| 词条 | Dimethylmercury |
| 释义 |
| Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 460790372 | ImageFile = Dimethylmercury Structural Formulae V2.svg | ImageFile_Ref = {{Chemboximage|correct|??}} | ImageSize = 150 | ImageName = Skeletal formula of dimethylmercury with all hydrogens added | ImageFile1 = Dimethyl-mercury-3D-vdW.png | ImageFile1_Ref = {{Chemboximage|correct|??}} | ImageSize1 = 150 | ImageName1 = Spacefill model of dimethylmercury | IUPACName = Dimethylmercury[1] |Section1={{Chembox Identifiers | CASNo = 593-74-8 | CASNo_Ref = {{cascite|changed|??}} | PubChem = 11645 | ChemSpiderID = 11155 | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | UNII = C60TQU15XY | UNII_Ref = {{fdacite|correct|FDA}} | EINECS = 209-805-3 | UNNumber = 3383 | MeSHName = dimethyl+mercury | ChEBI = 30786 | ChEBI_Ref = {{ebicite|correct|EBI}} | RTECS = OW3010000 | Beilstein = 3600205 | Gmelin = 25889 | SMILES = C[Hg]C | StdInChI = 1S/2CH3.Hg/h2*1H3; | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = ATZBPOVXVPIOMR-UHFFFAOYSA-N | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} }} |Section2={{Chembox Properties | Formula = {{Chem|HgC|2|H|6}} | MolarMass = 230.66 g mol−1 | Appearance = Colorless liquid | Density = 2.961 g mL−1 | MeltingPtC = -43 | BoilingPtC = 93 to 94 | RefractIndex = 1.543 | Odor = Sweet }} |Section3={{Chembox Thermochemistry | DeltaHf = 57.9–65.7 kJ mol−1 }} |Section4={{Chembox Hazards | GHSPictograms = {{GHS skull and crossbones}}{{GHS health hazard}}{{GHS environment}} | GHSSignalWord = DANGER | HPhrases = {{H-phrases|300|310|330|373|410}} | PPhrases = {{P-phrases|260|264|273|280|284|301+310}} | NFPA-H = 4 | NFPA-F = 4 | NFPA-R = 3 | FlashPtC = 5 }} }} Dimethylmercury ((CH3)2Hg) is an 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, and is easily absorbed through the skin. Dimethylmercury is capable of permeating many materials, including plastic and rubber compounds.[2] It has a slightly sweet odor, although inhaling enough of the chemical to notice this would be hazardous. The acute toxicity of the compound was demonstrated by the death of heavy metal chemist Karen Wetterhahn, who died 10 months after a single exposure permeated through her disposable latex gloves. Synthesis, structure, and reactionsThe compound was one of the earliest organometallics reported, reflecting its considerable stability. It is formed 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.[3] ReactionsAn interesting feature of this compound is its unreactivity toward water and the fact that it reacts with mineral acids at a significant rate only at elevated temperatures,[4][5] whereas the corresponding organocadmium and organozinc compounds hydrolyze rapidly. The difference reflects the low affinity of Hg(II) for oxygen ligands. The compound reacts with mercuric chloride to give the mixed chloro-methyl compound: (CH3)2Hg + HgCl2 → 2 CH3HgCl Whereas dimethylmercury is a volatile liquid, CH3HgCl is a crystalline solid.[6] UseDimethylmercury 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 acutely toxic nucleophiles such as dimethylzinc and trimethylaluminium, and the subsequent introduction of Grignard reagents (organometallic halides), has essentially rendered this compound obsolete in organic chemistry. It was formerly studied for reactions in which the methylmercury cation was bonded to the target molecule, forming potent bactericides; however, the bioaccumulation and ultimate toxicity of methylmercury has largely led it to be abandoned for this purpose in favor of the less toxic diethylmercury and ethylmercury compounds, which perform a similar function without the bioaccumulation hazard. In toxicology, it was formerly used as a reference toxin. It has also been used to calibrate NMR instruments for detection of mercury, although diethylmercury and less toxic mercury salts are now preferred.[7][8][9] SafetyDimethylmercury is extremely toxic and dangerous to handle. Absorption of doses as low as 0.1 mL can result in severe mercury poisoning.[10] The risks are enhanced because of the high vapor pressure of the liquid.[10] 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.[11] 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.[10][12] Dimethylmercury is metabolized after several days to methylmercury.[11] Methylmercury crosses the blood–brain barrier easily, probably owing to formation of a complex with cysteine.[13] It is eliminated from the organism slowly, 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 the point in which it is too late for an effective treatment regimen to be successful.