Excitonic Coupling in Acyclic and Cyclic Dithioaryl-Linked BODIPY DYEmers

BODIPY DYEmers with dithioaryl bridges have been prepared by nucleophilic substitution reactions of α‐brominated BODIPYs. The optical properties of these compounds can be predicted by the Kashas exciton coupling model up to a critical interchromophore distance. The first macrocyclic derivative with stacked subchromophores has been obtained and proves the suitability of the Kasha model for predicting H‐type behavior from the molecular structures of this type of DYEmer. Dithioarene‐bridged macrocyclic and linear BODIPY dimers with varying interchromophoric distances and conformations have been prepared by aromatic nucleophilic substitution. The new dyes show intramolecular H‐ and J‐type behavior, as predicted by the Kasha model, but also show the limitations of this simple concept to quantitatively predict absorption energies from conformational parameters.