Taboo

This article is about a chemical substance. For the paleontological site in Israel see Tabun Cave .

Structural formula
1: 1 mixture of ( R ) -Tabun (left) and ( S ) -Tabun (right)
General
Surname	Taboo
other names	( RS ) -Dimethylphosphoramidocyanidic acid ethyl ester P -Cyano- N , N -dimethylphosphonamic acid ethyl ester GA Trilon 83
Molecular formula	C 5 H 11 N 2 O 2 P
Brief description	colorless to brownish liquid with a fruity smell that is bitter almond-like when heated
External identifiers / databases
CAS number 77-81-6 ( racemate ) PubChem 6500 ChemSpider 6254 Wikidata Q143289
properties
Molar mass	162.13 g mol −1
Physical state	liquid
density	1.08 g cm −3
Melting point	−48 ° C
boiling point	246 ° C (decomposition)
Vapor pressure	9.7 Pa (20 ° C)
solubility	moderately soluble in water, slow hydrolysis
Refractive index	1.4250 (20 ° C)
safety instructions
GHS labeling of hazardous substances Caution H and P phrases H: 300-310-330-351 P: 260-264-270-280-284-302 + 350-304 + 340-310
Toxicological data	3.7 mg kg −1 ( LD 50 ,  rat ,  oral ) 2.5 mg kg −1 ( LD 50 , rabbit / mouse ,  transdermal )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Tabun is a nerve agent . The substance was discovered in 1936 by the German chemist Gerhard Schrader , who was doing research on new pesticides for IG Farben (Leverkusen) . From 1942 Tabun was produced industrially and filled in bombs and grenades for the German Wehrmacht during World War II , but not used.

history

In 1934 Gerhard Schrader was commissioned to develop insecticides based on organic phosphorus compounds. In 1936 he synthesized tabun. He first became aware of the unexpectedly high toxicity through a serious laboratory accident. According to the story, Schrader and colleagues are said to have suffered severe poisoning during experiments with tabun in late 1936. While at work, Gerhard Schrader suddenly developed visual disturbances, the symptoms of intoxication worsened to such an extent that he had to be admitted to hospital for 14 days. He recovered only slowly and was able to resume work in about 3 weeks. Since the new substance dimethylaminocyanophosphoric acid ethyl ester (initially referred to as preparation 9/91) was unusable ( taboo ) as an insecticide due to its extreme toxicity , it was given the code name Tabun. The discovery was reported to the Elberfeld Institute for Industrial Hygiene on February 5, 1937 and shortly thereafter to the Army Weapons Office. There, based on the structure of Tabun, the development of chemical weapons was initiated under the direction of Ministerialdirigent Christian Zahn. In the "Heeresgasschutzlaboratorium" in Spandau , its properties and effects as well as its suitability as a chemical weapon were examined in detail. The first test facility for production was set up in the robbery forest on what is now Munster's military training area . In 1940 the German Wehrmacht and the SS began building a chemical weapons facility with a forced labor camp 40 km north of Breslau in Dyhernfurth (part of the Groß-Rosen concentration camp ), mainly for the production of tabun (but also sarin ). Numerous slave laborers died during production. Around 12,000 tons of tabun were produced and processed there. Otto Ambros , the CEO of Anorgana GmbH , an IG Farben company, was one of the main people responsible for the plant.

At the end of the war, some of the stocks were transported westwards from the east by truck (for example , deaths occurred in Lossa when a lorry carrying tabun was shot at by Allied aircraft) and some by barges on the Elbe and Danube . The slave laborers in Dyhernfurth were forced to go on a death march and were often murdered. It was only when searching a barque on the Danube in Bavaria that the Allies discovered that nerve gases were being produced in Germany during the war , and the British Army found documentation on the development in the Tabun test facility in the robbery forest near Munster. The Soviets were informed of the developments in nerve gas earlier. They dismantled the plant in Dyhernfurth and rebuilt it in Stalingrad . Both the Allies (Great Britain, USA) and the Soviet occupiers employed German chemists after the war on their own chemical weapons developments (in the USA in the "Edgewood Arsenal" in Maryland ).

