between adjacent molecules became shorter. Meanwhile, the dihedral angles between two Cz units and dicyanopyridine core became smaller and smaller (Fig. ). In addition, the Cz units in DCzPy adopted a head-to-tail stacking interaction between adjacent molecules at 1 GPa, and the distance is 3.461 Å between two Cz plane (Fig. ). Upon increasing the pressure to 14 GPa, the two Cz units were in close proximity to a face-to-face arrangement, the distance shortened to 2.908 Å, suggesting a strong π-π interaction. Given above simulation results, it is envisioned that the red-shifted and weakened emission of DCzPy under hydrostatic pressure was mainly ascribed to conformational planarization and enhanced π-π interactions.