12Diethynylbenzene

1,2-Diethynylbenzene, also known as ortho-diethynylbenzene, is an organic compound with the chemical formula C10H6. It is a derivative of benzene where two ethynyl groups (–C≡CH) are attached to adjacent carbon atoms on the benzene ring. This compound is a colorless liquid at room temperature. Its structure features a rigid benzene core with two highly reactive alkyne functionalities. The proximity of the two ethynyl groups makes it a valuable building block in organic synthesis, particularly in the formation of complex cyclic structures.

1,2-Diethynylbenzene can be synthesized through various methods, often involving the coupling of suitable precursors. A common approach involves the Sonogashira coupling reaction or related palladium-catalyzed cross-coupling reactions. It is also known to be prepared from precursors like 1,2-dibromobenzene or 1,2-diiodobenzene. The compound is relatively stable but should be handled with care, as alkynes can be reactive under certain conditions.

Due to its difunctional nature, 1,2-diethynylbenzene is frequently employed in cycloaddition reactions, such as Diels-Alder reactions, and in the synthesis of novel heterocyclic compounds and polymers. It can undergo polymerization to form poly(phenylene ethynylene) derivatives, which are of interest for their electronic and optical properties. The compound's utility lies in its ability to introduce two alkyne units into a molecule in a specific spatial arrangement, facilitating intricate molecular architectures.