Sciencemadness Discussion Board

dimethyl mercury synthesis

Vikascoder - 1-6-2013 at 22:32

<div align="center"><img src="../scipics/_warn.png" /> <em>Mercury and it's compounds are <a href="http://en.wikipedia.org/wiki/Mercury_poisoning" target="_blank">cumulative neurotoxins</a> <img src="../scipics/_wiki.png" /> and <a href="http://en.wikipedia.org/wiki/Mercury_cycle" target="_blank">persistent environmental pollutants</a> <img src="../scipics/_wiki.png" />! Proceed at your own risk & <u>dispose of wastes responsibly</u>.</em> <img src="../scipics/_warn.png" /></div><br /><hr width="80%" />
I was searching for some toxic compounds of mercury . What I found that dimethyl mercury is very very toxic but I couldn't find its synthesis . If anyone knows the synthesis of dimethyl mercury then please post it and also post some extremely toxic compounds of mercury

<!-- bfesser_edit_tag -->[<a href="u2u.php?action=send&username=bfesser">bfesser</a>: added warning]

[Edited on 17.12.13 by bfesser]

12AX7 - 1-6-2013 at 23:56

I would imagine something simple like methyl lithium + mercuric chloride,
HgCl2 + 2 LiCH3 <--> Hg(CH3)2 + 2 LiCl
Done in a solvent where HgCl2 is soluble and LiCl is not (and where LiCH3 does not react..), it should proceed easily.

LiCH3 is pretty toxic in and of itself, so that should be of interest. Not so much chemically but more because it spontaneously bursts into flames.

There are probably simpler ways, including a bunch of stuff I used to know.

Or you can drop a bit of mercury into a sample of sea water and taste it infrequently. When you drop dead, you'll know it's working.

Tim

kristofvagyok - 2-6-2013 at 02:49

I have a little experience with organomercury chemistry, but I mostly worked with polyaromatic, large molecular weight substances what had limited solubility in water and could be easily decomposed to relative non toxic substances like HgI2.

For the commercial preparation they often cite the method what 12AX7 mentioned, or instead of MeLi what is not a really easily handled reagent they often use MeMgI.

There is also a third method, what is described in several journals, I first red it in "Inorganic Synthesis", it is based on the pyrolysis of mercury(II)-acetates. The only problem with this method is the high temperature. So if the glass breaks, you die.


And just some basic info what everyone knows, but its good to remind it:
Quote:

Dimethylmercury is extremely toxic and dangerous to handle. Absorption of doses as low as 0.1 mL has proven fatal.[6] The risks are enhanced because of the high vapor pressure of the liquid. Dimethylmercury passes through latex, PVC, butyl, and neoprene rapidly (within seconds) and is absorbed through the skin. Therefore, most laboratory gloves do not provide adequate protection from it, and the only safe precaution is to handle dimethylmercury while wearing highly resistant laminated gloves underneath long-cuffed neoprene or other heavy-duty gloves. A long face shield and work under a fume hood are also indicated.[6][7] Dimethylmercury crosses the blood–brain barrier easily, probably owing to formation of a complex with cysteine. It is eliminated from the organism slowly, and therefore has a tendency to bioaccumulate. The symptoms of poisoning may be delayed by months, possibly too late for effective treatment. The toxicity of dimethylmercury was highlighted with the death of the inorganic chemist Karen Wetterhahn of Dartmouth College in 1997, months after spilling no more than a few drops of this compound on her latex-gloved hand.[6]

weiming1998 - 2-6-2013 at 04:55

Wikipedia says that dimethyl mercury can be prepared by reacting sodium amalgam with a methyl halide (http://en.wikipedia.org/wiki/Dimethylmercury), which would be much easier than the route using methyllithium (extremely basic and pyrophoric). But just a word of advice: Do NOT actually make dimethyl mercury, unless you want to die several months later of mercury poisoning.

Hexavalent - 2-6-2013 at 05:49

Indeed, I recall a Dartmouth professor was killed some years ago by <FONT SIZE=+2> one drop of Me2Hg dropped on her gloved hand.</FONT SIZE=+2>

[Edited to correct HTML coding]



[Edited on 2-6-2013 by Hexavalent]

DJF90 - 2-6-2013 at 08:50

Quote: Originally posted by Vikascoder  
I was searching for some toxic compounds of mercury.


