PROFILPELAJAR.COM

Butalene
Names
	Preferred IUPAC name Bicyclo[2.2.0]hexa-1,3,5-triene
	Other names Butalene
Identifiers
CAS Number	1552-98-3 ;
3D model (JSmol)	Interactive image; Interactive image;
PubChem CID	3030745;
UNII	G5XZV75YZL ;
CompTox Dashboard (EPA)	DTXSID801047368 ;
	InChI InChI=1S/C6H4/c1-2-6-4-3-5(1)6/h1-4H Key: YHCJOCYHUDCVQI;
	SMILES c1cc2ccc12; C=1C=C2C=CC=12;
Properties
Chemical formula	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). verify (what is ?) Infobox references

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.

References

^ Warner, Philip M.; Jones, Graham B. (2001). "Butalene and Related Compounds: Aromatic or Antiaromatic?". J. Am. Chem. Soc. 123 (42): 10322–10328. Bibcode:2001JAChS.12310322W. doi:10.1021/ja011134v. PMID 11603982.
^ 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. Bibcode:2009JPCA..11313964S. doi:10.1021/jp906258e. PMID 20000386.