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Diamine-containing UiO-66 (UiO-66-(NH2)2) was utilized as a support to load PdAu nanoparticles (NPs) through a double-solvent strategy for the catalytic application in the dehydrogenation of formic...

Ultrafine and well-dispersed PdAu bimetallic nanoparticles (ca. 1.4 nm) are successfully immobilized on amine-containing UiO-66 frameworks (NH2-UiO-66) via a double-solvent impregnation method. By ...

MOFs with adequate free nitrogen sites have potential applications in dye adsorption and formic acid dehydrogenation. Here, we successfully synthesized a novel 3-D MOF 1 ([(CH

The simple solvothermal self-assemble of CuI, 1,4-bis(2-methyl-1H-imidazol-1-yl)butane (L1) and HI in a C2H5OH solvent at pH = 2 created a new H2(L1)2+-templated 1-D chained iodocuprate(I) [H2(L1)][Cu3I5] 1. The crystal data reveal that the Cu-I chain mode in 1 is rare. Two folded Cu2I2 cores first aggregate into a trinuclear cluster by sharing an edge. Then the extra I− ions doublely bridge these trinuclear clusters into the title 1-D chain of 1. Synchronously, a non-folded Cu2I2 cluster is formed. In 1, all of the Cu···Cu distances are smaller than 2.8 A. The investigation on photoluminescence property indicates that with the decrease of the temperature, the photoluminescence emission for 1 exhibits a minor change from the green-yellow light (298 K) to yellow light (77 K). This means that 1 might possess the fluorescent thermochromic property.

By employing the hydrothermal in situ acylation of organic acid with N2H4, we constructed a new acylhydrazidate-based Zn2+ coordination polymer [Zn2(apo)2]·H2O (H2(apo) = 4,5-diamino-1,2-dihydropyridazine-3,6-diol) 1. Interestingly, besides the acylation of 2,3-pyrazinedicarboxylic acid (pca) with N2H4, the breaking of partial C-(=)N bonds in the pyrazine ring also occurred, creating a new bridging-type acylhydrazide molecule H2(apo). In 1, the apo2- molecules exhibit a μ4 coordination mode, linking the tetrahedral Zn2+ centers into a 2-D layer network with a 44 topology. The photoluminescence analysis indicates that the title compound 1 emit the green light with the maximum at 490 nm upon excitation (λex = 380 nm, τ = 12.6 μs). Based on the better photoluminescence behavior of 1, the sensing ability of 1 on nitroaromatic explosives and inorganic anions were investigated. The results suggest that 1 can selectively detect 2,4,6-trinitrophenol (TNP) and Cr2O72-. This should be associated with the larger light adsorption at 380 nm for TNP and Cr2O72-. The light adsorption at 380 nm for the other nitroaromatic explosives and inorganic anions is weak.

Simple room-temperature self-assemblies between Cd2+ salts, SCN- and bisimidazole molecules at pH = 2 created three new organically templated thiocyanatocadmates [H2(L1)][Cd(SCN)4]·H2O (L1 = 1,4-bis(1H-imidazol-1-yl)benzene) 1, [H2(L2)][Cd(SCN)4] (L2 = 1,3-bis(2-methylimidazol-1-yl)propane) 2, and [H2(L3)][Cd2(SCN)6] (L3 = 1,4-bis(2-methyl-1H-imidazol-1-yl)butane) 3. X-ray single-crystal diffraction analysis reveals that (i) in 1-3, the SCN- groups doubly bridge the Cd2+ centers to form different thiocyanatocadmates: a linear chain in 1; a zigzag chain in 2; and a 2-D layer network (63 net) in 3; and (ii) in 1, via Nbase-HNSCN interactions, the L1 molecules extend the thiocyanatocadmate chains into a 2-D supramolecular layer, whereas in 2, the zigzag thiocyanatocadmate chains self-assemble into a 3-D supramolecular network via weak SS interactions. Photoluminescence analysis indicates that the three title compounds all emit light: blue light for 1 and 2 and green light for 3. At low temperatures, the emission positions of the three compounds hardly change, but the emission intensities are largely enhanced. Interestingly, after turning off the UV lamp, 1 and 2 still briefly emit light (ca. 2 s), which means that 1 and 2 possess phosphorescence properties. Phosphorescence lifetimes at 77 K are 1619 ms for 1 and 247 ms for 2.

By employing the solvothermal in situ N-alkylation of organic bases with alcohol molecules, four new organically templated iodometallates as [L1][Ag2I4] (L12+ = 1,1,4,4-tetramethyl-1λ4,4λ4-piperazinium) 1, [L2]1.5[AgI4] (L22+ = 1,4-dibenzyl-1λ4,4λ4-diazabicyclo[2.2.2]octanium) 2, [L2]1.5[CuI4] 3 and [L3][CuI3] (L32+ = 4,4′-bis(3-methyl-1H-3λ4-imidazol-1-yl)-1,1′-biphenylium) 4 were obtained. In 1, the in situ substitution and N-alkylation of 1,4-bis(pyridin-4-ylmethyl)piperazine (L1') with CH3OH has occurred, producing L12+. Templated by L12+, Ag+ and I- aggregate into a chained iodoargentate, which can be described as a linear arrangement of AgI4 tedrahedra by sharing the edges. 2 and 3 are isostructural. In 2 and 3, the in situ N-alkylation of 1,4-diazabicyclo[2,2,2]octane (L2') with phenylmethanol has occurred, generating L22+. Templated by L22+, Ag+ (or Cu+) and I- aggregate into a mononuclear iodometallate with a tetrahedral structure. In 4, the in situ N-alkylation of 4,4′-di(1H-imidazol-1-yl)-1,1′-biphenyl (L3') with CH3OH has occurred, creating L32+. Templating by L32+, Cu+ and I- aggregate into a mononuclear iodocuprate(I) with a planar trigonal structure. The photoluminescence analysis reveals that (i) at the room temperature, only 1 emits light (λem = 550 nm); (ii) at the low temperature, 4 is found to possess the photoluminescence property (λem = 546 nm at 77 K) with a ms-grade lifetime (τ = 4.915 ms).

Through employing the hydrothermal in situ acylation of organic acids with N2H4, six L12−-based coordination polymers, [M(L1)(H2O)]·H2O (M2+ = Cd2+1, Zn2+2, Fe2+3, Mg2+4; H2L1 = 6,6′-(perfluoropropane-2,2-diyl)bis(2,3-dihydrophthalazine-1,4-dione)), [Pb(L1)] 5, and [Er2(L1)2(ox)(H2O)2]·5H2O (ox = oxalate) 6, were obtained. X-ray single-crystal diffraction analysis reveals that (i) the L12−-based Cd2+, Zn2+, Fe2+ and Mg2+ coordination polymers are isostructural, and they possess a 2D single-layer network structure with a 44 topology; (ii) 5 possesses a 3D network structure, which is constructed from the dinuclear Pb2O812− clusters by the L12− molecules; (iii) 6 possesses a 2D double-layer network structure. Two 2D single-layer networks (the same as those in 1–4) are supported by ox to form this 2D double-layer network. 1D channels (428.9 A3 for total potential solvent-accessible void volume) are observed in 6. 1, 2, 5 and 6 are found to emit blue light, corresponding to the L12−-centered electronic excitation. Based on the photoluminescence properties, their sensing ability towards the inorganic Cr2O72− anion was investigated. 5 exhibits the better sensing ability towards Cr2O72−. The heavy-atom effect should play a key role.

