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Author: Subject: Introduction to "Novichok" Agents
sparkgap
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[*] posted on 5-9-2005 at 06:54


A bit off topic, but... oh well...

http://cns.miis.edu/pubs/npr/vol07/72/72bozh.pdf

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[*] posted on 5-9-2005 at 12:33


I think someone made a mistake Fritz or Samosa. When I looked once again through the attachments of Fritz and Samosa, I noticed that the compound CAS-RN 26102-97-6
When all the same atoms are counted together it’s C3H4Cl2F2NO3P
Which would be


Cl-CH2-CH2-O-PO(F)-O-N=C(F)(Cl)


But in Samosa’s drawing it’s C3Cl2F2NO3P, which would be


Cl-C≡C-O-PO(F)-O-N=C(F)(Cl)


I think Samosa forgot the hydrogen atoms, or is it really an unsaturated 1-chloracetylene group ?
The same thing is at the novichok CAS RN 26102-99-8 (C5H8Cl2F2NO3P at Fritz and C5Cl2F2NO3P at Samosa)

Maybe all organophosphate structures are wrong or does anyone know what fluorohydroxy group is (maybe P-O-F) ? (CAS-RN 26102-97-6 is
[[(2-chloroethoxy)fluorohydroxyphosphinyl]oxy]carbonimidic chloride fluoride )

And doesn’t … phosphin…stand for an trivalent phosphorous compound, the pentavalent compound would be …phosphon…

All the stuff is so strange and unfortunately secret, but I wan’t to know it, maybe someone could try to synthesize an easy organophospate (methyl or ethyl ) wit a double halogenated formaldoxime group. Maybe Ethyl dichlorformaldoxime fluorophosphate and test their toxicity. At the time I am working on a small furnace to produce some phosphorous and if I should have success I will try to syntesize some of the stuff here after I made some easy organophosphates.




[Edited on 6-9-2005 by hinz]
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Chris The Great
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[*] posted on 5-9-2005 at 13:46


Don't try it without a negative pressure glove box, or you might not ever get to post your results.....

I remember that you are correct in the structures. I think Megalomania over at E&W looked up the CAS numbers and found that the structures do not have the alkyne bond, and that the original auther was not clear in indicating the hydrogens or something.

Also, consider that dihalogenated formoximes are incredibly nasty substances on their own. Skin contact causes extreme pain and very slow healing wounds, the vapours cause blindness, etc. This assumes one merely mixes the formoxime with the phosphorus halide to get the wanted structure, there are other less direct (and extremely dangerous from what I understand) routes with chloropicrin, involving flames and explosions from the energy released.

As for the naming, I think that it is just a really bad name, and it has the 'oxy' group listed right after. I think that the name represents the structure but in a bad way. Or I'm misinterpreting the name... naming phosphorous compounds is quite strange In my opinion.
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sparkgap
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[*] posted on 7-9-2005 at 01:36


The reason organophosphorus nomenclature is confusing is that the first few workers on this subject didn't exactly have the same set of standards. For instance, one uses "phosphorothioate", while another uses "thiophosphate", and some go so far as to distinguish "phosphorothiolate" (>P-S) and "phosphorothionate" (>P=S).

Another source of confusion is that some workers tend to use a mix of the CAS and |IUPAC systems. :o

Here go some links on organophosphorus nomenclature:

http://www.acdlabs.com/iupac/nomenclature/93/r93_507.htm

http://www.chem.qmul.ac.uk/iupac/misc/phospho.html

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[*] posted on 6-8-2015 at 11:53


Wouldn't it be possible to replace certain chemicals in the Tabun synthesis pathway to make a variety nerve agent? I'm just asking since I've been looking at the synthesis and I've been thinking "Substitute the initial amine compound w/ another amine other than dimethylamine and then just use another salt having a halogen (sodium fluoride) and another organic oxide group (like methanol instead of ethanol) producing a whole new nerve agent plus an acid completely independent of cyanide" Is it possible to do it like that? Or no?
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[*] posted on 6-8-2015 at 16:04


This is exactly what Schrader et al were doing in the 1930s and 1940s to produce the thousands of candidate agents that were screened at the time. The agents you know about were the most successful ones.

There others that were almost as good, and which have been investigated by other weapon programs, like Iraq's.

You don't want to mess with this stuff unless you are doing microchemistry AND really, really know what you are doing.

