1412912-77-6Relevant articles and documents
1-Heteroaromatic-substituted tetraphenylboroles: π-π Interactions between aromatic and antiaromatic rings through a B-C bond
Braunschweig, Holger,Damme, Alexander,Jimenez-Halla, J. Oscar C.,H?rl, Christian,Krummenacher, Ivo,Kupfer, Thomas,Mail?nder, Lisa,Radacki, Krzysztof
, p. 20169 - 20177 (2012)
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.