That'll be most of them then.
Quote:
What I found that dimethyl mercury is very very toxic but I couldn't find its synthesis


You didn't look particularly hard then. Either that or you have no idea about general approaches to organometallic compounds.
Quote:
...also post some extremely toxic compounds of mercury


Uh I don't think so, thanks. You killing yourself with these things is one thing, but having you endangering the lives of others with these cumulative heavy metal poisons is something I'd rather avoid.
Quote:
Indeed, I recall a Dartmouth professor was killed some years ago by one drop of Me2Hg dropped on her gloved hand.
.

Yes, it really is this poisonous. Her name was Karen Wetterhahn, IIRC. Its worth considering that it is the reference standard for 199Hg-NMR. LD50 of Me2Hg is supposedly 0.1 mL (thats 100 microliters!). Theres also this link: http://chemgroups.northwestern.edu/ohalloran/HgNMRStandards/ . Sums it up nicely I think.

zenosx - 2-6-2013 at 20:48

I just have to say, I really hope this is only for theoretical usage.

Vikascoder - 3-6-2013 at 00:35

What amount of elemental mercury is fatal to human . And also how much time does it takes to kill human

turd - 3-6-2013 at 00:50

Depends on state of matter and mode of intake. I doubt there are LD50 studies on humans.

woelen - 3-6-2013 at 02:19

@Vikascoder: Is this just a theoretical exercise for you, or do you really plan to make some dimethylmercury? Don't think you can handle that safely. You can't.

Adas - 3-6-2013 at 04:26

Why would anybody even want to make that? I would rather store 30 kilos of TATP than few drops of DMM.

Vikascoder - 3-6-2013 at 04:49

I am never going to make it . My hobby is to pen down the synthesis of most of the compounds which are toxic or explosive or serve as a medicine or are used for some other purposes. For just my knowledge I am asking the synthesis.


Anyway could anyone tell me what is the minimum amount of elemental mercury which is fatal if eaten through mouth and after how much time how does symptoms occurs and after how much time does person dies

ScienceSquirrel - 3-6-2013 at 05:35

You can easily research mercury toxicity yourself.

Vikascoder - 6-6-2013 at 08:09

Quote: Originally posted by ScienceSquirrel  
You can easily research mercury toxicity yourself.


I searched a lot on google . Bit just found about a article on Wikipedia named mercury poisoning. But I could not find about the toxicity of metallic mercury if it is eaten by any person. I couldn't find how much metallic mercury eaten is fatal to human. If someone knows then pleas tell

kristofvagyok - 6-6-2013 at 08:22

DO NOT TRY THIS AT HOME! This is my fav. story from mercury poisong. Pretty interesting, I would recommend it for everyone to read it:

http://www.nejm.org/doi/full/10.1056/NEJM200006153422405

Variscite - 6-6-2013 at 10:03

If I recall correctly, eating elemental Hg is not that bad, I think something like .001% is absorbed via your G.I. tract. Breathing the vapor is what will get you. I strongly advise against any handling or synthesizing of any mercury salts.

BlackDragon2712 - 25-11-2013 at 20:58

If there is an element which I love to work with is with mercury and come on guys! INORGANIC SALTS OF mercury ARE not that bad when you apply all the safety requirements to work with it, also is a usefull catalyst in organic chemistry so it is essential in a lab!

[Edited on 06/11/2013 by BlackDragon2712]

[Edited on 06/11/2013 by BlackDragon2712]

Pyro - 26-11-2013 at 09:19

according to wiki: ''MeI can also be used to prepare dimethylmercury, by reacting 2 moles of MeI with a 2/1-molar sodium amalgam (2 moles of sodium, 1 mol of mercury).''

http://en.wikipedia.org/wiki/Methyl_iodide

bfesser - 26-11-2013 at 09:45

Quote: Originally posted by BlackDragon2712  
Mercury is not that bad when you apply all the safety requirements to work with it!
Untrue. It is <a href="http://en.wikipedia.org/wiki/Karen_Wetterhahn" target="_blank">worse than you know</a> <img src="../scipics/_wiki.png" />. Please don't spread dangerous misinformation.

BlackDragon2712 - 26-11-2013 at 09:59

Quote: Originally posted by bfesser  
Quote: Originally posted by BlackDragon2712  
Mercury is not that bad when you apply all the safety requirements to work with it!
Untrue. It is <a href="http://en.wikipedia.org/wiki/Karen_Wetterhahn" target="_blank">worse than you know</a> <img src="../scipics/_wiki.png" />. Please don't spread dangerous misinformation.


Sorry I didn't explained myself properly, I was talking about inorganic salts of mercury. i've never worked with organo-mercury compounds so I have no idea how to deal with them. Again I do apologize. btw I knew about Karen Watterhahn.

