•Three Ag(I)-organic frameworks, [Ag5(pydc)2(CN)]n, {[Ag4(pydc)2]CH3CN}n, and [Ag(4,4′-bpy)NO3]n were synthesized.•The Ag-organics embedded gels were prepared for micro-extraction of PBDEs.•Performance of Ag(I)-organic frameworks for the determination of soil PBDEs was studied.•Variables influencing the extraction efficiency of soil PBDEs were determined.•The use of Ag(I)-organic frameworks for micro-extraction of PBDEs was validated.Three Ag(I)-organic frameworks, [Ag5(pydc)2(CN)]n, {[Ag4(pydc)2]CH3CN}n, and [Ag(4,4′-bpy)NO3]n, were synthesized and embedded into silica gels to form metal-organic-framework (MOF)-embedded gels for the microextraction of polybrominated diphenyl ethers (PBDEs) in soils. Despite the great differences in the structures of the organic ligands, all three Ag(I)-organic frameworks were found to effectively accumulate and concentrate PBDEs from sample solutions prepared with contaminated soil and purified water, indicating the important roles of Ag centers in PBDE extraction. Under the optimal experimental conditions (MOF mass, water volume, temperature, extraction time, and back-extraction time) for PBDE extraction from sample solutions, the detection limits of seven PBDEs (BDE-28, 47, 99, 100, 153, 154, and 183) ranged from 0.01 to 2.6 ng g−1 for [Ag5(pydc)2(CN)]n, 0.20–0.64 ng g−1 for {[Ag4(pydc)2]CH3CN}n, and 0.60–3.08 ng g−1 for [Ag(4,4′-bpy)NO3]n. The reproducibilities of the three methods were all satisfactory with relative standard deviations (RSDs) in the range of 2.2–9.6%, 5.3–10.4%, and 6.9–9.4% for [Ag5(pydc)2(CN)]n, {[Ag4(pydc)2]CH3CN}n, and [Ag(4,4′-bpy)NO3]n, respectively. The use of Ag(I)-organic frameworks for the microextraction of PBDEs was validated using both certified reference soils and field-contaminated soils, and the proposed methods are recommended as rapid and environmentally friendly alternatives for the extraction and determination of PBDEs in soils.

Four porous coordination networks (PCNs), {[Zn3O(H2O)3(adc)3]·2(C2H6NH2)·2(DMF)·3(H2O)}n (PCN-131), Zn2(DMA)2(adc)2]·2(DMA)}n (PCN-132), {[Zn3O(DMF)(adc)3(4,4′-bpy)]·2(C2H6NH2)·S}n (PCN-131′), and {[Zn(adc)(4,4′-bpy)0.5]·S}n (PCN-132′), have been synthesized by the assembly of anthrancene-9,10-dicarboxylic acid (H2adc) with Zn(II) under different reaction conditions, including modifications of reactant ratio, acidity variations, and the use of a secondary ligand. Single-crystal X-ray diffraction studies reveal that PCN-131, obtained from the dimethylformamide (DMF) solution under acid condition, has a three-dimentional (3D) framework structure with one-dimensional (1D) honeycomb channels. PCN-132 isolated from dimethylacetamide (DMA) solution without adding acid in synthesis is a two-dimensional (2D) layer compound. By employing 4,4′-bipyridyl (4,4′-bpy) as a secondary ligand, PCN-131′ and PCN-132′ were synchronously synthesized as a mixture outcome with more PCN-131′ than PCN-132′. In PCN-131′, 4,4′-bpy acting as a secondary ligand is arranged inside the honeycomb channel of the 3D PCN-131, resulting in an effective improvement of thermal stability of the network, while in PCN-132′, 4,4′-bpy ligands link 2D layers of PCN-132 to form a pillared-layer 3D framework. Gas adsorption has been performed for selected materials. The results show that the framework of PCN-131 is thermally unstable after removing the solvent molecules coordinated to their metal sites. While PCN-131′ is stable for gas uptake, with an evaluated Langmuir surface area of 199.04 m2 g–1, it shows a selective adsorption of CO2 over CH4.

