“…Polyoxometalates (POMs) have attracted great interest due to their advantages of high negative charges, variable shape tunability, remarkable redox capability, and accessible organic grafting. − They have been widely applied in areas of catalysis, medicine, magnetism, electrochemistry, etc. − Lacunary POMs can be considered inorganic multidentate ligands that are capable of clustering multinuclear metal–oxygen fragments at vacant sites and generating transition-metal-added POMs (TMAPs). , A large amount of such intriguing assemblies have been reported, particularly these high-nuclear TMAPs, exhibiting distinct physical and chemical properties arising from their diverse hyper-nuclear cores. − In the past few decades, the outburst of high-nuclear TMAPs has been witnessed by the observation of Zr 24 , Fe 14 , Fe 48 , Ni 20 , Ni 28 , Ni 40 , Co 16 , Co 21 , Mn 19 , Cu 16 , etc.…”