The harvesting and transduction of the solar energy can be achieved by absorption of multiple photons (antenna effect) followed by electron transfer processes that lead to charge separation creating reduction/oxidation equivalents. An approach to provide antennae and/ or catalytic properties is the use of metal-organic supramolecular systems, where the ligands provide vast tunability of the electronic and structural properties.  We are embarked on ultrafast time-resolved studies to understand the first steps in photoinduced processes of Ru-based metal light-harvester through the lens of the coordination chemistry.  Potential candidates for the antenna unit involve supramolecular assemblies of chromophores with a polypyridil energetic bias that helps accumulate and localize the energy spatially.<br/>            We explore assemblies of increased complexity from having a single Ru center, where the photophysics is modulated by the orientation of different organic ligands to assemblies with 2 and 3 different metal centers (Ru:Ru, Ru:Fe, Ru:Os, Ru:Cr, Ru:Ru:Cr), all covalently bound through NC bridges whose own orbitals cannot trap the excitation but open coupling-channels between the different metal centers.   The ultrafast dynamics on the dimers depend strongly on the nature of the acceptor and the orientation of the ligand involved in the photoinduced transition. Hence, the competition between energy and electron transfer across the bridge is modulated by the selective choice of the secondary metal center.   In the case of triads, mixing on the excited state can lead to ps energy transfer from the farther away metal center to a Cr(III) acceptor.

Polynuclear Ru-based metal complexes for energy and electron transfer

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.