Diphenylacetylene is the
chemical compound C
6H
5C≡CC
6H
5. The molecule consists of two
phenyl groups attached to a C
2 unit. A colorless solid, it is used as a building block in
organic synthesis
Organic synthesis is a special branch of chemical synthesis and is concerned with the intentional construction of organic compounds. Organic molecules are often more complex than inorganic compounds, and their synthesis has developed into one o ...
and as a
ligand in
organometallic chemistry
Organometallic chemistry is the study of organometallic compounds, chemical compounds containing at least one chemical bond between a carbon atom of an organic molecule and a metal, including alkali, alkaline earth, and transition metals, and so ...
.
Preparation and structure
In one preparation for this compound,
benzil is condensed with
hydrazine
Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly toxic unless handled in solution as, for example, hydrazine ...
to give the bis(hydrazone), which is oxidized with
mercury(II) oxide.
Alternatively
stilbene is brominated, and the resulting dibromodiphenylethane is subjected to
dehydrohalogenation, Yet another method starts involves the coupling
iodobenzene and the copper salt of phenylacetylene in the
Castro-Stephens coupling.
Diphenylacetylene is a planar molecule. The central C≡C distance is 119.8 picometers.
[
]
Derivatives
Reaction of diphenylacetylene with tetraphenylcyclopentadienone results in the formation of hexaphenylbenzene in a Diels–Alder reaction
In organic chemistry, the Diels–Alder reaction is a chemical reaction between a conjugated diene and a substituted alkene, commonly termed the dienophile, to form a substituted cyclohexene derivative. It is the prototypical example of a peric ...
. Reaction of Ph2C2 with benzal chloride in the presence of potassium ''t''-butoxide affords the 3-alkoxy cyclopropene which converts to the cyclopropenium ion.[{{cite journal, first1 = Ruo, last1 = Xu, first2 = Ronald, year=1997, last2 = Breslow, title = 1,2,3-Triphenylcyclopropenium Bromide, journal=Organic Syntheses , volume = 74, pages = 72, doi = 10.15227/orgsyn.074.0072]
References
Phenyl compounds
Alkyne derivatives