Light-Driven CO2 Reduction Catalysis with Organic Thermally Activated Delayed Fluorescence (TADF) Sensitizers

Catalytic conversion of CO2 into carbon-based products (CO2 reduction reaction, CO2RR) using light can be profitably achieved through the merging of a molecular catalyst based on redox-active metals, a light-harvesting sensitizer, and an electron donor. Within this framework, the discovery of novel chromophores represents a critical task. Cyanoarenes are thermally-activated delayed fluorescence (TADF) dyes that have been largely considered as photoactive components in the field of lighting and organic photocatalysis. Only recently they have been also successfully employed as photosensitizers in light-driven CO2RR schemes. While their application in lieu of more classical inorganic or organometallic chromophores might seem straightforward, several open points are still present concerning, e.g., mechanistic aspects and stability issues. This Concept aims to collect the most recent studies dealing with the application of these TADF dyes in combination with molecular complexes catalyzing the CO2RR mainly to CO and/or formate, trying to highlight the most promising molecular scaffolds and identify possible misconceptions.