Focusing on quinone derivatives exist in photosynthetic system, my research targets developing catalytic hydrogen evolving system using new, anthraquinone structural metal complex. Crucial point is to provide complex that catalyze HER in aqueous media via proton-coupled electron transfer (PCET) pathway with lower overpotential than previous researches. My research also focuses clarifying the mechanism of HER in aqueous media catalyzed by Co-NHC complex, through electrochemical measurements.