title: Confirmed by X-ray crystallography: the B⋅B one-electron σ bond.
abstract: Is one electron sufficient to bring about significant σ bonding between two atoms? The chemist's view on the chemical bond is usually tied to the concept of shared electron pairs, and not too much experimental evidence exists to challenge this firm belief. Whilst species with the unusual one-electron σ-bonding motif between homonuclear atoms have so far been identified mainly by spectroscopic evidence, we present herein the first crystallographic characterization, augmented by a detailed quantum-chemical validation, for a radical anion featuring a B⋅B one-electron-two-center σ bond.
authors.affiliation: Institut für Anorganische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Strasse 7, 60438 Frankfurt (Main) (Germany).
authors.forename: Alexander
authors.initials: A
authors.lastname: Hübner
authors.forename: Andreas M
authors.initials: AM
authors.lastname: Diehl
authors.forename: Martin
authors.initials: M
authors.lastname: Diefenbach
authors.forename: Burkhard
authors.initials: B
authors.lastname: Endeward
authors.forename: Michael
authors.initials: M
authors.lastname: Bolte
authors.forename: Hans-Wolfram
authors.initials: HW
authors.lastname: Lerner
authors.forename: Max C
authors.initials: MC
authors.lastname: Holthausen
authors.forename: Matthias
authors.initials: M
authors.lastname: Wagner
keywords: bond theory; boron; odd-electron bonds; organoborane; σ bonds