By utilizing a solvothermal method, a series of six-membered cyclic lanthanide(III) clusters, {Gd6(H3L)6(benzoate)6}·2H2O·C7H8 (1), {Tb6(H3L)6(benzoate)6}·2H2O·C7H8 (2) and {Dy6(H3L)6(benzoate)6}·2H2O (3), have been constructed with the pentol ligand, 2,2-bis(hydroxymethyl)-2,2′,2″-nitrilotriethanol (H5L). Similar hexa-nuclear ring structures were observed in each of the crystal structures. In addition, magnetization studies indicated that Gd6 displays large magnetic entropy changes in low temperature regions. What is particularly interesting about this ring is the presence of slow magnetic relaxation behavior under a zero dc field, indicating a non-magnetic ground state with a net toroidal magnetic moment. Compared to the other reported Dy6 clusters, modulation of the ligand fields, the presence of amine coordinating sites and the subsequent electron density of the Dy centers along with the utilized pentol ligand might be indeed responsible for the improved barrier to magnetic relaxation.

Two diynes bearing functional groups with different binding modes, 3,6-diethynylpyrazine (H2L1) and 3,8-diethynyl-1,10-phenanthroline (H2L2), were utilized as ligands to synthesize two new organometallic units, Ag2L1·3AgNO3 (1) and Ag2L2·6AgNO3 (2), in order to investigate the effect of the bridging and chelating modes of the ligands on the structures of networks constructed from silver-ethynide compounds. Structural studies show that in 1, silver-ethynide cluster units aggregate to form chair-like organometallic slides through Ag–N coordination bonds. These slides are linked through argentophilic interaction to generate novel 2D ladder-like layers, and are further bridged by nitrate anions to afford a 3D network in the solid state. It is observed that all the Ag ions in one layer interact to afford a 2D silver network. However, in 2, the silver-ethynide cluster units only interact to generate unique sine wave-like organometallic chains through argentophilic interaction, which are further connected by nitrate anions to form a 3D network. In the solid state, both 1 and 2 are luminescent at room temperature.

Two coordination polymers (CPs) with a novel bifunctional ligand, [ZnL]n (1) and [CdL(H2O)]n (2), (L = rigid 6-(1H-tetrazol-5-yl)-2-naphthoic acid), have been synthesized and structurally characterized, which reveal that the two constructed CPs exhibit three dimensional structures. The two CPs consist of a one-dimensional Zn-tetrazole chain and a double-layered two-dimensional Cd-tetrazole structure. In addition, IR, elemental analysis, and luminescent spectra of 1 and 2 were also examined. At room temperature, 1 exhibits an intense emission at around 421 nm upon 370 nm excitation, whereas 2 exhibits an intense emission at 381 nm upon 350 nm excitation. Through variable-temperature luminescent and quantum calculations, the blue-shift of the peaks from the ligand and 1 and 2 is ascribed to the different configurations of L caused by the different coordination environments of the metal ions.

Two silver(I)-organometallic polymers have been constructed by utilizing the different silver(I) salts and a bowl-shaped calix[4]arene functionalized with tetra-allyl groups on the upper rim (L). Reacted with AgClO4 to afford 1, 1 exhibits a two-dimensional (2D) structure, where tetra-allyl-functionalized calix[4]arene units are linked through Ag–alkene interaction to generate wave-like organometallic chains and further connected by bridging by acetone molecules to afford a 2D network, giving a 2,4,4-net with the point (Schläfli) symbol {42·82·102}{42·84}2{4}2. Substituting ClO4– by NO3– as the counteranion of silver(I) salt, a three-dimensional organometallic polymer (2) encapsulating solvent molecules in the cavities was generated by connection of 2D inorganic AgNO3 layers and pillared L ligands, which gave a 3,3,4,4-net with the point (Schläfli) symbol {6·7·8}2{62·7·82·9}2{62·72·92}{62·7}2. In addition, thermogravimetric analysis, luminescent properties, and voltammetric behavior of 1 and 2 also have been investigated. Structural results for these complexes show that the different counteranions play an important role in constructing silver(I)-organometallic polymers with thus flexible tetra-allylcalix[4]arene.

