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

A facile synthesis of octabromoperylene-3,4,9,10-tetracarboxylic dianhydride (Br-8-PDA) (1), its diimides (Br-8-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).