Sciencemadness Discussion Board

Polar solvents

Hunterman2244 - 11-6-2018 at 12:20

Are there any polar solvents that won't react with sodium metal?
I have been trying to find some, but Google is horrible at providing relevant info when you have more than like one technical word.

DavidJR - 11-6-2018 at 12:21

Diethyl ether (and other ethers).

Hunterman2244 - 11-6-2018 at 12:27

Quote: Originally posted by DavidJR  
Diethyl ether (and other ethers).
From all I could find it is nonpolar.

DraconicAcid - 11-6-2018 at 12:33

How polar do you want? THF is more polar than diethyl ether, and so are the glymes.

DavidJR - 11-6-2018 at 12:38

Quote: Originally posted by Hunterman2244  
Quote: Originally posted by DavidJR  
Diethyl ether (and other ethers).
From all I could find it is nonpolar.


I suppose it's not that polar really. But categorization of polar/non-polar is sort of arbitrary. Diethyl ether has a dipole moment of 1.15D. For reference, completely non-polar molecules (e.g. alkanes) have dipole moment 0D and water has dipole moment 1.85D.

Hunterman2244 - 11-6-2018 at 12:58

Quote: Originally posted by DraconicAcid  
How polar do you want? THF is more polar than diethyl ether, and so are the glymes.
THF seems.just about perfect, anybody know if it can dissolve salt?

clearly_not_atara - 11-6-2018 at 13:32

If by "salt" you mean sodium chloride, no, it will not dissolve salt. Are you trying to electrolyze sodium chloride? You won't find a solvent that makes it easy, but you can dissolve sodium chloride in nitrobenzene in the presence of equimolar aluminum chloride and electrolyze it that way. Details are somewhere in this thread:

http://www.sciencemadness.org/talk/viewthread.php?tid=2105#p...

Warning: very difficult and dangerous reaction. Not for beginners. I suggest the "NurdRage" method instead.

Advice: Always post your actual goal when asking for help. If your idea is, in fact, really dumb, it's going to hurt much less to hear it from us than from the paramedics after you try it.

[Edited on 11-6-2018 by clearly_not_atara]

Hunterman2244 - 11-6-2018 at 14:12

Quote: Originally posted by clearly_not_atara  
If by "salt" you mean sodium chloride, no, it will not dissolve salt. Are you trying to electrolyze sodium chloride? You won't find a solvent that makes it easy, but you can dissolve sodium chloride in nitrobenzene in the presence of equimolar aluminum chloride and electrolyze it that way. Details are somewhere in this thread:

http://www.sciencemadness.org/talk/viewthread.php?tid=2105#p...

Warning: very difficult and dangerous reaction. Not for beginners. I suggest the "NurdRage" method instead.

Advice: Always post your actual goal when asking for help. If your idea is, in fact, really dumb, it's going to hurt much less to hear it from us than from the paramedics after you try it.

[Edited on 11-6-2018 by clearly_not_atara]

Yeah, I am working backwards. Starting at metal then medium, then compound. Will NaF dissolve?

DraconicAcid - 11-6-2018 at 14:21

If you want a sodium salt to dissolve in an organic solvent, you'd want an anion that is big and organic. Isopropoxide? Phenoxide?

Hunterman2244 - 11-6-2018 at 14:36

Quote: Originally posted by DraconicAcid  
If you want a sodium salt to dissolve in an organic solvent, you'd want an anion that is big and organic. Isopropoxide? Phenoxide?

Why so?
https://www.gelest.com/product/sodium-isopropoxide-20-in-tet... ironically

Sodium fluoride seems plausible, lack of data but still: http://ddbonline.ddbst.com/DDBSearch/onlineddboverview.exe?s...


[Edited on 11-6-2018 by Hunterman2244]

clearly_not_atara - 11-6-2018 at 14:37

Quote: Originally posted by Hunterman2244  
Quote: Originally posted by clearly_not_atara  
If by "salt" you mean sodium chloride, no, it will not dissolve salt. Are you trying to electrolyze sodium chloride? You won't find a solvent that makes it easy, but you can dissolve sodium chloride in nitrobenzene in the presence of equimolar aluminum chloride and electrolyze it that way. Details are somewhere in this thread:

http://www.sciencemadness.org/talk/viewthread.php?tid=2105#p...