Solvothermal reactions of tetrakis(4-pyridyloxymethyl)methane (TPOM) and 4,4′-oxybisbenzoic acid (H2oba) with different metal ions under different synthesis temperatures produced three new coordination polymers (CPs), namely, {[Co2(TPOM)(oba)2(H2O)2]}n (1), {[Zn2(TPOM)(oba)2]}n (2) and {[Cd2(TPOM)(oba)2(H2O)2]}n (3). 1 and 3 present similar topological structures which can be analyzed in two different ways. 2 exhibits a rare porous structure assembled by the tetra-pyridinate ligand TPOM. The luminescence properties of 2 and 3 as well as those of the corresponding samples immersed in different solvents have been investigated, and they suggested a potential application in luminescence sensing. In addition, the dye and iodine adsorption properties of an activated sample of 2 were also investigated. All of the results indicate that the proper selection of metal ions and auxiliary ligands plays an important role in constructing porous coordination polymers.

•A synthetic route to luminescent coordination compounds is proposed.•A new large conjugated bipyridyl ligand and a series of its Cu(I) compounds are synthesized.•Structure and luminescent property of the Cu(I) compound are dependent upon anions.A new conjugated ligand suitable to coordinate to tetranuclear copper(I) halides (Cu4X4, X = I− and Br-), 4,6-di(3-pyridylethynyl)dibenzothiophene (dpdbt), was rationally designed and synthesized. Reactions of dpdbt with CuI, CuBr and CuCN under solvothermal conditions led to Cu4I4(dpdbt)2 (1), Cu2Br2(dpdbt)2 (2) and [(CuCN)8(dpdbt)12]n (3), respectively. Crystallographic studies revealed that in 1, two dpdbt molecules coordinate to tetranuclear Cu4I4 cluster unit with cubane structure as chelating ligands, and these molecules for 1 interact through π–π interactions between conjugated dibenzothiophene groups to generate a supramolecular 2D network. In the similar way, two ligands in 2 coordinate to two Cu(I) centers bridged by two Br- anions, and the dimeric chair-like molecules also aggregate through π–π interactions to form supramolecular strips. However in 3, these ligands connect infinite Cu⋯CN⋯Cu chains in a different mode through Cu-N(py) coordination bonds to generate a 3D network. At room temperature, solid 1 displays typical emission bands relating to Cu4I4Py4 core, assigned as “cluster-centered’ excited states (CC) and MLCT (metal-to-ligand charge transfer) or XLCT (halide-to-ligand charge transfer), but the emissions for 2 and 3 only originates from MLCT mixed with XLCT or intraligand transitions.A conjugated dipyridyl ligand, di(3-pyridylethynyl)dibenzothiophene (dpdbt) is designed to synthesize a class of Cu(I) compounds with various anions, Cu4I4(dpdbt)2 (1), Cu2Br2(dpdbt)2 (2) and [(CuCN)8(dpdbt)12]n (3). The X-ray structures and the photoluminescent properties of the three compounds are highly dependent on the halide/pseudo-halide anions.

A new three-dimensional magnetic network, [Co9(OH)6(C42H24O18P3N3)2(H2O)8] (1), has been successfully prepared by utilizing the flexible hexacarboxylate ligand derived from cyclotriphosphazene, which had been characterized by single-crystal X-ray diffraction and magnetic measurement. This compound consists of one-dimensional (1D) cobalt-hydroxyl chains based on planar nonanuclear clusters, which are located in the b–c plane to form the nearly two-dimensional cobalt layer. Magnetic measurements reveal that 1 shows spin-canted antiferromagnetism with spin-glass behavior. These results suggest that reasonable design and choice of large carboxylate ligand based on a specific scaffold could be effective for the construction of magnetic materials based on a novel 1D magnetic chain.

Two distinct template mediated coordination polymers, [Co3(ina)4(N3)2(CH3OH)2] with tri-nuclear nodes (1) and [Co8(OH)(ina)8(N3)8·X] with dual tetra-nuclear cobalt nodes (2), have been synthesized under hydrothermal conditions by utilizing the template agent of pentaerythritol. 1 shows a 2D layer comprised of linear tri-nuclear CoII clusters, in which the central cobalt ion is inter-linked with two terminal ones via mixed bridges as syn–syn carboxylates and end-on azide ions. In contrast, compound 2 exhibits a three-dimensional framework based on two kinds of six-connected tetra-nuclear cobalt clusters: square-planar node and cuboidal node. Both 1 and 2 might exhibit spin-canted magnetism. In addition, the activated sample of 2 exhibits the sorption ability of H2 and CO2 molecules.

