| Pages:
1
2 |
fluorescence
Hazard to Others
Posts: 285
Registered: 11-11-2013
Member Is Offline
Mood: So cold outside
|
|
Thought Experiment: Making deuterated Compounds
So I recently went through some old Papers on the hunt for a certain
article in the very old Russian Journals or Inorganic Chemistry somewhere in our University Archive. And as I went through the pages I came across a
short article on the preparation of deuterated Perchloric Acid.
The way they did it was to use Barium Perchlorate and then add D2SO4 which is made by dissolving SO3 in
D2O.
So I really liked the idea and though of, how would you make your everyday compounds with Deuterium instead of Hydrogen in them if you only had
D2O laying around. Some would be quite easy, others quite tricky. And I think it's not about getting D into there but basically
understanding how H can be substituted in various organic or inorganic compounds. So I had time while I was in the train heading back from University
and made a list of things that just came into my mind.
Making Acids by Dissolving the Oxide in D2O:
That would work for SO3 and P2O5 giving you quite pure D2SO4 and
D3PO4.
Using these acids to generate other acids from their salts:
You could use the old way to synthesize HCl from NaCl using D2SO4 instead, which could give you DCl.
Then there is the Perchlorate method mentioned above.
So these methods should work for all mineral acids.
But what about organic molecules ?
What about Ethanol ? Using CH3COOD. What does the D do when it's getting reduced ? The question is which H is which after you reduced an
Acid to the Alcohol using LiAlH4 ? Two them go to the Carbon where the Alcohol group is attached to. Then you end up with a deprotonated
Alcohol that is protonated by either Water or Acid. So the R-OD Group comes in the very last step and could be controlled by the stuff added in the
second step. So you won't need to use something like LiAlD4. And since the Acid is deprotonated in the very first step you could take
regular Carboxylic Acid and don't need any Deuterium in that. So Alcohols would perhaps be possible, too.
But what about Deuterobenze. How can I control a symmetrical aromatic compound and only have like 1 H swaped by D or even all 6 of
them ?
I had to look that up in literature although I don't really like the method and think there should be better methods than that.
What they did was to add Pyridine Hydrochloride to D2O and added Sodium Tetraphenyl Boron to it. That was destilled and they got
C6H5D.
I'm still working on the list and it could be expanded for ever but I was curious what ideas you would come up with for generating our everyday
chemicals with Deuterium in it ? One idea I had, too was to have some finely powedered Lithium in a stream of pure Nitrogen to get the nitride and
then drop that into D2O. That should produce ND3.
So if you have an idea how to substitute a specific Hydrogen for a Deuterium in a certain molcule just post it. Perhaps some day someone will try that
stuff out. I'll keep that updated as soon as I come up with other stuff.
[Edited on 22-9-2015 by fluorescence]
Something that just came into my mind. What about Decarboxylations using NaOD ? What about Malonic Acid ? Both of the Carboxyl Groups with an D in it
and then decarboxylated could give you CH2D2. I just can't come up with a way to make CD4.
So what about Amines ?
The most simple amine would be Methylamine. That is made from Formaldehyde and Ammoniumchloride. So you would have to use Formaldehyde and
ND4Cl to make (CH2ND2)Cl.
And the other amines ? Since we have a long thread on hydrazines it would be to much to try to make Deuterohydrazine so not Gabriel reaction. But what
about Curtius-Reaction ? Using the Carboxylic Acids to make the corresponding Azide and then D2O to make the Amine from it.
[Edited on 22-9-2015 by fluorescence]
|
|
|
unionised
International Hazard
Posts: 5128
Registered: 1-11-2003
Location: UK
Member Is Offline
Mood: No Mood
|
|
Al4C3 + 12 D2O --> 4 Al(OD)3 + 3 CD4
|
|
|
fluorescence
Hazard to Others
Posts: 285
Registered: 11-11-2013
Member Is Offline
Mood: So cold outside
|
|
Nice idea  I didn't know Aluminiumcarbide would make such a reaction !
