Understanding the polymorphism-dependent emission properties of molecular crystals using a refined QM/MM approach

Abstract

A refined QM/MM approach demonstrated that a monomer model is suitable for describing the emission spectra of crystals without the π⋯π stacking interaction. Whereas for the crystals with notable intermolecular π⋯π stacking interaction, the most stable trimer model (or at least a dimer model) should be used for accurately describing the corresponding emission spectra. This approach is applied to understand the emission properties of two kinds of organic polymorphs.