Cyanate

Space-filling model of the cyanate anion

The cyanate ion is an anion with the chemical formula OCN. It is a resonance of three forms: [O−C≡N] (61%) ↔ [O=C=N] (30%) ↔ [O+≡C−N2−] (4%).

Cyanate is the derived anion of isocyanic acid, H−N=C=O, and its lesser tautomer cyanic acid (a.k.a. cyanol), H−O−C≡N.

Any salt containing the ion, such as ammonium cyanate, is called a cyanate.

The cyanate ion is an isomer of the much-less-stable fulminate anion, CNO or [C≡N+−O].[1]

The cyanate ion is an ambidentate ligand, forming complexes with a metal ion in which either the nitrogen or oxygen atom may be the electron-pair donor. It can also act as a bridging ligand.

Compounds that contain the cyanate functional group, −O−C≡N, are known as cyanates or cyanate esters. The cyanate functional group is distinct from the isocyanate functional group, −N=C=O; the fulminate functional group, −O−N+≡C; and the nitrile oxide functional group, −CNO or −C≡N+−O.

  1. ^ William R. Martin and David W. Ball (2019): "Small organic fulminates as high-energy materials. Fulminates of acetylene, ethylene, and allene". Journal of Energetic Materials, volume 31, issue 7, pages 70-79. doi:10.1080/07370652.2018.1531089