Just came up with that idea. Using Calcium Carbide to make Deuteroacetylene and then make C8D8 from it. Quite
nice molecule, too.
[Edited on 22-9-2015 by fluorescence]
What I just found the Reppe Synthesis for Cyclisation.
So from 3 C2D2 you could make C6D6
(ยต-1,4-Phenylen)dilithium from para-bromo Benzene and n-Butyllithium and then carefully add D2O to generate a para substituted
Dideuterobenze.
[Edited on 22-9-2015 by fluorescence]
|
|
|
phlogiston
International Hazard
Posts: 1379
Registered: 26-4-2008
Location: Neon Thorium Erbium Lanthanum Neodymium Sulphur
Member Is Offline
Mood: pyrophoric
|
|
I used enzymatic reactions to make all kinds of stable isotope labeled (13C, 2H and 15N) amino acids and alpha-keto acids.
Another easy reaction to label just the alpha-carbon of amino acids is to dissolve them in D2O, add a little NaOD and pyridoxal-5-fosfate and heat to
90 deg for a few minutes. It does cause some racemization though, and it doesn't work for all the amino acids.
-----
"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer |
|
|
aga
Forum Drunkard
Posts: 7030
Registered: 25-3-2014
Member Is Offline
|
|
Does D2O not behave (chemically) exactly like H2O ?
If not, then there's some stomping to do.
|
|
|
fluorescence
Hazard to Others
Posts: 285
Registered: 11-11-2013
Member Is Offline
Mood: So cold outside
|
|
Okay, I'm not very familiar with enzymes although they are very selective I rather stick to organic chemistry, but this seems to be a quite good
method for some stuff that can't be made selectively. Thanx for the idea. I think marking other Atoms is like the second part of the game here till we
can build every molecule by just placing atoms where we want them
What about Deuterated Chloroform ? I mean it's THE standart Deutrated Compound in the lab for NMR. The problem I see here is, that
using Chloral derivates like the hydrate will certainly have some H in it. And it would take to long to use fully deuterated compounds. Another method
I though of was to use Trichloroacetic Acid and Thionyl Chloride to make the Trichloroacetylchloride and use that to make D-Chloroform.
Also back to the Benzene problem. I found out that you can indeed prepare Dilithio and Trilithio Benzenes. The question is how to swap the Lithium for
the Deuterium ? I think polylithiated Molecules don't build the typical aggregates especially as they are synthesized in Hexane so the Benzene would
be really reactive. Just adding water could be quite dangerous...any other idea ?
|
|
|
Justin Blaise
Hazard to Self
Posts: 82
Registered: 5-10-2011
Location: Parts Unknown
Member Is Offline
Mood: No Mood
|
|
The rates of some reactions can be affected by having a different isotope of an atom present. It's called the kinetic isotope effect.
https://en.m.wikipedia.org/wiki/Kinetic_isotope_effect
|
|
|
The Volatile Chemist
International Hazard
Posts: 1981
Registered: 22-3-2014
Location: 'Stil' in the lab...
Member Is Offline
Mood: Copious
|
|
Yes aga, basically the same. Just has some slightly different bond lengths (no source) and bond angles. not good for your body in large amounts,
probably, but otherwise, the same.
But assuming it is safe, could you deuterate a person? 
Of course, one can react deurterated water with alkali metals, to make the deuteroxides. Also, A deuterated acid in deuterated water would saturate
double bonds with an D- and DO-, right? (if heated)
|
|
|
aga
Forum Drunkard
Posts: 7030
Registered: 25-3-2014
Member Is Offline
|
|
(i do not recall posting on this thread. if somebody finds me, please inform the authorities as i must be lost)
|
|
|
The Volatile Chemist
International Hazard
Posts: 1981
Registered: 22-3-2014
Location: 'Stil' in the lab...
Member Is Offline
Mood: Copious
|
|
Sorry for the foolhardy post, but...
I suppose deuterated chloroform is chloroform for use on guys...
