A red fluorogen: AIEE characteristic, photoluminescence mechanism and its application as chemosensor for ClO.

Red material is widely used in many fields because it has a lot of high performances such as strong penetrability, little trauma to cell and tissue, easy to prepare, and low background interference. However, a lot of organic materials were troubled with the aggregation caused emission quenching (ACQ) effect, which really limits their practical applications. In contrast, aggregation induced emission (AIE) and aggregation-induced enhanced emission (AIEE) effects provide an efficient method to break the obstacle of ACQ effect. Herein, a red light molecule was developed by integrating cyano and alkyl sulfide moieties. Its photoluminescence mechanism was further revealed by fluorescence spectrum, density functional theory (DFT) and X-ray single crystal diffraction, respectively. It is found that this compound has good planar construction and has no rotatory unit, it showed typical AIEE performance because of intramolecular D-π-A structure and the formation of J-aggregation. This molecular design principle may be able to offer an effective strategy to exploit red AIE/AIEE organic materials. Meanwhile, this fluorogen showed excellent response capability to ClO including high selectivity and sensitivity, and cell imaging performance.