Carbazole–Cyanobenzene Dyes Electrografted to Carbon or Indium-Doped Tin Oxide Supports for Visible Light-Driven Photoanodes and Olefin Isomerizations

The organic carbazole–cyanobenzene push–pull dye 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene was derivatized and attached to carbon or indium-doped tin oxide (ITO) electrodes by simple diazonium electrografting. The surface-bound dye is active and stable for the visible light photosynthetic isomerization of a wide range of functionalized stilbene and cinnamic acid derivatives. Up to 87,000 net turnovers were obtained for the isomerization of trans-stilbene. The isomerizations can be carried out in air with a 33% reduction in the rate. The ITO photoelectrodes are also active and stable toward photo-oxidations under basic and acidic conditions.