry Organochromium chemistry is a branch of organometallic chemistry that deals with organic compounds containing a chromium to carbon bond and their reactions. The field is of some relevance to organic synthesis. The relevant oxidation states for organ ...
, organomanganese chemistry, organoiron chemistry,
organocobalt chemistry Organocobalt chemistry is the chemistry of organometallic compounds containing a carbon to cobalt chemical bond. Organocobalt compounds are involved in several organic reactions and the important biomolecule vitamin B12 has a cobalt-carbon bond ...
, organonickel chemistry, organocopper chemistry, organozinc chemistry, organogallium chemistry, organogermanium chemistry, organoarsenic chemistry,
organoselenium chemistry Organoselenium compounds (or seleno-organic) are chemical compounds containing carbon-to-selenium chemical bonds. Organoselenium chemistry is the corresponding science exploring their properties and reactivity. Selenium belongs with oxygen and sul ...
* Period 5 elements:
organoyttrium chemistry Organoyttrium chemistry is the study of compounds containing carbon-yttrium Yttrium is a chemical element with the symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and has often ...
, organozirconium chemistry, organoniobium chemistry, organomolybdenum chemistry, organoruthenium chemistry, organorhodium chemistry, organopalladium chemistry, organosilver chemistry, organocadmium chemistry, organoindium chemistry, organotin chemistry,
organoantimony chemistry Organoantimony chemistry is the chemistry of compounds containing a carbon to antimony (Sb) chemical bond. Relevant oxidation states are Sb(V) and Sb(III). The toxicity of antimony limits practical application in organic chemistry. Organoantimo ...
, organotellurium chemistry *
Period 6 element A period 6 element is one of the chemical elements in the sixth row (or ''period'') of the periodic table of the elements, including the lanthanides. The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemica ...
s:
organolanthanide chemistry Organolanthanide chemistry is the field of chemistry that studies compounds with a lanthanide-to- carbon bond. Organolanthanide compounds are different from their organotransition metal analogues in the following ways: *They are far more air- a ...
, organocerium chemistry,
organotantalum chemistry Organotantalum chemistry is the chemistry of chemical compounds containing a carbon-to-tantalum chemical bond. A wide variety of compound have been reported, initially with cyclopentadienyl and CO ligands. Oxidation states vary from Ta(V) to Ta( ...
, organorhenium chemistry, organoosmium chemistry, organoiridium chemistry, organoplatinum chemistry, organogold chemistry, organomercury chemistry, organothallium chemistry, organolead chemistry,
organobismuth chemistry Organobismuth chemistry is the chemistry of organometallic compounds containing a carbon to bismuth chemical bond. Applications are few. The main bismuth oxidation states are Bi(III) and Bi(V) as in all higher group 15 elements. The energy of a ...
, organopolonium chemistry * Period 7 elements:
organoactinide chemistry Organoactinide chemistry is the science exploring the properties, structure and reactivity of organoactinide compounds, which are organometallic compounds containing a carbon to actinide chemical bond. Like most organometallic compounds, the org ...
,
organouranium chemistry Organouranium chemistry is the science exploring the properties, structure and reactivity of organouranium compounds, which are organometallic compounds containing a carbon to uranium chemical bond. The field is of some importance to the nuclea ...
, organoneptunium chemistry


