Role of Conical Intersections on the Efficiency of Fluorescent Organic Molecular Crystals

Organic molecular crystals are attractive materials for luminescent applications because of their promised tunability. However, the link between chemical structure and emissive behavior is poorly understood numerous interconnected factors which at play in determining radiative nonradiative behaviors solid-state level. In particular, decay through conical intersection dominates nonadiabatic regions potential energy surface, thus, accessibility a telling indicator luminosity material. this study, we investigate mechanism five organic display emission, with focus on role intersections photomechanisms. The objective to situate importance regards behavior, taking into account other channels, namely, vibrational decay, exciton hopping. We begin by giving brief overview structural patterns systems within larger pool 13 richer comparison. observe that prevalence sheet like herringbone packing crystals, conformational diversity crystal dimers limited. Additionally, similarly spaced have coupling values similar order 50 meV interval. Next, three exemplary cases, where disentangle mechanisms show how rotational minimum vacuum lead puckered ones crystal, increasing instability upon crystallization typical motifs. contrast, molecules tend conserve trait crystallization, therefore, quantum yield fluorescence determined predominantly mechanisms.