Organomercury refers to the group of

organometallic Organometallic chemistry is the study of organometallic compounds, chemical compounds containing at least one chemical bond between a carbon atom of an organic molecule and a metal, including alkali, alkaline earth, and transition metals, and ...

compounds that contain mercury. Typically the Hg–C bond is stable toward air and moisture but sensitive to light. Important organomercury compounds are the methylmercury(II) cation, CH₃Hg⁺; ethylmercury(II) cation, C₂H₅Hg⁺;

dimethylmercury Dimethylmercury (( C H3)2 Hg) is an extremely toxic organomercury compound. A highly volatile, reactive, flammable, and colorless liquid, dimethylmercury is one of the strongest known neurotoxins, with a quantity of less than 0.1 mL capable of i ...

, (CH₃)₂Hg,

diethylmercury Diethylmercury is a flammable, colorless liquid, and one of the strongest known neurotoxins. This organomercury compound is described as having a slightly sweet smell, though inhaling enough fumes to notice this would be hazardous. This chemical ...

and merbromin ("Mercurochrome").

Thiomersal Thiomersal ( INN), or thimerosal ( USAN, JAN), is an organomercury compound. It is a well-established antiseptic and antifungal agent. The pharmaceutical corporation Eli Lilly and Company gave thiomersal the trade name Merthiolate. It has bee ...

is used as a preservative for vaccines and intravenous drugs. The toxicity of organomercury compounds presents both dangers and benefits. Dimethylmercury in particular, is notoriously toxic, but found use as an

antifungal agent An antifungal medication, also known as an antimycotic medication, is a pharmaceutical fungicide or fungistatic used to treat and prevent mycosis such as athlete's foot, ringworm, candidiasis (thrush), serious systemic infections such as crypto ...

and insecticide. Merbromin and phenylmercuric borate are used as topical antiseptics, while nitromersol is used as a preservative for vaccines and antitoxins.

Synthesis

Organomercury compounds are generated by many methods, including the direct reaction of hydrocarbons and mercury(II) salts. In this regard, organomercury chemistry more closely resembles organopalladium chemistry and contrasts with

organocadmium compounds An organocadmium compound is an organometallic compound containing a carbon to cadmium chemical bond. Organocadmium chemistry describes physical properties, synthesis, reactions and use of these compounds. Cadmium shares group 12 with zinc an ...

Mercuration of aromatic rings

Electron-rich

arene Aromatic compounds, also known as "mono- and polycyclic aromatic hydrocarbons", are organic compounds containing one or more aromatic rings. The parent member of aromatic compounds is benzene. The word "aromatic" originates from the past grouping ...

s undergo mercuration upon treatment with Hg(O₂CCH₃)₂. The one acetate group that remains on mercury can be displaced by chloride: :C₆H₅OH + Hg(O₂CCH₃)₂ → C₆H₄(OH)–2-HgO₂CCH₃ + CH₃CO₂H :C₆H₄(OH)–2–HgO₂CCH₃ + NaCl → C₆H₄(OH)–2-HgCl + NaO₂CCH₃ The first such reaction, including a mercuration of

benzene Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen ato ...

itself, was reported by

Otto Dimroth Otto Dimroth (28 March 1872 – 16 May 1940) was a German chemist. He is known for the Dimroth rearrangement, as well as a type of condenser with an internal double spiral, the Dimroth condenser In chemistry, a condenser is laboratory apparat ...

between 1898 and 1902.

Addition to alkenes

The Hg²⁺ center binds to alkenes, inducing the addition of

hydroxide Hydroxide is a diatomic anion with chemical formula OH−. It consists of an oxygen and hydrogen atom held together by a single covalent bond, and carries a negative electric charge. It is an important but usually minor constituent of water ...

and alkoxide. For example, treatment of methyl acrylate with mercuric acetate in methanol gives an α--mercuri ester: :Hg(O₂CCH₃)₂ + CH₂=CHCO₂CH₃ → CH₃OCH₂CH(HgO₂CCH₃)CO₂CH₃ The resulting Hg-C bond can be cleaved with

bromine Bromine is a chemical element with the symbol Br and atomic number 35. It is the third-lightest element in group 17 of the periodic table (halogens) and is a volatile red-brown liquid at room temperature that evaporates readily to form a simil ...

to give the corresponding

alkyl In organic chemistry, an alkyl group is an alkane missing one hydrogen. The term ''alkyl'' is intentionally unspecific to include many possible substitutions. An acyclic alkyl has the general formula of . A cycloalkyl is derived from a cycloal ...

bromide: :CH₃OCH₂CH(HgO₂CCH₃)CO₂CH₃ + Br₂ → CH₃OCH₂CHBrCO₂CH₃ + BrHgO₂CCH₃ This reaction is called the Hofmann-Sand Reaction.

Reaction of Hg(II) compounds with carbanion equivalents

A general synthetic route to organomercury compounds entails alkylation with Grignard reagents and

organolithium compound In organometallic chemistry, organolithium reagents are chemical compounds that contain carbon–lithium (C–Li) bonds. These reagents are important in organic synthesis, and are frequently used to transfer the organic group or the lithium atom ...

s. Diethylmercury results from the reaction of

mercury chloride Mercury chloride can refer to: * Mercury(II) chloride or mercuric chloride (HgCl2) * Mercury(I) chloride or mercurous chloride (Hg2Cl2) {{Short pages monitor