It is a good thing that chemical weapons have fallen out of favor with advanced nations. With modern computational design technologies significantly more effective agents are no doubt possible.
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[*] posted on 6-8-2015 at 20:14


But how successful WERE the current nerve agents we know about? What others had they tested? I like to ask questions xD
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[*] posted on 7-8-2015 at 08:45


Quote: Originally posted by Conor579  
But how successful WERE the current nerve agents we know about? What others had they tested? I like to ask questions xD


Nothing wrong with asking questions. The answer is that current nerve agents we know about are extremely "successful" at producing lethality in mammals, including humans.
Just about every conceivable variation of (OR)2P=O-X (prototypically, X=F) type organo-phosphate compounds has been studied for non-reversible acetylcholine-esterase inhibitor activity. Some, like VX 'nerve gas', have been found to be extremely potent and environmentally persistant.
Even some of the simplest organo-phosphate compounds of this type, like di-isopropyl phosphorofluoridate are quite toxic. The LC 50 for 10 min exposure of di-isopropyl phosphorofluoridate was 0.36 mg/l for rats and 0.44 mg/l for mice. This makes the compound more toxic than cyanogen chloride (1); on par, more or less, with HCN . And it's not even considered a 'real' nerve gas.

There really is not very much interesting chemically about these compounds, aside from from them being able to be made very selective in their toxicity. So that potent insecticides can be made which have quite low toxicity in mammals (ie., Malathion). In general, these are not a fun group of chemicals to play with.


1. "Some Aspects Of The Chemistry of Organic Compounds Containing P and F", B. Saunders, A. Todd, 1957, Cambridge Press
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[*] posted on 7-8-2015 at 10:00


Quote: Originally posted by softbeard  
Quote: Originally posted by Conor579  
But how successful WERE the current nerve agents we know about? What others had they tested? I like to ask questions xD


Nothing wrong with asking questions. The answer is that current nerve agents we know about are extremely "successful" at producing lethality in mammals, including humans.
Just about every conceivable variation of (OR)2P=O-X (prototypically, X=F) type organo-phosphate compounds has been studied for non-reversible acetylcholine-esterase inhibitor activity. Some, like VX 'nerve gas', have been found to be extremely potent and environmentally persistant.
Even some of the simplest organo-phosphate compounds of this type, like di-isopropyl phosphorofluoridate are quite toxic. The LC 50 for 10 min exposure of di-isopropyl phosphorofluoridate was 0.36 mg/l for rats and 0.44 mg/l for mice. This makes the compound more toxic than cyanogen chloride (1); on par, more or less, with HCN . And it's not even considered a 'real' nerve gas.

There really is not very much interesting chemically about these compounds, aside from from them being able to be made very selective in their toxicity. So that potent insecticides can be made which have quite low toxicity in mammals (ie., Malathion). In general, these are not a fun group of chemicals to play with.


1. "Some Aspects Of The Chemistry of Organic Compounds Containing P and F", B. Saunders, A. Todd, 1957, Cambridge Press


The chemistry/biochemistry and history of these compounds can be quite interesting - and as pesticides have useful non military applications.

To qualify as a "good" nerve gas a compound has to have a favorable combination of physical, chemical, and biochemical characteristics: storage stability, volatility, resistance to hydrolysis, absorption, potency, and ease of manufacture.

Diisopropyl phosphorofluoridate (aka DFP or isoflurophate) was good enough to actually be stockpiled by the U.S. in WWII as a war gas (codename PF3), even though (as noted above) it is "only" as toxic as HCN.

A primary reason for standardizing this agent is that it causes extreme miosis (contraction of the pupil) at exposures far below the lethal level, which severely impairs vision giving it useful harrassing value. It is also a cumulative poison and persistent as well (unlike HCN). The miotic effect sees this chemical used in optometry today.

The common assertion found in the historical literature that the Allies did not know about nerve gases is wrong, they just did not know the superior ones found by Germany. Germany explored several thousand agents, the Allies just several hundred. The U.S. program worked with the direct predecessor of tabun, but did not try cyanidation (which makes tabun) among the substituents they tested.

Of the three G-agents well known after WWII tabun was the least toxic (5 times the maximum toxicity of HCN) but was sufficiently low volatility and good hydrolysis resistance to make it a persistent agent.

Sarin was 20 times as toxic as HCN and highly volatile (about the same as water). This was the standard agent adopted by the US.

Soman (O-Pinacolyl methylphosphonofluoridate) is about 30 times as toxic as HCN, persistent, and had a property making it one of most harmful nerve gases - it crosses the blood-brain barrier and breaks down slowly causing long-term CNS poisoning in survivors. It was however very expensive to manufacture due to the difficulty of making pinacolyl alcohol for which no good production processes existed at the time. After WWII Soviet chemists developed a good industrial process and this became one of their principal agents.

Cyclosarin (GF, cyclohexyl methylphosphonofluoridate) is somewhat similar to soman in being persistent (and is even more toxic). It was produced by Iraq, but the higher cost of manufacture kept it out of the US arsenal - which used the even more toxic V-agents for its persistent agents.

Many other related compounds are very toxic, without being super toxic, may be nonvolatile (making exposure difficult to arrange), may break down too easily, may not be stable in storage, may be expensive to make, etc. etc.

[Edited on 7-8-2015 by careysub]
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