title: Diborabutatriene: an electron-deficient cumulene.
abstract: The complexation of two equivalents of a cyclic (alkyl)(amino)carbene (CAAC) to tetrabromodiborane, followed by reduction with four equivalents of sodium naphthalide, led to the formation of the CAAC-stabilized linear diboracumulene (CAAC)2B2. The capacity of the CAAC ligand to facilitate B2 →CAAC donation of π-electron density resulted in important differences between this species and a previously reported complex featuring a B≡B triple bond stabilized by cyclic di(amino)carbenes, including a longer B-B bond and shorter B-C bonds. Frontier orbital analysis indicated sharing of valence electrons across the entire linear C-B-B-C unit in (CAAC)2B2, which is supported by natural population analysis and cyclic voltammetry.
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: William C
authors.initials: WC
authors.lastname: Ewing
authors.forename: Christian
authors.initials: C
authors.lastname: Hörl
authors.forename: Thomas
authors.initials: T
authors.lastname: Kramer
authors.forename: Ivo
authors.initials: I
authors.lastname: Krummenacher
authors.forename: Jan
authors.initials: J
authors.lastname: Mies
authors.forename: Alfredo
authors.initials: A
authors.lastname: Vargas
mesh_terms: D001896:Boron Compounds / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004583:Electrons; D008958:Models, Molecular; D011090:Polyenes / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D001896:Boron Compounds; D011090:Polyenes
keywords: boron; carbenes; cumulenes; main-group elements; multiple bonds