Structural Evolution of Giant Polyoxometalate: From "Keplerate" to "Lantern" Type Mo for Improved Oxidation Catalysis.

Structural variants of high-nuclearity clusters are extremely important for their modular assembly study and functional expansion, yet the synthesis of such giant structural variants remains a great challenge. Herein, we prepared a lantern-type giant polymolybdate cluster (L-Mo ) containing equal metal nuclearity with the famous Keplerate type Mo (K-Mo ). The skeleton of L-Mo features a rare truncated rhombic triacontrahedron, which is totally different with the truncated icosahedral K-Mo . To the best of our knowledge, this is the first time to observe such structural variants in high-nuclearity cluster built up of more than 100 metal atoms. Scanning transmission electron microscopy reveals that L-Mo has good stability. More importantly, because the pentagonal [Mo O ] building blocks in L-Mo are concave instead of convex in the outer face, it contains multiple terminal coordinated water molecules on its outer surface, which make it expose more active metal sites to display superior phenol oxidation performance, which is more higher than that of K-Mo coordinated in M=O bonds on the outer surface.