Warning: very difficult and dangerous reaction. Not for beginners. I suggest the "NurdRage" method instead.

Advice: Always post your actual goal when asking for help. If your idea is, in fact, really dumb, it's going to hurt much less to hear it from us than from the paramedics after you try it.

[Edited on 11-6-2018 by clearly_not_atara]

Yeah, I am working backwards. Starting at metal then medium, then compound. Will NaF dissolve?
Did you read anything past the first sentence in that post? I just told you what dissolves: sodium tetrachloroaluminate. Also what it dissolves in: nitrobenzene. Random guesses will not work. Sodium fluoride is poorly soluble in water much less organic solvents.

You may also have some luck with such oddities as sodium hexafluorophosphate, sodium bis(oxalato)borate, or sodium tetrakis(3,5-bis(trifluoromethyl)-phenyl)borate.

Hunterman2244 - 11-6-2018 at 14:47

Quote: Originally posted by clearly_not_atara  
Quote: Originally posted by Hunterman2244  
Quote: Originally posted by clearly_not_atara  
If by "salt" you mean sodium chloride, no, it will not dissolve salt. Are you trying to electrolyze sodium chloride? You won't find a solvent that makes it easy, but you can dissolve sodium chloride in nitrobenzene in the presence of equimolar aluminum chloride and electrolyze it that way. Details are somewhere in this thread:

http://www.sciencemadness.org/talk/viewthread.php?tid=2105#p...

Warning: very difficult and dangerous reaction. Not for beginners. I suggest the "NurdRage" method instead.

Advice: Always post your actual goal when asking for help. If your idea is, in fact, really dumb, it's going to hurt much less to hear it from us than from the paramedics after you try it.

[Edited on 11-6-2018 by clearly_not_atara]

Yeah, I am working backwards. Starting at metal then medium, then compound. Will NaF dissolve?
Did you read anything past the first sentence in that post? I just told you what dissolves: sodium tetrachloroaluminate. Also what it dissolves in: nitrobenzene. Random guesses will not work. Sodium fluoride is poorly soluble in water much less organic solvents.

You may also have some luck with such oddities as sodium hexafluorophosphate, sodium bis(oxalato)borate, or sodium tetrakis(3,5-bis(trifluoromethyl)-phenyl)borate.

You gave one vague example, and what I have found seems to point other ways. I am exploring all possible options.

clearly_not_atara - 11-6-2018 at 15:18

Quote:
You gave one vague example, and what I have found seems to point other ways. I am exploring all possible options.
What you have found does not point in any of the directions you seem to think it does. If you just want to learn the theory, by all means dive into the textbooks, but don't expect to start making any sodium in the next year.

Instead, you should consider "exploring" the not one but two stickied threads about making sodium:

https://www.sciencemadness.org/whisper/viewthread.php?tid=21...
https://www.sciencemadness.org/whisper/viewthread.php?tid=21...

FWIW, sodium acetate, sodium isopropoxide, and sodium phenoxide are not good substrates for this reaction. The reason is that NaOAc and NaOPh will not dissolve in the right solvents and NaOiPr features a covalently-bonded sodium atom. In order to achieve success, you need to choose an anion which is non-coordinating:

http://en.wikipedia.org/wiki/Non-coordinating_anion

These include tetrachloroaluminate and the other examples I listed in the last post. One thing that might work if you're lucky is sodium iodide. The reason for the use of a NCA is that generally in an aprotic solvent sodium salts which do dissolve will dissolve as a molecule rather than dissociating into ions. For example, sodium isopropoxide will dissolve in various organic solvents, but it does not dissociate into Na+ and OiPr- ions in those solvents. Instead it is present as the molecule Na-OiPr which usually coordinates to several solvent molecules. You can only electrolyse a salt if it not only dissolves but dissociates in the solvent system in question.

https://en.wikipedia.org/wiki/Dissociation_(chemistry)

When the dissociated ions are present in solution the solution is called an electrolyte:

https://en.wikipedia.org/wiki/Electrolyte

DraconicAcid - 11-6-2018 at 15:38

Yes, but I would expect the aluminum in tetrachloroaluminate would be more easily reduced than the sodium ion. But if it's been shown to work, I won't argue with that.

