Structural Evolution of Giant Polyoxometalate: From "Keplerate" to "Lantern" Type Mo132 for Improved Oxidation Catalysis

Angew Chem Int Ed Engl. 2023 Aug 14;62(33):e202304728. doi: 10.1002/anie.202304728. Epub 2023 Jul 10.

Abstract

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-Mo132 ) containing equal metal nuclearity with the famous Keplerate type Mo132 (K-Mo132 ). The skeleton of L-Mo132 features a rare truncated rhombic triacontrahedron, which is totally different with the truncated icosahedral K-Mo132 . 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-Mo132 has good stability. More importantly, because the pentagonal [Mo6 O27 ]n- building blocks in L-Mo132 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-Mo132 coordinated in M=O bonds on the outer surface.

Keywords: Phenol Oxidation; Polyoxometalate; Structural Variants.