Diphenylacetylene

Diphenylacetylene is the chemical compound C₆H₅C≡CC₆H₅. The molecule consists of two phenyl groups attached to a C₂ unit. A colorless solid, it is used as a building block in organic synthesis and as a ligand in organometallic chemistry.

Diphenylacetylene

Names
Preferred IUPAC name 1,1′-Ethynediyldibenzene
Other names Tolane 1,2-Diphenylethyne Diphenylethyne 2-Phenylethynylbenzene Tolan
Identifiers
CAS Number	501-65-5 Y
3D model (JSmol)	Interactive image
Beilstein Reference	606478
ChEBI	CHEBI:51579 Y
ChEMBL	ChEMBL223309 Y
ChemSpider	9961 Y
ECHA InfoCard	100.007.206
EC Number	207-926-6
PubChem CID	10390
UNII	Y70JA8HB75
CompTox Dashboard (EPA)	DTXSID4060109
InChI InChI=1S/C14H10/c1-3-7-13(8-4-1)11-12-14-9-5-2-6-10-14/h1-10H Y Key: JRXXLCKWQFKACW-UHFFFAOYSA-N Y InChI=1/C14H10/c1-3-7-13(8-4-1)11-12-14-9-5-2-6-10-14/h1-10H Key: JRXXLCKWQFKACW-UHFFFAOYAN
SMILES c1ccc(cc1)C#Cc2ccccc2
Properties
Chemical formula	C14H10
Molar mass	178.234 g·mol−1
Appearance	Colorless solid
Density	1.136 g cm−3[1]
Melting point	62.5 °C (144.5 °F; 335.6 K)
Boiling point	170 °C (338 °F; 443 K) at 19 mmHg
Solubility in water	Insoluble
Structure
Dipole moment	0 D
Hazards
Safety data sheet (SDS)	Fisher Scientific MSDS
Related compounds
Related compounds	But-2-yne Dimethyl acetylenedicarboxylate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Preparation and structure

In one preparation for this compound, benzil is condensed with hydrazine to give the bis(hydrazone), which is oxidized with mercury(II) oxide.^[2] Alternatively stilbene is brominated, and the resulting dibromodiphenylethane is subjected to dehydrohalogenation.^[3] Yet another method involves the coupling of iodobenzene and the copper salt of phenylacetylene in the Castro-Stephens coupling. The related Sonogashira coupling involves the coupling of iodobenzene and phenylacetylene.

Diphenylacetylene is a planar molecule. The central C≡C distance is 119.8 picometers.^[1]

Derivatives

1,2,3,4-Tetraphenylbutadiene is prepared by reductive coupling of diphenylacetylene using lithium metal followed by hydrolysis of the resulting 1,4-dilithiobutadiene:^[4]

2 PhC≡CPh + 2 Li → LiCPh=CPh−CPh=CPhLi (Ph = C₆H₅)

LiCPh=CPh−CPh=CPhLi + 2 H₂O → PhCH=CPh−CPh=CHPh + 2 LiOH

Reaction of diphenylacetylene with tetraphenylcyclopentadienone results in the formation of hexaphenylbenzene in a Diels–Alder reaction.^[5]

Dicobalt octacarbonyl catalyzes alkyne trimerisation of diphenylacetylene to form hexaphenylbenzene.^[6]

Reaction of Ph₂C₂ with benzal chloride in the presence of potassium t-butoxide affords 3-tert-butoxy-1,2,3-triphenylcyclopropene, which converts to 1,2,3-triphenylcyclopropenium bromide after the elimination of tert-butoxide.^[7]