Tetracyanoethylene

Danger

H300 (100%): Fatal if swallowed [Danger Acute toxicity, oral]

P261, P262, P264, P264+P265, P270, P271, P280, P301+P316, P302+P352, P304+P340, P305+P351+P338, P316, P317, P319, P321, P330, P332+P317, P337+P317, P361+P364, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 46 reports by companies from 6 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Chemical: Ethenetetracarbonitrile

Tetracyanoethylene: Does not have an individual approval but may be used under an appropriate group standard

Causes conjunctive irritation and respiratory obstruction in ocular lethal-dose studies of rabbits; Causes convulsions, regional or general arteriolar or venous dilation, dyspnea, and respiratory obstruction in oral lethal-dose studies of mice; [RTECS] A skin and strong eye irritant; Highly toxic by ingestion and skin absorption; [Alfa Aesar MSDS] See NITRILES. See Hydrogen cyanide.

Antidotes to cyanide poisoning include hydroxocobalamin and sodium nitrite, which release the cyanide from the cytochrome system, and rhodanase, which is an enzyme occurring naturally in mammals that combines serum cyanide with thiosulfate, producing comparatively harmless thiocyanate. Oxygen therapy can also be administered. (L97)

Exposure to high levels of cyanide for a short time harms the brain and heart and can even cause coma, seizures, apnea, cardiac arrest and death. Chronic inhalation of cyanide causes breathing difficulties, chest pain, vomiting, blood changes, headaches, and enlargement of the thyroid gland. Skin contact with cyanide salts can irritate and produce sores. (L96, L97)

Organic nitriles decompose into cyanide ions both in vivo and in vitro. Consequently the primary mechanism of toxicity for organic nitriles is their production of toxic cyanide ions or hydrogen cyanide. Cyanide is an inhibitor of cytochrome c oxidase in the fourth complex of the electron transport chain (found in the membrane of the mitochondria of eukaryotic cells). It complexes with the ferric iron atom in this enzyme. The binding of cyanide to this cytochrome prevents transport of electrons from cytochrome c oxidase to oxygen. As a result, the electron transport chain is disrupted and the cell can no longer aerobically produce ATP for energy. Tissues that mainly depend on aerobic respiration, such as the central nervous system and the heart, are particularly affected. Cyanide is also known produce some of its toxic effects by binding to catalase, glutathione peroxidase, methemoglobin, hydroxocobalamin, phosphatase, tyrosinase, ascorbic acid oxidase, xanthine oxidase, succinic dehydrogenase, and Cu/Zn superoxide dismutase. Cyanide binds to the ferric ion of methemoglobin to form inactive cyanmethemoglobin. (L97)

Organic nitriles are converted into cyanide ions through the action of cytochrome P450 enzymes in the liver. Cyanide is rapidly absorbed and distributed throughout the body. Cyanide is mainly metabolized into thiocyanate by either rhodanese or 3-mercaptopyruvate sulfur transferase. Cyanide metabolites are excreted in the urine. (L96)

Used to make spiro compounds, in modified Diels-Alder reactions, and as an aromatizing agent; [Merck Index]

Tetracyanoethylene is used to prepare numerous organic superconductors, usually by serving as a single electron oxidant of an organic electron donor. Such charge-transfer salts are sometimes called Bechgaard salt. (L615)