Nucleophilic Substitution of Tetrachloroperylene Diimide in Fluorescent Polyvinylpyrrolidone Film

A stable fluorescent polyvinylpyrrolidone (PVP) film is successfully prepared in one pot by using N,N ′‐bis‐(2,6‐diisopropylphenyl)‐1,6,7,12‐tetrachloroperylene‐3,4,9,10‐tetracarboxyldiimide (4Cl‐PDI) as the fluorophore. Aromatic nucleophilic substitution between the chlorine atom in 4Cl‐PDI and the secondary amine in ring‐opened PVP is proposed and demonstrated by a small‐molecule model reaction. In contrast, N,N ′‐bis(2,6‐diisopropylphenyl)‐perylene‐3,4,9,10‐tetracarboxyl diimide (PDI), which does not possess any chlorine atoms, has no such functions and can be easily disassociated from the produced PVP film. The chlorine atom is essential for the covalent bonding of the 4Cl‐PDI molecules in the fluorescent PVP film, thus leading to stable optical properties. The facile synthesis approach is especially suitable for the preparation of fluorescent PVP film, by using perylene species as the fluorophore, which usually contains a halogen element in the bay region.