Tuning the LUMO Levels of Z-Shaped Perylene Diimide via Stepwise Cyanation

Abstract

The central dogma in constructing organic electron acceptors is to attach electron-withdrawing groups to polycyclic aromatic hydrocarbons. Yet, the full potentials of many organic acceptors were never realized due to synthetic obstacles. By combining the Wittig−Knoevenagel benzannulation, the Pd(0)catalyzed cyanation, and nucleophilic addition/oxidation cyanation, six polynitrile Z-shaped perylene diimide were synthesized. These stable and soluble electron acceptors possess LUMO energy levels comparable with those of benchmark compounds. Electrochemical investigation reveals that each additional nitrile group reduces the LUMO energy by 0.2 eV.

A perylene five-membered ring diimide for organic semiconductors and π-expanded conjugated molecules

“…5–10 However, the core-variation of PDIs with five-membered ring imides has rarely been investigated. 11–13 In this communication, we report a perylene-2,3;8,9-tetracarboxylic acid diimide ( PDI39 , Scheme 1a) which contains two five-membered ring imides connected at the 2,3- and 8,9-positions of perylene.…”