Triangulenium as robust organic dyes for production of solar fuels – TATADyes

TataDyes is a basic research project which aims at designing and investigating trianguleniums as an original class of robust organic dyes to challenge rare metal based photosensitizers for the catalytic reduction of protons (H2 production) and CO2 using visible light. Coupled to Co, Ni, Fe or Mn molecular catalysts (simply mixed or covalently linked), these dyes will give access to efficient and stable photocatalytic systems only composed of earth-abundant elements. These organic dyes based on aza/seleno-triangulenium platforms will exhibit key features for photo-induced catalysis, never combined in the same organic dye: (i) a strong absorption in the visible spectrum, (ii) a relatively long lifetime at excited state (>10 ns) to allow bimolecular electron transfer, (iii) a significantly negative reduction potential (= -1.2 V vs SCE) to allow the catalysts activation, and (iv) a high stability during photocatalysis due to a strong electronic delocalization in their reduced radical form. In addition, such platforms have the great asset of being chemically versatile, which will allow adjusting their electronic, redox properties and solubility by introducing appropriate substituents.

This proposal is built on our recent work with a triazatriangulenium dye for visible-light H2 production in water which highlights for the first time the great potential of this family of organic dyes in photo-induced electron transfer reactions to drive catalytic processes. Such fundamental achievements will have a direct impact on the development of artificial photosynthetic systems still greatly limited by the use of rare metal based photosensitizers.