Sciencemadness Discussion Board

Metal Isopropoxides

Abromination - 13-8-2018 at 23:18

I have been wondering lately if I could make isopropoxide metal salts with the same mercury and iodine catalyzed reaction as the one used to make aluminum isopropoxide. Lets say, oh, copper isopropoxide as copper salts are so beautiful.

If the procedure is the same with aluminium isopropoxide, I would require the following:
300mL isopropanol
.2g iodine
27g copper metal
1.65g mercuric chloride

Add the coarsely cut pieces of copper foil to a 2 necked flask with a condenser and drying tube with magnesium sulfate on the middle neck. The preparation is quite water sensitive.
Then add the isopropanol (pure as possible) to the flask via the other opening.
Dissolve the mercuric chloride in 40mL of isopropanol and add dropwise to the flask. Proceed to add the iodine.
Turn on the condenser and heat the mixture with stirring.
Let react until all copper is consumed.

This entire reaction depends on whether or not an amalgum is formed with the copper or if copper is even capable to react with isopropanol. I dont know the point of the iodine. Maybe to help form the aluminium amalgum? The procedure is just NileReds aluminium isopropoxide procedure with copper instead of aluminum. Ill sleep on it but I can think of a better procedure (and maybe one that might work) involving lithium (cause I dont have sodium).
Id appreciate some suggestions.

DavidJR - 14-8-2018 at 02:52

Not sure that will work... From what I've read you can prepare copper alkoxides by reacting lithium alkoxides with anhydrous copper (II) chloride.

http://sci-hub.tw/https://onlinelibrary.wiley.com/doi/pdf/10...

CobaltChloride - 14-8-2018 at 03:13

I'm almost sure this wouldn't work. Copper doesn't convert to Cu 2+ ions without the addition of an oxidizing agent. In the mixture you proposed there is no oxidizing agent. If the reaction proposed by you would be possible, then copper should dissolved in HCl, which it obviously doesn't.

The iodine added in the procedure for making aluminium isopropoxide has the role to etch the surface of the metal in order to allow it to react with the isopropanol.

On the other hand, I'm almost sure you could make magnesium and lanthanide isopropoxides by the same procedure used for making aluminium isopropoxide because all those metals are fairly reactive.

Abromination - 14-8-2018 at 12:36

Exactly what I thought. It might work with zinc or something, but no matter. I think a better way would to be to add lithium metal to pure isopropanol to make lithium isopropoxide which would then be mixed with copper sulfate. What is the acid for isopropanol? (Like methanol and formic acid)

fusso - 14-8-2018 at 12:43

Quote: Originally posted by Abromination  
Exactly what I thought. It might work with zinc or something, but no matter. I think a better way would to be to add lithium metal to pure isopropanol to make lithium isopropoxide which would then be mixed with copper sulfate. What is the acid for isopropanol? (Like methanol and formic acid)
IPA would only be oxidized to acetone and not to an acid

DraconicAcid - 14-8-2018 at 12:47

Quote: Originally posted by Abromination  
Exactly what I thought. It might work with zinc or something, but no matter. I think a better way would to be to add lithium metal to pure isopropanol to make lithium isopropoxide which would then be mixed with copper sulfate. What is the acid for isopropanol? (Like methanol and formic acid)


Zinc won't react with an alcohol in the same way that it doesn't react readily with water. Water is more reactive with metals than alcohols are.

Copper sulphate wouldn't be a good source of copper because it's poorly soluble in organic solvents (and you MUST keep this reaction anhydrous, or all you'll get is copper(II) hydroxide, or oxide if you heat it). Anhydrous copper(II) chloride would work better. I'm not sure how stable copper(II) isopropoxide is- I wouldn't be surprised if it decomposed.

I don't know what you mean about "What is the acid for isopropanol?" Methanol can be oxidized to formic acid because it is a primary alcohol (or, close enough). Isopropanol is a secondary alcohol, and can only be oxidized to a ketone (acetone in this case).

[Edited on 14-8-2018 by DraconicAcid]

Abromination - 14-8-2018 at 13:55

Quote: Originally posted by DraconicAcid  
Quote: Originally posted by Abromination  
Exactly what I thought. It might work with zinc or something, but no matter. I think a better way would to be to add lithium metal to pure isopropanol to make lithium isopropoxide which would then be mixed with copper sulfate. What is the acid for isopropanol? (Like methanol and formic acid)


Zinc won't react with an alcohol in the same way that it doesn't react readily with water. Water is more reactive with metals than alcohols are.

Copper sulphate wouldn't be a good source of copper because it's poorly soluble in organic solvents (and you MUST keep this reaction anhydrous, or all you'll get is copper(II) hydroxide, or oxide if you heat it). Anhydrous copper(II) chloride would work better. I'm not sure how stable copper(II) isopropoxide is- I wouldn't be surprised if it decomposed.

I don't know what you mean about "What is the acid for isopropanol?" Methanol can be oxidized to formic acid because it is a primary alcohol (or, close enough). Isopropanol is a secondary alcohol, and can only be oxidized to a ketone (acetone in this case).

[Edited on 14-8-2018 by DraconicAcid]


Anh. Copper chloride will work. I forgot that isopropanol was a secondary alcohol.

"Zinc isopropyl"

WGTR - 14-8-2018 at 14:01

This book is on Google Books:

The Chemical News and Journal of Industrial Science; with which is Incorporated the "Chemical Gazette.": A Journal of Practical Chemistry in All Its Applications to Pharmacy, Arts and Manufactures, Volumes 31-32

On page 195:
https://books.google.com/books?id=kAYAAAAAMAAJ&pg=RA1-PA...

There is a list of some different reactions of the zinc-copper couple with different materials. I've also found that a good way to speed these reactions along (or get them started) is to use ultrasonics. It's an interesting read.

I find it rather funny that Gladstone used several pages to describe his experiments in glowing description and infectious enthusiasm, and then brushed off the practical aspects of his findings at the end of the article. It was obviously someone who enjoyed doing things like this just for the sake of doing them.


[Edited on 8-14-2018 by WGTR]