Simulating the Structure of Carbon Dots via Crystalline pi-Aggregated Organic Nanodots Prepared by Kinetically Trapped Self-Assembly

This work reports the successful preparation of a new type of crystalline luminescent organic nanodot (<3.5 nm) by kinetically trapped self-assembly, which is then used as a simplified pi-packing model to simulate the structure of CDs. The precise structure and J-aggregation-induced photoluminescence (PL) of the nanodots are revealed by investigating the structural relationship between the nanodots and the corresponding single crystals and their properties. Compared with the single crystals, crystalline organic nanodots show longer PL lifetime, higher PL quantum yield, and narrower PL peak, indicating that they are potential organic quantum nanodots. In addition, the efficient pi-stacking environment in the corresponding single crystals can promote pi-aggregation-induced PL anisotropy. This work indicates crystalline organic nanodots with precise structures to be potentially useful for understanding the structures of CDs and to be attractive potential luminescent materials.