Porous coordination polymers with organic aminium as one of the guest species possess a potential application in dye adsorption and white-light material manufacture. Polycarboxylic acid with multiple COOH substituents tends to form this type of porous material (with metal ion). Here the solvothermal self-assembly between Cd

In this article, two organic bases (dtb = 1,4-di(1H-1,2,4-triazol-1-yl)benzene; mimb = 1,2-bis((2-methyl-1H-imidazole-1-yl)methyl)benzen) were employed to solvethermally react with AgI in an strong acidic environment, creating two new hybrid haloargentates [pbmt]0.5[AgI2] 1 (pbmt2+ = 1,1'-(1,4-phenylene)bis(4-methyl-1H-1,2,4-triazol-4-ium)) and [H2(mimb)]0.5[Ag2I3] 2. Note that pbmt2+ in 1 originated from the in situ N-alkylation of dtb with CH3OH. X-ray single-crystal diffraction analysis reveals that (i) 1 exhibits 1-D chain structure, which can be described as an infinite extension of AgI4 tetrahedra via sharing edge; (ii) in 2, Ag+ and I− aggregate to form a 3-D iodoargentate with open-framework structure. The photoluminescence analysis reveals that at room temperature, 1 emit yellow light, while at low temperature, it just occasionally emits yellow light, and in most cases it emits yellow-green light. Whether at room temperature or low temperature, 2 always emits yellow light. It means that 1 possesses the fluorescent photo(thermo)chromic properties, whereas 2 does not have these properties. The related mechanism was also discussed.

Seven compounds based on [P2W18O62]6– ({P2W18}) were successfully prepared and carefully characterized. [HC5H5N][Cu(2,2′-bpy)2]2[HP2W18O62]·2H2O (bpy = bipyridine) (1) is constructed from {P2W18} bridged by [Cu(2,2′-bpy)2]2+. [HC5H5N][Zn(2,2′-bpy)2]2[HP2W18O62]·4H2O (1a) is isostructural and isomorphous with compound 1. [Cu4(2,2′-bpy)3(nic)3(OH)2(H2O)][H3P2W18O62]·0.5H2O (nic = nicotinic acid) (2) is formed by {P2W18} and tetracopper transition metal mixed organic ligand complexes (TMMCs). [Cu2(2,2′-bpy)2(C2O4)]3[P2W18O62]·3H2O (3) is made up of {P2W18} and bicopper TMMCs, [Cu6(2,2′-bpy)6(OH)6][P2W18O62]·2H2O (4) is built up from {P2W18}, and hexacopper complexes of 2,2′-bpy and hydroxyls. [Cu(2,2′-bpy)(hnic)0.5][Cu3(2,2′-bpy)3(hnic)2(H2O)2][H3P2W18O62] (hnic = hydroxyl nicotinic acid) (5a) contains two different TMMCs. In addition, compound 5a is the first example of a compound that contains Cu−π interactions. [Cu2(2,2′-bpy)2(hnic)][H4P2W18O62]·xH2O (x ≈ 50) (5b) is based on {P2W18} and [Cu2(2,2′-bpy)2(h...

We employed a rigid bridging-type tetracarboxylic acid molecule, namely, 5,5′-(pyridine-3,5-diyl)diisophthalic acid (H4L; containing two isophthalic acid moieties and one pyridine spacer), to construct three new isomorphic Ln-metal–organic framework (Ln-MOF) materials [(CH3)2NH2]2[Ln2(L)2(H2O)2]·2DMF·2H2O (Ln3+ = Tb3+ 1, Eu3+ 2, Gd3+ 3; DMF = N,N-dimethylformamide). Since the pyridyl N atom does not coordinate to Ln3+, the larger pores are observed in the three-dimensional networks of 1–3. On the basis of their photoluminescence properties, the white-light-emitting materials 4–7 with longer fluorescence lifetime (millisecond grade) and higher quantum yield (e.g., 48.29% for 5) are fabricated. We also find that the title Ln-MOF materials not only can selectively sense polychlorinated benzenes, but also can highly sensitively detect the Fe3+ ion (Ksv = 7.58 × 104 M–1). This should be associated with these three structural factors in 1–3: the larger π-conjugated structure of L4–; the larger porous structures...

Under the hydrothermal conditions, the simple self-assembly between Cd2+, 2,3,5,6-pyridinetetracarboxylic acid (L1′), and N2H4 created a L12−-based Cd2+ coordination polymer [Cd(L1)(N2H4)] · 2H2O (L12− = 2,3,5,6-pyridinetetracarboxylhydrazidate) 1. H2L1 derived from the in situ acylation of L1′ with N2H4. X-ray single-crystal diffraction analysis reveals that 1 possesses a 1-D chained structure co-bridged by L12− and N2H4, where a castellated CdO single-chain is observed. It is noteworthy that between the L12− molecules, two types of cyclic hydrogen-bonded synthons are found. Via these weak intermolecular interactions, 1 self-assembles into a 3-D porous supramolecular network (window size: 8 × 7 A2). The tetrahenuclear water clusters with a tetrahedral structure are observed in the pores.

At pH 2, the simple room-temperature self-assemblies between Cd2+ salts, SCN− and organic bases created one new thiocyanatocadmate as [H2(L1)][Cd2(SCN)6] (L1 = 1,4-bis(2-methyl-1H-imidazol-1-ylmethyl)benzene) 1, and two new halo-thiocyanatocadmates as [H2(L2)][CdI2(SCN)2]·H2O (L2 = 3,5-bis (4-pyridyl)-1,2,4-triazole) 2, and [CdCl(SCN)(L3)] (L3 = 3-pyrazinyl-1,2,4-triazole) 3. X-ray single-crystal diffraction analysis reveals that (a) in 1, with H2(L1)2+ as the countercation, the SCN− groups tri-bridge the Cd2+ centers into a 1-D chained thiocyanatocadmate; (b) 2 is only a mononuclear iodo-thiocyanatocadmate, and H2(L2)2+ acts as the countercation. But via the π···π and Npyridyl–H···NSCN interactions, H2(L2)2+ and CdI2(SCN) 2 2− aggregate together to form a 1-D supramolecular tube. Amongst the tubes, a chained water cluster with a zig-zag shape is observed; (c) 3 is an organically extended chloro-thiocyanatocadmate. Note that the report on this type of material is rather rare. It possesses a 3-D network structure with a dia topology, in which a castellated CdCl+ single chain is observed. L3 and Cl− act as a mixed bridge, whereas SCN− just serves as a terminal ligand in 3. The photoluminescence analysis indicates that the title compounds 1–3 all emit light (green light for 1, blue light for 2 and 3), which should be attributed to the ligand-centered electronic excitations.

