Synthesis of bifunctional Ru complexes with 1,2-dithiolane and carboxylate-substituted ligands

An N3-type, Ru heteroleptic complex, AK1, having one bipyridyl ligand modified with COOH groups for tethering to TiO2 and a second bipyridyl ligand modified with two lipoic acid units for binding to platinum, was synthesized. The photophysical and spectroelectrochemical properties were studied in solution, on TiO2, in a dye-sensitized solar cell and on a Pt wire electrode. The results showed that AK1 can produce a photocurrent on TiO2. Furthermore, AK1 binds to Pt via the lipoic acid ligand but not via the carboxylic acid group, and can be electrochemically addressed by the Pt via the lipoic acid linkage.

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