In organic chemistry, a cycloalkyne is the cyclic analog of an alkyne (−C≡C−). A cycloalkyne consists of a closed ring of carbon atoms containing one or more triple bonds. Cycloalkynes have a general formula CnH2n−4. Because of the linear nature of the C−C≡C−C alkyne unit, cycloalkynes can be highly strained and can only exist when the number of carbon atoms in the ring is great enough to provide the flexibility necessary to accommodate this geometry. Large alkyne-containing carbocycles may be virtually unstrained, while the smallest constituents of this class of molecules may experience so much strain that they have yet to be observed experimentally.[1] Cyclooctyne (C8H12) is the smallest cycloalkyne capable of being isolated and stored as a stable compound.[2] Despite this, smaller cycloalkynes can be produced and trapped through reactions with other organic molecules or through complexation to transition metals.