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IUPAC name Diphenylacetylene
Other names Tolan
CAS number 501-65-5
SMILES C(#Cc1ccccc1)c2ccccc2
Molecular formula C14H10
Molar mass 178.24 g/mol
Appearance colorless solid
Density 0.990 g/cm³ solid
Melting point

62.5 °C

Boiling point

0–97 °C/0.3 mmHg

Solubility in water insoluble
Molecular shape sp2 and sp at carbon
Dipole moment 0 D
Main hazards innocuous
Related Compounds
Related compounds C2Me2
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Diphenylacetylene is the chemical compound C6H5C≡CC6H5. The molecule consists of phenyl groups attached to both ends of an alkyne. It is a colorless crystalline material that is widely used as a building block in organic and as a ligand organometallic chemistry.


Several preparations for this compound exist:

  • one being from benzil which is condensed with hydrazine to give the bis(hydrazone) that in turn suffers oxidation with mercury oxide.[1]
  • The compound is usually prepared from stilbene by bromination dehydrohalogenation sequence, but the product can be contaminated with stilbene, which is difficult to remove.
  • One methods starts from iodobenzene and the copper salt of phenylacetylene in the Castro-Stephens coupling

Interesting derivatives

  • Reaction of Ph2C2 with tetraphenyl substituted cyclopentadienone results in the formation of hexaphenylbenzene.[2]
  • Reaction of Ph2C2 with benzal chloride in the presence of potassium t-butoxide affords the 3-alkoxycyclopropene which coverts to the cyclopropenium ion.[3]


  1. ^ Cope, A. C.; Smith, D. S.; Cotter, R. J.. "Phenylacetylene". Org. Synth.; Coll. Vol. 4: 377. 
  2. ^ Fieser, L. F.. "Hexaphenylbenzene". Org. Synth.; Coll. Vol. 5: 604. 
  3. ^ Xu, R. Breslow, R.. "1,2,3-Triphenylcyclopropendium Bromide". Org. Synth.; Coll. Vol. 9: 730. 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Diphenylacetylene". A list of authors is available in Wikipedia.
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