Cyanoform (tricyanomethane) is an

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

with the

chemical formula A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as pare ...

. It is a colorless liquid. It is a cyanocarbon 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 abundance of methane on Earth makes ...

with three

cyano group In chemistry, cyanide () is an inorganic chemical compound that contains a functional group. This group, known as the cyano group, consists of a carbon atom triple-bonded to a nitrogen atom. Ionic cyanides contain the cyanide anion . This an ...

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

acid An acid is a molecule or ion capable of either donating a proton (i.e. Hydron, hydrogen cation, H+), known as a Brønsted–Lowry acid–base theory, Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis ...

. 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 with a lone pair attached to a tervalent carbon atom. This gives the carbon atom a negative charge. Formally, a carbanion is the conjugate base of a carbon acid: : where B stands for the base. The ca ...

s with an estimated p''K''_a of -5.1 in water and measured p''K''_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 class ...

. The reaction of

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

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

hydronium In chemistry, hydronium (hydroxonium in traditional British English) is the cation , also written as , the type of oxonium ion produced by protonation of water. It is often viewed as the positive ion present when an Arrhenius acid is dissolved ...

tricyanomethanide or the formation of (''Z'')-3-amino-2-cyano-3-hydroxyacrylamide, , depending on the precise conditions. The reaction of

HCl HCL may refer to: Science and medicine * Hairy cell leukemia, an uncommon and slowly progressing B cell leukemia * Harvard Cyclotron Laboratory, from 1961 to 2002, a proton accelerator used for research and development * Hollow-cathode lamp, a s ...

gas with sodium tricyanomethanide dissolved in

THF Tetrahydrofuran (THF), or oxolane, is an organic compound with the formula (CH2)4O. The compound is classified as heterocyclic compound, specifically a cyclic ether. It is a colorless, water-miscible organic liquid with low viscosity. It is ma ...

is reported to yield 1-chloro-1-amino-2,2-dicyanoethylene () and its

tautomer In chemistry, 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 reloca ...

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, LMU or LMU Munich; ) is a public research university in Munich, Bavaria, Germany. Originally established as the University of Ingolstadt in 1472 by Duke Ludwig IX of Bav ...

Munich Munich is the capital and most populous city of Bavaria, Germany. As of 30 November 2024, its population was 1,604,384, making it the third-largest city in Germany after Berlin and Hamburg. Munich is the largest city in Germany that is no ...

. The team discovered that cyanoform was stable at temperatures below −40°C; 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