[(H2O)(terpy)Mn(mu-O)2Mn(terpy)(OH2)](NO3)3 (terpy = 2,2':6,2''-terpyridine) and its relevance to the oxygen-evolving complex of photosystem II examined through pH dependent cyclic voltammetry.
Photosynthetic water oxidation occurs naturally at a tetranuclear manganese center in the photosystem II protein complex. Synthetically mimicking this tetramanganese center, known as the oxygen-evolving complex (OEC), has been an ongoing challenge of bioinorganic chemistry. Most past efforts have centered on water-oxidation catalysis using chemical oxidants. However, solar energy applications have drawn attention to electrochemical methods. In this paper, we examine the electrochemical behavior of the biomimetic water-oxidation catalyst [(H(2)O)(terpy)Mn(mu-O)(2)Mn(terpy)(H(2)O)](NO(3))(3) [terpy = 2,2':6',2''-terpyridine] (1) in water under a variety of pH and buffered conditions and in the presence of acetate that binds to 1 in place of one of the terminal water ligands. These experiments show that 1 not only exhibits proton-coupled electron-transfer reactivity analogous to the OEC, but also may be capable of electrochemical oxidation of water to oxygen.
Cady
Clyde W
CW
Department of Chemistry, Yale University, PO Box 208107, New Haven, CT 06520-8107, USA.
Shinopoulos
Katherine E
KE
Crabtree
Robert H
RH
Brudvig
Gary W
GW
D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D055664:Electrochemical Techniques; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008345:Manganese / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D045332:Photosystem II Protein Complex / Q000737:chemistry*
C550429:((H2O)(terpy)Mn(mu-O)2Mn(terpy)(OH2))(NO3)3; D056831:Coordination Complexes; D009942:Organometallic Compounds; D045332:Photosystem II Protein Complex; D008345:Manganese; D010100:Oxygen