Diphenylacetylene
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| Names | |
|---|---|
| Preferred IUPAC name
1,1′-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·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 |
| Insoluble | |
| Structure | |
| 0 D | |
| Hazards | |
| Safety data sheet (SDS) | Fisher Scientific MSDS |
| Related compounds | |
Related compounds
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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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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.
Preparation and structure
[edit]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
[edit]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]
References
[edit]- ^ a b Mavridis, A.; Moustakali-Mavridis, I. (1977). "A Reinvestigation of Tolane". Acta Crystallographica Section B: Structural Crystallography and Crystal Chemistry. 33 (11): 3612–3615. doi:10.1107/S0567740877011674.
- ^ Cope, A. C.; Smith, D. S.; Cotter, R. J. (1954). "Diphenylacetylene". Organic Syntheses. 34: 42. doi:10.15227/orgsyn.034.0042.
- ^ Lee Irvin Smith; M. M. Falkof (1942). "Diphenylacetylene". Organic Syntheses. 22: 50. doi:10.15227/orgsyn.022.0050.
- ^ Leavitt, F. C.; Manuel, T. A.; Johnson, F.; Matternas, L. U.; Lehman, D. S. (1960). "Novel Heterocyclopentadienes. II". Journal of the American Chemical Society. 82 (19): 5099–5102. Bibcode:1960JAChS..82.5099L. doi:10.1021/ja01504a021.
- ^ Fieser, L. F. (1966). "Hexaphenylbenzene". Organic Syntheses. 46: 44. doi:10.15227/orgsyn.046.0044.
- ^ Vij, V.; Bhalla, V.; Kumar, M. (8 August 2016). "Hexaarylbenzene: Evolution of Properties and Applications of Multitalented Scaffold". Chemical Reviews. 116 (16): 9565–9627. doi:10.1021/acs.chemrev.6b00144.
- ^ Xu, Ruo; Breslow, Ronald (1997). "1,2,3-Triphenylcyclopropenium Bromide". Organic Syntheses. 74: 72. doi:10.15227/orgsyn.074.0072.