Sesquifulvalene or pentaheptafulvalene is a hydrocarbon in the fulvalene class with chemical formula C12H10. It is composed of linked cyclopentadiene and cycloheptatriene rings.

Sesquifulvalene
Names
Preferred IUPAC name
7-(Cyclopenta-2,4-dien-1-ylidene)cyclohepta-1,3,5-triene
Other names
Pentaheptafulvalene
Identifiers
3D model (JSmol)
ChemSpider
  • InChI=1S/C12H10/c1-2-4-8-11(7-3-1)12-9-5-6-10-12/h1-10H
    Key: JYRVSRMFQWYDGM-UHFFFAOYSA-N
  • C1=CC=CC(=C2C=CC=C2)C=C1
Properties
C12H10
Molar mass 154.212 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Properties

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In the ground state, which is a singlet state, the central double bond is polarized, with a partial positive charge on the carbon atom of heptagonal ring and a partial negative charge on the carbon atom of pentagonal ring. This shift makes each ring have closer to 4n+2 π electrons, in keeping with the Hückel's pattern of aromatic stability. However, in the lowest quintet state, the central double bond is polarized with a partial negative charge on the carbon atom of heptagonal ring and a partial positive charge on the carbon atom of pentagonal ring due to Baird's rule.[2]

See also

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References

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  1. ^ "7-(2,4-Cyclopentadien-1-ylidene)-1,3,5-cycloheptatriene". webbook.nist.gov.
  2. ^ Christian Dahlstrand; Martin Rosenberg (2012). "Exploration of the π-Electronic Structure of Singlet, Triplet, and Quintet States of Fulvenes and Fulvalenes Using the Electron Localization Function". The Journal of Physical Chemistry A. 116 (20): 5008–5017. Bibcode:2012JPCA..116.5008D. doi:10.1021/jp3032397. PMID 22536920.