Calicene
Chemical compound
From Wikipedia, the free encyclopedia
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.
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| Names | |
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| Preferred IUPAC name
5-(Cycloprop-2-en-1-ylidene)cyclopenta-1,3-diene | |
| Other names
Triapentafulvalene | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
PubChem CID |
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CompTox Dashboard (EPA) |
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| Properties | |
| C8H6 | |
| Molar mass | 102.136 g·mol−1 |
| none in warter | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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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 contain 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]
