chemrox
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electrochem reductionof org halides
I just got an article from Solo in refs on electrochemical reductions in DMF with TBAP as the catalyst. I don't have TBAP but I do have some other PTC
reagents. TBAP is decomposed to tributylamine as I read it. What was really cool is no formation of biphenyl side products. I wonder if I could sub
in TBAB? Also the article specifies emf in farads and a Hg electrode wtf? Could I use a DC 12 v. source and a more friendly electrode set?
Attachment: Electroreductive dehalogenation of chlorinated aromatic ethers. Unexpected electrogenerated base-catalyzed reactions.pdf (825kB)
This file has been downloaded 336 times
I should mention that I have 0 experience with electrochem
[Edited on 12-3-2016 by chemrox]
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
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Pumukli
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As I read the article it talks about Pb electrode not Hg, mentioning that Pb was the most effective cathode material, Hg, Pt, graphite and Al produced
inferior results.
(Btw. in electroreduction of various organic compounds Pb seems to be the best choice in general.)
1 F is roughly 96500 Coulomb/mole, they used constant current method, so you can calculate the required current for a given time knowing that 1 A is 1
Coulomb/sec. Current will depend on electrode area (via current density , A/cm2) and the geometry of the actual cell you use. Too much
current: too much heat generated, too low the current: too long reaction time.
I hope it was useful. :-)
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Crowfjord
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TBAP (tetrabutylammonium perchlorate) is trivial to prepare from TBAB (tetrabutylammonium bromide). One simply adds the stoichiometric amount of
perchloric acid, or maybe a slight excess, to an aqueous solution of TBAB with stirring. The formed TBAP is quite insoluble in water and can be
filtered and air dried.
I did the above preparation years ago for a research project that involved electro-polymerizing cobalt-tetraaminophthalocyanine onto a glassy carbon
electrode. The procedure also used DMF as solvent - perhaps TBAP has better solubility in DMF than TBAB?
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