dimethylmercury dimethylmercury dimethylmercury ((ch3)2hg), also known as mercury dimethanide, 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 inducing severe mercury poisoning resulting in death, and is easily absorbed through the skin. dimethylmercury is capable of permeating many materials, including plastic and rubber compounds. it has been described as having a slightly sweet odor, although those who have reported its smell were exposed to harmful amounts. dimethylmercury names iupac name dimethylmercury other names mercury dimethanide identifiers cas number 593-74-8 n 3d model (jsmol) interactive image beilstein reference 3600205 chebi chebi:30786 y chemspider 11155 y echa infocard 100.008.916 ec number 209-805-3 gmelin reference 25889 mesh dimethyl+mercury pubchem cid 11645 rtecs number ow3010000 unii c60tqu15xy y un number 2929 comptox dashboard (epa) dtxsid5047742 inchi inchi=1s/2ch3.hg/h2*1h3; ykey: atzbpovxvpiomr-uhfffaoysa-n y smiles cc properties chemical formula c2h6hg(ch3)2hg molar mass 230.66 g mol−1 appearance colorless liquid odor sweet density 2.961 g ml−1 melting point −43 °c (−45 °f; 230 k) boiling point 93 to 94 °c (199 to 201 °f; 366 to 367 k) refractive index (nd) 1.543 thermochemistry std enthalpy offormation (δfh⦵298) 57.9–65.7 kj mol−1 hazards occupational safety and health (ohs/osh): main hazards extremely flammable, extremely poisonous, persistent environmental pollutant ghs labelling: pictograms signal word danger hazard statements h224, h300+h310+h330, h372, h410 precautionary statements p260, p264, p273, p280, p284, p301+p310 nfpa 704 (fire diamond) 4 4 3 flash point 5 °c (41 °f; 278 k) related compounds related compounds dimethylzincdimethylcadmium except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). n verify (what is yn ?) infobox references synthesis, structure, and reactions the compound was one of the earliest organometallics reported, reflecting its considerable stability. the compound was first prepared by george buckton in 1857 by a reaction of methylmercury iodide with potassium cyanide: 2 ch3hgi + 2 kcn → hg(ch3)2 + 2 ki + (cn)2 + hg later, frankland discovered that it could be synthesized by treating sodium amalgam with methyl halides: hg + 2 na + 2 ch3i → hg(ch3)2 + 2 nai it can also be obtained by alkylation of mercuric chloride with methyllithium: hgcl2 + 2 lich3 → hg(ch3)2 + 2 licl the molecule adopts a linear structure with hg–c bond lengths of 2.083 å. reactivity and physical properties an unusual feature of this compound is its low reactivity towards proton sources, being stable in water and reacting with mineral acids at a significant rate only at elevated temperatures, whereas the corresponding organocadmium and organozinc compounds (and most metal alkyls in general) hydrolyze rapidly. the difference reflects the high electronegativity of hg (pauling en = 2.00) low affinity of hg(ii) for oxygen ligands. the compound undergoes a redistribution reaction with mercuric chloride to give methylmercury chloride: (ch3)2hg + hgcl2 → 2 ch3hgcl whereas dimethylmercury is a volatile liquid, methylmercury chloride is a crystalline solid. use dimethylmercury currently has few applications because of the risks involved. as with many methyl-organometallics, it is a methylating agent that can donate its methyl groups to an organic molecule; however, the development of less toxic nucleophiles such as dimethylzinc, trimethylaluminium, and grignard reagents (organomagnesium halides), has essentially rendered this compound obsolete in organic chemistry. it was also studied for reactions involving bonding methylmercury cations to target molecules, forming potent bactericides, but methylmercury's bioaccumulation and ultimate toxicity has led it to be largely abandoned in favor of the less toxic ethylmercury and diethylmercury compounds, which perform a similar function without the bioaccumulation hazard. in toxicology, it still finds limited use as a reference toxin. it is also used to calibrate nmr instruments for detection of mercury (δ 0 ppm for 199hg nmr), although diethylmercury and less toxic mercury salts are now preferred. safety dimethylmercury is extremely toxic and dangerous to handle. absorption of doses as low as 0.1 ml can result in severe mercury poisoning. the risks are enhanced because of the compound's high vapor pressure. medicinal chemist derek lowe called it "deadly and hideous" in a 2013 article. permeation tests showed that several types of disposable latex or polyvinyl chloride gloves (typically, about 0.1 mm thick), commonly used in most laboratories and clinical settings, had high and maximal rates of permeation by dimethylmercury within 15 seconds. the american occupational safety and health administration advises handling dimethylmercury with highly resistant laminated gloves with an additional pair of abrasion-resistant gloves worn over the laminate pair, and also recommends using a face shield and working in a fume hood. dimethylmercury is metabolized after several days to methylmercury. methylmercury crosses the blood–brain barrier easily, probably owing to formation of a complex with cysteine. it is not quickly eliminated from the organism, and therefore has a tendency to bioaccumulate. the symptoms of poisoning may be delayed by months, resulting in cases in which a diagnosis is ultimately discovered, but only at a point in which it is too late or almost too late for an effective treatment regimen to be successful. methylmercury poisoning is also known as minamata disease. incidents as early as 1865, two workers in the laboratory of frankland died after exhibiting progressive neurological symptoms following accidental exposure to the compound. karen wetterhahn, a professor of chemistry at dartmouth college, died in 1997, ten months after spilling only a few drops of dimethylmercury onto her latex gloves. this incident resulted in improved safety procedures for chemical-protection clothing and fume hood use. on 15 july 2011, de:christoph bulwin, a 40 year old german database administrator for ig bergbau, chemie, energie was stabbed by a yet unidentified suspect with a bulgarian umbrella in the city of hanover, germany (at 52.37828°n 9.71976°e﻿ / 52.37828; 9.71976), with no apparent motive. bulwin, who died a year later, had managed during an ensuing confrontation to take the syringe from the umbrella, which was later analyzed to contain dimethylmercury; the reported cause of death was mercury poisoning.