Good? Sorry, my joke filter is all-or-nothing; I'm bad at telling if a joke is good.
|
|
|
MeshPL
Hazard to Others
Posts: 329
Registered: 20-4-2015
Location: Universe
Member Is Offline
Mood: No Mood
|
|
Another interesting D related problem is: how to make deuterated water via electrolysis the most efficient way assuming we can do both:
2H2O --> 2H2 + O2
And:
2H2 + O2 --> 2H2O
Although at start the electrolysis will be producing mostly H2, after some time HD may became a significant part of produced hydrogen and it may be
beneficial to oxidise it and use it as a starting point for another batch... so finding out a mathematically best way to do that may be interesting.
Also CDCl3 synthesis:
CD4 + 3Cl2 --> CDCl3 + 3DCl
We can recycle D in this way:
Al4C3 + 12DCl --> 4AlCl3 + 3CD4
[Edited on 11-10-2015 by MeshPL]
|
|
|
halogen
Hazard to Others
Posts: 372
Registered: 18-4-2004
Member Is Offline
Mood: No Mood
|
|
Because of the kinetic effect the preparation of perdeuterated benzene is just the water and sulfuric acid. The benzene is protonated, and as there is
concentrated enough instead of 0.015 percent it's selective what sticks and what is taken off. I believe it is then repeated with fresh heavy water to
be sure.
[Edited on 12-10-2015 by halogen]
F. de Lalande and M. Prud'homme showed that a mixture of boric oxide and sodium chloride is decomposed in a stream of dry air or oxygen at a red heat
with the evolution of chlorine.
|
|
|
The Volatile Chemist
International Hazard
Posts: 1981
Registered: 22-3-2014
Location: 'Stil' in the lab...
Member Is Offline
Mood: Copious
|
|
Very interesting, about the benzene synthesis. Do you have a source?
|
|
|
BromicAcid
International Hazard
Posts: 3253
Registered: 13-7-2003
Location: Wisconsin
Member Is Offline
Mood: Rock n' Roll
|
|
Discussion on some deuterated compounds and their preparation including my favorite exchange with JohnWW (may he rest in peace).
http://www.sciencemadness.org/talk/viewthread.php?tid=2514
|
|
|
The Volatile Chemist
International Hazard
Posts: 1981
Registered: 22-3-2014
Location: 'Stil' in the lab...
Member Is Offline
Mood: Copious
|
|
Bromic, good to see you around. I see that thread has a discussion of the deuterated benzene I was asking about, thanks.
|
|
|
j_sum1
Administrator
Posts: 6333
Registered: 4-10-2014
Location: At home
Member Is Offline
Mood: Most of the ducks are in a row
|
|
On a related topic... deuterated fatty acids! http://www.compoundchem.com/2015/10/22/rtcweek4/
|
|
|
deltaH
Dangerous source of unreferenced speculation
Posts: 1663
Registered: 30-9-2013
Location: South Africa
Member Is Offline
Mood: Heavily protonated
|
|
Using D2 with an iron-based catalyst in a high-temperature Fischer-Tropsch (F-T) reaction would yield a range of perdeuterated olefins, lots of
D6-benzene and perdeuterated alkanes.
While I have not done that with D2, I have personally prepared fully substituted 13C benzene using 13CO, H2 and a F-T reaction.
With the F-T reaction and a low-temperature cobalt catalyst, you can make a heavy paraffin wax much more selectively than trying to isolate
intermediate length hydrocarbons, so you could make a heavy deuterium paraffin wax using D2.
I have written about the possibility of using isotopic bullion, like enriched copper or silver, here and elsewhere, but before that I was considering
deuterated versions since D2O is comparatively cheap and easy to work with. A deuterated F-T paraffinic wax was the ideal candidate as it could be
made easily from D2O, electrolysis (to obtain D2) and CO in a F-T pilot-sized rig. The resulting wax would not exchange its D and also have a very
high mass density of D and could be easily cast and remain stable indefinitely because of the chemical inertness of the heavy paraffin wax.
One could even make a 13C version for a VERY expensive material. In fact, you could make a pure D2-13C wax as a double whammy 
Sadly the idea has never caught on 
PS.
