Asymmetric Triple Helical Nonbenzenoid Nanographenes with Controllable Helicene Lengths.

ABSTRACT: Helical nanographenes (NGs) play a crucial role in the development of chiral nanomaterials due to their distinctive optoelectronic and chiroptical properties. Herein, we report the efficient synthesis of two unprecedented azulene-embedded asymmetric triple helical NGs (1 and 2) with controllable helicene subunit lengths and π-extension. The crystallographic analysis confirms their highly twisted and asymmetric geometries. Both compounds exhibit narrow and tunable optical energy gaps (1: 1.74 eV; 2: 1.63 eV), as determined by UV-vis absorption and cyclic voltammetry measurements. Moreover, the enantiomers of 1 display pronounced chiroptical activity with a g_abs of up to 3.1 × 10^-3.

SUBMITTER: Yang L 

PROVIDER: S-EPMC12455654 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature