Chiral Distorted Hexa? <i>peri</i> ?hexabenzocoronenes Bearing a Nonagon?Embedded Carbohelicene

A new family of chiral saddle-helix hybrid nanographenes is reported. The first hexa-peri-hexabenzocoronene (HBC) analogues bearing a nine-membered carbocycle are presented. Furthermore, for the time, ?-extended carbo[n]helicenes containing ring as part helical moiety have been synthesized. combination [5]helicene and nonagon in single motif induces tremendous distortion from planarity into nanographenic structures compared to other hybrids such heptagon- octagon-containing carbo[5]helicenes. In fact, interplanar angle two terminal rings reaches largest (134.8°) carbohelicene reported date, thus being by far most twisted helicene yet prepared. Photophysical properties evaluation showed improved absorption dissymmetry factors (|gabs|=4.2×10?3) nonagon-containing