title: The hexacyanodiborane(6) dianion [B2(CN)6](2-).
abstract: Diborane(6) dianions with substituents that are bonded to boron via carbon are very reactive and therefore only a few examples are known. Diborane(6) derivatives are the simplest catenated boron compounds with an electron-precise B-B σ-bond that are of fundamental interest and of relevance for material applications. The homoleptic hexacyanodiborane(6) dianion [B2 (CN)6 ](2-) that is chemically very robust is reported. The dianion is air-stable and resistant against boiling water and anhydrous hydrogen fluoride. Its salts are thermally highly stable, for example, decomposition of (H3 O)2 [B2 (CN)6 ] starts at 200 °C. The [B2 (CN)6 ](2-) dianion is readily accessible starting from 1) B(CN)3 (2-) and an oxidant, 2) [BF(CN)3 ](-) and a reductant, or 3) by the reaction of B(CN)3 (2-) with [BHal(CN)3 ](-) (Hal=F, Br). The latter reaction was found to proceed via a triply negatively charged transition state according to an SN 2 mechanism.
authors.affiliation: Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg (Germany).
authors.forename: Johannes
authors.initials: J
authors.lastname: Landmann
authors.affiliation: Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg (Germany).
authors.forename: Jan A P
authors.initials: JA
authors.lastname: Sprenger
authors.affiliation: Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg (Germany).
authors.forename: Michael
authors.initials: M
authors.lastname: Hailmann
authors.affiliation: Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg (Germany).|Anorganische Chemie, Bergische Universität Wuppertal, Gaussstrasse 20, 42119 Wuppertal (Germany).
authors.forename: Vera
authors.initials: V
authors.lastname: Bernhardt-Pitchougina
authors.affiliation: Anorganische Chemie, Bergische Universität Wuppertal, Gaussstrasse 20, 42119 Wuppertal (Germany).
authors.forename: Helge
authors.initials: H
authors.lastname: Willner
authors.affiliation: PM-APR-FT, Merck KGaA, Frankfurter Strasse 250, 64293 Darmstadt (Germany).
authors.forename: Nikolai
authors.initials: N
authors.lastname: Ignat'ev
authors.affiliation: Anorganische Chemie, Bergische Universität Wuppertal, Gaussstrasse 20, 42119 Wuppertal (Germany). edbern@uni-wuppertal.de.
authors.forename: Eduard
authors.initials: E
authors.lastname: Bernhardt
authors.affiliation: Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg (Germany). maik.finze@uni-wuerzburg.de.
authors.forename: Maik
authors.initials: M
authors.lastname: Finze
keywords: borates; boron; cyanoborates; diborane(6)