Diborane(2) or diborene is a theoretical/hypothetical inorganic compound with the formula B2H2. It is predicted to have a symmetric covalently bonded structure of H–B=B–H with linear geometry.[1] It has been suggested that the boron–boron bonding in this compound may be a pure pi bond, one that does not have any net sigma bonding associated with it.[2] The compound will be a very strong Lewis acid as each boron has a share in only 6 valence electrons.

Other names
3D model (JSmol)
  • Interactive image
  • 24807783
  • 15334965
  • InChI=1S/B2H2/c1-2/h1-2H
  • B=B
Molar mass 23.64 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Related compounds, with the general formula R:(BH)=(BH):R, known as diborenes, are stable. The two substituents, R:, supply the two additional electron pairs needed for there to be a conventional double bond between the boron atoms in these compounds.[3]


  1. ^ Treboux, Gabin; Barthelat, Jean Claude (1993). "X-X direct bonds versus bridged structures in group 13 X2H2 potential energy surfaces". J. Am. Chem. Soc. 115 (11): 4870–4878. doi:10.1021/ja00064a056.
  2. ^ Jemmis, Eluvathingal D.; Pathak, Biswarup; King, R. Bruce; Schaefer III, Henry F. (2006). "Bond length and bond multiplicity: σ-bond prevents short π-bonds". Chemical Communications (20): 2164–2166. doi:10.1039/b602116f. PMID 16703142.
  3. ^ Yuzhong Wang, Brandon Quillian, Pingrong Wei, Chaitanya S. Wannere, Yaoming Xie, R. Bruce King, Henry F. Schaefer, III, Paul v. R. Schleyer, and Gregory H. Robinson (2007). "A Stable Neutral Diborene Containing a B=B Double Bond". J. Am. Chem. Soc. 129 (41): 12412–12413. doi:10.1021/ja075932i. PMID 17887683.{{cite journal}}: CS1 maint: uses authors parameter (link)