Highly efficient binuclear ruthenium catalyst for water oxidation.
Water splitting is one of the key steps in the conversion of sunlight into a usable renewable energy carrier such as dihydrogen or more complex chemical fuels. Developing rugged and highly efficient catalysts for the oxidative part of water splitting, the water oxidation reaction generating dioxygen, is a major challenge in the field. Herein, we introduce a new, and rationally designed, pyrazolate-based diruthenium complex with the highest activity in water oxidation catalysis for binuclear systems reported to date. Single-crystal X-ray diffraction showed favorable preorganization of the metal ions, well suited for binding two water molecules at a distance adequate for OO bond formation; redox titrations as well as spectroelectrochemistry allowed characterization of the system in several oxidation states. Low oxidation potentials reflect the trianionic character of the elaborate compartmental pyrazolate ligand furnished with peripheral carboxylate groups. Water oxidation has been mediated both by a chemical oxidant (Ce(IV) )-by means of manometry and a Clark electrode for monitoring the dioxygen production-and electrochemically with impressive activities.
Institute of Inorganic Chemistry, Georg-August-University Göttingen, Tammannstraße 4, 37077 Göttingen (Germany) www.meyer.chemie.uni-goettingen.de.
Anett C
AC
Sander
Institute of Chemical Research of Catalonia (ICIQ), Av. Països Catalans 16, 43007 Tarragona (Spain).
Somnath
S
Maji
Institute of Chemical Research of Catalonia (ICIQ), Av. Països Catalans 16, 43007 Tarragona (Spain).
Laia
L
Francàs
Institute of Inorganic Chemistry, Georg-August-University Göttingen, Tammannstraße 4, 37077 Göttingen (Germany) www.meyer.chemie.uni-goettingen.de.
Torben
T
Böhnisch
Institute of Inorganic Chemistry, Georg-August-University Göttingen, Tammannstraße 4, 37077 Göttingen (Germany) www.meyer.chemie.uni-goettingen.de.
Sebastian
S
Dechert
Institute of Chemical Research of Catalonia (ICIQ), Av. Països Catalans 16, 43007 Tarragona (Spain). allobet@iciq.cat.
Antoni
A
Llobet
Institute of Inorganic Chemistry, Georg-August-University Göttingen, Tammannstraße 4, 37077 Göttingen (Germany) www.meyer.chemie.uni-goettingen.de. franc.meyer@chemie.uni-goettingen.de.
Franc
F
Meyer
D002384:Catalysis; D056831:Coordination Complexes / Q000737:chemistry*; D010084:Oxidation-Reduction; D011720:Pyrazoles / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*; D014867:Water / Q000737:chemistry
D056831:Coordination Complexes; D011720:Pyrazoles; D014867:Water; D012428:Ruthenium
artificial photosynthesis; binuclear complexes; oxygen evolving complex; ruthenium; water oxidation catalysis