1,3,5,7-Cyclooctatetraene (COT) is an unsaturated

Saturation (chemistry)

In chemistry, saturation has six different meanings, all based on reaching a maximum capacity...

 derivative

Derivative (chemistry)

In chemistry, a derivative is a compound that is derived from a similar compound by some chemical or physical process. In the past it was also used to mean a compound that can be imagined to arise from another compound, if one atom is replaced with another atom or group of atoms, but modern...

 of cyclooctane

Cyclooctane

Cyclooctane is a cycloalkane with the molecular formula 8. It is a simple colourless hydrocarbon, but it is often a reference compound for saturated eight-membered ring compounds in general.- Conformation :...

, with the formula C₈H₈. It is also known as [8]annulene

Annulene

Annulenes are completely conjugated monocyclic hydrocarbons. They have the general formula CnHn or CnHn+1...

. This polyunsaturated hydrocarbon

Hydrocarbon

In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....

 is a colorless to light yellow flammable liquid at room temperature. Because of its stoichiometric relationship to benzene

Benzene

Benzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....

, COT has been the subject of much research and some controversy.

Unlike benzene, C₆H₆, however, cyclooctatetraene, C₈H₈, is not aromatic

Aromaticity

In organic chemistry, Aromaticity is a chemical property in which a conjugated ring of unsaturated bonds, lone pairs, or empty orbitals exhibit a stabilization stronger than would be expected by the stabilization of conjugation alone. The earliest use of the term was in an article by August...

, although its dianion, C₈H₈^2- (cyclooctatetraenide), is.