摘要
The two 16-manganese-containing, Keggin-based 36-tungsto-4-silicates [Mn III 10 Mn II 6 O 6 (OH) 6 (PO 4 ) 4 (A-α-SiW 9 O 34 ) 4 ] 28- (1) and [Mn III 4 Mn II 12 (OH) 12 (PO 4 ) 4 (A-α-SiW 9 O 34 ) 4 ] 28- (2) have been prepared by reaction of the trilacunary Keggin precursor [A-α-SiW 9 O 34 ] 10- with either Mn(OOCCH 3 ) 3 ·2H 2 O (for 1) or MnCl 2 ·4H 2 O (for 2), in aqueous phosphate solution at pH 9. Polyanions 1 and 2 comprise mixed-valent, cationic {Mn III 10 Mn II 6 O 6 (OH) 6 } 24+ and {Mn III 4 Mn II 12 (OH) 12 } 24+ cores, respectively, encapsulated by four phosphate groups and four {SiW 9 } units in a tetrahedral fashion. Both polyanions were structurally and compositionally characterized by single-crystal XRD, IR, thermogravimetric analysis, and X-ray absorption spectroscopy. Furthermore, studies were performed probing the magnetic, electrochemical, oxidation catalytic, and Li-ion battery performance of 1 and 2.