A Configurationally Stable Helical Indenofluorene.

We report the synthesis and study of the optoelectronic, magnetic, and chiroptical properties of a helically chiral diradicaloid based on dibenzoindeno[2,1-c]fluorene. The molecule shows a small HOMO-LUMO gap and a moderate singlet-triplet gap, which agrees with the results of DFT calculations. The helical structure of the compound, confirmed by X-ray diffraction, is configurationally stable, which allows the isolation of both enantiomers and the evaluation of the chiroptical properties (ECD).