After the end of the war, Wehrmacht stocks of bombs and grenades filled with tabun were sunk in the Baltic Sea . The poison leaking from the corroded containers is now endangering the fish population there.

It was not known until 2008 that in 1949 grenades with up to ten tons of tabun were sunk about 2.5  nautical miles (approx. 4.6 km) south of Heligoland . In total there are around 90 tons of poison gas grenades (approx. 6000 individual grenades) that are stored there on the bottom of the North Sea .

In 1955/56, large stocks of German taboo that had been temporarily stored by the British armed forces in Wales after the Second World War were sunk by the Royal Navy and Royal Air Force in Operation Sandcastle for safety reasons on disused merchant ships northwest of Ireland : on July 27, 1955 the steamer Empire Castle , on May 30, 1956 the motor ship Vogtland and on July 21, 1956 the steamer Kotka .

Tabun is the oldest of the five so-called G-warfare agents (code: GA) next to soman (GD), sarin (GB), GV and cyclosarin (GF). After the Second World War, the USA and Great Britain took over the production of this warfare agent. The Soviet Union, on the other hand, showed little interest in tabun and concentrated more on soman. Tabun was also used by Saddam Hussein in the Iran-Iraq war and in 1988 against his own population in Kurdish northern Iraq in the poison gas attack on Halabja .

The diethylaminocyanophosphoric acid ethyl ester, which is very similar to the tabun, is said to have been manufactured by Carl Schall (a student of August Michaelis ) as early as 1898 , without the high toxicity being noticed.

Extraction and presentation

In Germany, Tabun was manufactured on an industrial scale from dimethylaminophosphoryl dichloride with absolute ethanol and excess sodium cyanide in chlorobenzene during World War II .

properties

Tabun is an ester of a doubly substituted phosphoric acid and its structure is similar to many pesticides (organophosphorus insecticides , e.g. Methamidophos ). Tabun is a colorless to brownish liquid with a fruity smell that is bitter almond- like when heated . Hydrocyanic acid can be formed when it is used .

Analogues

Numerous structural analogues were made by Tabun. While the analogous isopropyl ester (dimethylaminocyanophosphoric acid isopropyl ester) is slightly (1.3 times) more toxic than tabun, dimethylaminofluorophosphoric acid ethyl ester (fluorine tabun) is about 3–4 times less toxic. A substance that combines structural elements of tabun (the dimethylamido fragment) and the so-called Tammelin esters (the dialkylaminoalkyl ester fragment) is dimethylaminofluorophosphoric acid dimethylaminoethyl ester ( GV ).

Mode of action

Tabun can be absorbed through the skin and breathing . In the body, tabun blocks acetylcholinesterase , which breaks down the neurotransmitter acetylcholine in the nervous system and is therefore essential for the transmission of stimuli. Compared to the other G-substances (sarin, cyclosarin, soman) tabun has the lowest toxicity. Sarin is about 3–4 times and soman 10–15 times more toxic than tabun.

Depending on the severity of the poisoning, the following symptoms occur: headache, nausea with vomiting and diarrhea, eye pain, fatigue, seizures, tremors, twitching of the muscles, uncontrolled urination and stool, shortness of breath, loss of appetite, anxiety, tension, confusion, unconsciousness . Death occurs through respiratory paralysis .

Protective measures

Nerve agents are deadly even in the smallest amounts. The target is the entire body. Therefore, only a full-body protective suit and a protective mask with a respiratory filter offer sufficient protection. Before using warfare agents, oxime tablets or carbamates such as pyridostigmine or physostigmine can be taken. In the case of poisoning, atropine or hyoscyamine ( alkaloid of deadly nightshade ) are injected , which block the acetylcholine receptor and thus neutralize the effect of the acetylcholine. In the course of the week-long follow-up treatment, an attempt is made to regenerate the AcChE with obidoxime .

