Synthesis of symmetrical and unsymmetrical ferrocenyl substituted disketopyrrolopyrroles

Abstract

Ferrocenyl-substituted diketopyrrolopyrroles (DPPs) with the symmetrical π-bridged donor–acceptor (D–π–A) frameworks D′–π–D–A–D–π–D′ as well as unsymmetrical D–A–D–π–D′ frameworks were designed and synthesized by a Pd-catalyzed Sonogashira cross-coupling reaction. The photophysical, computational, and electrochemical properties were also investigated and show substantial donor–acceptor interactions between the ferrocene and DPP moieties. DFT studies reveal that HOMO-LUMO gap decreases on incorporation of ferrocenyl unit to DPP. The symmetrical ferrocenyl-DPPs have more thermal stability than the unsymmetrical derivatives.