An 1,4,7,10-tetraazacyclododecane-nickel complex functionalized polymolybdate acting as artificial oxidase in removing methylene blue

The reactive oxygen species (ROS), serving as a crucial biochemical reaction medium, is intricately involved in a myriad of physiological and pathological processes. The proper use of ROS can solve many practical problems, for example killing harmful microorganisms or cells, removing pollutants in water, etc. Therefore, the design and synthesis of artificial oxidase with catalytic activity in producing ROS become a hot research spot from bio-inorganic chemistry to catalytic industry. Herein, a cyclen-nickel complex functionalized polymolybdate, [Ni(cyclen)(H2O)2]2[(AsO)6(NiMo6O24)]·3H2O (abbreviated as NiAM, cyclen = 1,4,7,10-tetrazacyclododecane), which can acting as a catalyzed oxidase to generating ROS, has been structurally characterized by means of single-crystal X-ray diffraction (SXRD), elemental analyses, IR and UV–vis spectra, powder X-ray diffraction (PXRD), and bond valence sums (Σs) calculation. The NiAM's principal element, as revealed by SXRD, indicates that it is an ionic complex that composed by two [Ni(cyclen)(H2O)2]2+and one modified Anderson-type cluster [(AsO)6(NiMo6O24)]4–. Interestingly, NiAM possesses effective ability in catalyzing the ROS generation in aqueous solution. As a result, it can remove methylene blue (MB) dyes from the stable solution system.