Efficient Ferredoxin Reduction by Silicon Phthalocyanine: A Red-Light-Activated Radical-Based Photosensitizer

The water-soluble silicon phthalocyanine derivative SiPc with two cationic pyrrolidinium ligands absorbs low-energy red light and, in the presence of a sacrificial electron donor (SD), generates the radical anion SiPc•–. This species and its photocatalytic properties were extensively characterized in a previous study. In this work, further properties of the radical were elucidated, such as its significant stability with a half-life of 30 min in aqueous solution. Following this, a system was developed and optimized to efficiently reduce ferredoxin (Fd).