Industrial applications

Organometallic compounds find wide use in commercial reactions, both as homogenous catalysts and as stoichiometric reagents. For instance, organolithium, organomagnesium, and organoaluminium compounds, examples of which are highly basic and highly reducing, are useful stoichiometrically but also catalyze many polymerization reactions. Almost all processes involving carbon monoxide rely on catalysts, notable examples being described as
carbonylation Carbonylation refers to reactions that introduce carbon monoxide into organic and inorganic substrates. Carbon monoxide is abundantly available and conveniently reactive, so it is widely used as a reactant in industrial chemistry. The term carbon ...
s. The production of acetic acid from methanol and carbon monoxide is catalyzed via metal carbonyl complexes in the Monsanto process and Cativa process. Most synthetic aldehydes are produced via
hydroformylation Hydroformylation, also known as oxo synthesis or oxo process, is an industrial process for the production of aldehydes from alkenes. This chemical reaction entails the net addition of a formyl group (CHO) and a hydrogen atom to a carbon-carbon ...
. The bulk of the synthetic alcohols, at least those larger than ethanol, are produced by
hydrogenation Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organic ...
of hydroformylation-derived aldehydes. Similarly, the Wacker process is used in the oxidation of
ethylene Ethylene (IUPAC name: ethene) is a hydrocarbon which has the formula or . It is a colourless, flammable gas with a faint "sweet and musky" odour when pure. It is the simplest alkene (a hydrocarbon with carbon-carbon double bonds). Ethylene ...
to
acetaldehyde Acetaldehyde (IUPAC systematic name ethanal) is an organic chemical compound with the formula CH3 CHO, sometimes abbreviated by chemists as MeCHO (Me = methyl). It is a colorless liquid or gas, boiling near room temperature. It is one of the ...
. Almost all industrial processes involving
alkene In organic chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond. Alkene is often used as synonym of olefin, that is, any hydrocarbon containing one or more double bonds.H. Stephen Stoker (2015): General, Organic ...
-derived polymers rely on organometallic catalysts. The world's polyethylene and polypropylene are produced via both heterogeneously via Ziegler–Natta catalysis and homogeneously, e.g., via constrained geometry catalysts. Most processes involving hydrogen rely on metal-based catalysts. Whereas bulk
hydrogenation Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organic ...
s (e.g., margarine production) rely on heterogeneous catalysts, for the production of fine chemicals such hydrogenations rely on soluble (homogenous) organometallic complexes or involve organometallic intermediates. Organometallic complexes allow these hydrogenations to be effected asymmetrically. Many
semiconductors A semiconductor is a material which has an electrical conductivity value falling between that of a conductor, such as copper, and an insulator, such as glass. Its resistivity falls as its temperature rises; metals behave in the opposite way. ...
are produced from trimethylgallium, trimethylindium,
trimethylaluminium Trimethylaluminium is one of the simplest examples of an organoaluminium compound. Despite its name it has the formula Al2( CH3)6 (abbreviated as Al2Me6 or TMA), as it exists as a dimer. This colorless liquid is pyrophoric. It is an industriall ...
, and trimethylantimony. These volatile compounds are decomposed along with
ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous ...
,
arsine Arsine (IUPAC name: arsane) is an inorganic compound with the formula As H3. This flammable, pyrophoric, and highly toxic pnictogen hydride gas is one of the simplest compounds of arsenic. Despite its lethality, it finds some applications ...
,
phosphine Phosphine (IUPAC name: phosphane) is a colorless, flammable, highly toxic compound with the chemical formula , classed as a pnictogen hydride. Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like rotting ...
and related hydrides on a heated substrate via
metalorganic vapor phase epitaxy Metalorganic vapour-phase epitaxy (MOVPE), also known as organometallic vapour-phase epitaxy (OMVPE) or metalorganic chemical vapour deposition (MOCVD), is a chemical vapour deposition method used to produce single- or polycrystalline thin films. ...
(MOVPE) process in the production of
light-emitting diode A light-emitting diode (LED) is a semiconductor Electronics, device that Light#Light sources, emits light when Electric current, current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy i ...
s (LEDs).


Organometallic reactions

Organometallic compounds undergo several important reactions: *
associative In mathematics, the associative property is a property of some binary operations, which means that rearranging the parentheses in an expression will not change the result. In propositional logic, associativity is a valid rule of replacement ...
and dissociative substitution * oxidative addition and reductive elimination * transmetalation * migratory insertion * β-hydride elimination * electron transfer * carbon-hydrogen bond activation *
carbometalation A carbometalation is any reaction where a carbon-metal bond reacts with a carbon-carbon π-bond to produce a new carbon-carbon σ-bond and a carbon-metal σ-bond. The resulting carbon-metal bond can undergo further carbometallation reactions (oli ...
* hydrometalation * cyclometalation * nucleophilic abstraction The synthesis of many organic molecules are facilitated by organometallic complexes.
Sigma-bond metathesis In organometallic chemistry, sigma-bond metathesis is a chemical reaction wherein a metal-ligand sigma bond undergoes metathesis (exchange of parts) with the sigma bond in some reagent. The reaction is illustrated by the exchange of lutetium Lutet ...
is a synthetic method for forming new carbon-carbon sigma bonds. Sigma-bond metathesis is typically used with early transition-metal complexes that are in their highest oxidation state. Using transition-metals that are in their highest oxidation state prevents other reactions from occurring, such as oxidative addition. In addition to sigma-bond metathesis, olefin metathesis is used to synthesize various carbon-carbon pi bonds. Neither sigma-bond metathesis or olefin metathesis change the oxidation state of the metal. Many other methods are used to form new carbon-carbon bonds, including
beta-hydride elimination β-Hydride elimination is a reaction in which an alkyl group bonded to a metal centre is converted into the corresponding metal-bonded hydride and an alkene. The alkyl must have hydrogens on the β-carbon. For instance butyl groups can undergo th ...
and insertion reactions.


