51�Թ�

In both cases, a neutral organic molecule acts as the catalyst; this is reduced electrochemically on a cathode to produce a radical anion, which is then excited by visible light to form a strong reductant with an oxidation potential more negative than −3.0 V versus SCE.

For instance, the excited radical anion formed from the catalyst Rhodamine 6G has an oxidation potential of −2.4 V versus SCE, which is sufficiently negative to reduce aryl bromides and aryl chlorides that have a reduction-facilitating group6.

They report that, when Mes-Acr• is irradiated with light of wavelength 390 nm, it forms an excited neutral radical that acts as an extremely strong reducing agent, with a maximum oxidation potential of −3.36 V versus SCE.