Carbon diselenide is an

inorganic compound An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds⁠that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorgan ...

with the chemical formula . It is a yellow-orange oily liquid with pungent odor. It is the

selenium Selenium is a chemical element; it has symbol (chemistry), symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elem ...

analogue of

carbon disulfide Carbon disulfide (also spelled as carbon disulphide) is an inorganic compound with the chemical formula and structure . It is also considered as the anhydride of thiocarbonic acid. It is a colorless, flammable, neurotoxic liquid that is used as ...

() and

carbon dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...

(). This light-sensitive compound is insoluble in water and soluble in

organic solvents A solvent (from the Latin language, Latin ''wikt:solvo#Latin, solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a Solution (chemistry), solution. A solvent is usually a liquid but can also be a solid, a gas ...

Synthesis, structure and reactions

Carbon diselenide is a linear molecule with D_∞h

symmetry Symmetry () in everyday life refers to a sense of harmonious and beautiful proportion and balance. In mathematics, the term has a more precise definition and is usually used to refer to an object that is Invariant (mathematics), invariant und ...

. It is produced by reacting

powder with

dichloromethane Dichloromethane (DCM, methylene chloride, or methylene bichloride) is an organochlorine compound with the formula . This colorless, volatile liquid with a chloroform-like, sweet odor is widely used as a solvent. Although it is not miscible with ...

vapor near 550 °C. : It was first reported by Grimm and Metzger, who prepared it by treating

hydrogen selenide Hydrogen selenide is an inorganic compound with the formula H2Se. This hydrogen chalcogenide is the simplest and most commonly encountered hydride of selenium. H2Se is a colorless, flammable gas under standard conditions. It is the most toxic se ...

with

carbon tetrachloride Carbon tetrachloride, also known by many other names (such as carbon tet for short and tetrachloromethane, also IUPAC nomenclature of inorganic chemistry, recognised by the IUPAC), is a chemical compound with the chemical formula CCl4. It is a n ...

in a hot tube. Like

, carbon diselenide polymerizes under high pressure. The structure of the polymer is thought to be a head-to-head structure with a

backbone The spinal column, also known as the vertebral column, spine or backbone, is the core part of the axial skeleton in vertebrates. The vertebral column is the defining and eponymous characteristic of the vertebrate. The spinal column is a segmente ...

in the form of . The polymer is a

semiconductor A semiconductor is a material with electrical conductivity between that of a conductor and an insulator. Its conductivity can be modified by adding impurities (" doping") to its crystal structure. When two regions with different doping level ...

with a room-temperature conductivity of 50 S/cm. In addition, carbon diselenide is a precursor to tetraselenafulvalenes, the selenium analogue of

tetrathiafulvalene Tetrathiafulvalene (TTF) is an organosulfur compound with the formula . It is the parent of many tetrathiafulvenes. Studies on these heterocyclic compound contributed to the development of molecular electronics, although no practical applications ...

, which can be further used to synthesize organic conductors and

organic superconductor An organic superconductor is a synthetic organic compound that exhibits superconductivity at low temperatures. As of 2007 the highest achieved critical temperature for an organic superconductor at standard pressure is , observed in the alkali-dope ...

s. Carbon diselenide reacts with

secondary amine In chemistry, amines (, ) are organic compounds that contain carbon-nitrogen bonds. Amines are formed when one or more hydrogen atoms in ammonia are replaced by alkyl or aryl groups. The nitrogen atom in an amine possesses a lone pair of elec ...

s to give : :

Safety

Carbon diselenide has high vapor pressure. It has a moderate

toxicity 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, bacteria, bacterium, or plant, as well as the effect o ...

and presents an inhalation hazard. It may be dangerous due to its easy

membrane transport In cellular biology, membrane transport refers to the collection of mechanisms that regulate the passage of solutes such as ions and small molecules through biological membranes, which are lipid bilayers that contain proteins embedded in them. Th ...

. It decomposes slowly in storage (about 1% per month at –30 °C). When obtained commercially, its cost is high. Pure distilled carbon diselenide has an odor very similar to that of carbon disulfide, but mixed with air, it creates extremely offensive odors (corresponding to new, highly toxic reaction products). Its smell forced an evacuation of a nearby village when it was first synthesized in 1936. Because of the odor, synthetic pathways have been developed to avoid its use..

References

{{Selenides Selenides Inorganic carbon compounds Foul-smelling chemicals Dichalcogenides IV-VI semiconductors