Self‐Organization of Hyperbranched Polyesters Functionalized with Pyrrolo[2,1‐a]isoquinoline End Groups and Their Fluorescent Recognition of Anthracene and Pyrene

Abstract

The structurally controllable hyperbranched aromatic–aliphatic copolyesters HBPE‐MPICB4 and HBPE‐MPICB2 are synthesized by incorporating the periphery of a second‐generation hyperbranched polyester (HBPE) with methylpyrrolo[2,1‐a]isoquinoline‐1‐carbonitrile(E)‐4‐oxo‐[2‐(oxo‐λ3‐methyl)hydrazinyl]but‐2‐enoate (MPICB) groups via one‐pot synthesis. Organized supramolecular structures are self‐assembled in different organic media. Lamellar structure with a length of around 10 µm can be obtained in ethyl acetate. However, the identical HBPE‐MPICB4 and HBPE‐MPICB2 building blocks can self‐organize into flower‐like and vesicular structure in ethanol, with particle sizes around 12 and 5 µm, respectively. The noncovalent interactions of HBPE‐MPICB4 and HBPE‐MPICB2, that is, hydrogen bonding and π–π stacking, are critical for the construction of organized structures. Furthermore, host–guest recognitions by HBPE‐MPICB4 and HBPE‐MPICB2 are investigated by fluorescence studies. The results indicate that HBPE‐MPICB4 microflowers respond selectively to anthracene and pyrene through π–π stacking interactions.