In this article, three bisimidazole derivatives (1,4-bis(2-ethylimidazol-1-yl)butane, L1; 4,4′-di(1H-imidazol-1-yl)-1,1′-biphenyl, L2′; and 1,3-bis(2-ethylimidazol-1-yl)propane, L3) were employed to solvothermally react with AgI in an acidic environment, creating three new 1-D chained iodoargentates [H(L1)][Ag5I6]·DMF (DMF = N,N′-dimethylformamide) 1, [L2][Ag3I5] (L22+ = 4,4′-di(1H-imidazol-1-ium)-1,1′-biphenyl) 2, and [H2(L3)][Ag2I4] 3. L22+ in 2 originated from the in situ N-alkylation of L2′ with the CH3OH solvent. X-ray single-crystal diffraction analysis reveals that (i) in 1, Ag+ and I− aggregate to form a 1-D tube-like iodoargentate, which exhibits the same topology as the carbon tube; (ii) the chain structure of the iodoargentate in 2 is based on a kind of trinuclear Ag–I cluster, which can be viewed as a segment of the classical cubic M4I4 cluster; (iii) the chain structure of the iodoargentate in 3 is simple, which can be described as a linear arrangement of the AgI4 tetrahedra by sharing edges. The photoluminescence analysis reveals that at 77 K, (i) 1 and 2 emit strong yellow light with ms-grade photoluminescence lifetimes (5.460 ms for 1, 6.931 ms for 2); (ii) 3 possesses photochromic luminescence properties. Upon excitation at 254 nm, it emits blue-green light, whereas upon excitation at 365 nm, it emits yellow light.

Through employing the in situ acylation of N2H4 with ODPA (ODPA = 4,4′-oxydiphthalic dianhydride), three diacylhydrazidate-extended coordination polymers, M(ODPTH)(H2O)3 (M = Fe (1), Co (2), Ni (3); ODPTH = 4,4′-oxydiphthalhydrazidate), were obtained under solvothermal conditions. The X-ray single-crystal diffraction analysis reveals that compounds 1, 2 and 3 are isomorphous and feature 1D double chain structures that are further connected through O–H⋯O hydrogen bonds into 3D supramolecular networks, which are stabilized by two kinds of offset face-to-face π⋯π interactions. All of title compounds were characterized by IR spectroscopy, elemental analysis, X-ray power diffraction and TG analysis. Furthermore, variable-temperature magnetic susceptibilities of compounds 1, 2 and 3 indicate that there exist antiferromagnetic interactions between Fe(II), Co(II) and Ni(II) ions, respectively.

Through employing the in situ acylation of N 2 H 4 with 2, 3-quinoline dicarboxylic acid, three acylhydrazidate-extended coordination complexes, M(QLH)(H 2 O) 2 Cl (M = Mg ( 1 ) or Mn ( 2 ); QLH = 2, 3-quinolinedicarboxylhydrazidate) and Mn(QLH) 2 (H 2 O) 2 ( 3 ), were obtained under solvothermal conditions. The X-ray single-crystal diffraction analysis reveals that: (i) compounds 1 and 2 feature a dinuclear structure. Via two kinds of O–H⋯O and O–H⋯Cl hydrogen bonds, the discrete dinuclear units of 1 and 2 self-assemble into 3-D supramolecular networks, which are stabilized by the offset face-to-face π···π interactions; (ii) compound 3 features a mononuclear structure, which self-assembles into a 2-D supramolecular network via two types of O–H⋯O and N–H⋯N hydrogen bonds, and the strong face-to-face π···π interactions strengthen the 2D supramolecular layers. All of title compounds were characterized by IR spectroscopy, elemental analysis, power X-ray diffraction and TG analysis. The photoluminescent properties of 1 , 2 and 3 were investigated. Compounds 1 and 3 emitted green light with maxima at 529 nm for 1 ( λ ex = 364 nm), and 498 nm for 3 ( λ ex = 366 nm), while compound 2 emitted purple light with maxima at 381 nm ( λ ex = 338 nm). Furthemore, density functional theory (DFT) calculations were carried out on the excited electronic states of 1 , 2 and 3 in order to further investigate the emission mechanism. Meanwhile, variable-temperature magnetic susceptibilities of 2 and 3 indicated that there existed weak antiferromagnetic interactions between Mn (II) ions.

The hydro(solvo)thermal reactions of CuI with diverse bisimidazole molecules were investigated, affording five new copper(I) iodides [Cu4I4(L1)2] (L1=1,3-bis(2-methylimidazol-1-ylmethyl)benzene) 1, [CuI(L2)] (L2=4,4′-bis(imidazolyl)biphenyl) 2, [Cu4I4(L3)] (L3=1,3-bis(2-methylimidazol-1-yl)propane) 3, [Cu4I4(L4)2] (L4=1,4-bis(2-ethylimidazol-1-yl)butane) 4, and [Cu4I4(L5)] (L5=1,4-bis(1-imidazoly)benzene) 5. X-ray single-crystal diffraction analysis reveals that (i) in 1, a tetranuclear Cu-I cluster (stepped cubane) is observed, and the L1 molecule only acts as an ancillary ligand; (ii) in 2, the L2 molecules extend the castellated Cu-I chains into a 2-D layer network with a certain thickness; (iii) in 2-D single-layer network of 3, a 1-D Cu-I column is found, which can be viewed as a longitudinal packing of stepped Cu4I4 cubanes; (vi) in 4, the L4 molecules propagate the cubic Cu4I4 cubanes into a 3-D 4-fold interpenetrated network with a cds topology; and (v) in 5, the L5 molecules link the 1-D Cu-I ribbons into a 2-D single-layer network. The photoluminescence analysis indicates that 1, 2 and 4 emit light (red light for 1; yellow light for 2 and 4), while 3 and 5 are not emissive. Their photoluminescence behaviors are confirmed to be related to the Cu···Cu interactions in the molecules.

Under hydrothermal conditions, the simple self-assembly of Ni 2+ , H 2 C 2 O 4 and N 2 H 4 created a new 3-D Ni 2+ coordination polymer, [Ni(C 2 O 4 )(N 2 H 4 )]·H 2 O (C 2 O 4 2− = oxalate, N 2 H 4 = hydrazine) 1 , in which C 2 O 4 2− ligands link Ni 2+ ions into a left-hand helical Ni(C 2 O 4 ) chain, while N 2 H 4 extends the Ni(C 2 O 4 ) chains into a 3-D network with a 10 3 topology. A magnetic susceptibility study indicates that between the neighboring Ni 2+ centers, there exist antiferromagnetic interactions.

