Water‐Soluble Doubly‐Strapped Isolated Perylene Diimide Chromophore

Abstract Perylene diimides (PDIs), a well‐studied class of organic dyes, have a strong tendency to self‐aggregate in water, thus greatly restricting their phototheranostic applications. Herein, we report a water‐soluble PDI cyclophane “Gemini Box” ( GBox‐1 4+ ), consisting of a central PDI chromophore enclosed by double‐sided cationic molecular straps. Owing to the effective spatial isolation, the chromophore self‐aggregation can be completely eliminated, even in a concentrated aqueous solution up to 2 mM. To our knowledge, GBox‐1 4+ represents an interesting example of a fluorescent PDI cyclophane in water, capable of being employed for lysosome‐targetable live‐cell imaging. More importantly, the highly concentrated aqueous solution of PDI radical anion can be significantly stabilized by GBox‐1 4+ to exhibit an excellent near‐infrared photothermal effect, which was further exploited for efficient and selective antibacterial applications. This work provides a new access to water‐soluble non‐aggregated organic dyes and promotes their potential biomedical applications.