Catalysis

Organometallic complexes are commonly used in catalysis. Major industrial processes include
hydrogenation Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organic ...
, hydrosilylation, hydrocyanation, olefin metathesis, alkene polymerization, alkene oligomerization, hydrocarboxylation, methanol carbonylation, and
hydroformylation Hydroformylation, also known as oxo synthesis or oxo process, is an industrial process for the production of aldehydes from alkenes. This chemical reaction entails the net addition of a formyl group (CHO) and a hydrogen atom to a carbon-carbon ...
. Organometallic intermediates are also invoked in many heterogeneous catalysis processes, analogous to those listed above. Additionally, organometallic intermediates are assumed for Fischer–Tropsch process. Organometallic complexes are commonly used in small-scale fine chemical synthesis as well, especially in
cross-coupling reaction In organic chemistry, a cross-coupling reaction is a reaction where two fragments are joined together with the aid of a metal catalyst. In one important reaction type, a main group organometallic compound of the type R-M (R = organic fragment, M ...
s that form carbon-carbon bonds, e.g.
Suzuki-Miyaura coupling The Suzuki reaction is an organic reaction, classified as a cross-coupling reaction, where the coupling partners are a boronic acid and an organohalide and the catalyst is a palladium(0) complex. It was first published in 1979 by Akira Suzuki, ...
, Buchwald-Hartwig amination for producing aryl amines from aryl halides, and
Sonogashira coupling The Sonogashira reaction is a cross-coupling reaction used in organic synthesis to form carbon–carbon bonds. It employs a palladium catalyst as well as copper co-catalyst to form a carbon–carbon bond between a terminal alkyne and an aryl or vi ...
, etc.


Environmental concerns

Natural and contaminant organometallic compounds are found in the environment. Some that are remnants of human use, such as organolead and organomercury compounds, are toxicity hazards.
Tetraethyllead Tetraethyllead (commonly styled tetraethyl lead), abbreviated TEL, is an organolead compound with the formula Pb( C2H5)4. It is a fuel additive, first being mixed with gasoline beginning in the 1920s as a patented octane rating booster that ...
was prepared for use as a
gasoline Gasoline (; ) or petrol (; ) (see ) is a transparent, petroleum-derived flammable liquid that is used primarily as a fuel in most spark-ignited internal combustion engines (also known as petrol engines). It consists mostly of organic c ...
additive but has fallen into disuse because of lead's toxicity. Its replacements are other organometallic compounds, such as
ferrocene Ferrocene is an organometallic compound with the formula . The molecule is a complex consisting of two cyclopentadienyl rings bound to a central iron atom. It is an orange solid with a camphor-like odor, that sublimes above room temperature, ...
and methylcyclopentadienyl manganese tricarbonyl (MMT). The
organoarsenic compound Organoarsenic chemistry is the chemistry of compounds containing a chemical bond between arsenic and carbon. A few organoarsenic compounds, also called "organoarsenicals," are produced industrially with uses as insecticides, herbicides, and fun ...
roxarsone is a controversial animal feed additive. In 2006, approximately one million kilograms of it were produced in the U.S alone. Organotin compounds were once widely used in anti-fouling paints but have since been banned due to environmental concerns.


See also

* Bioorganometallic chemistry * Metal carbon dioxide complex


References


Sources

* * * * * * * * *


External links


MIT OpenCourseWare: Organometallic Chemistry

Rob Toreki's Organometallic HyperTextbook

web listing of US chemists who specialize in organometallic chemistry
{{DEFAULTSORT:Organometallic Chemistry