[Edited on 11-6-2018 by DraconicAcid]

Hunterman2244 - 11-6-2018 at 18:26

Quote: Originally posted by DraconicAcid  
Yes, but I would expect the aluminum in tetrachloroaluminate would be more easily reduced than the sodium ion. But if it's been shown to work, I won't argue with that.

[Edited on 11-6-2018 by DraconicAcid]

I thought that too

Hunterman2244 - 11-6-2018 at 19:43

Sodium cyclopentadienide in THF seems reasonalbe.

Hunterman2244 - 11-6-2018 at 20:27

Borax on the also looks plausible.

walruslover69 - 12-6-2018 at 05:26

Propylene carbonate and some related compounds are polar with a dipole moment of 4.8 and inert to alkali metal.

Hunterman2244 - 12-6-2018 at 06:42

Quote: Originally posted by walruslover69  
Propylene carbonate and some related compounds are polar with a dipole moment of 4.8 and inert to alkali metal.
Based on the available literature this seems good. Getting it is another story, synthesis seems easy.

[Edited on 12-6-2018 by Hunterman2244]

clearly_not_atara - 12-6-2018 at 07:30

Quote: Originally posted by Hunterman2244  
Quote: Originally posted by DraconicAcid  
Yes, but I would expect the aluminum in tetrachloroaluminate would be more easily reduced than the sodium ion. But if it's been shown to work, I won't argue with that.

[Edited on 11-6-2018 by DraconicAcid]

I thought that too
Experiment says otherwise
Quote:
Sodium cyclopentadienide in THF

http://bard.cm.utexas.edu/resources/Bard-Reprint/428.pdf

Cyclopentadienide is more work than tetrachloroaluminate, though.

Quote:
Borax

You must be joking.

Hunterman2244 - 12-6-2018 at 08:51

Quote: Originally posted by clearly_not_atara  

Quote:
Borax

You must be joking.

No, why would I be? Just listing things.

Any way to do the propylene carbonate synthesis without heating.

clearly_not_atara - 12-6-2018 at 10:18

Sodium borates have no solubility in organic solvents. This information is easy to find.
Quote:
Any way to do the propylene carbonate synthesis without heating.
Honestly if you're not comfortable heating a mixture of propylene glycol and urea you have no business making sodium. Electrolysis of sodium salts in propylene carbonate is going to generate a lot of heat. It's not something that should be attempted without a plan in place for, say, the possibility that you start a fire in the flask. It should not catch fire, but that doesn't mean you can bet your life that it won't start a fire.

Your lackadaisical attitude towards the difficulty of sodium electrolysis strongly indicates that you are not prepared to attempt such a dangerous procedure. Propylene carbonate is flammable. Sodium is very flammable.

And anyway the far easier method of producing sodium (the NurdRage method) was pointed out to you earlier and you don't seem to have considered it, or, for that matter, to know what it is.

[Edited on 12-6-2018 by clearly_not_atara]

Hunterman2244 - 12-6-2018 at 11:45

Quote: Originally posted by clearly_not_atara  
Sodium borates have no solubility in organic solvents. This information is easy to find.
Quote:
Any way to do the propylene carbonate synthesis without heating.
Honestly if you're not comfortable heating a mixture of propylene glycol and urea you have no business making sodium. Electrolysis of sodium salts in propylene carbonate is going to generate a lot of heat. It's not something that should be attempted without a plan in place for, say, the possibility that you start a fire in the flask. It should not catch fire, but that doesn't mean you can bet your life that it won't start a fire.

Your lackadaisical attitude towards the difficulty of sodium electrolysis strongly indicates that you are not prepared to attempt such a dangerous procedure. Propylene carbonate is flammable. Sodium is very flammable.

And anyway the far easier method of producing sodium (the NurdRage method) was pointed out to you earlier and you don't seem to have considered it, or, for that matter, to know what it is.

[Edited on 12-6-2018 by clearly_not_atara]

Not uncomfortable, just wondering.
Its $30 on amazon.