Optimizing the oxidation potential of perylenes in the singlet and triplet states

Kimika Teorikoa Seminar

Rylenes are a family of polycyclic aromatic hydrocarbons (PAHs) formed by the linear fusion of naphthalene units through their peri positions, resulting in extended π-conjugated systems with strong electronic delocalization. Despite their attractive optoelectronic properties, pristine rylenes exhibit poor solubility and pronounced aggregation, limiting their synthesis and practical use.

Among rylene derivatives, perylene diimides (PDIs) stand out as robust chromophores capable of overcoming these challenges. The incorporation of electron-withdrawing imide groups at the peri positions imparts exceptional chemical stability, tunable solubility, and strong visible-light absorption, while allowing fine control over redox potentials, reaching up to +1.5 V vs SCE. Moreover, rylenes can undergo singlet fission (SF), where one photoexcited singlet state yields two triplet states, providing access to long-lived, high-energy triplets suitable for multi-electron photooxidation.
However, reliable estimation of singlet and triplet-state oxidation potentials remains largely unexplored. In this seminar, we present a computational framework for
designing functionalized rylenes with enhanced oxidative power. We validate the method against experimental data and extend it to predict triplet-state oxidation potentials. Moreover, we propose simplified approximations to enable high-throughput approach for testing new potential rylene derivatives.