Oligo(borolyl)benzenes-Synthesis and properties
Journal
Chemistry - A European Journal
Journal Volume
18
Journal Issue
45
Pages
14292-14304
Date Issued
2012
Author(s)
Braunschweig, H.
Damme, A.
Engels, B.
Gamon, D.
H?rl, C.
Kupfer, T.
Krummenacher, I.
Radacki, K.
Walter, C.
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.
SDGs
Type
journal article