Cyanogen fluoride (IUPAC name: carbononitridic fluoride) is an inorganic compound 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 ...

. The molecule of this compound is

linear In mathematics, the term ''linear'' is used in two distinct senses for two different properties: * linearity of a '' function'' (or '' mapping''); * linearity of a '' polynomial''. An example of a linear function is the function defined by f(x) ...

, having the

structural formula The structural formula of a chemical compound is a graphic representation of the molecular structure (determined by structural chemistry methods), showing how the atoms are connected to one another. The chemical bonding within the molecule is al ...

. It consists of a

fluorine Fluorine is a chemical element; it has Chemical symbol, symbol F and atomic number 9. It is the lightest halogen and exists at Standard temperature and pressure, standard conditions as pale yellow Diatomic molecule, diatomic gas. Fluorine is extre ...

atom in a single bond with a

carbon Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...

atom of a cyano group. It is a

toxic Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subst ...

and explosive gas at room temperature. It is used in

organic synthesis Organic synthesis is a branch of chemical synthesis concerned with the construction of organic compounds. Organic compounds are molecules consisting of combinations of covalently-linked hydrogen, carbon, oxygen, and nitrogen atoms. Within the gen ...

and can be produced by

pyrolysis Pyrolysis is a process involving the Bond cleavage, separation of covalent bonds in organic matter by thermal decomposition within an Chemically inert, inert environment without oxygen. Etymology The word ''pyrolysis'' is coined from the Gree ...

of cyanuric fluoride or by fluorination of

cyanogen Cyanogen is the chemical compound with the chemical formula, formula . Its structure is . The simplest stable carbon nitride, it is a Transparency and translucency, colorless and highly toxic gas with a pungency, pungent odor. The molecule is a ...

Synthesis

Cyanogen fluoride, is synthesized by the pyrolysis of cyanuric fluoride (C₃N₃F₃) at 1300 °C and 50

mmHg A millimetre of mercury is a manometric unit of pressure, formerly defined as the extra pressure generated by a column of mercury one millimetre high. Currently, it is defined as exactly , or approximately 1 torr = atmosphere = &nb ...

pressure; this process gives a maximum of 50% yield. Other products observed were

and . For pyrolysis, an induction heated carbon tube with an internal diameter of 0.75 inches is packed with 4 to 8 mesh carbon granules and is surrounded by graphite powder insulation and a water-jacketed shell. The cyanuric fluoride is pyrolyzed (becoming a pyrolysate) at a rate of 50g/hr, and appears as fluffy white solid collected in liquid nitrogen traps. These liquid nitrogen traps are filled to atmospheric pressure with nitrogen or helium. This process yields crude cyanogen fluoride, which is then distilled in a glass column at atmospheric pressure to give pure cyanogen fluoride. Another method of synthesizing cyanogen fluoride is by the fluorination of cyanogen. Nitrogen trifluoride can fluoridate cyanogen to cyanogen fluoride when both the reactants are injected downstream into the nitrogen arc plasma. With carbonyl fluoride and carbon tetrafluoride, FCN was obtained by passing these fluorides through the arc flame and injecting the cyanogen downstream into the arc plasma.

Properties

Cyanogen fluoride is a toxic, colorless gas with a molecular mass of 45.015 g/mol. Cyanogen fluoride has a boiling point of −46.2 °C and a melting point of −82 °C. The stretching constant for the CN bond was 17.5 mdyn/A and for the CF bond it was 8.07 mdyn/A, but this can vary depending on the interaction constant. At room temperature, the condensed phase converts rapidly to polymeric materials. Liquid FCN explodes at −41 °C when initiated by a squib.

Spectroscopy

The fluorine NMR pattern for FCN showed that there was a triplet peak centered at 80 ppm (3180 cps) with a 32-34 cps splitting between adjacent peaks because of the ¹⁴N nucleus. This splitting is absent near freezing point and it collapses to a singlet peak. The IR spectrum of FCN shows two doublet bands at around 2290 cm⁻¹ (for the C≡N) and 1078 cm⁻¹ (for the C-F). The C-F doublet band has a 24 cm⁻¹ separation between the two branches. A triplet band is observed at around 451 cm⁻¹.

Chemical reactions

Cyanogen fluoride reacts with

benzene Benzene is an Organic compound, organic chemical compound with the Chemical formula#Molecular formula, molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal Ring (chemistry), ring with one hyd ...

in the presence of

aluminium chloride Aluminium chloride, also known as aluminium trichloride, is an inorganic compound with the formula . It forms a hexahydrate with the formula , containing six water molecules of hydration. Both the anhydrous form and the hexahydrate are col ...

to form

benzonitrile Benzonitrile is the chemical compound with the formula , abbreviated PhCN. This aromatic organic compound is a colorless liquid with a cherry or almond like odour. It is mainly used industrially to produce the melamine resin precursor benzoguanam ...

in 20% conversion. It also reacts with

olefin In organic chemistry, an alkene, or olefin, is a hydrocarbon containing a carbon–carbon double bond. The double bond may be internal or at the terminal position. Terminal alkenes are also known as α-olefins. The International Union of Pu ...

s to yield an alpha,beta-fluoronitriles.Lipscomb, R. D., & Smith, W. C. (1961). ''U.S. Patent No. 3,008,798''. Washington, DC: U.S. Patent and Trademark Office. FCN also adds to olefins which have internal

double bond In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist betw ...

s in the presence of

strong acid Acid strength is the tendency of an acid, symbolised by the chemical formula , to dissociate into a hydron (chemistry), proton, , and an anion, . The Dissociation (chemistry), dissociation or ionization of a strong acid in solution is effectivel ...

catalyst Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quick ...

Storage

FCN can be stored in a

stainless steel Stainless steel, also known as inox, corrosion-resistant steel (CRES), or rustless steel, is an iron-based alloy that contains chromium, making it resistant to rust and corrosion. Stainless steel's resistance to corrosion comes from its chromi ...

cylinders for over a year when the temperature is −78.5 °C (

solid carbon dioxide Dry ice is the solid form of carbon dioxide. It is commonly used for temporary refrigeration as CO2 does not have a liquid state at normal atmospheric pressure and sublimes directly from the solid state to the gas state. It is used primarily ...

temperature).

Safety

Cyanogen fluoride undergoes violent reaction when in the presence of

boron trifluoride Boron trifluoride is the inorganic compound with the formula . This pungent, colourless, and toxic gas forms white fumes in moist air. It is a useful Lewis acid and a versatile building block for other boron compounds. Structure and bonding The g ...

hydrogen fluoride Hydrogen fluoride (fluorane) is an Inorganic chemistry, inorganic compound with chemical formula . It is a very poisonous, colorless gas or liquid that dissolves in water to yield hydrofluoric acid. It is the principal industrial source of fluori ...

. Pure gaseous FCN at atmospheric pressure and room temperature does not ignite by a spark or hot wire. FCN air mixtures however are more susceptible to ignition and explosion than pure FCN.

Uses

FCN is useful in synthesis of important compounds such as dyes, fluorescent brighteners and photographic sensitizers. It is also very useful as a fluorinating and nitrilating agent. Beta-fluoronitriles, which are produced when FCN is reacted with olefins, are useful intermediates for preparing polymers, beta-fluorocarboxylic acids and other fluorine containing products. Useful amines can be obtained. Cyanogen fluoride is a very volatile fumigant, disinfectant and animal pest killer.

References

{{Cyanides Nonmetal halides Fluorides Triatomic molecules Cyano compounds Pseudohalogens