Stereospecific Synthesis and Photophysical Properties of Propeller‐Shaped C ₉₀ H ₄₈ PAH

Abstract

Herein, we have synthesized an enantiomerically pure propeller-shaped PAH, C₉₀ H₄₈ , possessing three [7]helicene and three [5]helicene subunits. This compound can be obtained in gram quantities in a straightforward manner. The photophysical and chiroptical properties were investigated using UV/Vis absorption and emission, optical rotation and circular dichroism spectroscopy, supported by DFT calculations. The nonlinear optical properties were investigated by two-photon absorption measurements using linearly and circularly polarized light. The extremely twisted structure and packing of the homochiral compound were investigated by single-crystal X-ray diffraction analysis.