Self-condensed organometallo Ir(III) ionosilica for sustainable visible-light promoted electron-transfer photocatalysis

Abstract

Visible light photocatalysis represents a powerful approach to advancing the principles of green chemistry. Consequently, there is considerable research interest in the development of novel photocatalysts that are not only highly active but also readily reusable. To this end, we report here the synthesis of a novel luminescent organometallo-ionosilica obtained by sol–gel reactions. This material consists of discrete nanoparticles composed entirely of cationic cyclometallated iridium(III) fragments and their corresponding PF₆^- counterions. This organometallo-ionosilica has been extensively tested as a photocatalyst under heterogeneous conditions in both reductive and oxidative single electron transfer deactivation reactions, achieving reaction yields of around 90% and retaining up to 80% of its efficiency after seven consecutive reuse cycles. These results demonstrate the potential of our self-condensation strategy to heterogenize photoactive complexes, while retaining their catalytic activity and showing excellent reusability.