Cyanocarbons

Abstract

Cyanocarbons are organic compounds in which a substantial portion of the total functionality consists of cyano groups. As a consequence of the large number of cyano groups, the cyanocarbons are highly reactive electrophilic molecules. The most important members of the cyanocarbon family are tetracyanomethane, hexacyanoethane, tetracyanoethylene (TCNE), tetracyanoquinodimethan (TCNQ), hexacyanobutadiene, dicyanoacetylene, hexacyanobenzene, tetracyanoquinone, tricyanomethanide, pentacyanopropenide, pentacyanocyclopentadienide, tetracyanoethylene oxide, tetracyanofuran, tetracyanothiophene, tetracyanodithiin, diaminomaleonitrile (DAMN), diiminosuccinonitrile, tetracyanopyrazine, diazotetracyanocyclopentadiene, diazodicyanoimidazole, tetracyanopyrole, tricyanoimidazole, and pentacyanopyridine. Examples of unusual reactivity are numerous. TCNE forms colored charge‐transfer complexes with aromatic hydrocarbons, tetracyanoethylene oxide adds to olefins by cleavage of its carbon‐carbon bond, and TCNE and TCNQ react with metals to produce anion radicals.

Elusive Cyanoform: Computational Probing Its Stability and Reactivity with Accurate Ab Initio Methods

“…Scheme indicates that the closed-shell cyanocarbons C x (CN) y ( x = 1, 2, or 6; y = 4 or 6) are the products of a number of reactions examined (, , –, and ). The CCSD­(T)/cc-pVTZ optimized geometries of these species ( 8 – 11 ) are summarized in Figure .…”

“…In this section, we are dealing again with the reactivity of cyanoform toward itself by providing the energies corresponding to different modes of cyanoform dimerization, which unlike , afford the covalently bound products (–). In addition, these energies are compared to that of the HC­(CN) 3 + HCN reaction () because the four processes have a common feature in the formation of the closed-shell species C x (CN) y ( x = 1 or 2, and y = 4 or 6) as one of the products.…”