Sciencemadness Discussion Board

Recovering palladium from triphenylphosphene palladium

danieldavies - 11-12-2023 at 23:41

Hello. Does anyone know how i can recover the palladium from triphenylphosphene palladium, safely. Thanks.

Sulaiman - 12-12-2023 at 03:33

Please excuse my ignorance but,
surely triphenylphosphene palladium is much more valuable than the recoverable palladium.
Its like recovering silver from silver nitrate, but more extreme.
Maybe you could purify it for sale?

Rainwater - 12-12-2023 at 03:41

That is one cool looking molecule.

Its got carbon in it so combustion is an option
No telling what toxic little things will come flying off.

danieldavies - 12-12-2023 at 03:50

Quote: Originally posted by Sulaiman  
Please excuse my ignorance but,
surely triphenylphosphene palladium is much more valuable than the recoverable palladium.
Its like recovering silver from silver nitrate, but more extreme.
Maybe you could purify it for sale?

danieldavies - 12-12-2023 at 03:51

A customer wants me to recover the palladium from it.

Texium - 12-12-2023 at 06:47

Is it tetrakis(triphenylphosphine)palladium(0) or bis(triphenylphosphine)palladium(II) chloride? That will make a difference on how you proceed.

danieldavies - 12-12-2023 at 09:39



IMG-20231211-WA0016.jpg - 180kB

Texium - 12-12-2023 at 10:02

Jeez, that’s a ton! Ok, so it’s the chloride. That means the palladium is in the +2 oxidation state. If you can oxidize all the triphenylphosphine to triphenylphosphine oxide, you should be able to partition it into an organic and aqueous phase, with the organic containing the triphenylphosphine oxide and the aqueous containing palladium(II) chloride. Then it’s just a matter of reducing it to the metal.

danieldavies - 12-12-2023 at 10:44

Seems like a lot of work.. would low heat oxidise the triphenylphosphene?

Texium - 12-12-2023 at 11:07

See my U2U message.

clearly_not_atara - 12-12-2023 at 11:34

:o

That's a fucking ton dude... I hope this customer is paying you well.

I suspect that alkali might give a precipitate of PdO. If the ppt is contaminated with TPP this might be effectively removed with oil. Hydroxide is a pretty strong ligand. This can be reverted to the metal directly by heating.

Rainwater - 12-12-2023 at 13:36

After a little research, you would be better off titrating a sample, comparing that to the theoretical yield, and sending your customer a mented platnium coin

clearly_not_atara - 12-12-2023 at 15:14

Quote: Originally posted by Rainwater  
After a little research, you would be better off titrating a sample, comparing that to the theoretical yield, and sending your customer a mented platnium coin

Palladium. But yes, if you can verify that the material is still what it says on the label, it's far more valuable than the palladium it contains -- assuming that you can unload it at a market price. So it would net a nice profit to just send back an equivalent amount of palladium and keep the "change", as it were.

Texium - 12-12-2023 at 16:15

That’s a great point. Many organic chemists would happily buy some of this compound for more than the price of the palladium since it is a very useful catalyst, though you may be hard pressed to find anyone wanting to buy more than a few grams of it, since it is used in catalytic amounts.

numos - 12-12-2023 at 21:22

The problem is that you have no way of certifying the purity to a point where a chemical plant (the only people buying this much) is going to buy this from you - not to mention they have dedicated vendors and would likely not buy from an individual. The only people you'll have luck selling this to is are amateur chemists, and then you'll have to deal with shipping pea size quantities over the course of years if not decades.

The current price for this catalyst from sigma is $17/g - and that's from a trusted vendor with a certificate of purity so you're not gonna get anything near that much. Still, that's around $42k for the bucket.

Turn this into Pd and you get ~380 g of Pd which you can easily sell close to spot at around $33/g (currently) for a total of $12.5k.

So yes there is a price difference but it seems much less significant that one might assume at first glance... Generally the work in making chemicals is much more valuable than the feedstocks. In this case, the feedstock itself IS actually a significant portion of the cost. Decisions, decisions....

edit

Oh I almost forgot - I tried converting 25 g of crappy brown Pd(PPh3)4 into Pd metal a while back - boy what a mess!!! I got a slimy phosphine goo with some Pd powder/oxides/phosphides and ended up dumping it all after a few days of toiling. Good luck with 2.5 kg, that's gonna be a doozy!

[Edited on 12-13-2023 by numos]

Fleaker - 16-12-2023 at 12:38

Let me know if you want to sell it.


Dr.Bob - 17-12-2023 at 10:17

Wow, I thought I had a lot of Pdterakis that had gone bad. But the dichloride should be stable as a rock, so it should be quite valuable as that, moreso than as the metal. But your call. There us a paper that describes the recovery of precious metals in the references section, look here:

http://www.sciencemadness.org/talk/viewthread.php?tid=157863...

or try this link:

http://www.sciencemadness.org/talk/files.php?pid=672948&...

You may need to request access to that part of the forum. Or I can send it.