title: 1-Heteroaromatic-substituted tetraphenylboroles: π-π interactions between aromatic and antiaromatic rings through a B-C bond.
abstract: A series of 2,3,4,5-tetraphenylboroles substituted with different aromatic heterocycles (thiophene, furan, pyrrole, and dithiophene) in the 1-position were synthesized and characterized by means of NMR, elemental analysis, and X-ray crystallography. In contrast to known 2,3,4,5-tetraphenylboroles, X-ray diffraction revealed a nearly coplanar arrangement of the aromatic heterocycles and the antiaromatic borole scaffold as a result of π-conjugation, which could be substantiated by DFT calculations. Furthermore, the 2,2'-dithiophene-bridged bisborole (14) exhibits a large bathochromic shift in the absorption spectrum, demonstrating the exceptional Lewis acidity of the nonannulated borolyl moiety.
authors.affiliation: Institut für Anorganische Chemie, Julius-Maximilians Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany. h.braunschweig@uni-wuerzburg.de
authors.forename: Holger
authors.initials: H
authors.lastname: Braunschweig
authors.forename: Alexander
authors.initials: A
authors.lastname: Damme
authors.forename: J Oscar C
authors.initials: JO
authors.lastname: Jimenez-Halla
authors.forename: Christian
authors.initials: C
authors.lastname: Hörl
authors.forename: Ivo
authors.initials: I
authors.lastname: Krummenacher
authors.forename: Thomas
authors.initials: T
authors.lastname: Kupfer
authors.forename: Lisa
authors.initials: L
authors.lastname: Mailänder
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Radacki
mesh_terms: D001896:Boron Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D055664:Electrochemical Techniques; D005663:Furans / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D011758:Pyrroles / Q000737:chemistry*; D011789:Quantum Theory; D013056:Spectrophotometry, Ultraviolet; D013876:Thiophenes / Q000737:chemistry*
chemical_list: C581442:2,3,4,5-tetraphenylborole; D001896:Boron Compounds; D005663:Furans; D011758:Pyrroles; D013876:Thiophenes; C039281:furan