Based on an aim of introducing the SCN− or SO42− group into the organically templated chlorocadmates, a series of room-temperature reactions at pH 2 were performed, creating four new Cd(II) hybrids as [L1]4[Cd4Cl6(SCN)10(H2O)2] (L1 = 1,1′-dibenzyl-4,4′-bipyridium) 1, [H4L2][CdCl4(SCN)2] (L2 = 1,4-bis(4-pyridylmethyl)piperazine) 2, [HL3]3[CdCl3]SO4 (L3 = 2-amino-6-chloropyridine) 3, and [HL4]3[CdCl3]SO4 (L4 = 2-amino-6-bromopyridine) 4. X-ray single-crystal diffraction analysis reveals that (i) templated by L12+, 1 shows a 1-D single-chain structure, which is based on the dinuclear [Cd2Cl3(SCN)4(H2O)]3− clusters by the μ-1,3-mode SCN− groups; (ii) templated by H4L24+, 2 only exhibits a mononuclear structure. However, via the intermolecular weak Npyridine H⋯Cl, Npiperazine H⋯Cl and SSCN⋯SSCN interactions, 2 self-assembles into a 3-D supramolecular network with a (4,6)-connected topology; (iii) 3 and 4 possess the similar structures. Via the Npyridine/amino H⋯O and π⋯π interactions, the introduced SO42− groups and the organic base molecules aggregate together into a 3-D supramolecular network with the 1-D channels. Within the channel, the Cl− ions triplely bridge the Cd2+ centers into a 1-D linear [CdCl3]− chain. Based on the structural information and the previous related reports, the role of the introduced SCN− or SO42− group in the hybrid is revealed. SCN− acts as two roles: (i) a linker; (ii) a cutter. Sometimes SO42− serves as a linker, while sometimes SO42− connects with organic base into a supramolecular aggregation, acting as a new templating agent. The photoluminescence analysis reveals that 2, 3 and 4 emit light with the maxima at 535 nm for 2 (λex = 465 nm), 462 nm for 3 (λex = 428 nm), and 465 nm for 4 (λex = 430 nm), respectively. In particular, the emissions for all are strong, and can be seen under the ultraviolet (UV) lamp.

Based on a strategy of incorporating the SCN− group into the organically templated halocadmate, the reactions of CdCl2, SCN−, and bisimidazole molecules in a strong acidic environment at 4 °C were carried out, creating two new organically templated 2-D layered thiocyanato-chlorocadmates [H2(L1)][Cd2Cl5(SCN)] (L1 = bis(1H-imidazole-1-yl)methane) 1 and [H2L2]2[Cd5Cl12(SCN)2] (L2 = 1,3-bis(2-ethylimidazol-1-yl)propane) 2. Both layers are based on a kind of tetranuclear Cd–Cl cluster. Since the employed organic cations are different, the neighboring tetranuclear Cd–Cl clusters are linked together by the different bridges into the 1-D endless chains. In 1, the Cl− ions act as the bridges, while in 2, the CdCl6 units serve as the bridges. Finally, the 1-D Cd–Cl chains are further linked by SCN− into the 2-D layer networks of 1 and 2. Both layers possess a simple (4,4) topology. Based on the structural characterization of the title compounds, the role of the introduced SCN− group on the organically templated halocadmates is discussed.

Based on the hydrothermal in situ acylation reaction of benzene-1,2,4-tricarboxylic acid (btca) with N2H4·H2O, two containing-4-carboxylphthalhydrazidate Mn2+/In3+ coordination polymers, [Mn(cpth)(phen)] 1 and [In(cpth)(ox)0.5(phen)]·H2O 2 (cpth = 4-carboxylphthalhydrazidate, phen = 1,10-phenanthroline, ox = oxalate), were obtained and characterized by elemental analysis, IR spectroscopy, X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), and single-crystal X-ray diffraction. In compound 1, the cpth ligands exhibit a μ4-bridging mode, which link Mn(II) centers into a 2-D layer structure with ancillary phen molecules. In compound 2, the cpth ligands exhibit a μ2-bridging mode, which link In(III) centers into a binuclear unit. Ox ligands act as the second linkers, extending binuclear unit into a 1-D chain with ancillary phen molecules. Via N H⋯O interactions, compound 2 self-assembles into a 2-D supramolecular layer. The magnetic analysis indicates that there exists antiferromagnetic interactions between magnetic centers in compound 1. The photoluminescence properties of compounds 1 and 2 were also investigated in an aqueous solution.

Three new organic–inorganic hybrid compounds based on [SiNb12V2O42]12− have been obtained under hydrothermal conditions and characterized by IR, XRD, and single crystal X-ray diffraction analysis. Single crystal X-ray analysis reveals that [Cu(en)2]4[Cu(en)2(H2O)2]2[SiNb12V2O42]·14H2O (1) is constructed from [SiNb12V2O42]12− and two kinds of copper complexes, polyoxoanions in [Cu(en)2]2[Cu(en)2(H2O)]4[SiNb12V2O42]·4H2O (2) and [Cu(en)2(H2O)2]4[Cu(en)2(H2O)]2[SiNb12V2O42]·11H2O (3) are identical to compound 1, but the copper complex combinations of these two compounds are different from that of compound 1. Therefore, the final structures of the three are different from one another. All the three compounds are excellent catalysts for the epoxidation of styrene. In addition, we also synthesized an isopolyniobate K6H2Nb6O19·17H2O (4), which exhibits a 3-D structure constructed from [Nb6O19]8− and potassium clusters.

Through employing the solvothermal in situ N-alkylation of organic bases with alcohol molecules, four new iodometallates [L1]2[Ag8I12]I2 (L13+ = 1,1′,1′′-(benzene-1,3,5)tris(3-methyl-1H-imidazol-3-ium)) 1, [L1]2[Ag6I12] 2, [L1]2[Pb3I12]·2H2O 3, and [L1][Bi2I9] 4 were obtained. L13+ originates from the in situ N-alkylation between 1,3,5-tri(1H-imidazol-1-yl)benzene (L2) and CH3OH. X-ray single-crystal diffraction analysis reveals that all of the title compounds possess zero-dimensional (0D) structures. The octanuclear anionic cluster [Ag8I12]4− of 1 possesses a sphere-like structure. An Ag6I6 unit with a hexagram structure occupies the equatorial position, while two AgI4 tetrahedra (sharing point) occupy the axial positions. The anionic cluster, [Ag6I12]6−, of 2 exhibits a hexanuclear structure, which can be described as an aggregation of two incomplete cubanes (each lacking an Ag+ corner). The anionic cluster [Pb3I12]6− of 3 can be described as an aggregation of three PbI6 octahedra (sharing face), whereas two BiI6 octahedra (also sharing face) aggregate to form a dinuclear cluster [Bi2I9]3− of 4.

Based on the hydrothermal in situ acylation reaction of 4,4′-sulfoyldiphthalic anhydride (sdpha) with N2H4⋅H2O, two isostructural oxalate-propagated Mn2+/Fe2+-diacylhydrazidate coordination polymers, [M3(sdpth)2(ox)(H2O)2]⋅2H2O (M2+ = Mn2+ 1, Fe2+ 2; sdpth = 4,4′-sulfoyldiphthalhydrazidate, ox = oxalate), were obtained and characterized by elemental analysis, IR spectroscopy, X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), and single-crystal X-ray diffraction. In both compounds, ox ligands act as the second linkers, extending the metal-diacylhydrazidate chains into a 2-D layer. Via N H⋯O interactions, compounds 1 and 2 self-assemble into 3-D supramolecular networks. The magnetic analyses indicate that there are antiferromagnetic interactions between magnetic centers in compounds 1 and 2. The photoluminescence properties of compounds 1 and 2 were also investigated in an aqueous solution.

