Quieraña
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I have 5% Pd/C and need a reaction to do...
Hello there fellow Chem enthusiasts. I've received a nice package in the mail and feel a little excited. There are plenty of options to do with such
an awesome, versatile catalyst. If you had the stuff, what would you do? Reduction seems to be the most obvious answer, but I recognized that this can
be more fun than that. Any ideas? Thank you advance. The day I do anything with this stuff I will of course include pictures. Cheers, friends.
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dettoo456
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Pretty much all Pd/C is used for is hydrogenations. If you don’t have the equipment or reagents though, keeping it as an investment is also fine -
it is a (or at least a mixture of a) precious metal.
Is the Pd/C impregnated at all (on zeolite or silica)? If so, it’d be a lot easier to recycle. If not, before any reaction, make sure you have a
procedure in place to recapture any and all of it from your rxn mix.
I personally wanted to look into reductive aziridine ring opening, as a new way to produce N-substituted isopropyl amines (internal alkenes can be
aminated electrochemically to aziridines then reduced).
[Edited on 9-6-2024 by dettoo456]
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Fery
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I did these 2 experiments, the first one was hydrogenation (a product with flowers scent) and the second one dehydrogenation (into an aromatic
heterocycle)
https://www.sciencemadness.org/whisper/viewthread.php?tid=15...
https://www.sciencemadness.org/whisper/viewthread.php?tid=15...
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Anthracene
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How about a reduction with Al/H2O as the hydrogen source?
https://pubs.rsc.org/en/content/articlelanding/2017/gc/c6gc0...
Unfortunately I don't have access from home, so I can't quote a procedure right now.
The approach seems quite variable, you could reduce acetophenone to ethylbenzene or benzaldehyde to either benzylalcohol or toluene, depending on how
long you run it. Also double bonds and nitro groups are possible targets. Heck, even Ullman coupling of halobenzenes.
Fery gave some great examples how you can use Pd/C without a fancy pressure vessel or even a hydrogen tank, but aluminum and water would be even more
approachable for the home chemist.
The author affiliations don't make me think it's a bs paper, I'd love to give it a try myself if I could find the time.
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stoichiometric_steve
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Quote: Originally posted by dettoo456  |
Is the Pd/C impregnated at all (on zeolite or silica)?
If so, it’d be a lot easier to recycle. If not, before any reaction, make sure you have a procedure in place to recapture any and all of it from
your rxn mix. |
1. Carbon is the carrier in Pd/C. i thought this was common knowledge and don't see how and/or why further "impregnation" would need to happen, and to
what effect?
2. the procedure commonly used is called filtration and is very well suited to capture all but the absolute finest of particulates.
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dettoo456
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My apologies, I didn’t realize that the Pd was just on C. I have seen Pd itself impregnated on alumina, zeolite, Ca salts, etc before.
And yes filtration would be basically be the only way to recapture the Pd/C, but larger or even smaller scale setups should involve centrifuging,
decanting, and several washing steps (much more complex than simple filtration) to fully ensure the expensive Pd is recovered, and recovered cleanly
at that.
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stoichiometric_steve
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| Quote: Originally posted by dettoo456 | | larger or even smaller scale setups should involve centrifuging, decanting, and several washing steps (much more complex than simple filtration) to
fully ensure the expensive Pd is recovered, and recovered cleanly at that. |
You can adequately wash Pd/C while it's a filter cake as long as it's kept damp. All those additional steps are just that, additional but not
particularly useful and certainly not necessary. Reactivation of Pd/C, if it's even required at all, can't be done in situ anyways.
Centrifugation just to obtain an additional few milligrams of material at best doesn't seem to be justifiable to me. I have worked with Pd/C
extensively and have never had any trouble getting back 99.999% of its mass by simple filtration, first through regular filter paper, then a finer
analytical one, the latter removing basically all of the visible residual particles.
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