title: Oligo(borolyl)benzenes--synthesis and properties.
abstract: Herein, we report the synthesis of boroles that are linked by a conjugated phenylene spacer. The characterization of these compounds was completed by NMR and UV/Vis spectroscopy, as well as X-ray crystal diffraction. Furthermore, the coordination behavior of these oligoboroles towards five electronically and sterically disparate pyridine derivatives was studied and revealed fundamental differences in the properties of the resulting adducts. The experimental results were supported by density functional theory (DFT) calculations that showed a charge-transfer effect upon formation of the pyridine-4-carbonitrile adduct. By chemical reduction of a tris(borolyl)-substituted benzene derivative, a hexaanion was isolated as a result of a two-electron reduction of each borolyl moiety. The interaction of the borolyl units through the aryl spacer, and the possible increase of the Lewis acidity due to the conjugation of the borolyl moieties, were investigated by base transfer reactions.
authors.affiliation: Institut für Anorganische Chemie, Julius-Maximilians Universität Würzburg, Am Hubland, 97074 Würzburg, Germany. h.braunschweig@uni-wuerzburg.de
authors.forename: Holger
authors.initials: H
authors.lastname: Braunschweig
authors.forename: Ching-Wen
authors.initials: CW
authors.lastname: Chiu
authors.forename: Alexander
authors.initials: A
authors.lastname: Damme
authors.forename: Bernd
authors.initials: B
authors.lastname: Engels
authors.forename: Daniela
authors.initials: D
authors.lastname: Gamon
authors.forename: Christian
authors.initials: C
authors.lastname: Hörl
authors.forename: Thomas
authors.initials: T
authors.lastname: Kupfer
authors.forename: Ivo
authors.initials: I
authors.lastname: Krummenacher
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Radacki
authors.forename: Christof
authors.initials: C
authors.lastname: Walter