Five new organic–inorganic hybrid compounds based on [P2W18O62]6− (abbreviated as {P2W18}) and several types of transition metal complexes (TMCs) have been synthesized and characterized by IR, UV-Vis, XRD, cyclic voltammetry measurements and single crystal X-ray diffraction analysis. [Cu(phen)2][Cu(phen)(H2O)3][Cu(phen)2(H2O)][P2W18O62]·8H2O (1) (phen = 1,10-phenanthroline) is a {P2W18} bi-supported complex of phen, while [Cu(2,2′-bpy)(H2O)2]2[Cu(2,2′-bpy)2][P2W18O62]·3.5H2O (2) (2,2′-bpy = 2,2′-bipyridine) is a 1-D chain structure formed by {P2W18} and copper complexes of 2,2′-bpy. [Ag(2,2′-bpy)2]5[HP2W18O62]·H2O (3), [Ag(2,2′-bpy)(H2O)]2[Ag(2,2′-bpy)]2[Ag2(2,2′-bpy)3][P2W18O62] (4), and [Ag(2,2′-bpy)(H2O)]3[Ag2(2,2′-bpy)3][Ag(2,2′-bpy)][P2W18O62]·H2O (5) are constructed from {P2W18} and silver complexes of 2,2′-bpy. Compounds 4 and 5 are novel dimers of {P2W18} joined by silver complexes, while compound 3 contains two different kinds of silver complexes, forming a novel supramolecular structure. Each of the five compounds is formed by {P2W18} and more than one type of TMC. The formation mechanism of these compounds has been carefully discussed. In addition, we also synthesized two supramolecular structures based on {P2W18} and organic moieties: [H6P2W18O62](phen)5.5 (6) and [H6P2W18O62](phen)3·43H2O (7). The catalytic properties of these compounds were also tested.

A series of compounds based on vanadate, [Zn(1,10-phen)3][Zn(dap)2]0.5[Zn(dap)2(H2O)]2[VV6VIV10O38Cl]·2H2O (1), [Ni(im)6]3[VV7VIV8O36Cl]·17H2O (2), [Zn(2,2′-bpy)3]2[H2VV10O28]·6H2O (3), [Fe(Phen)3]3[V16O39Cl]·8.5H2O (4), [Zn(2,2′-bpy)]3[V15O36Cl] (5), [Co(2,2′-bpy)]3[V15O36Cl] (6), [Ni(en)2]3[V18O42Cl]·18H2O (7), [Cd(2,2′-bpy)2]2[V4O12]·0.5H2O (8), [Ni(2,2′-bpy)3]2[V4O12]·11H2O (9), [Zn(2,2′-bpy)3][V4O12]·11H2O (10) and [Ni(phen)3]2[V4O12]·12H2O (11) (1,10-phen = 1,10-phenanthroline, dap = 1,2-propanediamine, 2,2′-bpy = 2,2′-bipyridine, im = imidazole), has been synthesized under hydrothermal conditions and characterized using IR, UV-vis, XRD, ESR, elemental analysis and crystal structure analysis. Out of the eleven compounds, 1–3 and 11 are novel. Compound 1 is based on [V16O38Cl]7− anions and [Zn(dap)2]2+ and [Zn(dap)2(H2O)]2+ cations, forming a novel dimer of cluster supported coordination complexes. Compound 2 has a supramolecular structure based on [V15O36Cl]6− anions (V15) and [Ni(im)6]2+ cations. Compound 3 also has a supramolecular structure, which is constructed from [H2V10O28]4− and [Zn(2,2′-bpy)3]2+ cations. Compound 11 is formed by [V4O12]4− clusters and [Ni(phen)3]2+ cations. Compounds 4–10 are also based on vanadate and are not new compounds. Here, we investigate the catalytic properties of these eleven compounds, and the photocatalytic properties of some of these compounds.

Porous coordination polymers with organic aminium as one of the guest species possess a potential application in dye adsorption and white-light material manufacture. Polycarboxylic acid with multiple COOH substituents tends to form this type of porous material (with metal ion). Here the solvothermal self-assembly between Cd2+ and a hexacarboxylic acid creates such a porous material [(CH3)2NH2]6[Cd3(L)2]·5DMF·3H2O (H6L = 3,4-di(3,5-dicarboxyphenyl)phthalic acid) 1. Total potential guest accessible void volume in 3-D 1 is found to be 4327 A3. Based on its better porous structure and stability, the ability of 1 to adsorb organic dyes is investigated. It has been proved that (i) 1 can selectively adsorb cationic dyes as Azure A (AA+) and/or Methylene Blue (MB+), rather than neutral and anionic ones; (ii) the maximum adsorption capacity is 698.2 mg·g−1 for AA+ and 573.2 mg·g−1 for MB+, respectively; and (iii) to the adsorption of AA+, it can be recycled for at least five rounds. Also, it is utilized to fabricate the while-light emitting material. Based on the blue-light emission of 1, the trace Eu3+ and Tb3+ ions are introduced into the pores of 1 successfully, obtaining a white-light emitting material Eu3+/Tb3+@1 (CIE chromaticity coordinates: (0.33, 0.32)). Meanwhile, Eu3+/Tb3+@1 is found to be a potential fluorescence photochromic material, showing a yellow-white-blue light emission. According to these investigations, the relationship between material structure and its adsorption property for dyes, the points that should be paid attention to in the construction of white-light emitting materials as well as the potential adsorption mechanism for dyes and rare earth ions are deeply discussed.

2,4,6-Trinitrophenol (TNP), compared with the other nitro compounds, not only has a strong electron-withdrawing ability, but also has a strong light absorption capacity at a large excitation wavelength. Therefore, the fluorescence material with a large excitation wavelength might be a potential probe for the detection of TNP. Here, by employing the in situ acylation of organic acid with N2H4, two acylhydrazinotetracarboxylate-based coordination polymers [Cd2(HL1)(phen)2(H2O)]·4.5H2O (H5L1 ​= ​5,5′-(1,4-dioxo-1,2,3,4-tetrahydrophthalazine-6,7-diyl)bis(oxy)diisophthalic acid; phen ​= ​1,10-phenanthroline) 1 and [Mn2(HL1)(phen)2]·7H2O 2 were obtained. Phen is used to prevent the formation of a dense network and many hydrogen bonds, which might quench any emission of material. As predicted, 1 only possesses a 1-D broad-ribbon structure, whereas 2 just has a 1-D tube-like structure. And both are found to emit the yellow light, corresponding to the charge transfer from benzene ring moiety to acylhydrazine ring moiety. It means that the acylation changes thoroughly the photoluminescence behavior of organic ligand. Based on their good photoluminescence properties, the sensing ability of both towards TNP was investigated. It is turned out that 1 is not an ideal sensor, even though it can also sense TNP. However, 2 can be considered as an excellent sensor for the detection of TNP. The emission of 2 is almost completely quenched by TNP, while only 20% quenching is observed for the potential interfering analyte 4-nitroaniline (4-NA). The related sensing mechanism is discussed in details.

