Re: ORGLIST: Production of deuterated solvents

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From: Jonas Nilsson (jonni$##$ifm.liu.se)
Date: Thu Dec 21 2000 - 09:28:50 EST


A search on Beilstein gives several methods.

ethyne-d2 (650 deg C/cat.)->Benzene-d6
toluene+D2+MgO (high temp.) -> toluene-d8
ethyne-d2+charcoal->Benzene-d6+Toluene-d8

And much more. Look for yourself.
/jN
 _____________________ _____________________
| Jonas Nilsson | | |
|Linkoping University | | Telephone |
| IFM | | --------- |
| Dept. of Chemistry | | work: +46-13-285690 |
| 581 83 Linkoping | | fax: +46-13-281399 |
| Sweden | | home: +46-13-130294 |
|_____________________| |_____________________|
  ----- Original Message -----
  From: Michael Fassbender
  To: Multiple recipients of list orglist
  Sent: Wednesday, December 20, 2000 5:15 PM
  Subject: ORGLIST: Production of deuterated solvents

  Hi colleagues

  After some months of recess, I am back to Orglist again. I would like
  to draw the attention back to an interesting question raised by the Swedish colleague Jonas
  Nilsson (Hej Jonas! Haelsningar till Sverige, min Mormor aer svensk. ;-)) quite
  a while ago:

  On 28-Apr-2000 14:38:16 Jonas Nilsson wrote:
> Dear Members
>
> My collegue an I was discussing over a cup of coffe about how
> isotopically enriched materials are produced. Especially deuterated
> solvents are of interest.
> I just read on the internet about how "heavy water" was made during
> world war two by careful electrolysis of large quantities of water
> which
> if I understand it right tends to make H2 leave easier than both HD
> and
> D2, thus enriching the remainder in deuterium.
>
> Questions:
> Is this still how it is made?

  The question was responded to by a reference to an Oak Ridge Lab Web page,
  outlining the principles of deuterium enrichment in water using H2S/NH3 exchange
  equilibria. Now, since we have protic (i.e. acidic) molecules here, the issue is not
  that complicated.

  However, I would like to know how even non-protic, rather weakly acidic solvents are
  deuterated as for instance benzene, toluene or THF. What exchange mechanism is
  applicable in that cases?

  These are extremely weak acids, yet they are acids, so I can imagine that treating normal
  benzene or toluene with an excessive amount of solutions of e.g. NaOD (hydroxide) or even
  Na ND2 (amide) would give us -after boiling long enough- a certain D-enrichment in the organic phase.
  For more acidic molecules as acetone and acetonitrile these exchange rates are quite acceptable.

  But is there a more viable process for the technical deuteration of benzene and toluene? I'm looking
  forward to your input!

  Thanks

  <><><><><><><><><><><><><><><><>
  Dr. Michael Fassbender
  Isotope and Nuclear Chemistry
  Chemistry Division, MS J514
  Los Alamos National Laboratory
  Los Alamos, NM 87545, U.S.A.
  Phone: +1-505- 665-7306
  Fax: +1-505- 665-4955
  Email: mifa$##$lanl.gov
  <><><><><><><><><><><><><><><><>

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