Strengthening C–H⋯π intermolecular interactions induces emission enhancement of anthracene derivatives under high pressure

Abstract

Aggregated anthracene derivatives typically display fluorescence quenching, which limits the application of anthracene derivatives in photonics. However, appropriate molecular design and pressure modulation can effectively regulate the luminescent properties of anthracene-based materials. Consequently, we successfully synthesized CZANP crystals that exhibit long-range, herringbone-like stacking arrangements of anthracene molecules, utilizing carbazole as a rigid steric hindrance substituent. The emission intensity of CZANP exhibits a significant increase within the pressure range of 1 atm to 1.0 GPa. Intermolecular C–H⋯π interactions between the carbazole and anthracene groups suppress the vibration and rotation of each corresponding group, thereby reducing non-radiative transitions. This accounts for the pressure-induced emission enhancement. The observed emission enhancement under low pressure conditions holds significant promise for advancing the potential of CZANP in optoelectronic applications.