Borylated perylenediimide: self-assembly, photophysics and sensing application

Abstract

Triarylboryl appended perylenediimide (PDI-TAB) is designed and synthesized. The incorporation of triarylboranes (TABs) decreases self-aggregation and increases the solubility of PDI-TAB in common organic solvents. Fluorescence emission colors ranging from red, yellow and green are realized by judiciously modulating the concentration of PDI-TAB in solution. The morphology and dimensions of the self-assemblies formed by PDI-TAB can be controlled by changing the experimental conditions. For example, PDI-TAB forms fibers of finite length when bulk powder is dispersed in methanol; it shows flexible lengthy 1D fibers when dichloromethane solution of PDI-TAB is injected into methanol solvent. PXRD analysis indicates that the molecular organization remains the same in both cases. PDI-TAB functions as a selective fluorogenic sensor for toxic fluoride anions; the sensing mechanism is explained by using theoretical calculations.