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Abstract: Two new compounds based on Weakley-sandwich-type polyanion (WSP), H2[Mn(en)2]2[Mn(en)2(H2O)]2[Mn4(H2O)2(PW9O34)2]·9H2O (1) and Na2[Co(en)2]2[{Co(en)2(H2O)]2[Co4(H2O)2(PW9O34)2]·9H2O (2) (en=ethylenediamine), have been synthesized by the hydrothermal reaction of the trivacant Keggin polyoxoanion [a-A-PW9O34]9− with transition metal ions and en, and structurally characterized by routine physical methods and single-crystal X-ray diffraction. Compound 1 represents a 1D chain structure made up of WSPs and [Mn(en)2]2+ ions. Compound 2 represents a 2D layer structure formed by the interconnection of WSPs, [Co(en)2]2+ and Na+ ions. Compounds 1 and 2 represent the first example of high-dimensional construction based on WSPs and transition metal complexes (TMCs), in which the water molecules located on the featured tetra-metal unit are still remained, and exhibit the property of sorption/desorption of water molecules. [Copyright &y& Elsevier]

A photoluminescent multilayer film based on Keggin-type polyoxometalate PMo12O403- (PMo12) and transition metal complex tris(2,2-bipyridine) ruthenium [Ru(bpy)3]2+ (Ru(bpy)) was prepared by using layer-by-layer assembly(LBL). The formation of multilayer film was monitored by ultraviolet absorption spectra. The absorption intensity of characteristic peaks increase with a four-layer cycle, indicating that the LBL assembly film grow linearly and reproducibly from layer to layer. The composition of the film was measured by X-ray photoelectron spectrum (XPS). The data of XPS confirmed the presence of the expected elements. The film exhibited photoluminescence arising from π*-t2g ligand-to-metal transition of Ru(bpy) and redox activity attributing to molybdenum-centered redox processes of PMo12. The surface morphology of multilayer film was characterized by atomic force microscopy (AFM). The result shows that the film had a smooth surface with root-mean-square (rms) roughness ca. 1.363 nm for {PEI/(PSS/PEI/PMo12/Ru(bpy))3}. The grains are homogeneously dispersed in the substrate and have a rather narrow diameter size distribution. [Copyright &y& Elsevier]