I forgot to mention that before thinking of the D-based paraffin wax, I was first toying with the notion of using a salt that forms a water-rich
hydrate, dehydrating it and then hydrating it with D2O as a bullion store for D. Options included magnesium sulfate and sodium carbonate or sulfate,
but while this would work, it would also most likely exchange D with atmospheric humidity over long periods of time if not sealed and a bullion that
degrades is no bullion at all. Also, the resulting product is brittle and shitty. I did not see any significant gain in attractiveness than simply
storing D2O.
Another version instead of a heavy paraffin wax based one is a perdeuterated polyethylene based bullion bar 
Finally, to reverse it and make D2O from the deuterated wax bullion, would simply be a matter of burning the wax in anhydrous oxygen and condensing
the product D2O in a suitable apparatus.
[Edited on 25-10-2015 by deltaH]
|
|
|
The Volatile Chemist
International Hazard
Posts: 1981
Registered: 22-3-2014
Location: 'Stil' in the lab...
Member Is Offline
Mood: Copious
|
|
Vaska's complex (MOTM: http://www.chm.bris.ac.uk/motm/vaska/vaskajm.htm) could be used to deuterate in a few different ways.
|
|
|
Heavy Walter
Hazard to Others
Posts: 127
Registered: 17-12-2015
Location: Argentina
Member Is Offline
Mood: No Mood
|
|
perdeuterated benzene
Hi
New to the forum, I made a brief description of my successful experience deuterating benzene, probably posted in the wrong thread (posted on
17-12-2015 at 10:51).
Now I am planning to deuterate PAH but some products are not manufactured in my country so I depend of slow importation procedures.
Anyone with experience labeling with deuterium?
|
|
|
alexchim
Harmless
Posts: 8
Registered: 23-12-2015
Location: France
Member Is Offline
Mood: No Mood
|
|
I work in organic synthesis of labelled compounds. Due to the lability of hydrogen, it's both easy and difficult to produce deuterated compounds. It
could be exchanged easily via acidobasic reactions, as performed industrially for deuterated solvents production... Efficience of the labeling
experiments could be only checked by NMR, if you couldn't use that technique, it is useless to attempt such chemistry.
|
|
|
Heavy Walter
Hazard to Others
Posts: 127
Registered: 17-12-2015
Location: Argentina
Member Is Offline
Mood: No Mood
|
|
labelling with D2
Hi
I agree with you.
NMR services are provided at local university.
The C6D6 I prepared was checked by GCMS.
Now planning to use the HTDA method to prepare small quantities of PAH.
I imagine you are involved in complex organic labeling, as hormones. Not my case!
|
|
|
alexchim
Harmless
Posts: 8
Registered: 23-12-2015
Location: France
Member Is Offline
Mood: No Mood
|
|
No no, i'm involved in classical organic chemistry, total synthesis of pharmaceutical compounds labelled with stable isotopes.
Deuterated benzene looks alike classical benzene by GC technique, and couldn't be seen on MS... So, what's the use?
|
|
|
Heavy Walter
Hazard to Others
Posts: 127
Registered: 17-12-2015
Location: Argentina
Member Is Offline
Mood: No Mood
|
|
Ah, good!
C6D6 is typically used as surrogate in BTX controls by GCMS.
I agree with you that GC techniques hardly differentiates C6H6 from C6D6 but GCMS is able to do so. Remember that their molecular masses are slightly
different.
|
|
|
alexchim
Harmless
Posts: 8
Registered: 23-12-2015
Location: France
Member Is Offline
Mood: No Mood
|
|
Different of 6 atomic mass units for sure... It depends of the technique of ionization which is used. Because it is not very easy to ionize ^^
|
|
|
Heavy Walter
Hazard to Others
Posts: 127
Registered: 17-12-2015
Location: Argentina
Member Is Offline
Mood: No Mood
|
|
Standard conditions.
Electron impact, with quadrupole or magnetic sector.
|
|
|
| Pages:
1
2 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
