Synthesis and optical properties of chiral graphene quantum dots

The bottom-up synthesis of graphene-related materials has emerged as a powerful approach for the fabrication of molecularly defined nanographenes with tailored structural and electronic properties. In particular, graphene quantum dots (GQDs) have attracted considerable attention, owing to their unique combination of extended π-conjugation, tunable optoelectronic properties, and structural versatility. More recently, increasing efforts have focused on the synthesis of twisted and helical nanographenes, which introduce three-dimensionality and chirality into the graphene framework. These features open new opportunities for the development of advanced optical and chiroptical materials. Since the first reports of chiral GQDs based on helicene-derived or sterically constrained precursors, the field has rapidly expanded, giving rise to a remarkable diversity of chiral and structurally distorted nanographene architectures. Recently, we reported the synthesis and comprehensive characterization of a family of elongated graphene quantum dots (GQDs). These GQDs display excellent solubility in common organic solvents, high photoluminescence stability, and remarkably high photoluminescence quantum yields. Building on these promising properties, we sought to introduce chiroptical activity into this family of GQDs by incorporating helical moieties at their termini. Structure of the chiral nanographene containing helical moieties GQDs.