The Molecular Origin of Perylene Fluorescence in Gas, Solution and Crystal Phases: A Comparative Theoretical Study

However, the molecular-level understanding of how changing the aggregation phase determines the optical modulation remains elusive. This work addresses this gap using density functional calculations at ground and excited state.

Using these data we present the systematic assignment of experimental spectra in dilute solutions, dimeric aggregates and the α-polymorph to the corresponding molecular structures through a comparison to simulated spectra obtained with the inclusion of two elements with pronounced interplay: (i) explicit vibrational effects, arising from strong coupling between electronic structure and molecular vibrations, and (ii) stacking of monomers in aggregates, to give dimers as fundamental optical units.