Converting p-terphenyl into a novel organo-catalyst for LED-driven energy and electron transfer photoreactions in water.

p-Terphenyl is a potent photoredox catalyst under UV-irradiation. Aiming for more sustainable reaction conditions, we added two sulfonate groups to this key structure to achieve water solubility and incorporated an SO-bridge thereby shifting the absorption spectrum towards the visible. The resulting photocatalyst shows unexpected triplet reactivity in several test reactions.