By utilizing the hydrothermal in situ acylation of organic acids with N2H4, three acylhydrazidate-coordinated compounds [Mn(L1)2(H2O)2] (L1 = 2,3-quinolinedicarboxylhydrazidate; HL1 = 2,3-dihydropyridazino[4,5-b] quinoline-1,4-dione) 1, [Mn2(ox)(L2)2(H2O)6]·2H2O (L2 = benzimidazolate-5,6-dicarboxylhydrazide; HL2 = 6,7-dihydro-1H-imidazo[4,5-g]phthalazine-5,8-dione; ox = oxalate) 2, and [Cd(HL3)(bpy)] (L3 = 4,5-di(3′-carboxylphenyl)phthalhydrazidate; H3L3 = 6,7-dihydro-1H-imidazo[4,5-g]phthalazine-5,8-dione; bpy = 2,2′-bipyridine) 3, as well as two acylhydrazide molecules L4 (L4 = oxepino[2,3,4-de:7,6,5-d′e′]diphthalazine-4,10(5H,9H)-dione) 4 and L5 (L5 = 4,5-dibromophthalhydrazide; L5 = 6,7-dibromo-2,3-dihydrophthalazine-1,4-dione) 5 were obtained. X-ray single-crystal diffraction analysis reveals that (i) 1 only possesses a mononuclear structure, but it self-assembles into a 2-D supramolecular network via the Nhydrazine H ⋯ Nhydrazine and Ow H ⋯ Ohydroxylimino interactions; (ii) 2 exhibits a dinuclear structure. Ox acts as the linker, while L2 just serves as a terminal ligand; (iii) In 3, L3 acts as a 3-connected node to propagate the 7-coordinated Cd2 + centers into a 1-D double-chain structure; (iv) 4 is a special acylhydrazide molecule. Two OH groups for the intermediates 3,3′-biphthalhydrazide further lose one water molecule to form 4; (v) 5 is a common monoacylhydrazide molecule. Via the Nhydrazine H ⋯ Ohydrazine, Ohydroxylimino H ⋯ Oacylamino and the π ⋯ π interactions, it self-assembles into a 2-D supramolecular network. The photoluminescence analysis reveals that 4 emits light with the maxima at 510 nm.

Under hydro(solvo)thermal conditions, the reactions between transition-metal salts and tetracarboxylic acid molecules, with the assistance of organic base molecules, created three new coordination polymers, namely [H2(bpp)]2[Zn2(sph)2]·H2O (sph = 4,4′-sulfonediphthalate, bpp = 1,3-bis(piperidyl)propane) 1, [H2(bpp)]2[Ni2(oph)2(H2O)2]·2H2O (oph = 4,4′-oxydiphthalate) 2 and [H2(bpe)]2[Ni(Hfph)2(bpe)] (bpe = 1,2-bis(pyridyl)ethylene; fph = 4,4′-(hexafluoroisopropylidene)diphthalate) 3. X-ray single-crystal diffraction analysis reveals that (i) in 1, the diprotonated bpp molecule acts as a templating agent. The quadruple-bridged sph molecules propagate the tetrahedral Zn2+ ions into a 2-D layer network in 1, where two types of circle loops are found; (ii) in 2, the bpp molecule is also diprotonated. The triple-bridged oph molecules extend the octahedrally coordinated Ni2+ ions into a 2-D layer network, in which a carboxylate-bridged Ni2+ chain is observed; (iii) in 3, the non-protonated bpe molecules link the Ni2+ ions into a 1-D linear chain. The diprotonated bpe molecule acts as the countercation, while the fph molecule serves as the chelating ligand, existing in the form of Hfph3−; and (iv) the 2-D layers for 1 and 2 can both be simplified as a (4,4) net. The photoluminescence analysis reveals that 1 emits blue light with a maximum at 415 nm upon excitation at 355 nm. A magnetic property investigation indicates that antiferromagnetic interactions exist between the Ni2+ ions in 2.

A new 3-D Zn(2+) coordination polymer (CP) [(CH3)2NH2]3[Zn6(ox)4.5(trz)6]⋅4H2O (ox=oxalate; trz=1,2,4-triazolate) 1 was obtained by a simple solvothermal self-assembly. The crystal structural analysis demonstrates that the trz molecules link the Zn(2+) ions into a two-dimensional (2-D) layer network, which is based on the trinuclear Zn3(trz)6 clusters. The ox molecules serve as the linkers to propagate the 2-D layers into a three-dimensional (3-D) network of 1. The thermogravimetry (TG) behavior, photoluminescence property, and the sensing ability of 1 are investigated. The sensing experiment on nitrobenzene (NB) reveals that 1 can serve as a fluorescence probe to detect NB at the ppm concentration.

A novel two-dimensional (2-D) solid material [Ni(en)2]2{SiMoVI8VIV6O42[Ni(en)2]2}·4H2O 1 (en = ethylenediamine) has been hydrothermally synthesized and structurally characterized by IR, UV–Vis spectrum, elemental analysis, XRD, ESR, XPS, X-ray diffraction analysis, magnetic property analysis and electrochemistry study. Single-crystal X-ray analysis reveals that the 2-D framework of compound 1 is based on Mo/V/Si bicapped Keggin clusters interconnected by nickel ethylenediamine complexes. Magnetic susceptibility measurement indicates that compound 1 exhibits antiferromagnetic coupling interactions.

Three new compounds based on arsenic–vanadium clusters {[Cu(im)2]4[H2As8V14O42(SO4)]}·H2O (1) and [Cu(phen)(im)]3[Cu(phen)2][As8V14O42(H2O)] (2, 3) (im = imidazole, phen = phenanthroline) have been synthesized and characterized by IR, UV–Vis, XRD, TG analysis, elemental analysis, single-crystal X-ray diffraction analysis and catalytic properties. Crystal analysis reveals that compound 1 shows an unprecedented 3-D twofold interpenetrating network structure with each of the two interpenetrating frameworks exhibiting a novel diamondoid framework structure based on POMs and transition metal complexes. Compounds 2 and 3 are based on identical polyanions and identical transition metal complexes. However, the two compounds are not isomorphous and isostructural with each other. That is to say, the two compounds have an identical chemical formula with different structures: the two are polymorphs of each other. In addition, catalytic properties of compounds 1–3 have been studied.

