Synthesis of Octabromoperylene Dianhydride and Diimides: Evidence of Halogen Bonding and Semiconducting Properties

A facile synthesis of octabromoperylene-3,4,9,10-tetracarboxylic
dianhydride (Br8-PDA) (1), its diimides (Br8-PDIs) (2a–e), and bis-,
tris-, and tetra-amino substituted diimides (5a–c) with six, five, and four remaining substitutable Br atoms,
respectively, is reported. Octabromination results in facile chemical/electrochemical
reduction, radical anion formation, and red-shifted optical properties.
For the first time, diverse halogen-bonding interactions were identified
in the PDA/PDI, which along with the attractive electronic features
enhance the electron-transport characteristics compared to the di-/tetra-brominated
PDIs (3/4).