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.
^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. PMID11603982.
^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. PMID20000386.