A star-like tris(4-ethynylphenyl)amine was used as a ligand to link Ag30 and Ag17 cluster units via argentophilic, Ag(I)-ethynide, and Ag-nitrate interactions to construct one 3D organometallic network possessing small cavities. The solid network displays a yellowish-green emission at room temperature.

Utilizing the flexible hexa-carboxylate ligand derived from cyclotriphosphazene, a novel anionic metal–organic framework based on an octa-nuclear zinc cluster has been synthesized, showing the variable luminescent properties controlled by different guest cations.

An axial substitution of the coordinated acetonitrile molecules in dinuclear Cu(I) compound, [Cu2(μ-PhPPy2)2(CH3CN)2](ClO4)2 (1) (PhPPy2 = bis(2-pyridyl)phenylphosphine) by various dicarboxylates (isophthalate, terephthalate and naphthalene-2,6-dicarboxylate) led to a class of new linear coordination polymers, {[Cu2(μ-PhPPy2)2](μ-1,3-C6H4(CO2)2)}∞ (2), {[Cu2(μ-PhPPy2)2](μ-1,4-C6H4(CO2)2)}∞ (3) and {[Cu2(μ-PhPPy2)2](μ-2,6-C12H6(CO2)2)}∞ (4). X-ray crystallographic studies reveals that all the polymers adopt almost linear structures, where the dicarboxylate groups connect dinuclear Cu(I) units as linkers. In 2 and 4, polymeric chains are parallel to each other. However the chains in 3 are arranged layer by layer, where polymeric chains are parallel in one layer, but chains in the neighboring layers are aligned with the angle (42°). The detailed structural analyses demonstrate that in solid state, the polymeric chains display different orientations which are controlled by interchain π–π and CH–π interactions. In solid state, all the coordination polymers are highly emissive at room temperature, which exhibit phosphorescence characteristics and are assigned as metal to ligand charge transfer.

Solvothermal reactions of two ligands with different geometries, derived from cyclotriphosphazene, hexakis(4-carboxylato-phenoxy)cyclotriphosphazene (H6L1) and hexakis(3-carboxylato-phenoxy)cyclotriphosphazene (H6L2) with Eu(NO3)3·6H2O in H2O/DMF under similar synthesis conditions produced three new compounds, namely, {[Eu2(L1)(H2O)4]·(H2O)4·(DMA)2}n (1), {[Eu2(L1)(H2O)8]·(H2O)2·DMA}n (2), and {[Eu2(L2)(H2O)3(DMF)]·(H2O)2·(DMA)}n (3). Compounds 1 and 2 display a 2D layer crystal structure with a distinct topological network incorporating the extended hexa-carboxylate ligand L1; in contrast, 3 has a 1D crystal structure with the highly distorted hexa-carboxylate ligand L2. In these three compounds, the ligands L1 and L2 are fully deprotonated, whose six extended carboxyl arms connect six different/same metallic nodes to generate metal–organic frameworks. The luminescence properties of three compounds have been studied at room temperature in relative detail.

Two diynes bearing functional groups with different binding modes, 3,6-diethynylpyrazine (H2L1) and 3,8-diethynyl-1,10-phenanthroline (H2L2), were utilized as ligands to synthesize two new organometallic units, Ag2L1·3AgNO3 (1) and Ag2L2·6AgNO3 (2), in order to investigate the effect of the bridging and chelating modes of the ligands on the structures of networks constructed from silver-ethynide compounds. Structural studies show that in 1, silver-ethynide cluster units aggregate to form chair-like organometallic slides through Ag–N coordination bonds. These slides are linked through argentophilic interaction to generate novel 2D ladder-like layers, and are further bridged by nitrate anions to afford a 3D network in the solid state. It is observed that all the Ag ions in one layer interact to afford a 2D silver network. However, in 2, the silver-ethynide cluster units only interact to generate unique sine wave-like organometallic chains through argentophilic interaction, which are further connected by nitrate anions to form a 3D network. In the solid state, both 1 and 2 are luminescent at room temperature.