Quinoxalinophenanthrophenazine Based Cruciforms

Quinoxalinophenanthrophenazines (QPPs) and related structures are an emerging class of stable fused N-heteropolycyclic aromatics. By vertical attachment of aromatic substituents at the pyrene core, cruciform QPPs are accessible, which open new opportunities to adjust HOMO and LUMO levels of the QPPs nearly independent from each other.
A series of cruciform aryl-substituted quinoxalinophenanthrophenazine derivatives (QPPs) was synthesized through Suzuki-Miyaura cross-coupling of a 2,7-diborylated pyrene tetraketal building block. The QPPs were analyzed for their optoelectronic properties by absorption and emission spectroscopy, cyclic voltammetry and quantum-chemical calculations. The solid-state packing was investigated as well and evaluated for its charge transport properties by calculated charge transfer integrals.