[13] The toxicity of dimethylmercury was highlighted with the death of Karen Wetterhahn, a professor of chemistry at Dartmouth College, in 1997. Professor Wetterhahn specialized in heavy metal poisoning. After she spilled a few drops of this compound on her latex glove, the barrier was compromised, and within minutes it was absorbed into her skin. It circulated through her body and accumulated in her brain, resulting in her death ten months later.[10] This accident is a common toxicology case-study and directly resulted in improved safety procedures for chemical-protection clothing and fume use, which are now called for when any exposure to such severely toxic and/or highly penetrative substances is possible (e.g., in chemical munitions stockpiles and decontamination facilities).{{citation needed|date=April 2016}} See also
References1. ^{{Cite web|title=dimethyl mercury - Compound Summary|url=https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=11645&loc=ec_rcs#x291|work=PubChem Compound|publisher=National Center for Biotechnology Information|accessdate=10 March 2012|location=USA|date=16 September 2004|at=Identification and Related Records}} 2. ^{{cite web | last = Agency for Toxic Substances and Disease Registry | authorlink = Agency for Toxic Substances and Disease Registry | title = Toxological profile for mercury | url = http://www.atsdr.cdc.gov/toxprofiles/tp.asp?id=115&tid=24 | publisher = United States Department of Health and Human Services, Public Health Service | date = March 1999 | accessdate = 16 August 2014 }} 3. ^{{ cite book |author1=Holleman, A. F. |author2=Wiberg, E. | title = Inorganic Chemistry | publisher = Academic Press | location = San Diego | year = 2001 | isbn = 0-12-352651-5 }} 4. ^{{Cite book|url=https://www.worldcat.org/oclc/61520528|title=The organometallic chemistry of the transition metals|last=1948-|first=Crabtree, Robert H.,|date=2005|publisher=John Wiley|year=|isbn=0471662569|edition= 4th|location=Hoboken, N.J.|pages=424|oclc=61520528}} 5. ^{{Cite book|url=https://books.google.com/books?id=GezvAAAAMAAJ|title=Chemistry of organomercurials in aquatic systems|last=Baughman|first=George L.|last2=Or.)|first2=National Environmental Research Center (Corvallis|date=1973|publisher=For sale by the Supt. of Docs., U.S. Govt. Print. Off.|year=|isbn=|location=|pages=34–40|language=en}} 6. ^{{Cite web|url=https://pubchem.ncbi.nlm.nih.gov/compound/Methylmercuric_chloride#section=Top|title=Methylmercury chloride|last=Pubchem|website=pubchem.ncbi.nlm.nih.gov|language=en|access-date=2018-09-16}} 7. ^{{ cite web | url = http://www.chem.northwestern.edu/~ohallo/HgNMRStandards/ | title = 199Hg Standards | date = 1998-03-10 |author1=O'Halloran, T. V. |author2=Singer, C. P. | publisher = Northwestern University | accessdate = 2012-05-24 }} 8. ^{{ cite web | title = (Hg) Mercury NMR | author = Hoffman, R. | date = 2011-08-01 | url = http://chem.ch.huji.ac.il/nmr/techniques/1d/row6/hg.html | publisher = The Hebrew University | location = Jerusalem | accessdate = 2012-05-24 }} 9. ^{{ cite web | url = http://orise.orau.gov/files/reacts/aoo-course-handouts/Module-6-Terrorism-by-Fear-and-Uncertainty-Delayed-Toxic-Syndromes.pdf | format = pdf | title = Delayed Toxic Syndromes | work = Terrorism by Fear and Uncertainty | publisher = ORAU }} 10. ^1 2 3 {{ cite web | url = http://www.osha.gov/dts/hib/hib_data/hib19980309.html | title = OSHA Safety Hazard Information Bulletin on Dimethylmercury | publisher = OSHA | work = Safety and Health Information Bulletins (SHIBs), 1997-1998 | date = 1991-02-15 }} 11. ^1 {{cite journal|last1=Nierenberg|first1=David W.|last2=Nordgren|first2=Richard E.|last3=Chang|first3=Morris B.|last4=Siegler|first4=Richard W.|last5=Blayney|first5=Michael B.|last6=Hochberg|first6=Fred|last7=Toribara|first7=Taft Y.|last8=Cernichiari|first8=Elsa|last9=Clarkson|first9=Thomas|title=Delayed Cerebellar Disease and Death after Accidental Exposure to Dimethylmercury|journal=New England Journal of Medicine|volume=338|issue=23|year=1998|pages=1672–1676|doi=10.1056/NEJM199806043382305|pmid=9614258}} 12. ^{{ cite web | author = Cotton, S. | url = http://www.chm.bris.ac.uk/motm/dimethylmercury/dmmh.htm | title = Dimethylmercury and Mercury Poisoning. The Karen Wetterhahn story | work = Molecule of the Month | date = October 2003 | publisher = Bristol University }} 13. ^1 {{Cite web|url = http://www.chm.bris.ac.uk/motm/dimethylmercury/dmmh.htm|title = The Karen Wetterhahn story|date = |accessdate = 1 September 2014|website = |publisher = }} External links
2 : Neurotoxins|Organomercury compounds |
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