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By the hydrothermal technique, a series of organic–inorganic hybrid polyoxometalates (POMs) Hx(H2en)y [Fe2Ln(β-PW10O37)2(Tart)]·nH2O (Ln = La3+, (x, y, n) = (5, 3, 9) for 1; Ln = Ce3+, (x, y, n) = (5, 3, 7) for 2; Ln = Sm3+, (x, y, n) = (3, 4, 25) for 3; Ln = Tb3+, (x, y, n) = (3, 4, 21) for 4; H2Tart = tartaric acid) have been obtained and structurally characterized by elemental analyses, IR spectroscopy, thermogravimetric analyses and single-crystal X-ray diffraction. The common structural characteristics of 1–4 consist of a [Fe2Ln(β-PW10O37)2(Tart)]9− unit, in which transition metal and lanthanide ions co-exist in the vacant site of divacant [β-PW10O37]9− with the assistance of Tart ligands. It should be pointed out that 1–4 represent the first 3d–4f heterometallic cluster sandwiched phosphotungstate dimers, [Fe2Ln(β-PW10O37)2(Tart)]9−, linked by Fe–O–Ln–O–Fe bonds. Furthermore, 3 and 4 exist as rare supramolecular nanotubes built from the organic–inorganic hybrid 3d–4f POM units. Also, the photochromism and optical properties of 1–4 have been studied.

Six new coordination compounds, namely [Co(H2bptc)]n (1), [Mn(H2bptc)]n (2), [Cd2(bptc)(phen)2(H2O)2]n (3), [Eu2(cpa)3(DMF)2]n (4), [Nd2(cpa)3(DMF)2]n (5) and [Pr2(cpa)3(DMF)2]n (6) (bptc4− = biphenyl-2,2′,4,4′-tetracarboxylate anion, phen=1,10-phenanthroline, cpa2− = 4-chloroisophthalic acid anion) were synthesized under hydrothermal conditions. Their structures have been determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR spectra, and thermogravimetric analysis. Co and Mn compounds are isostructural, and possess a three-dimensional 5, 5-connected network. In Cd compound, multicarboxylate ligand H4bptc link Cd centers to generate a two-dimensional 4, 4-c net structure with phen acting as terminal ligand. Eu, Nd, and Pr compounds have similar structures, and cpa2− ligands link lanthanide cations to generate a two-dimensional sheet structure. Magnetic susceptibility measurements indicate that the Co compound has a dominating ferromagnetic coupling between Co(II) ions, and Mn compound exhibits antiferromagnetic coupling between Mn(II) ions. Furthermore, their luminescent properties are also determined in the solid state at room temperature.

Five new coordination compounds, namely [Zn(Hbtc)(1,3-bix)(H2O)]n (1), {Zn2(µ-O)(btc)(timp)]·3(H2O)}n (2), {[Zn3(4,4′-bibp)2(btc)2(H2O)2]·4(H2O)}n (3), {[Ni3(4,4′-bibp)2(btc)2(H2O)2]·3(H2O)}n (4), {[Cu3(4,4′-bibp)2(btc)2(H2O)]·2(H2O)}n (5), where 1,3 - bix = 1- (3 - (1H -inidazol - 1 − yl)methyl)benzyl)-1H-imidazole, timp = 1- (3,5-di (1H-imidazol-1-yl)phenyl)-1H-imidazole, 4,4′-bibp = 4,4′-bisimidazolylbiphenyl, and btc = 1,3,5-benzenetricarboxylate anion, were synthesized under hydrothermal conditions. In compound 1, both 1,3-bix ligand and btc anion act as bidentate bridging ligands, and connect the zinc cations into a one-dimensional chain. In compound 2, timp and btc anions as tridentate ligands coordinate to zinc cations to form a three-dimensional 3,6-connected network. Compounds 3–5 have similar structures, 4,4′-bibp and btc anions act as bidentate and tetradentate ligands, respectively, and coordinate to metal cations to form a three dimensional 4,4-connected network. The luminescence properties for 1–3 and magnetic properties for 4–5 are also discussed in detail.

Two new 3D frameworks [(WS4Cu6Br4)(timp)8/3(H2O)40/3]n (1) and [(WS4Cu6Br4) (timtz)8/3(H2O)40/3]n (2), containing heptanuclear cluster blocks (one W atom and six Cu atoms) bridged by trigonal ligands timp or timtz (timp = 1-(3,5-di (1H-imidazol-1-yl)phenyl)-1H-imidazole; timtz = 2,4,6-tri(1H-imidazol-1-yl)-1,3,5-triazine), were successfully synthesized. Both compounds were characterized by single-crystal X-ray diffraction, elemental analysis, XRD, IR, TGA. X-ray determination shows that 1 and 2 can be topologically represented as (3,4)-connected networks with α-C3N4 (or ctn) topology where [WS4Cu6] act as the 4-connecting nodes, and the timp or timtz ligands bridge in pairs that act as the three-connecting nodes. Both compounds have the high symmetry of space group I-43d, which is the maximum symmetry for this net topology. The luminescent spectra and N2 absorption behaviors for 1 and 2 have also been investigated.

Three heterothiometallic cluster–organic nanospheres have been synthesized and characterized. They own identical cationic cluster–organic nanoball frameworks and show selectivity towards charge-balancing anions. It is also interesting that the morphology of the as-prepared particles can be tuned by simply varying the polarity of the solvent.