Abstract
The mononuclear ruthenium(II) complex [Ru]2+ (Ru = Ru(dpp)(pic)2, where dpp is the tetradentate 2,9-dipyrid-2′-yl- 1,10-phenanthroline ligand and pic is 4-picoline) reported by Thummel's group (Inorg. Chem. 2008, 47, 1835-1848) that contains no water molecule in its primary coordination shell is evaluated as a catalyst for water oxidation in artificial photosynthesis. A detailed theoretical characterization of the energetics, thermochemistry, and spectroscopic properties of intermediates allowed us to interpret new electrochemical and spectroscopic experimental data, and propose a mechanism for the water oxidation process that involves an unprecedented sequence of seven-coordinate ruthenium complexes as intermediates. This analysis provides insights into a mechanism that generates four electrons and four protons in the solution and a gas-phase oxygen molecule at different pH values. On the basis of the calculations and corroborated substantially by experiments, the catalytic cycle goes through [2Ru III]3+ and [2RuV(O)]3+ to [1RuIV(OOH)]3+ then [2Ru III(···3O2)]3+ at pH 0, and through [3RuIV(O)]2+, [ 2RuV(O)]3+, and [1Ru IV(OO)]2+ at pH 9 before reaching the same [ 2RuIII(···3O 2)]3+ species, from which the liberation of the weakly bound O2 might require an additional oxidation to form [ 3RuIV(O)]2+ to initiate further cycles involving all seven-coordinate species.
| Original language | English |
|---|---|
| Pages (from-to) | 6904-6913 |
| Number of pages | 10 |
| Journal | Inorganic Chemistry |
| Volume | 53 |
| Issue number | 13 |
| DOIs | |
| Publication status | Published - Jul 7 2014 |
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ASJC Scopus subject areas
- Inorganic Chemistry
- Physical and Theoretical Chemistry
Cite this
New water oxidation chemistry of a seven-coordinate ruthenium complex with a tetradentate polypyridyl ligand. / Muckerman, James; Kowalczyk, Marta; Badiei, Yosra M.; Polyansky, Dmitry; Concepcion, Javier J.; Zong, Ruifa; Thummel, Randolph P.; Fujita, Etsuko.
In: Inorganic Chemistry, Vol. 53, No. 13, 07.07.2014, p. 6904-6913.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - New water oxidation chemistry of a seven-coordinate ruthenium complex with a tetradentate polypyridyl ligand
AU - Muckerman, James
AU - Kowalczyk, Marta
AU - Badiei, Yosra M.
AU - Polyansky, Dmitry
AU - Concepcion, Javier J.
AU - Zong, Ruifa
AU - Thummel, Randolph P.
AU - Fujita, Etsuko
PY - 2014/7/7
Y1 - 2014/7/7
N2 - The mononuclear ruthenium(II) complex [Ru]2+ (Ru = Ru(dpp)(pic)2, where dpp is the tetradentate 2,9-dipyrid-2′-yl- 1,10-phenanthroline ligand and pic is 4-picoline) reported by Thummel's group (Inorg. Chem. 2008, 47, 1835-1848) that contains no water molecule in its primary coordination shell is evaluated as a catalyst for water oxidation in artificial photosynthesis. A detailed theoretical characterization of the energetics, thermochemistry, and spectroscopic properties of intermediates allowed us to interpret new electrochemical and spectroscopic experimental data, and propose a mechanism for the water oxidation process that involves an unprecedented sequence of seven-coordinate ruthenium complexes as intermediates. This analysis provides insights into a mechanism that generates four electrons and four protons in the solution and a gas-phase oxygen molecule at different pH values. On the basis of the calculations and corroborated substantially by experiments, the catalytic cycle goes through [2Ru III]3+ and [2RuV(O)]3+ to [1RuIV(OOH)]3+ then [2Ru III(···3O2)]3+ at pH 0, and through [3RuIV(O)]2+, [ 2RuV(O)]3+, and [1Ru IV(OO)]2+ at pH 9 before reaching the same [ 2RuIII(···3O 2)]3+ species, from which the liberation of the weakly bound O2 might require an additional oxidation to form [ 3RuIV(O)]2+ to initiate further cycles involving all seven-coordinate species.
AB - The mononuclear ruthenium(II) complex [Ru]2+ (Ru = Ru(dpp)(pic)2, where dpp is the tetradentate 2,9-dipyrid-2′-yl- 1,10-phenanthroline ligand and pic is 4-picoline) reported by Thummel's group (Inorg. Chem. 2008, 47, 1835-1848) that contains no water molecule in its primary coordination shell is evaluated as a catalyst for water oxidation in artificial photosynthesis. A detailed theoretical characterization of the energetics, thermochemistry, and spectroscopic properties of intermediates allowed us to interpret new electrochemical and spectroscopic experimental data, and propose a mechanism for the water oxidation process that involves an unprecedented sequence of seven-coordinate ruthenium complexes as intermediates. This analysis provides insights into a mechanism that generates four electrons and four protons in the solution and a gas-phase oxygen molecule at different pH values. On the basis of the calculations and corroborated substantially by experiments, the catalytic cycle goes through [2Ru III]3+ and [2RuV(O)]3+ to [1RuIV(OOH)]3+ then [2Ru III(···3O2)]3+ at pH 0, and through [3RuIV(O)]2+, [ 2RuV(O)]3+, and [1Ru IV(OO)]2+ at pH 9 before reaching the same [ 2RuIII(···3O 2)]3+ species, from which the liberation of the weakly bound O2 might require an additional oxidation to form [ 3RuIV(O)]2+ to initiate further cycles involving all seven-coordinate species.
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U2 - 10.1021/ic500709h
DO - 10.1021/ic500709h
M3 - Article
VL - 53
SP - 6904
EP - 6913
JO - Inorganic Chemistry
JF - Inorganic Chemistry
SN - 0020-1669
IS - 13
ER -