Chemistry:Calicene
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| Preferred IUPAC name
5-(Cycloprop-2-en-1-ylidene)cyclopenta-1,3-diene | |
| Other names
Triapentafulvalene
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| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
PubChem CID
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| Properties | |
| C8H6 | |
| Molar mass | 102.136 g·mol−1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Calicene or triapentafulvalene is a hydrocarbon of the fulvalene class with chemical formula C8H6, composed of a cyclopentadiene ring and a cyclopropene ring linked by a double bond. Its name is derived from the Latin calix meaning "goblet", from its shape.
Properties
Very high resonance energy is predicted by the Hückel method,[1] however its resonance energy is not high. The central double bond is polarized with a partial positive charge on the carbon atom of triangular ring and a partial negative charge on the carbon atom of pentagonal ring, in keeping with added Hückel's rule stability of rings containing 2 π electrons and 6 π electrons respectively. Calicene's dipole moment has been computed to be 4.66 D.[2] Several compounds that contains two or more calicene subunits are aromatic, such as trans-bicalicene[2] (ring compound) or poly-2,7-[N]calicenes (chain compound)[3]
Despite several attempts to prepare it, the parent calicene has so far defied attempts at synthesis.[4] However, 1,2,3,4,5,6-hexaphenylcalicene has been prepared and an experimental dipole moment of 6.3 D was measured.[5]
References
- ↑ Schaad, L. J.; B. Andes Hess, Jr (2001). "Dewar Resonance Energy". Chemical Reviews 101 (5): 1465–1476. doi:10.1021/cr9903609. PMID 11710229.
- ↑ 2.0 2.1 Oziminski, W. P.; M. Palusia (2013). "Capturing the elusive aromaticity of bicalicene". Physical Chemistry Chemical Physics 15 (9): 3286–3293. doi:10.1039/C2CP43426A. PMID 23358331. Bibcode: 2013PCCP...15.3286O.
- ↑ Ratanadachanakin, Thawalrat; Collier, Willard E. R. (2015). "Aromaticity of a series of poly-2,7-[Ncalicenes"]. Maejo International Journal of Science and Technology 9 (1): 21–31. http://www.mijst.mju.ac.th/vol9/21-31.pdf.
- ↑ de Meijere, Armin (2014). Houben-Weyl Methods of Organic Chemistry Vol. E 17d, 4th Edition Supplement: Carbocyclic Three-Membered Ring Compounds, Cyclopropenes, Author Index, Compound Index. Stuttgart: Georg Thieme Verlag. pp. 2967. ISBN 978-3131819741.
- ↑ Agranat, Israel; Bergmann, Ernst D. (1965-01-01). "Hexaphenyltriapentafulvalene" (in en). Chemical Communications (21): 512–513. doi:10.1039/C19650000512. ISSN 0009-241X.
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