title: From an electron-rich bis(boraketenimine) to an electron-poor diborene.
abstract: The reaction of the bisboracumulene (CAAC)2 B2 (CAAC=1-(2,6-diisopropylphenyl)-3,3,5,5-tetramethylpyrrolidin-2-ylidene) with excess tert-butylisocyanide resulted in complexation of the isocyanide at boron. Though this compound might be formally drawn with a lone pair on boron, these electrons are highly delocalized throughout a conjugated π-network consisting of the π-acidic CAAC and isocyanide ligands. Heating this compound to 110 °C liberated the organic periphery of both isocyanide ligands, yielding the first example of a dicyanodiborene. Cyclic voltammetry conducted on this diborene indicated the presence of reduction waves, making this compound unique among diborenes, which are otherwise highly reducing.
authors.affiliation: Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg (Germany).
authors.forename: Julian
authors.initials: J
authors.lastname: Böhnke
authors.forename: Holger
authors.initials: H
authors.lastname: Braunschweig
authors.forename: Theresa
authors.initials: T
authors.lastname: Dellermann
authors.forename: William C
authors.initials: WC
authors.lastname: Ewing
authors.forename: Thomas
authors.initials: T
authors.lastname: Kramer
authors.forename: Ivo
authors.initials: I
authors.lastname: Krummenacher
authors.forename: Alfredo
authors.initials: A
authors.lastname: Vargas
keywords: boron; diborenes; main-group elements; multiple bonds; thermolysis