Research

Transition Metal Catalysis for Photo-Driven Material Transformations

Most of homogenous organometallic photocatalysts have been reported for redox reactions meaning single electron transfer between organometallic compounds and external electron donors/acceptors. Recently, LMCT or MLCT is driven for chemical reactions like material transformations except the single electron transfer reactions. Such advanced method unable us to expand the possibility of photo-induced organometallic catalysis.

Photo-Driven Aerobic Transformation of Methane to C1 Chemicals of Methanol and Formaldehyde by an Organometallic Ru Complex with O2

CH4 is one of the most promising resources for energy as well as materials since it has high affinity with renewable energy, and has become easily and abundantly obtained as biomethane from biomass by recent technological developments. However, transformation of CH4 to the useful materials is one of the most challenging themes because of its inertness in terms of physical and chemical properties. By means of light energy input into a bis(µ-oxido) Ru2IV species derived from O2, we have achieved photo-driven C-H bond breaking of CH4 and successive C-O bond formation to form CH3OH together with HCHO. 

Master course students, Mr. Nakano, Mr. Kimura, and Mr. Nakamura, have carefully done experiments and achieved innovative methane transformation.

Collaborated with Assist. Prof. Abe, Assoc. Prof. Shiota, and Prof. Yoshizawa to elucidate photo-driven methane transformation with organoruthenium complex including photo-excited state by DFT calculations.

Photo-Driven Conversion of NO3– to NH3 by CH4 as a Reductant in Homogenous Re Catalysis

We present a Re catalysis of one-pot synthesis of NH3 from NO3– using CH4 as a reductant under UV light irradiation. We are able to directly convert NO3–, leading to several environmental issues, to NH3, an essential compound as a fertilizer and industrial raw material, by means of CH4, which has a high affinity with renewable resource/energy, as a reductant under light, a renewable energy.

Angew. Chem. Int. Ed. 2025, e202423543. [Hot Paper]