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Author: Subject: Preparation of NaH from sodium metal.
draculic acid69
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[*] posted on 29-6-2021 at 00:44


What is RM R2M RMX?
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cirice1
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[*] posted on 29-6-2021 at 02:41


Quote: Originally posted by draculic acid69  
What is RM R2M RMX?

R - a carbon chain
M - metal
X - a halogen
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S.C. Wack
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[*] posted on 29-6-2021 at 14:16


It's a sign that beta-hydride elimination is a deep organometallic rabbit hole.



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njl
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[*] posted on 30-6-2021 at 04:49


Might the same concept apply to more easily obtained alkoxides? Equivalent beta elimination would give a carbonyl and hydride, right?



Reflux condenser?? I barely know her!
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Jenks
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[*] posted on 30-6-2021 at 07:54


Quote: Originally posted by njl  
Might the same concept apply to more easily obtained alkoxides? Equivalent beta elimination would give a carbonyl and hydride, right?

It would give a hydroxide and an alkene if it happened the same way.

[Edited on 30-6-2021 by Jenks]
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njl
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[*] posted on 30-6-2021 at 12:55


No, elimination of a beta hydrogen + electron from an alkoxide would give a carbonyl and hydride, elimination of hydroxide from an alkoxide is different and would give the alkene. I'm asking if beta hydride elimination with alkoxides is a viable path for hydrides ie elimination of hydride from methoxide to give formaldehyde.



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Panache
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[*] posted on 22-7-2021 at 17:59


Quote: Originally posted by S.C. Wack  
Quote: Originally posted by draculic acid69  
I think that Li reacts with the H2 around 60'c which is a bit easier than molten metals.


500

The easiest route to hydrides (not in the literature as a preparative method AFAIK) is by heating RM (R2M or RMX for Mg, etc) in oil.

[Edited on 28-6-2021 by S.C. Wack]


You can't stop there, especially when youve said the method cant be found in the lit (and this from the lit guru, one is inclined to believe you)
So dont be coy, time for shyness is over, off with your pants, what do you know, is it a huge one you are hiding, i dare say it is, as rm, rmgx's are a bit of a no brainer to make

Sorry if the sexual reference offends any....
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Panache
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[*] posted on 22-7-2021 at 18:05


Quote: Originally posted by S.C. Wack  
It's a sign that beta-hydride elimination is a deep organometallic rabbit hole.


oh and then this.....haha

here ill make it easy

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S.C. Wack
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[*] posted on 23-7-2021 at 16:07


It would be one of those reactions listed under formation (Bildung) rather than preparation (Darstellung), if it's listed anywhere at all. Yes, many organometallics are easy to make if the perfectly inert environment is provided for, and easy to decompose with enough heat (let's say 150-200C), this is what I know.

This elimination has been a noted reaction of all kinds of expensive organometallics when people are trying to make something else with maybe a little too much heat. No clue of the yield or purity of any hydride (when a metal hydride is formed) from the process, because AFAIK the hydride is completely ignored because no one cares, except maybe for noting that something found to be the hydride was identified. This is going back to at least 190-something (for Mg), if not earlier.




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S.C. Wack
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[*] posted on 24-7-2021 at 21:57


Quote: Originally posted by Panache  
(and this from the lit guru, one is inclined to believe you)


I've read very little of the organometallic original literature (none at all in German or French) however, and am as infallible as Catch-22's protagonist: ‘You’re going to be all right, kid,’ Yossarian assured him, patting his arm comfortingly. ‘Everything’s under control.’ Snowden shook his head feebly. ‘I’m cold,’ he repeated, with eyes as dull and blind as stone. ‘I’m cold.’
‘There, there,’ said Yossarian, with growing doubt and trepidation.


...but I'm good at quoting fiction. There's no doubt that hydrides can be formed in this way, but whether they should is unclear.

A brief search gave an example where the yield of metal cpd. is given. It's 95% but unfortunately there's no beta carbon, much less hydrogen, and thus no hydride. Heating methyllithium to 225C, etc., gives CH2Li2 and methane. If they still had Star Trek conventions, one could make an impression, and get the bomb squad called and venue evacuated, with (amorphous) (methylene)dilithium "crystals".




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S.C. Wack
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[*] posted on 10-8-2021 at 14:50


With the more reactive metals, hydrides can be made without heat from RM and H, easily, sometimes, says JACS 60, 2336 (1938). This works with sodium but is better with the heavier alkalis. BTW previous articles from that year are interesting...at p. 1019 (EtMgBr, vacuum, 220C, using the residue to reduce benzophenone) and p. 2333, where phenyllithium is added to slightly hydrogenated rings and refluxed in ether, producing the aromatic and LiH.



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JohnnyBuckminster
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[*] posted on 11-8-2021 at 00:09


Quote: Originally posted by rockyit98  
Thoisoi2 - Chemical Experiments! uploaded: This Chemical is Not from Our Planet! shows how dangerous NaH is


Demonstration of NaH starts at 08.40,

https://youtu.be/4EkbcBJnJk4?t=520
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