Dimethylzinc, also known as zinc methyl, DMZ, or DMZn, is a toxic

organozinc compound Organozinc chemistry is the study of the physical properties, synthesis, and reactions of organozinc compounds, which are organometallic compounds that contain carbon (C) to zinc (Zn) chemical bonds.The Chemistry of Organozinc Compounds' (Patai S ...

with the

chemical formula A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as pare ...

. It belongs to the large series of similar compounds such as

diethylzinc Diethylzinc, or DEZ, is an organozinc compound with the chemical formula . It is highly pyrophoric and reactive, consisting of a zinc center bound to two ethyl groups. This colourless liquid is an important reagent in organic chemistry. It is avail ...

Preparation

It is formed by the action of

methyl iodide Iodomethane, also called methyl iodide, and commonly abbreviated "MeI", is the chemical compound with the formula CH3I. It is a dense, colorless, volatile liquid. In terms of chemical structure, it is related to methane by replacement of one h ...

zinc Zinc is a chemical element; it has symbol Zn and atomic number 30. It 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 periodic tabl ...

or zinc-

sodium Sodium is a chemical element; it has Symbol (chemistry), symbol Na (from Neo-Latin ) and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 element, group 1 of the peri ...

alloy An alloy is a mixture of chemical elements of which in most cases at least one is a metal, metallic element, although it is also sometimes used for mixtures of elements; herein only metallic alloys are described. Metallic alloys often have prop ...

at elevated temperatures. : Sodium assists the reaction of the zinc with the methyl iodide.

Zinc iodide Zinc iodide is the inorganic compound with the formula ZnI2. It exists both in anhydrous form and as a dihydrate. Both are white and readily absorb water from the atmosphere. It has no major application. Preparation It can be prepared by the dire ...

is formed as a byproduct.

Properties

Dimethylzinc is a colorless mobile volatile

liquid Liquid is a state of matter with a definite volume but no fixed shape. Liquids adapt to the shape of their container and are nearly incompressible, maintaining their volume even under pressure. The density of a liquid is usually close to th ...

, which has a characteristic disagreeable garlic-like

odor An odor (American English) or odour ( Commonwealth English; see spelling differences) is a smell or a scent caused by one or more volatilized chemical compounds generally found in low concentrations that humans and many animals can perceive ...

. It is a very reactive and strong

reducing agent In chemistry, a reducing agent (also known as a reductant, reducer, or electron donor) is a chemical species that "donates" an electron to an (called the , , , or ). Examples of substances that are common reducing agents include hydrogen, carbon ...

. It is soluble in

alkanes In organic chemistry, an alkane, or paraffin (a historical trivial name that also has other meanings), is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in whi ...

and often sold as a solution in

hexanes The molecular formula C6H14 (molar mass: 86.17 g/mol) may refer to: * Dimethylbutanes ** 2,2-Dimethylbutane ** 2,3-Dimethylbutane * Hexane Hexane () or ''n''-hexane is an organic compound, a straight-chain alkane with six carbon atoms and t ...

. The

triple point In thermodynamics, the triple point of a substance is the temperature and pressure at which the three Phase (matter), phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium.. It is that temperature and pressure at ...

of dimethylzinc is ± 0.02 K. The

monomeric A monomer ( ; ''mono-'', "one" + '' -mer'', "part") is a molecule that can react together with other monomer molecules to form a larger polymer chain or two- or three-dimensional network in a process called polymerization. Classification Chemis ...

molecule of dimethylzinc is

linear In mathematics, the term ''linear'' is used in two distinct senses for two different properties: * linearity of a '' function'' (or '' mapping''); * linearity of a '' polynomial''. An example of a linear function is the function defined by f(x) ...

at Zn center and

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 (geometry), cube becomes a rectangular Pri ...

at C centers.

Structure

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

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 Vector (geometric), vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in t ...

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

gas-phase Gas is a state of matter that has neither a fixed volume nor a fixed shape and is a compressibility, compressible fluid. A ''pure gas'' is made up of individual atoms (e.g. a noble gas like neon) or molecules of either a single type of atom (ch ...

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

History

Dimethylzinc was first prepared by Edward Frankland 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 () is a public research university located in Marburg, Germany. It was founded in 1527 by Philip I, Landgrave of Hesse, which makes it one of Germany's oldest universities and the oldest still operating Prote ...

. After heating a mixture of zinc and

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; it has symbol Cu (from Latin ) 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 pinkish-orang ...

or copper compounds are used to activate the zinc.

Uses

Dimethylzinc has been of great importance in the

synthesis Synthesis or synthesize may refer to: Science Chemistry and biochemistry *Chemical synthesis, the execution of chemical reactions to form a more complex molecule from chemical precursors **Organic synthesis, the chemical synthesis of organi ...

organic compounds Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

. It was used for a long time to introduce methyl groups into organic molecules or to synthesize organometallic compounds containing methyl groups. Grignard reagents, (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 byproducts) 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 the production of

semiconductors A semiconductor is a material with electrical conductivity between that of a conductor and an insulator. Its conductivity can be modified by adding impurities (" doping") to its crystal structure. When two regions with different doping levels ...