For the decontamination , among other things, oxidizing agents such. B. chlorinated lime or calcium hypochlorite , alkaline solutions and non-aqueous media such as amino alcoholates can be used, since nerve agents are sensitive to oxidizing agents and their hydrolysis is accelerated in a basic environment. Sodium carbonate solution can also be used on sensitive surfaces, but it works more slowly.

Analytics

Reliable detection of tabun and other neurotoxins is made possible by portable devices that use capillary gas chromatography with mass spectrometry for separation and identification. The examination of physiological material requires adequate sample preparation .

See also

• List of chemical warfare agents

literature

• Roy Sloan: The tale of taboo. Nazi chemical weapons in North Wales. Gwasg Carreg Gwalch, Llanrwst 1998, ISBN 0-86381-465-4 .

Individual evidence

1. ↑ ^{a b c} Entry on Tabun. In: Römpp Online . Georg Thieme Verlag, accessed on June 12, 2014.
2. ↑ ^{a b c d e f g} Entry for CAS no. 77-81-6 in the GESTIS substance database of the IFA , accessed on December 27, 2019(JavaScript required) .
3. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-466.
4. ^ ^{A b} Günter Hommel: Handbook of dangerous goods. Volume 6. Springer, Berlin / Heidelberg 2012, ISBN 978-3-642-25051-4 , p. 2317.
5. ^ Nachr. Chem. 2012, 60 , 1194.
6. ↑ Sarah Everts: The Nazi origins of deadly nerve gases. In: Chemical and Engineering News , October 17, 2016. The report follows Jonathan Tucker: War of nerve. Pantheon Books, 2006.
7. ^ Florian Schmaltz: Warfare agent research under National Socialism: on the cooperation of Kaiser Wilhelm Institutes, the military and industry. Wallstein, 2005, ISBN 3-89244-880-9 , pp. 453–455 ( limited preview in Google book search).
8. ^ Sarah Everts: Chemical Engineering News. 2016.
9. ↑ 6000 grenades with neurotoxins wanted off Heligoland. In: Hamburger Abendblatt. December 9, 2008.
10. ^ Poison gas off Heligoland. In: Hamburger Abendblatt. June 17, 2009.
11. ↑ Saskia Eckert: Development of a dynamic model for studying the protective effects of reversible acetylcholinesterase inhibitors against irreversible inhibition by highly toxic organophosphates. (PDF; 1.2 MB), dissertation , University of Munich, 2006, p. 1.
12. ↑ L. Szinicz, SI Baskin: Chemical and biological warfare agents. In: Textbook of Toxicology. 2nd edition, WV mbH, Stuttgart 2004, ISBN 978-3-8047-1777-0 , pp. 865-895.
13. ↑ Entry on nerve warfare agents. In: Römpp Online . Georg Thieme Verlag, accessed on June 12, 2014.
14. ↑ H. Nagashima, T. Kondo, T. Nagoya, T. Ikeda, N. Kurimata, S. Unoke, Y. Seto: Identification of chemical warfare agents from vapor samples using a field-portable capillary gas chromatography / membrane-interfaced electron ionization quadrupole mass spectrometry instrument with Tri-Bed concentrator. In: J Chromatogr A. 1406, Aug 7, 2015, pp. 279-290. PMID 26118803 .
15. ↑ BS Crow, BG Pantazides, J. Quiñones-González, JW Garton, MD Carter, JW Perez, CM Watson, DJ Tomcik, MD Crenshaw, BN Brewer, JR Riches, SJ Stubbs, RW Read, RA Evans, JD Thomas, TA Blake, RC Johnson: Simultaneous measurement of tabun, sarin, soman, cyclosarin, VR, VX, and VM adducts to tyrosine in blood products by isotope dilution UHPLC-MS / MS. In: Anal Chem. 86 (20), Oct 21, 2014, pp. 10397-10405. PMID 25286390 .