Cyanoform (tricyanomethane) is a

cyanocarbon In organic chemistry, cyanocarbons are a group of chemical compounds that contain several cyanide functional groups. Such substances generally are classified as organic compounds, since they are formally derived from hydrocarbons by replacing one ...

and derivative of

methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Eart ...

with three

cyano group Cyanide is a naturally occurring, rapidly acting, toxic chemical that can exist in many different forms. In chemistry, a cyanide () is a chemical compound that contains a functional group. This group, known as the cyano group, consists of a ...

s. For many years, chemists have been unable to isolate this compound as a neat, free

acid In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ...

. However, in September 2015, reports surfaced of a successful isolation.

Properties

Dilute solutions of this acid, as well as its salts, have long been well known. Cyanoform ranks as one of the most acidic of the

carbon acid In organic chemistry, a carbanion is an anion in which carbon is trivalent (forms three bonds) and bears a formal negative charge (in at least one significant resonance form). Formally, a carbanion is the conjugate base of a carbon acid: :R3C ...

s with an estimated pK_a of -5.1 in water and measured pK_a of 5.1 in

acetonitrile Acetonitrile, often abbreviated MeCN (methyl cyanide), is the chemical compound with the formula and structure . This colourless liquid is the simplest organic nitrile (hydrogen cyanide is a simpler nitrile, but the cyanide anion is not clas ...

. The reaction of

sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular formu ...

with

sodium tricyanomethanide Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable isot ...

in water (a reaction first tried by H. Schmidtmann in 1896 with inconclusive results) is reported to result in the formation of the

hydrate In chemistry, a hydrate is a substance that contains water or its constituent elements. The chemical state of the water varies widely between different classes of hydrates, some of which were so labeled before their chemical structure was understo ...

or the formation of (''Z'')-3-amino-2-cyano-3-hydroxyacrylamide, , depending on the precise conditions. The reaction of HCl gas with sodium tricyanomethanide dissolved in THF is reported to yield 1-chloro-1-amino-2,2-dicyanoethylene () and its

tautomer Tautomers () are structural isomers (constitutional isomers) of chemical compounds that readily interconvert. The chemical reaction interconverting the two is called tautomerization. This conversion commonly results from the relocation of a hydr ...

Isolation

In September 2015 cyanoform was successfully isolated by a team of scientists at

Ludwig Maximilian University The Ludwig Maximilian University of Munich (simply University of Munich or LMU; german: Ludwig-Maximilians-Universität München) is a public research university in Munich, Germany. It is Germany's sixth-oldest university in continuous operatio ...

of Munich. The team discovered that cyanoform was stable at temperatures below –40° Celsius; previous beliefs were that cyanoform was stable at room temperature. The isolation confirmed that cyanoform is a colorless liquid.Mole, B - Elusive acid finally created https://www.sciencenews.org/article/elusive-acid-finally-created

References

{{reflist, 30em Organic acids Nitriles Substances discovered in the 2010s