Furan-Containing Double Tetraoxa[7]Helicene And Its Radical Cation

An unprecedented furan-based double oxa[7]helicene 1 was achieved, featuring a stable twisted conformation with pi-overlap at both helical ends. The excellent conformational stability allowed for optical resolution of 1, which provided a pair of enantiomers exhibiting pronounced mirror-imaged circular dichroism and circularly polarized luminescence activity. The radical cation of 1 was obtained by chemical oxidation as evidenced by UV-Vis-NIR absorption, electron paramagnetic resonance spectroscopy and in situ spectroelectrochemistry. The present work is the starting point for the investigation of open-shell oxahelicenes.