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Updated: Sep 15, 2025

The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
Photoinduced Nitrite Reduction to NO: Closing the Cycle with Dinuclear Ruthenium Complexes
Yasuhiro Arikawa1, Shintaro Yoshida2, Taiji Nakamura3
1Graduate School of Integrated Science and Technology, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan.
Abstract:
The reduction of nitrite to nitric oxide (NO) is a crucial step in the nitrogen cycle, catalyzed by nitrite reductase in nature, and its efficient catalysis is of great interest. This study reports the achievement of a reduction cycle that releases NO from nitrite using a dinuclear ruthenium complex (NO2 - + 2H+ + e- → NO + H2O). Irradiation or thermolysis of a nitrite-bridged complex, [(TpRu)2(μ-Cl)-(μ-NO2)-(μ-pz)] (1) (Tp = HB-(pyrazol-1-yl)3), resulted in the formation of an oxido-bridged complex, [(TpRu)2(μ-Cl)-(μ-O)-(μ-pz)] (2), and the release of NO. The reaction mechanism from 1 to 2 was investigated through theoretical calculations. To complete the reduction cycle, complex 1 was reproduced from complex 2 using two protons and one electron in the presence of a nitrite salt. This study demonstrated the successful mimicking of the function of nitrite reductase using a dinuclear ruthenium complex.
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