Dr. Beaker
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synthesis of dimethyl zinc
Hi all,
I need to make ZnMe2, and have ZnCl2 and MeLi*LiBr in ether at my disposal. I think salt metathesis would work, but the questions are:
1. can I get read of the ether by vacuum (since I assume ether may complex the ZnMe2)
2. does ZnMe2 stable at RT? and in pure form? and to light?
3. what's its m.p and b.p (or sub. point)?
4. are there any good alternatives? since I also have MeI and Zn metal...
5. any recommanded purification techniques?
answer to one or more of these questions is highly appreciated .
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not_important
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Zn(CH3)2
BP 44, freezes ~ -29, bursts into enthusiastic flames if you so much as think of oxygen.
Can be made from MeI and a zn-Cu (5% or so) alloy.
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benzylchloride1
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A Grignard reagent could be used to synthesize Dimethyl Zinc. Example: Methyl Magnesium Iodide. Made from anhydrous Methyl Iodide, Anhydrous Diethyl
Ether and Magnesium. Anhydrous Zinc chloride could be used to add the zinc to the Grignard Reagent, producing Dimethyl Zinc.
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Dr. Beaker
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how can I seperate the ether from the ZnMe2? considering their close b.p
I was thinking to make the grignard in a higher b.p ether such as dibutyl ether or anisole (which I have).
or to add "something" (a lewis acid) which can bond the ether - much like a drying agent bond water.
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Nicodem
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| Quote: | Originally posted by Dr. Beaker
how can I seperate the ether from the ZnMe2? considering their close b.p |
Are you absolutely sure you want to do such insane things as isolating ZnMe<sub>2</sub>? I would not try to do that even in an
appropriately and fully equipped lab unless forced or well paid. Be careful and good luck. Out of curiosity, why do you need isolated
ZnMe<sub>2</sub> anyway?
You might want to check the hystorical account about organozinc compounds that was posted here of which however the Rapidshare link died, so out of courtesy I attached the paper bellow.
[Edited on by Nicodem]
Attachment: Zinc Alkyls, Edward Frankland, and the Beginnings of Main-Group Organometallic Chemistry.pdf (376kB)
This file has been downloaded 1114 times
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chemrox
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Nicodem-than ks for the post. Dr. Beaker- you couldn't look up the properties and you want to make the stuff? Maybe you might reconsider?
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Dr. Beaker
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Nicodem - thanx for your usefull input. I need it without ether, since it can interfeer with one of the next steps in the synthesis. and I'm not doing
it at my kitchen... I have high vacuum lines.
chemrox - I could take a month and do a complete lit. survey on Zn alkyls, becoming an expert myself, but it is sometimes more convinient to get leads
from ppl. with more experience on the matter, that will help me focus my survey.
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Dr. Beaker
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btw - 50 ml 2M sulution in toluene costs about 350$ at aldrich...
so this is a synthesis worth doing - economically.
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unionised
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this is a synthesis worth doing
Only if you need ZnEt2
What do you want it for> Have you looked to see if you can use something less dangerous?
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Dr. Beaker
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After considering it - I can use diethyl zinc, however it may affect some aspects of my next steps. but taking this line of thought further - I can
use dibenzyl zinc!
Zn(CH2ph)2 - I think I'll be able to evap. ether by reduced pressure, I just need to check that the dibenzyl deriv. is as unvolitile as I think it is.
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Eclectic
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This is Science Madness. We don't need no stinkin' safety!
I once made 100 ml of triethyl borane with only a small BLEVE when I discovered to my surprise that the reaction was highly exothermic AND the product
was spontainiously flammable.
Boiling ether fires are exciting! 
[Edited on 4-28-2007 by Eclectic]
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