The paper of Prof. Seiji OGO, Assoc. Prof. Hidetaka NAKAI and Assist. Prof. Takahiro MATSUMOTO (I²CNER Material Transformations Research Division) was published in “CHEMISTRY – AN ASIAN JOURNAL” on May 25, 2012, and their paper was adopted as the cover.
＜Title of Paper＞
Simple Ligand Effects Switch a Hydrogenase Mimic between H2 and O2 Activation (Chem. Asian J. 6/2012)
Kyoungmok Kim, Dr. Takahiro Matsumoto, Dr. Andrew Robertson, Dr. Hidetaka Nakai and Prof. Seiji Ogo. DOI: 10.1002/asia.201101020
Herein, we report a [NiRu] biomimetic system for O2-tolerant [NiFe]hydrogenases and demonstrate that electron donation to the [NiRu] center can switch the system between the activation of H2 and O2 through simple ligand effects by using hexamethylbenzene and pentamethylcyclopentadienyl ligands, respectively. Furthermore, we present the synthesis and direct observations of a [NiRu]–peroxo species, which was formed by the oxygenation of a Ni-SIa model [NiRu] complex, that we propose as a biomimetic analogue of O2-bound species (OBS) of O2-tolerant [NiFe]hydrogenases. The [NiRu]–peroxo complex was fully characterized by X-ray analysis, X-ray photoelectron spectroscopy (XPS), mass spectrometry, and 1H NMR spectroscopy. The OBS analogue was capable of oxidizing p-hydroquinone and sodium borohydride to turn back into the Ni-SIa model complex.
＜Comments by Chemistry – An Asian Journal＞
The twin catalytic capabilities of an aqueous phase hydrogenase mimic are illustrated. Seiji Ogo et al. report that a very small change in the ligand system switches the catalyst between dihydrogen activation, to produce protons and electrons, and dioxygen activation, to produce reduced oxygen species. The harmonious blending of these two cycles opens up a new field in fuel cell catalysis by providing a starting point for future molecular catalysts. In addition, the crystal structure of the oxygen-bound catalyst gives an insight into the acquisition of oxygen tolerance by some NiFe hydrogenases.
Chemistry – An Asian Journal
Volume 7, issue 6, pages 1394-1400, June 2012
150 years of German–Japanese friendship was celebrated last year. This issue of Chemistry – An Asian Journal is a special issue dedicated to the occasion.