Butalene
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| Names | |
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| IUPAC name
Bicyclo[2.2.0]hexa-1,3,5-triene
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| Other names
Butalene
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| Identifiers | |
3D model (JSmol)
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PubChem CID
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CompTox Dashboard (EPA)
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| Properties | |
| C6H4 | |
| Molar mass | 76.098 g·mol−1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Butalene is a polycyclic hydrocarbon composed of two fused cyclobutadiene rings.[1] A reported possible synthesis of it involves an elimination reaction from a Dewar benzene derivative. The structure itself can be envisioned as benzene with an internal bridge, and calculations indicate it is somewhat less stable than the open 1,4-didehydrobenzene biradical, the valence isomer in which that bridged bond is broken.
Structure and bonding
Ab initio calculations indicate butalene has a planar geometry and, in keeping with a planar structure with 6 π-electron configuration, is aromatic. Thus, the most significant π bonding interactions involve conjugation around the periphery of the whole six-atom structure, similar to benzene, rather than cross-ring resonance along the bridging bond.[2] Significant resonance around one or the other four-membered ring alone would be a less-stable antiaromatic form, as is seen in cyclobutadiene itself.
See also
References
- ^ Warner, Philip M.; Jones, Graham B. (2001). "Butalene and Related Compounds: Aromatic or Antiaromatic?". J. Am. Chem. Soc. 123 (42): 10322–10328. doi:10.1021/ja011134v.
- ^ Sakai, Shogo; Udagawa, Taro; Kita, Yuki (2009). "Theoretical Studies on the Structures and the Aromaticity for Condensed Cyclobutadienoids Series: The Combination of Kekulé Structures". J. Phys. Chem. A. 113 (50): 13964–13971. doi:10.1021/jp906258e.