A Ruthenium Complex–Porphyrin–Fullerene‐Linked Molecular Pentad as an Integrative Photosynthetic Model

Abstract

A ruthenium complex, porphyrin sensitizer, fullerene acceptor molecular pentad has been synthesized and a long-lived hole-electron pair was achieved in aqueous solution by photoinduced multistep electron transfer: Upon irradiation by visible light, the excited-state of a zinc porphyrin ( ZnP*) was quenched by fullerene (C ) to afford a radical ion pair, (ZnP -C ). This was followed by the subsequent electron transfer from a water oxidation catalyst unit (Ru ) to ZnP to give the long-lived charge-separated state, Ru -ZnP-C , with a lifetime of 14 μs. The ZnP worked as a visible-light-harvesting antenna, while the C acted as an excellent electron acceptor. As a consequence, visible-light-driven water oxidation by this integrated photosynthetic model compound was achieved in the presence of sacrificial oxidant and redox mediator.

A Noble‐Metal‐Free Heterogeneous Photosensitizer‐Relay Catalyst Triad That Catalyzes Water Oxidation under Visible Light

“…Of these, dye‐sensitized photoelectrochemical cells (DS‐PECs) utilize covalently coordinated chromophore‐water oxidation catalyst (WOC) dyad assemblies in an effort to mimic natural photosynthesis. This approach has further been expanded by integrating suitable donor and acceptor units to prepare molecular triads, tetrads, and pentads for efficient charge separation . Molecular ruthenium complexes (as photosensitizers and/or WOCs) remain the most widely used despite their high cost and easy decomposition under photocatalytic conditions .…”

“…An assembly, in which a molecular chromophore is coordinated to a heterogeneous cyanide‐based catalyst, was prepared with this synthetic route. The synthetic pathway adopts a molecular bottom‐up approach similar to the ones previously reported for chromophore‐catalyst assemblies, while it differs significantly from those by the formation of a heterogeneous assembly in the final step.…”

Charge transfer dynamics at the boron subphthalocyanine chloride/C60 interface: non-adiabatic dynamics study with Libra-X

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14] Phthalocyanines constitute a class of organic chromophores that bear a close resemblance to the naturally occurring porphyrin molecules, which are employed in nature itself as the key components of photosynthetic complexes in plants and photosynthetic bacteria. 15,16 Both porphyrins and phthalocyanines are remarkable for their high molar extinction coefficient, 17,18 which is a prerequisite for efficient solar energy harvesting. For these reasons, phthalocyanines and their derivatives have been attracting continuous interest as potential template chromophores that could be used in OPV materials.…”

A Noble‐Metal‐Free Heterogeneous Photosensitizer‐Relay Catalyst Triad That Catalyzes Water Oxidation under Visible Light

“…[1] Several innovative photoelectrochemical cells for water splitting have been proposed since the pioneering work by Fujishima and Honda. [7][8][9] Molecular ruthenium complexes (as photosensitizers and/or WOCs) remain the most widely used despite their high cost and easy decomposition under photocatalytic conditions. This approach has further been expanded by integrating suitable donor and acceptor units to prepare molecular triads, tetrads,a nd pentads for efficient charge separation.…”