Can Gold Oxalate Be Synthesized Using Oxalic Acid and Gold (III) Chloride?

[dcolt319]

TL;DR Summary

Looking for a way to synthesize this ccompound.

Hello,
I'm trying to find a way to form gold oxalate. I'm wondering if anyone has any information on reacting oxalic acid with gold (III) chloride. The literature on this reaction is quite sparse, and I'm curious if simply combining aqueous solutions of the salt and acid would precipitate the oxalate. Trying to get more information on this before purchasing the AuCl3.
Thanks

 

[TeethWhitener]

I doubt this will work. There’s at least a smattering of evidence that oxalate will reduce Au(III):
https://pubs.acs.org/doi/10.1021/jp0744782
I find this easy to believe: gold chloride reduces very easily. In addition, AuCl3 is present in aqueous solution largely as a tetrachloroaurate anion, not as an uncomplexed metal ion. Is there some reason you want gold oxalate specifically? There might be a different way to achieve what you want if the compound you’re wanting to make is a means to an end.

 

[jim mcnamara]

Some points:
Gold reagents are inordinately expensive. 1g of most gold salt reagents is on the order of $200USD.

What is the endpoint result you need? Gold oxalate? I cannot see much out there on the uses for it much less the synthesis of it or any uses in the synthesis of other products with gold oxalate as a catalyst..

Which you said was the case for you as well.

There has to be something else that satisfies your need that is much less pricey.
@TeethWhitener and @Borek can probably help in that regard.

This will allow you to search for related compounds:
https://pubchem.ncbi.nlm.nih.gov/compound/22141734#section=Parent-Compound

Edit: @TeethWhitener beat me to it

 

[hilbert2]

Silver oxalate is known to decompose, with explosive release of carbon dioxide, when heated. It's possible that gold oxalate is even more sensitive in this respect. Maybe this is what the starter of the thread wants to test?

 

[berkeman]

Maybe this is what the starter of the thread wants to test?

You mean like a really expensive bomb?

 

[hilbert2]

You mean like a really expensive bomb?

You wouldn't need more than few tens of milligrams to find the decomposition temperature as a pyrotechnics experiment. No one would make a bomb from something of that price per mass.

 

[chemisttree]

Potassium oxalate is reported to reduce HAuCl4.

 

[dcolt319]

I doubt this will work. There’s at least a smattering of evidence that oxalate will reduce Au(III):
https://pubs.acs.org/doi/10.1021/jp0744782
I find this easy to believe: gold chloride reduces very easily. In addition, AuCl3 is present in aqueous solution largely as a tetrachloroaurate anion, not as an uncomplexed metal ion. Is there some reason you want gold oxalate specifically? There might be a different way to achieve what you want if the compound you’re wanting to make is a means to an end.

Thanks for the reply. I left the forum for the Christmas holiday and promptly forgot I made this thread. @jim mcnamara @hilbert2 wanted to reply to you guys as well

I'm an experimental petrologist that studies molten silicate materials primarily with pressure vessels. We typically use oxalic acid dihydrate (OXA-D) as a carbon source in our experiments especially when we also use natural rocks as starting materials. The alternative is to synthesize an analogous mixture of element oxides/carbonates that approximate a natural rock composition, but there are more potential pitfalls with this method. In any case, upon breakdown, OXA-D consumes 1 mol of oxygen for every mol of OXA-D added. This is disadvantageous to our experiments, as we are interested in oxidizing sulfur in the presence of molten rock. Upon breakdown the OXA-D reduces the system, including added sulfur, which combines with Fe upon melting to produce immiscible sulfide phases. We buffer the availability of oxygen to our system using an external mineral or oxide buffer, but it takes time for the buffer to establish. We are finding that it takes an exorbitant amount of time to get rid of the immiscible sulfide phase.

Thus, we are looking for alternative carbon sources for our initial mixture. We use sealed gold capsules for these melting experiments, so we figure upon breakdown the gold oxalate will provide some carbon and the gold will migrate to and bond with the capsule wall.

No explosives. Nothing like that. But we would like to avoid using alkali-bearing materials, as the initial rock composition should not deviate from its natural state. Alkali metal-oxide concentrations in natural rocks are commonly limited to the single percent, and addition of an alkali-bearing carbon source would inflate these concentrations beyond natural levels.

 

[chemisttree]

How about calcium salts? Calcium formate would break down to an active calcium species and CO2. Is water an ingredient in your experiments?

Zinc diformate and ferric formate are also possibilities.

 

[dcolt319]

How about calcium salts? Calcium formate would break down to an active calcium species and CO2. Is water an ingredient in your experiments?

Zinc diformate and ferric formate are also possibilities.

I'll have to check, but I'm almost certain the CaO concentration of the bulk rock is on par with the alkalis, so the same caveat that I'm applying to alkali-bearing additives will also apply to alkaline ones... I thought about adding the sulfur as a sulfate mineral as well, but every commonly available mineral species includes cations which will adversely affect the rest of the composition.

 

[chemisttree]

Sounds like formic acid is your only choice then.

 

[snorkack]

A problem here is that formic acid, like oxalic acid, is a reducer. The same issues with reducing your sample.
What you need is a CO₂ source that somehow leaves your sample´s redox state unchanged in the end...
One approach would be to tackle the physical issues of adding CO₂ itself as pressurized gas or solution.
Another approach would be to use a carbonate of a metal that is rare enough that you do not plan on analyzing your sample for it - anything you find is what you added yourself.