Sciencemadness Discussion Board

Does anyone know much about how the mg catalyzed alkali reduction purification with dioxane works?

draculic acid69 - 6-3-2019 at 23:14

Does anyone understand much about how the dioxane separation of mg and Na or K works and what could work as a substitute or what is needed in order to affect separation? 1,4dioxane works, dimethyl dioxane doesn't,eucalyptol doesn't work.am I in the ball park by thinking diglyme might work because of its chelating properties that dioxane apparently has as well?

[Edited on 7-3-2019 by draculic acid69]

j_sum1 - 6-3-2019 at 23:38

All I know is that it works better if you have a good yield of dioxane. I have been miserable with my clean-up and it has affected what I have been able to accomlish.

12thealchemist - 7-3-2019 at 01:05

I suspect that sterics are a factor as well as chelating. Assuming you need chelating properties, eucalyptol automatically doesn't work. Throw in sterics, and eucalyptol is firmly out. Diglyme could well work, since it is very similar to dioxane. The only way to find out would be for someone to try it.

draculic acid69 - 7-3-2019 at 04:13

that's still one part of the rxn that hasn't been figured out yet.what is needed to affect the separation from magnesium? I think chelating properties participate for sure but it's just a guess. does b.p. or density play a role like they do in cleaning old alkali metals with isopropyl alcohol like in nilered's videos. Why does dioxane work but not dimethyl dioxane? I think steric hindrance may stop dimethyl dioxane working?does there need to be ether function to work? these still need to be answered to call it a day on this rxn.

draculic acid69 - 7-3-2019 at 04:17

What if 1,3propanediol was reacted like ethylene glycol to its ether(if it works) would it create an 8 membered cyclic ether like dioxane or are there completely different rxn products?

Dan Vizine - 7-3-2019 at 06:04

Quote: Originally posted by draculic acid69  
..... does b.p. or density play a role like they do in cleaning old alkali metals with isopropyl alcohol like in nilered's videos....



Just a side note to anyone who believes that 2-PrOH "cleans" Na or K...it doesn't. I'll admit that it makes it much prettier, nice and silvery, but it actually creates a largely invisible impurity which is very difficult to remove, the metal alkoxide. I have prepared literally hundreds of Na and K ampoules for the old GalliumSource site and for eBay. All Na or K "cleaned" by alcohols will wet glass, and all Na and K samples cleaned by cutting, washing, melting, filtering and vacuum application don't. Fluxing of metals and of some other solids by hot alkoxides is a well-known phenomenon.

[Edited on 3/7/2019 by Dan Vizine]

Endo - 7-3-2019 at 07:34

I was under the impression that the purification use of 1,4-dioxane was chosen for three reasons.

1)density between that of liquid sodium and magnesium, Dioxane density (1.03) Sodium Density (0.97) Magnesium density (1.74).
2) Unreactive to sodium metal
3) BP above the melting point of sodium metal.

This allows the sodium to be melted, and mechanically stirred allowing the beads to separate and drop out magnesium to the bottom of the beaker, a process driven almost exclusively by the density differences.

morganbw - 7-3-2019 at 14:42

Quote: Originally posted by Dan Vizine  
Quote: Originally posted by draculic acid69  
..... does b.p. or density play a role like they do in cleaning old alkali metals with isopropyl alcohol like in nilered's videos....



Just a side note to anyone who believes that 2-PrOH "cleans" Na or K...it doesn't. I'll admit that it makes it much prettier, nice and silvery, but it actually creates a largely invisible impurity which is very difficult to remove, the metal alkoxide. I have prepared literally hundreds of Na and K ampoules for the old GalliumSource site and for eBay. All Na or K "cleaned" by alcohols will wet glass, and all Na and K samples cleaned by cutting, washing, melting, filtering and vacuum application don't. Fluxing of metals and of some other solids by hot alkoxides is a well-known phenomenon.

[Edited on 3/7/2019 by Dan Vizine]


I may have a few pounds of sodium that passed by you. :)
Not ampoules but foil wrapped ounce sizes in transport can.

clearly_not_atara - 7-3-2019 at 14:51

Why do you want to substitute dioxane? It's not commercially available, but it's one of the easiest solvents to synthesize and it's made from a very common commodity chemical.

Eucalyptol, 1,3-propanediol, diglyme are all way harder to get than dioxane -- and no safer!

draculic acid69 - 9-3-2019 at 01:44

Quote: Originally posted by clearly_not_atara  
Why do you want to substitute dioxane? It's not commercially available, but it's one of the easiest solvents to synthesize and it's made from a very common commodity chemical.

Eucalyptol, 1,3-propanediol, diglyme are all way harder to get than dioxane -- and no safer!



That's a valid point but I was just curious as to whether diglyme would work and if it does will this help us better understand the mechanism behind it

draculic acid69 - 9-3-2019 at 01:47

Quote: Originally posted by Dan Vizine  
Quote: Originally posted by draculic acid69  
..... does b.p. or density play a role like they do in cleaning old alkali metals with isopropyl alcohol like in nilered's videos....



Just a side note to anyone who believes that 2-PrOH "cleans" Na or K...it doesn't. I'll admit that it makes it much prettier, nice and silvery, but it actually creates a largely invisible impurity which is very difficult to remove, the metal alkoxide. I have prepared literally hundreds of Na and K ampoules for the old GalliumSource site and for eBay. All Na or K "cleaned" by alcohols will wet glass, and all Na and K samples cleaned by cutting, washing, melting, filtering and vacuum application don't. Fluxing of metals and of some other solids by hot alkoxides is a well-known phenomenon.

[Edited on 3/7/2019 by Dan Vizine]



Didn't know that and now I do.

Dan Vizine - 22-3-2019 at 08:27

Quote: Originally posted by morganbw  
Quote: Originally posted by Dan Vizine  
Quote: Originally posted by draculic acid69  
..... does b.p. or density play a role like they do in cleaning old alkali metals with isopropyl alcohol like in nilered's videos....



Just a side note to anyone who believes that 2-PrOH "cleans" Na or K...it doesn't. I'll admit that it makes it much prettier, nice and silvery, but it actually creates a largely invisible impurity which is very difficult to remove, the metal alkoxide. I have prepared literally hundreds of Na and K ampoules for the old GalliumSource site and for eBay. All Na or K "cleaned" by alcohols will wet glass, and all Na and K samples cleaned by cutting, washing, melting, filtering and vacuum application don't. Fluxing of metals and of some other solids by hot alkoxides is a well-known phenomenon.

[Edited on 3/7/2019 by Dan Vizine]


I may have a few pounds of sodium that passed by you. :)
Not ampoules but foil wrapped ounce sizes in transport can.


Nope, not mine. I never sold any Na or K that wasn't sealed in vacuo in an ampoule.

[Edited on 3/22/2019 by Dan Vizine]