Tabun (nerve agent)

Tabun

Names
IUPAC name (RS)-Ethyl N,N-Dimethylphosphoramidocyanidate
Other names GA; Ethyl dimethylphosphoramidocyanidate; Dimethylaminoethoxy-cyanophosphine oxide; Dimethylamidoethoxyphosphoryl cyanide; Ethyl dimethylaminocyanophosphonate; Ethyl ester of dimethylphosphoroamidocyanidic acid; Ethyl phosphorodimethylamidocyanidate; Cyanodimethylaminoethoxyphosphine oxide; Dimethylaminoethodycyanophosphine oxide; EA-1205; TL-1578
Identifiers
CAS Number	77-81-6 Y
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL1097650 N
ChemSpider	6254 Y
PubChem CID	6500
UNII	S45M750QSH Y
CompTox Dashboard (EPA)	DTXSID80861631
InChI InChI=1S/C5H11N2O2P/c1-4-9-10(8,5-6)7(2)3/h4H2,1-3H3 Y Key: PJVJTCIRVMBVIA-UHFFFAOYSA-N Y InChI=1/C5H11N2O2P/c1-4-9-10(8,5-6)7(2)3/h4H2,1-3H3 Key: PJVJTCIRVMBVIA-UHFFFAOYAG
SMILES N#CP(=O)(OCC)N(C)C
Properties
Chemical formula	C5H11N2O2P
Molar mass	162.129 g·mol−1
Appearance	Colorless to brown liquid
Density	1.0887 g/cm3 at 25 °C 1.102 g/cm3 at 20 °C
Melting point	−50 °C (−58 °F; 223 K)
Boiling point	247.5 °C (477.5 °F; 520.6 K)
Solubility in water	9.8 g/100 g at 25 °C 7.2 g/100 g at 20 °C
Vapor pressure	0.07 mmHg (9 Pa)
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Highly toxic. Fires involving this chemical may result in the formation of hydrogen cyanide
NFPA 704 (fire diamond)	4 2 1
Flash point	78 °C (172 °F; 351 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Tabun (military designation GA) is an extremely toxic compound of the organophosphate family.^[1][2] It is not present in nature. At room temperature, the pure compound presents itself as a clear and viscous liquid. However, impurities imparted during its manufacture are almost always present in some amount, turning it into a yellow or brown liquid. Exposed to environs, it slowly volatizes into the atmosphere,^[3] with the vapor having a slight fruity or almond-like odor.^[4] As the compound has a much higher molecular mass (162 g/mol) compared to air, Tabun gas tends to accumulate in low-lying areas.^[4]

It is a potent inhibitor of a key enzyme, acetylcholinesterase, within the human body as well as in other animals.^[5] It is responsible for breaking down acetylcholine, a neurotransmitter released into the synaptic cleft by motor neurons. The presence of acetylcholine within the cleft signals the post-synaptic (downstream) motor neuron to contract the neuron's associated muscle fibers, and vice versa. By irreversibly phosphorylating the enzyme,^[2] Tabun accomplishes a constant and involuntary contraction of the affected muscles, as the acetylcholine is not recycled and continues to build up within the cleft. Death of the organism ensues when respiratory muscles, such as the diaphragm and intercostals, become exhausted and paralyzed from constant contraction, leading to loss of respiratory functions.^[2]

The production and storage of Tabun has been strictly regulated under the Chemical Weapons Convention and its implementing agency OPCW since 1997.^[6] As a Schedule 1 Toxic Chemical,^[7] the synthesis of more than 100 grams of the substance per year must be declared to the organization, and no signing nation can possess more than 1 ton of the chemical.^[8] Modern usage of Tabun is limited to research purposes in minute amounts.^[9]