DIMETHYLMERCURY Chemical Properties
- Melting point:
- −43 °C(lit.)
- Boiling point:
- 93-94 °C(lit.)
- 2.961 g/mL at 25 °C(lit.)
- refractive index
- Flash point:
- 42 °F
- storage temp.
- Flammables area
- Water Solubility
- insoluble H2O; soluble ether, alcohol [MER06]
- Exposure limits
- TLV-TWA: 0.01 mg (Hg)/m3 (ACGIH)
PEL-TWA: 0.01 mg (Hg)/m3 (OSHA)
STEL: 0.03 mg (Hg)/m3 (ACGIH)
The tolerable weekly intake (TWI) levels set by World Health Organization for methyl mercury is 1.6 μg/kg body weight. The reference dose (RfD) set by the U.S. EPA is 0.1 μg/kg body weight/day (Booth and Zeller (2005).
- Stable. Highly flammable. Incompatible with strong oxidizing agents.
- EPA Substance Registry System
- Dimethylmercury (593-74-8)
DIMETHYLMERCURY Usage And Synthesis
Mercury dimethyl is a toxic environmental pollutant. It is found in polluted bottom sediments and in the bodies of fishes and birds. In the bodies of fishes and birds it occurs along with monomethyl mercury. The latter, as CH3Hg+ ion, is formed by microorganism-induced biological methylation of elemental mercury or agricultural fungicide mercury compounds that are discharged into the environment.
Mercury dimethyl is used in inorganic synthesis; and as a reference standard for Hg-NMR.
Mercury dimethyl, unlike zinc dimethyl, is fairly stable at ordinary temperatures, and is not attacked by air or water.
Mercury dimethyl undergoes single replacement reactions with several metals such as alkali and alkaline earth metals, zinc, aluminum, tin, lead and bismuth forming their corresponding dialkyls.
Such reaction is a synthetic route to prepare many organometallic compounds. Thus, reaction with metallic zinc yields zinc dimethyl:
(CH3)2Hg + Zn → (CH3)2Zn + Hg
Mercury dimethyl is a highly toxic substance by all routes of exposure. Several cases of human poisoning are well documented. (Patnaik, P. 1999. A Comprehensive Guide to the Hazardous Properties of Chemical Substances, 2nd ed. p. 574, New York: John Wiley & Sons.) The compound can accumulate in the brain and blood of humans. Intake of small quantities can cause death.
Dimethyl mercury is a volatile colorless liquid with faint sweet odor.
As inorganic reagent.
Dimethylmercury is used as a reagent ininorganic synthesis, and as a reference standardfor mercury nuclear magnetic resonance(Hg NMR). It is an environmental pollutantfound in bottom sediments and also inthe bodies of birds and marine mammalssuch as whales and fishes. It occurs in fishesand birds along with monomethylmercury. Inhumans, its presence is attributed to the consumptionof pilot whale meat, cod fish, andother sea food.
All alkylmercury compounds are highly toxicby all routes of exposure. There are manyserious cases of human poisoning frommethylmercury (Lu 2003). Outbreaks ofmass poisoning from consumption of contaminatedfish occurred in Japan during the1950s, causing a severe neurological disease,so-called “Minamata disease,” whichresulted in hundreds of deaths. A similaroutbreak of food poisoning from contaminatedwheat caused several hundred deathsin Iraq in 1972. A tragic death from a singleacute transdermal exposure to dimethylmercury(estimated between 0.1 to 0.5 mL) thatpenetrated into the skin through disposablelatex gloves has occurred (Blayney et al.1997; The New York Times, June 11, 1997).The symptoms reported were episodes ofnausea and vomiting occurring three monthsafter the exposure followed by onset ofataxia, slurred speech (dysarthia), and loss ofvision and hearing 2 months after that. Thedeath occurred in about six months after theaccident.
Methylmercury can concentrate in certainfetal organs, such as the brain. Thetarget organs are the brain and the centralnervous system. It can cause death, miscarriage,and deformed fetuses. Unlike inorganicmercury compounds, it can penetrate throughthe membrane barrier of the erythrocyte,accumulating at about 10 times greater concentrationthan that in the plasma (WHO1976). Its rate of excretion on the bloodlevel is very slow. It gradually accumulatesin the blood. Such accumulation was found toreach 60% equilibrium at about 90 days, culminatedafter 270 days (Munro and Willes,1978). Skin absorption exhibits the symptomsof mercury poisoning. The toxic thresholdconcentration of mercury in the wholeblood is usually in the range 40 to 50 μg/L,while the normal range should be below10 μg/L.
It is a flammable liquid; flash point 38°C (101°F). The flammability of this compound, its ease of oxidation and the energy of decomposition is relatively lower than the alkyls of lighter metals. It is mildly endothermic. The heat of formation, △H°f is ＋75.3 kJ/mol (Bretherick 1995). Unlike most other metal alkyls formed by elements of lower atomic numbers, dimethylmercury does not pose any serious fire or explosion hazard. Although it does not ignite in air, the compound is easily inflammable. It dissolves in lower alcohols without any violent decomposition. Heating with oxidizing substances can cause explosion. Violent explosion is reported with diboron tetrachloride at －63°C (－81°F) under vacuum (Wartik et al. 1971).
Suspected carcinogen. Highly toxic. Mutation data reported. Easily flammable. When heated to decomposition it emits toxic fumes of Hg.
Dimethyl mercury has been used as seed disinfectants and for fungicides. It has also been used in organic synthesis.
UN2025 Mercury compounds, solid, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required.
Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides. May be sensitive to light.
- MERCURIC POTASSIUM CYANIDE
- MERCURIC OXYCYANIDE
- DITHYMINYL MERCURY
- ZERENEX ZX011627
- MERCURY DI-N-HEXYL
- MERCURIC CYANIDE
- DIPROPYL MERCURY
- MERCURY(II) DITHIZONATE
- DIISOPROPYL MERCURY
- DIBUTYL MERCURY
- 021-54306202- ;021-54308259-
- Please Email
- 021-58892003- ;021-50396381