Thousandfold Enhancement of Photoreduction Lifetime in Re(bpy)(CO)(3) via Spin-Dependent Electron Transfer from a Perylenediimide Radical Anion Donor

• Spin-dependent intramolecular electron transfer is revealed in the Re-I(CO)(3)(py)(bpy-Ph)perylenediimide radical anion (Re-I-bpy-PDI-(.)) dyad, a prototype model system for artificial photosynthesis. Quantum chemical calculations and ultrafast transient absorption spectroscopy experiments demonstrate that selective photoexcitation of Re-I-bpy results in electron transfer from PD-(.) to Re-I-bpy, forming two distinct charge-shifted states. One is an overall doublet whose return to the ground state is spin-allowed. The other, high spin quartet state, persists for 67 ns due to spin-forbidden back-electron transfer, constituting a more than thousandfold lifetime improvement compared to the low-spin state. Exploiting this spin dependency holds promise for artificial photosynthetic systems requiring long-lived reduced states to perform multi-electron chemistry.

Subject headings

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Publication and Content Type

ref (subject category)

art (subject category)