Tetracyanoethylene

From Wikipedia, the free encyclopedia
(Redirected from TCNE)
Jump to navigation Jump to search

Template:Short description <templatestyles src="Chembox/styles.css"/>

Template:Chembox image cellTemplate:Chembox AllOtherNamesTemplate:Chembox headerbarTemplate:Chembox IndexlistTemplate:Chembox JmolTemplate:Chembox ChEMBLTemplate:Chembox ECHATemplate:Chembox E numberTemplate:Chembox IUPHAR ligandTemplate:Chembox UNIITemplate:Chembox CompToxTemplate:Chembox headerbarTemplate:Chembox Datapage checkTemplate:Chembox Footer
Tetracyanoethylene
Template:Chembox image sbs cell
Template:Longitem Template:Unbulleted list
ChEBI Template:Unbulleted list
ChemSpider Template:Unbulleted list
DrugBank Template:Unbulleted list
EC Number Template:Unbulleted list
KEGG Template:Unbulleted list
Template:Longitem Template:Unbulleted list
RTECS number Template:Unbulleted list
Script error: No such module "collapsible list".
Script error: No such module "collapsible list".
Template:Longitem Template:Chem2
Molar mass Template:Chem molar mass
Density 1.35 g/cm3
Melting point Template:Chembox CalcTemperatures
Boiling point Template:Chembox CalcTemperatures

Template:Chembox Footer/trackingScript error: No such module "TemplatePar".Template:Short description

Tetracyanoethylene (TCNE) is organic compound with the formula Template:Chem2. It is a colorless solid, although samples are often off-white. It is an important member of the cyanocarbons.

Synthesis and reactions

TCNE is prepared by brominating malononitrile in the presence of potassium bromide to give the KBr-complex, and dehalogenating with copper.[1]

Oxidation of TCNE with hydrogen peroxide gives the corresponding epoxide, which has unusual properties.[2]

In the presence of base, TCNE reacts with malononitrile to give salts of pentacyanopropenide:[3]

Template:Chem2

Redox chemistry

TCNE is an electron acceptor. Cyano groups have low energy π* orbitals, and the presence of four such groups, with their π systems (conjugated) to the central Template:Chem2 double bond, gives rise to an electrophilic alkene. TCNE is reduced at −0.27 V vs ferrocene/ferrocenium:[4]

Template:Chem2

Because of its ability to accept an electron, TCNE has been used to prepare numerous charge-transfer salts[5] and magnetic molecular materials.

The central C=C distance in TCNE is 135 pm.[6] Upon reduction, this bond elongates to 141–145 pm, depending on the counterion.[7]

Safety

TCNE hydrolyzes in moist air to give hydrogen cyanide and should be handled accordingly.[1]

References

<templatestyles src="Reflist/styles.css" />

  1. a b c Script error: No such module "Citation/CS1"..
  2. Script error: No such module "Citation/CS1"..
  3. Script error: No such module "Citation/CS1".
  4. Script error: No such module "Citation/CS1".
  5. Script error: No such module "Citation/CS1".
  6. Script error: No such module "Citation/CS1".
  7. Script error: No such module "Citation/CS1".

Script error: No such module "Check for unknown parameters".