With the assistance of various organic bases, hydrothermal reactions of transition-metal salts with a kind of tripodal tricarboxylic acid, 3,5-bis((4′-carboxylbenzyl)oxy)benzoic acid (H3(bcbob)), at different pH values were carried out, producing four new bcbob-based 3-D coordination polymers: [Ni2(Hbcbob)2(bimb)2] (bimb = 1,4-bis(imidazol-1-yl-methyl)benzene) 1, [Zn3(bcbob)2(bpe)2] (bpe = 1,2-bis(4-pyridyl)ethene) 2, [H2(bpp)][Mn2(bcbob)2] (bpp = 1,2-bis(4-piperidyl)propane) 3, and [Cd2(OH)(bcbob)(bpe)0.5]·H2O 4. X-ray single-crystal diffraction analysis reveals that (i) in 1, the bcbob molecules link the Ni2+ centers into a 2-D layer with a (6,3) net, and then the bimb molecule serves as the pillar linker; (ii) in 2, the bpe molecule is only used to stabilize the 3-D network. The bcbob molecules link two types of tetrahedral Zn2+ ions into a 3-D network with a pcu topology; and (iii) the 3-D networks of 3 and 4 are both built up from carboxylate-bridged rod-shaped secondary building units (SBUs) by the bcbob molecules (acting as a 3-connected node), and three types of 1-D channels are observed. However, since the rod-shaped SBUs contain different structures, the side walls of the channels exhibit different arrangements. In particular, the side wall in 4 adopts a helical arrangement. The bcbob molecules act as the side wall of the channel. In 3, the H2(bpp)2+ molecules occupy the space of the largest channels, while in 4, the bpe molecules occlude one type of smaller channels by coordinating to the Cd2+ ions on the side wall. The photoluminescence analysis reveals that 2 and 4 can serve as chemosensors to detect the ppm-grade nitrobenzene (250 ppm for 2, 150 ppm for 4).

Seven novel compounds based on arsenic–vanadium clusters [Ni(im)(2,2′-bpy)]2[Ni(im)2]2[Ni(2,2′-bpy)][As8V14O42(H2O)] (1), [Ni(2,2′-bpy)3][Ni(im)2]0.5[Ni(2,2′-bpy)(im)][As8V14O42(H2O)] (1a), [Ni(2,2′-bpy)(phen)][Ni(2,2′-bpy)2][As8V14O42(H2O)]·H2O (2) and [Ni(2,2′-biim)(2,2′-bpy)2]2[As8V14O42(H2O)]·6H2O (3), [Cd(2,2′-bpy)(phen)2]2[As8V14O42(H2O)]·4H2O (4), [Cd4(phen)4(ox)(H2O)6][As6V15O42(H2O)]·2H2O (5) and [Co2(phen)4(ox)][H2As8V14O42(H2O)]·(apy)2·2H2O (6) (Him = imidazole, phen = 1,10-phenanthroline, 2,2′-biim = 2,2′-biimidazole, apy = 2-aminopyridine) have been synthesized and characterized by IR, UV-vis, XRD, TG, CD spectrum, elemental analysis and single-crystal X-ray diffraction analysis. Crystal analysis reveals that compound 1 is the first example of a hybrid compound constructed from polyoxometalates and transition metal mixed-organic-ligand complexes of negatively charged nitrogen-containing ligands and neutral nitrogen-containing ligands. Compound 1a is the first example of a POM supported TMC which is formed via arsenic–metal contact. Compound 2 is a chiral compound which exhibits a novel 1-D triple-chain structure constructed from [As8V14O42(H2O)]4− clusters, a type of chiral transition metal mixed-organic-ligand complex and a type of chiral transition metal complex. Compounds 3 and 4 are supramolecular compounds which are formed by [As8V14O42(H2O)]4− clusters and transition metal mixed-organic-ligand complexes, respectively. Compounds 5 and 6 are constructed from arsenic–vanadium clusters and transition metal complexes of nitrogen-containing ligands and oxalic groups. The catalytic properties of compounds 1 and 2–6 have been investigated and we found that the transition metal mixed-organic-ligand complexes have dramatic influences on the catalytic properties of catalysts.

Five new organic-inorganic hybrid compounds based on different polyoxoanions [HxGeW12O40](n-) or [H3As2W18O62](3-) (x = 0, 2; n = 4, 2), namely [Cu3(2,2'-bpy)3(inic)(OH)(H2O)][GeW12O40]·1.5H2O (1), [Cu2(phen)2(μ2-Cl)2(inic)]2[H2GeW12O40]·2H2O (2), [Cu2(phen)2(μ2-Cl)Cl(nic)]2[H2GeW12O40] (3), [Cu2(2,2'-bpy)2(hnic)Cl]2[H2GeW12O40] (4), [Cu(phen)(inic)H2O][Cu2(phen)2(inic)2(H2O)][H3As2W18O62]·3H2O (5) (inic = isonicotinic acid, nic = nicotinic acid, hnic = 2-hydroxy-nicotinic acid, 2,2'-bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline), have been synthesized and characterized by IR, UV-Vis, XRD, cyclic voltammetric measurements and single crystal X-ray diffraction analysis. Single crystal X-ray analysis reveals that compound 1 is isomorphous and isostructural with a compound reported by us recently, the main difference between the two is the heteroatom of the polyoxoanions in the two compounds. Compound 2 is a supramolecular structure constructed from polyoxoanions and transition metal mixed-organic-ligand complexes. Compound 3 is a novel polyoxoanion bi-supported transition metal mixed-organic-ligand complex. Compound 4 is a 1-D chain structure constructed from polyoxoanions and transition metal mixed-organic-ligand complexes. The photodegradation properties of compounds 1-5 have been analyzed.

Five new vanadoantimonates [Cd(en)3]3[Sb6V15O42(H2O)]·8H2O (1), [Ni(en)3]2[H2Sb6V15O42(H2O)]·5H2O (2), [Co(en)3]2[H2Sb6V15O42(H2O)]·5H2O (3), [H4Sb8V14O42(H2O)]·5H2O (4) and [Co(enMe)3]2[Sb8V14O42(H2O)]·4H2O (5) (en = ethylenediamine, enMe = 1,2-propanediamine) have been obtained under hydrothermal conditions and characterized by IR, UV-Vis, XRD, ESR and CD spectroscopy. Compound 1 is a chiral compound constructed from [Sb6V15O42(H2O)]6− (Sb6V15) and [Cd(en)3]2+. Compounds 2 and 3 are isostructural and isomorphous. Both compounds are chiral, each of which contains a 2-D inorganic layer formed by [H2Sb6V15O42(H2O)]4−via V–O⋯Sb contacts. Compound 4 contains a 2-D inorganic layer formed by [H4Sb8V14O42(H2O)], of which [H4Sb8V14O42(H2O)] is directed by both V–O⋯Sb and Sb–O⋯Sb interactions. Compound 5 contains a 1-D zigzag chain structure formed by [Sb8V14O42(H2O)]4− (Sb8V14) via Sb–O⋯Sb contacts.

