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 Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...

at elevated temperature or on zinc sodium alloy. :2Zn + 2CH₃I → Zn(CH₃)₂ + ZnI₂ The sodium assists the reaction of the zinc with the methyl iodide. Zinc iodide is formed as a byproduct. It has a disagreeable odor, and is

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 organolit ...

. It has been of great importance in the synthesis of

organic compounds 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 s ...

. It is soluble in alkanes and often sold as a solution in hexanes. It belongs to the large series of similar compounds such as

diethylzinc Diethylzinc (C2H5)2Zn, or DEZ, is a highly pyrophoric and reactive organozinc compound consisting of a zinc center bound to two ethyl groups. This colourless liquid is an important reagent in organic chemistry. It is available commercially as a ...

History

This substance was first prepared by

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 ...

during his work with

Robert Bunsen Robert Wilhelm Eberhard Bunsen (; 30 March 1811 – 16 August 1899) was a German chemist. He investigated emission spectra of heated elements, and discovered caesium (in 1860) and rubidium (in 1861) with the physicist Gustav Kirchhoff. The Bu ...

in 1849 at the

University of Marburg The Philipps University of Marburg (german: Philipps-Universität Marburg) was founded in 1527 by Philip I, Landgrave of Hesse, which makes it one of Germany's oldest universities and the oldest still operating Protestant university in the wor ...

. After heating a mixture of zinc and methyl iodide in an airtight vessel, a flame burst out when the seal was broken. In the laboratory, this synthesis method remains unchanged today, except that

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 pinkis ...

or copper compounds are used to activate the zinc.

Uses

Dimethyl zinc was used for a long time to introduce methyl groups into organic molecules or to synthesize organometallic compounds containing methyl groups.

Grignard reagents 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 . ...

, (organo-magnesium compounds), which are easier to handle and less flammable replaced organo-zinc compounds in most laboratory syntheses. Due to differences in reactivity (as well as in reaction by-products) between organo-zinc compounds and Grignard reagents, organo-zinc compounds may be preferred in some syntheses. Its high vapor pressure has led to extensive uses in metalorganic chemical vapor deposition (

MOCVD 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. ...

) for the preparation of wide

band gap In solid-state physics, a band gap, also called an energy gap, is an energy range in a solid where no electronic states can exist. In graphs of the electronic band structure of solids, the band gap generally refers to the energy difference ( ...

II–VI

semiconducting A semiconductor is a material which has an electrical resistivity and conductivity, electrical conductivity value falling between that of a electrical conductor, conductor, such as copper, and an insulator (electricity), insulator, such as glas ...

films (e.g. ZnO,

ZnS ZNS or ZnS may refer to: * Zinc sulfide or zinc sulphide (ZnS), a chemical compound * ZNS-TV, a national radio and TV broadcaster operated by the state-owned Broadcasting Corporation of The Bahamas ** ZNS-1 ZNS-1 (branded as ''Radio Bahamas'') i ...

, ZnSe,

ZnTe Zinc telluride is a binary chemical compound with the formula ZnTe. This solid is a semiconductor material with a direct band gap of 2.26 eV. It is usually a p-type semiconductor. Its crystal structure is cubic, like that for sphalerite and ...

) and as p-

dopant A dopant, also called a doping agent, is a trace of impurity element that is introduced into a chemical material to alter its original electrical or optical properties. The amount of dopant necessary to cause changes is typically very low. When ...

precursors for III–V semiconductors (e.g.

GaAs Gallium arsenide (GaAs) is a III-V direct band gap semiconductor with a zinc blende crystal structure. Gallium arsenide is used in the manufacture of devices such as microwave frequency integrated circuits, monolithic microwave integrated circ ...

InP Indium phosphide (InP) is a binary semiconductor composed of indium and phosphorus. It has a face-centered cubic (" zincblende") crystal structure, identical to that of GaAs and most of the III-V semiconductors. Manufacturing Indium phosphide c ...

, Al_xGa_1−xAs), which have many

electronic Electronic may refer to: *Electronics, the science of how to control electric energy in semiconductor * ''Electronics'' (magazine), a defunct American trade journal *Electronic storage, the storage of data using an electronic device *Electronic co ...

and

photonic Photonics is a branch of optics that involves the application of generation, detection, and manipulation of light in form of photons through emission, transmission, modulation, signal processing, switching, amplification, and sensing. Though ...

applications.

Structure

In the solid state the compound exists in two modifications. The

tetragonal In crystallography, the tetragonal crystal system is one of the 7 crystal systems. Tetragonal crystal lattices result from stretching a cubic lattice along one of its lattice vectors, so that the cube becomes a rectangular prism with a squar ...

high-temperature phase shows a two-dimensional disorder, while the low-temperature phase which is

monoclinic In crystallography, the monoclinic crystal system is one of the seven crystal systems. A crystal system is described by three vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in the orthorhombic s ...

is ordered. The molecules are linear with Zn-C bond lengths measuring 192.7(6) pm. The structure of the

gas-phase Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma). A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or ...

shows a very similar Zn-C distance of 193.0(2) pm.

References

{{Authority control Methylating agents Organozinc compounds Foul-smelling chemicals Methyl complexes