Diphenylacetylene
Chemical compound
From Wikipedia, the free encyclopedia
Diphenylacetylene is the chemical compound C6H5Câ¡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.
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| Names | |
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| Preferred IUPAC name
1,1â²-Ethynediyldibenzene | |
| Other names
Tolane 1,2-Diphenylethyne Diphenylethyne 2-Phenylethynylbenzene Tolan | |
| Identifiers | |
3D model (JSmol) |
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| 606478 | |
| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.007.206 |
| EC Number |
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PubChem CID |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| C14H10 | |
| Molar mass | 178.234 g·molâ1 |
| Appearance | Colorless solid |
| Density | 1.136 g cmâ3[1] |
| Melting point | 62.5 °C (144.5 °F; 335.6 K) |
| Boiling point | 170 °C (338 °F; 443 K) at 19 mmHg |
| Insoluble | |
| Structure | |
| 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).
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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 Câ¡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 PhCâ¡CPh + 2 Li â LiCPh=CPhâCPh=CPhLi (Ph = C6H5)
- LiCPh=CPhâCPh=CPhLi + 2 H2O â PhCH=CPhâCPh=CHPh + 2 LiOH
Reaction of diphenylacetylene with tetraphenylcyclopentadienone results in the formation of hexaphenylbenzene in a DielsâAlder 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]