| Polyoxometalates (POMs) have attracted more attentions owing to their structural versatilities and potential applications in many diverse fields including catalysis, magnetism, medicine, materials science, and chemical analysis. In this paper, eight new POM-based supramolecular compounds have been hydrothermally synthesized and characterized by elemental analyses, IR, UV, TGA, XPS, XRD, single-crystal X-ray diffraction. The solid state luminescent properties, cyclic voltammetry and the thermal stabilities of these compounds have also been studied.(1)Two novel POM polymers have been gained based on P-Mo Keggin polyoxoanion cluster: [La(H2O)4(pdc)]4[PMoVMoVI11O40]·2H2O (1) [Nd(H2O)4(pdc)]4[PMoVMoVI11O40]·2H2O (2) (pdc= Pyridine-2,6-dicarboxylic acid) Both of compounds 1 and 2 exhibit the similar structural features. The structures of 1 and 2 are built on Keggin-type polyoxoanions [PMoVMoVI11O40]4- with the difference between them is in metal-organic moiety.(2) Three novel POM polymers have been obtained based on Ge-W Keggin polyoxoanion cluster: [Ce(H2O)4(pdc)]4[GeW12O40]·H2O (3) [La(H2O)4(pdc)]4[GeW12O40]·H2O (4) [Nd(H2O)4(pdc)]4[GeW12O40]·H2O (5) (pdc=Pyridine-2,6-dicarboxylic acid) Compounds 3, 4 and 5 have similar structures. All of them consist of [GeW12O40]4- polyoxoanions as inorganic subunit. The difference is still in metal-organic moiety. All compounds present 3D supramolecular structure.(3) Two new supramolecular assemblies have been synthesized based on {V18O42} cluster. (H3tren)(H2tren)[VV8VIV10O42(Cl)]·6H2O (6) [Zn(dien)2]2(H2dien)2[VV9V<sub>IV9O42(Cl)](7) (tren= tris(2-aminoethyl)amine, dien= Diethylenetriamine)Both of two compounds were built upon {V18O42} clusters. The bond valence sum (BVS) calculations indicate that V in both {V18O42} clusters are in different oxidation states: [VV8VIV10O42(Cl)]5- and [VV9V<sub>IV9O42(Cl)]4-, respectively. The anions contain a common structural, approximately spherical {V18O42} shell, which can act as a unique host system for anionic guests. In compound 7, the cation contains one diethylenetriamine molecule and one metal-organic moiety.(4) One novel 3D POM polymers have been achieved based on Ge-W Keggin polyoxoanion cluster capped by vanadium-oxygen groups: [Na(H2O)6]0.5(NH4)6[GeW12O40(VO)3]·XH2O (8)The crystal system of compound 8 is Cubic. Polyoxoanion is based on Keggin cluster capped by vanadium-oxygen groups, according to V-O-V forming a 3D space framework structure. In this compound, vanadium is coordinated by five oxygen formed {VO5}.
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