| Highly valent ions can be stabilized by the lacunary polyoxoanion.In this paper,we synthesized two Ce?IV?sandwich complexes based on lacunary Keggin structure 1:9 heteropolytungstate in the sodium acetate buffer solution,successfully.These complexes have been characterized by single-crystal X-ray diffraction,IR,TG,NMR and XPS,meanwhile,electrochemical behavior of complexes have been investigated.Complex 1 is composed of two trilacunary[?-A-GeW9O34]10-units and a tetranuclear cerium cluster,showing a sandwich-type structure.In the central,two cerium atoms are coordinated with CH3COO-ions,forming CH3COO-ions modified polyoxoanion complex.Adjacent polyanions are combined with the surface of oxygen atoms and Na + ions,forming a one-dimensional chain structure.Complex 2 is consists of two[?-A-PW9O34]9-units and a trinuclear cerium cluster.In the central,three oxygen atoms and three cerium atoms alternately form a six-member ring,two of three cerium atoms have connected with water molecule,respectively.Electrochemical analyses of complexes 1 and 2 indicate that,compared with ammonium ceric nitrate,tetravalent cerium ion anodic peak negative shift,from 0.906 to 0.877V for complex 1,from 0.906 to 0.880V for complex 2,indicating that Ce?IV?ions can be stabilized by polyoxoanions.NH4Na2H7[Ce4O2?CH3COO?2(?-A-GeW9O34)2]·17H2O?1?Cs3.5Na2H6.5[Ce3O3?H2O?2(?-A-PW9O34)2]·23H2O?2?By hydrothermal synthesis strategy,we synthesized one complex containing Tb?III?ions and Preyssler polyxometalates,K4Na4H4[Tb?H2O?P5W30O110]·27H2O?3?.By using single crystal X-ray diffraction technology to determine its composition and structure.Moreover,electrocatalytic activity towards the reduction of sodium nitrite and hydrogen peroxide have been also investigated. |
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