, e.g. metalorganic chemical vapor deposition ( MOCVD) for the preparation of wide

band gap In solid-state physics and solid-state chemistry, a band gap, also called a bandgap or energy gap, is an energy range in a solid where no electronic states exist. In graphs of the electronic band structure of solids, the band gap refers to t ...

II–VI semiconducting films (e.g. ZnO, ZnS, ZnSe, ZnTe, ) and as p-

dopant A dopant (also called a doping agent) is a small amount of a substance added to a material to alter its physical properties, such as electrical or optics, optical properties. The amount of dopant is typically very low compared to the material b ...

precursors for III–V semiconductors (e.g.

AlN Aln, ALN, or AlN may refer to: Organizations Paramilitary * Ação Libertadora Nacional, a Brazilian Marxist–Leninist guerrilla movement * Armée de Libération Nationale, the armed wing of the nationalist National Liberation Front of Alge ...

, AlP, ,

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 circui ...

, InP), which have many electronic and photonic applications. It is used as an accelerator in rubber vulcanization, as a

fungicide Fungicides are pesticides used to kill parasitic fungi or their spores. Fungi can cause serious damage in agriculture, resulting in losses of yield and quality. Fungicides are used both in agriculture and to fight fungal infections in animals, ...

, and as a

methylating agent Methylation, in the chemical sciences, is the addition of a methyl group on a substrate, or the substitution of an atom (or group) by a methyl group. Methylation is a form of alkylation, with a methyl group replacing a hydrogen atom. These term ...

in methyltitanium trichloride.

Toxicity and hazards

Inhalation of dimethylzinc mist or vapor causes immediate irritation of the upper respiratory tract, and may cause

pneumonia Pneumonia is an Inflammation, inflammatory condition of the lung primarily affecting the small air sacs known as Pulmonary alveolus, alveoli. Symptoms typically include some combination of Cough#Classification, productive or dry cough, ches ...

and death. Eyes are immediately and severely irritated and burned by liquid, vapor, or dilute solutions. If not removed by thorough flushing with water, this chemical may permanently damage the

cornea The cornea is the transparency (optics), transparent front part of the eyeball which covers the Iris (anatomy), iris, pupil, and Anterior chamber of eyeball, anterior chamber. Along with the anterior chamber and Lens (anatomy), lens, the cornea ...

, eventually causing blindness. If dimethylzinc contacts the skin, it causes thermal and acid burns by reacting with moisture on skin. Unless washed quickly, skin may be scarred. Ingestion, while unlikely, also causes immediate burns. Nausea, vomiting, cramps, and diarrhea may follow, and tissues may

ulcer An ulcer is a discontinuity or break in a bodily membrane that impedes normal function of the affected organ. According to Robbins's pathology, "ulcer is the breach of the continuity of skin, epithelium or mucous membrane caused by sloughin ...

ate if not promptly treated. Upon heating, dimethylzinc vapor decomposes to irritating and toxic products. Contact of dimethylzinc with oxidants may form explosive

peroxides In chemistry, peroxides are a group of compounds with the structure , where the R's represent a radical (a portion of a complete molecule; not necessarily a free radical) and O's are single oxygen atoms. Oxygen atoms are joined to each other and ...

. Dimethylzinc oxidises in

air An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...

very slowly, producing methylzinc methoxide . Dimethylzinc is very

pyrophoric A substance is pyrophoric (from , , '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 organolithium compounds and triethylb ...

and can spontaneously ignite in air. It burns in air with a blue flame, giving off a garlic-like odor. The products of decomposition (fire smoke) include

zinc oxide Zinc oxide is an inorganic compound with the Chemical formula, formula . It is a white powder which is insoluble in water. ZnO is used as an additive in numerous materials and products including cosmetics, Zinc metabolism, food supplements, rubbe ...

, which itself is not toxic, but its fumes can irritate lungs and cause

metal fume fever Metal fume fever, also known as brass founders' ague, brass shakes, zinc shakes, galvie flu, galvo poisoning, metal dust fever, welding shivers, or Monday morning fever, is an illness primarily caused by exposure to chemicals such as zinc oxide (Zn ...

, severe injury, or death. Dimethylzinc fire must be extinguished with dry sand. The fire reacts violently or explosively with water, generating very flammable

methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The abundance of methane on Earth makes ...

gas which can explode in air upon catching fire, and lung-irritating smoke of

. Dimethylzinc fire reacts violently or explosively with

methanol Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical compound and the simplest aliphatic Alcohol (chemistry), alcohol, with the chemical formula (a methyl group linked to a hydroxyl group, often ab ...

ethanol Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...

and 2,2-dichloropropane. It explodes in

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

and

ozone Ozone () (or trioxygen) is an Inorganic compound, inorganic molecule with the chemical formula . It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope , break ...

. Improperly handled containers of dimethylzinc can explode, causing serious injuries or death.

References

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