Random - 26-11-2013 at 10:30

Nerve agents and compounds like these would be where I draw the line.

bismuthate - 26-11-2013 at 13:05

This site is dedicated to amateur science and as I see it Me2Hg should never be used in a home lab.

ScienceSquirrel - 26-11-2013 at 13:40

Metallic mercury is not very toxic as it is quite unreactive.
It had a lot of uses in the 17th to 19th century in the hat making business, scientific instruments, etc.
Long term exposure is not good; inhalation of the vapour seems worse than dealing with the liquid.
Mercury compounds vary in their toxicity.
Mercury I chloride is very insoluble and was used as a garden chemical until the latter part of the 20th century.
Similarly mercurochrome was widely available as a topical antiseptic and it is still available quite widely.
These compounds have quite low toxicity and are safe in the normal amounts used.
Soluble mercury salts eg mercury II chloride and nitrate are very toxic.
Alkyl mercury II compounds eg dimethyl mercury and diphenyl mercury are extremely toxic.

Random - 29-11-2013 at 04:57

There is also what is called mad hatter disease.

bismuthate - 29-11-2013 at 05:10

It's to late my dear. We're all mad here.
Sorry couldn't resist the the reference, though come to think of it this is a site for mad science

zed - 4-12-2013 at 16:28

Um. Seems like I remember how to do that. Isn't too difficult. But, since it is a serious environmental pollutant, could potentially be used as a WMD, and it doesn't even have the redeeming quality of getting folks high.......I'm not going to tell you.



...................................................................................................
"A man has to have a code" Omar (The Wire)

vmelkon - 5-12-2013 at 09:53

Quote: Originally posted by ScienceSquirrel  
Metallic mercury is not very toxic as it is quite unreactive.
It had a lot of uses in the 17th to 19th century in the hat making business, scientific instruments, etc.
Long term exposure is not good; inhalation of the vapour seems worse than dealing with the liquid.
Mercury compounds vary in their toxicity.
Mercury I chloride is very insoluble and was used as a garden chemical until the latter part of the 20th century.
Similarly mercurochrome was widely available as a topical antiseptic and it is still available quite widely.
These compounds have quite low toxicity and are safe in the normal amounts used.
Soluble mercury salts eg mercury II chloride and nitrate are very toxic.
Alkyl mercury II compounds eg dimethyl mercury and diphenyl mercury are extremely toxic.


It was used in the garden? I had heard it was in some facial cream for making your skin whiter. It has been reported that some creams in China still have it.

It is insane. No amount is safe since it bio accumulates.
Unfortunately it is everywhere (fluorescent tubes, mercury-argon "neon" signs for their blue color, low pressure and high pressure sodium lights.

Random - 5-12-2013 at 11:43

They also used to eat arsenic to whiten their face. Half dead but fashionable.

testimento - 6-12-2013 at 15:21

And the chinese emperor or whatever liked it enough to drink it and eventually ending up buried in it.

Dimethyl mercury is not that nasty in matter of amount required to kill: VX and Sarin can be counted in micrograms per minute, doses so small that with ordinary chemist equipment and safety precautions it is quite unavoidable to end up dead.

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

zed - 6-12-2013 at 17:04

VX and Sarin are hard to make, and quickly degraded. Building materials are hard to come by, and there are antidotes.

When that famous chemist was poisoned by a miniscule amount of Dimethyl-Mercury, the best doctors in the world were unable to diagnose and save her.

Grrr. This is why we usually don't give machine-guns to monkeys.

[Edited on 7-12-2013 by zed]

TheChemiKid - 6-12-2013 at 18:51

Quote: Originally posted by testimento  
And the chinese emperor or whatever liked it enough to drink it and eventually ending up buried in it.


Hah, what a coincidence. I learned about this in social studies just recently. This was Qin Shi Huang. He believed that it would provide immortality.
How wrong he was.:P

HarryB1 - 8-4-2016 at 23:15

Dissolve your mercury in chlorine bleach to obtain the chloride, neutralise the NaOH from the bleach with HCl carefully. I like to extract the chloride from the mess. Then simply dissolve in excess methanol with reflux. You can use your fractional distillation outfit or a simple reflux column to remove the excess methanol if you want or even distill the product, if you have any. I leave it in the methanol and freeze it until the guys from the I section or SAS pick it up.
I routinely use amalgams as catalysts so I take an excess of selenium to sequester heavies at ALL times. I'm still here.:P