Magic-Angle Stacking and Strong Intermolecular π–π Interaction in a Perylene Bisimide Crystal: An Approach for Efficient Near-Infrared (NIR) Emission and High Electron Mobility

A single crystal of N,N′-bis­(4-methoxybenzyl)­perylene-3,4,9,10-bis­(dicarboximide) (mb-PBI) that possesses novel magic-angle stacking (M-type stacking) and strong intermolecular π–π interaction is achieved by physical vapor transport (PVT), which shows attractive optoelectronic functions such as efficient NIR emission and high electron mobility. In this special M-type staking, the strong Frenkel/CT mixing state promotes fluorescence and, importantly, the elimination of long-distance Förster resonance energy transfer enables the minimization of the possible fluorescence quenching, which ensure the highly efficient emission. Moreover, the strong π–π interaction elongates the “supramolecular conjugation” to reduce the energy gap and also benefits the electron mobility of the crystal. The experimental results clearly indicate that M-type staking is a novel approach to optimize the optoelectronic functions of organic semiconducting materials.