Under hydro(solvo)thermal conditions, four organic bidentate bridging N,N′-donor ligands 1,3-bis(2-methylimidazol-1-yl)propane (L1), 4,4′-di(1H-imidazol-1-yl)-1,1′-biphenyl (L2), 1,2-bis(2-methyl-1H-imidazol-1-ylmethyl)benzene (L3) and 5,6,7,8-tetrahydroquinoxaline (L4) were employed to react with CuBr/CuI, generating four 2-D layered copper(I)–polymer coordination polymer materials [Cu2Br2(L1)] 1, [CuI(L2)] 2, [CuI(L3)] 3 and [CuI(L4)0.5] 4. In 1–4, different Cu–X motifs are found: a cubic Cu4Br4 core in 1; a castellated Cu–I single chain in 2; a rhombic Cu2I2 core in 3; and a staircase-like Cu–I double chain in 4. The 2-D layer networks of 1–3 can all be simplified into a simple 44 topology (planar for 1 and 3; wave-like for 2), while the 2-D layer network of 4 has a 63 topology. The photoluminescence behaviors of 1–4 under a UV lamp suggest that 1 and 2 possess fluorescence thermochromism properties. Under the UV lamp, with the decrease in temperature, (i) 1 exhibits a yellow-to-red emission; (ii) 2 exhibits a yellow-to-green emission; (iii) 3 always emits green light; and (iv) 4 never emits light. These are further confirmed by their emission spectra. From 297 K to 77 K, the emission of 1 exhibits a large red shift from 561 nm to 623 nm; the emission of 2 exhibits a large blue shift from 571 nm to 515 nm; only a minor red shift is observed for the emission of 3; and no peaks appear in the emission spectra of 4. The crystal data of 1 and 2 at different temperatures have been collected for revealing the origination of their fluorescence thermochromism properties. Based on the above investigations, the effect of the rigidity/flexibility of the organic ligand on the fluorescence thermochromism properties of copper(I)–polymer coordination polymer materials is discussed. The quantum yields at 297 K and the photoluminescence lifetimes at 297 K and 77 K for 1–3 were also measured for better understanding their photoluminescence properties.

The quinoline-monoacylhydrazidate-coordinated transition-metal compound Cd(QLH)2(H2O)2 (1) (QLH = 2,3-quinoline dicarboxylhydrazidate) was obtained by the hydrothermal in situ acylation reaction between 2,3-quinoline dicarboxylic acid and hydrazine hydrate. X-ray single-crystal diffraction analysis reveals that compound 1 features a mononuclear structure. Through the O–H···O and C–H···O hydrogen bonds between the neighboring molecules, the mononuclear units of 1 aggregate together into a 3D supramolecular network, which is stabilized by offset face-to-face π···π interactions. Compound 1 was characterized by IR spectroscopy, elemental analysis, TGA, and photoluminescence analysis, and it shows good photoluminescent property in the solid state at room temperature. In order to understand the emission mechanism, DFT calculations were carried out on the excited electronic states of compound 1.

Three compounds, [AsMo8V6O42][Cu(2,2ʹ-bpy)2]2[Cu(2,2ʹ-bpy)]·4H2O (1), [PMo8V6O42][Cu(2,2ʹ-bpy)2]2[Cu(2,2ʹ-bpy)]·3H2O (2) and [PMo8V6O42][Cu(2,2ʹ-bpy)2]2[Cu(2,2ʹ-bpy)]·3.5H2O (3), have been synthesized under hydrothermal conditions and characterized by IR, UV–vis, XRD, TG, elemental analysis, and X-ray diffraction analysis. Single-crystal X-ray structure analysis reveals that 1 and 2 are isostructural and isomorphous, whereas 2 and 3 are polymorphs. Polymorphs of 1 have not been synthesized yet. The mixed-valent transition metal ion in 1–3 has been further confirmed by TG analyses. Catalytic properties of 1 and 2 have also been studied.

5-(3',4'-Dicarboxylphenoxy)isophthalic acid (H4 L1) and 5-(2',3'-dicarboxylphenoxy)isophthalic acid (H4 L2) were reacted with Cd2+ salt with/without the assistance of N-donor ligands, creating five 3D CdII coordination polymers [Cd2 (L1)(H2 O)5 ]⋅H2 O (1), [Cd2 (L1)(bpe)(H2 O)] (bpe=1,2-bis(4-pyridyl)ethene; 2), [Cd2 (L1)(bpa)(H2 O)] (bpa=1,2-bis(4-pyridyl)ethane; 3), [Cd2 (L1)(bpp)] (bpp=1,3-bis(4-pyridyl)propane; 4), and [Cd2 (L2)(bpp)2 (H2 O)2 ]⋅H2 O (5). Crystal-structure analysis reveals 1) in 1, phthalate moieties for L1 link Cd1 centers into a 1D slightly helical chain; Cd2 centers act as bridges, linking 1D helical chains into a 3D network with a (3,5)-connected topology; 2) in 2-4, although Cd2+ centers were further modified by the introduction of organic bases, L1 molecules still link Cd2+ centers into 3D networks, which can all be simplified as pcu topology; 3) in 2-4, phthalate moieties first link Cd2+ centers into an oligomer, in which carboxylate-bridged discrete or rod-shaped secondary building units (SBUs) are found (tetranuclear SBU in 2 and 3, rod-shaped SBU in 4); and 4) in 5, L2 molecules link Cd2+ centers into a 2D (4,4) net; introduced bpp molecules serve as pillar linkers, extending Cd2+ -L2 layers into a 3D network of 5. The sensing abilities of 2-5 for nitrobenzene (NB) were investigated. Results revealed that they could all serve as fluorescence probes to sense NB at ppm concentrations.

Two supramolecular compounds [Cu(imz)2][Cu(phen)(imz)]2{[Cu(phen)]2[PMo6 VIMo6 VV2 IVO42]}(1) and [Co2(2,2′-bpy)4(C2O4)][Co(2,2′-bpy)3][PMo7 VIMo5 VV2 IVO42](2,2′-bpy)0.5·H2O(2)(phen=1,10′-phenanthroline, imz= imidazole, 2,2′-bpy=2.2′-bipyridine) have been synthesized hydrothermally and characterized by elemental analyses, infrared spectrum, UV-Vis, X-ray photoelectron spectroscopy(XPS), electron spin resonance(ESR) spectra, thermogravimetry analyses and single crystal X-ray diffraction analyses. Single-crystal X-ray diffraction analyses revealed that both the compounds represent the examples of compounds based on the bi-capped Keggin polyoxoanion {PMo12V2O42} and transition metal mixed-organic-ligand coordination complexes. Compound 1 consists of bi-capped Keggin polyoxoanion [PMo12V2O42]5− supported copper coordination groups, which are further inter-connected with two types of copper complex fragments forming a 3D supramolecular framework via π⋯π stacking, C-H⋯O and N-H⋯O hydrothermal bonding interactions. Compound 2 is a new hybrid consisted of polyoxoanion [PMo12V2O42]4−, [Co2(2,2′-bpy)4(C2O4)]2+ and [Co(2,2′-bpy)3]2+. There are no direct interactions in compound 2, but the polyoxoanions together with two different cobalt complex groups construct a 3D supramolecular network through C-H⋯O hydrogen bonding interactions.

Having been designed via bottom-up strategy based on density functional theory(DFT) calculations, a complex of ytterbium(II) with pyridyl amido ligand was successfully synthesized by one-pot reaction in laboratory. DFT calculation shows that pyridyl amido ligands can stabilize the complex via steric and electron effect. This success in integrating computation with synthesis will inspire more explorations in the development of a new complex in lanthanide chemistry.