The reaction of the organic ligand, 4-quinolineacarboxylate (L) with Pr(ClO4)3·6H2O and Dy(ClO4)3·6H2O, leads to the formation of two novel complexes [Pr2(L)6(H2O)4]2H2O 1 and [Dy2(L)6(H2O)4]2H2O 2, which have been characterized by elemental analysis, IR and single-crystal X-ray diffraction analysis (monoclinic system, space group P2(1)/n, with a = 11.805(2), b = 16.645(3), c = 15.367(3) Å, β = 106.78(3)°, V = 2891.1(10) Å3, Z = 4 for 1, monoclinic system, space group P2(1)/n, with a = 11.629(2), b = 16.478(3), c = 5.336(3) Å, β = 105.83°, V = 2827.4(10) Å3, Z = 4). The two isostructure complexes are binuclear and possess an inversion center which is at the midpoint of the linkage of two symmetrical La(III) centers. In two complexes, each metal center adopts nine-coordinated mode coordinated by nine O atoms from two H2O molecules and three carboxyls of three ligands, and L displays three different coordination modes. Hydrogen bonds join the binuclear complexes into 3D networks.

A series of lanthanide binuclear complexes, [Ln2(L)6(H2O)4]·2H2O (Ln=Sm(III), Gd(III), Er(III), Yb(III), HL=4-quinolineacarboxylic acid, were synthesized by reactions of corresponding rare earth salts with 4-quinolineacarboxylic acid at room temperature and were characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. X-ray diffraction analyses showed that they exhibited the same binuclear architecture and crystallized in monoclinic system and P21/c space group. In four complexes, each metal center adopted nine-coordinated mode coordinated by nine O atoms from two H2O molecules and three carboxyls of three ligands, and HL showed three different coordination modes. The variable-temperature magnetic susceptibility showed that complex [Gd2(L)6(H2O)4]·2H2O performed very weak antiferromagnetic property at low temperature and exchange was almost paramagnetic at high temperature. Complexes [Er2(L)6(H2O)4]·2H2O and [Yb2(L)6(H2O)4]·2H2O performed dominating antiferromagnetic coupling.

The reaction of the dithioether ligand, 2,3-bis(pyrimidine-2-thiomethyl)quinoxaline (L) with AgNO3, leads to the formation of a novel complex {[Ag5(L)2(NO3)4](NO3)(CHCl3)2}n 1, which has been characterized by single-crystal X-ray diffraction analysis: monoclinic, space group C2/c, with a = 34.741(7), b = 9.930(2), c = 17.004(4) Å, β = 106.497(6)° and V = 5625(2) Å3.Complex 1 consists of 2D {[Ag5(L)2(NO3)4]+}n cations, uncoordinated \( {\text{NO}}^{ - }_{{\text{3}}} \) anions and CHCl3 solvent molecules. In 1, there exist three crystallographic independent AgI centers, which adopt different coordination geometries. There exist π–π stacking interactions in the complex and these weak interactions further stabilize the crystal structure in the solid state. The coordination feature of the ligand has been investigated by DFT calculations.Synthesis and Structure of a Silver(I) Complex {[Ag5(L)2(NO3)4](NO3)(CHCl3)2}n [L = 2,3-bis(pyrimidine-2-thiomethyl)quinoxaline]Chao-Yan Zhang, Qian Gao, Ya-Bo Xie*, and Jian-Bo Feng

A new dinuclear hydrated nickel(II) tartrate has been isolated and structurally characterized by single-crystal X-ray diffraction. The title compound formulated as [Ni4(C4H4O6)4(H2O)8](EtOH)0.5(H2O)10.25 (C17H55.5Ni4O42.75) crystallizes in monoclinic system, space group P2(1)/c with a = 13.684(5), b = 17.143(6), c = 18.586(6) Å, β = 96.638(6)°, V = 4331(3) Å3, Z = 4. The unit cell contains two crystallographic independent dimeric units of [Ni2(C4H4O6)2(H2O)4] without significant structural difference, half of menthol molecule and ten and a quarter packing water molecules. In each dimeric unit, one (R,R)-tartrato dianion chelates two Ni(II) ions by the use of two hydroxy oxygen and two carboxyl oxygen atoms as donor atoms, and another tartrato dianion chelates the same pair of Ni(II) cations in the same way. Each Ni(II) atom is six-coordinated by six O atoms from two tartrate units and two water molecules.

The reaction of the organic ligand, 5,6-dicyano-2,3-di(2-pyridyl)pyrazine (L) with AgClO4, leads to the formation of a novel complex {[Ag(L)(CH3CN)](ClO4)}n 1, which has been characterized by elemental analysis, IR and single-crystal X-ray diffraction analysis (monoclinic system, space group P2(1)/n, with a = 11.290(4), b = 12.660(5), c = 15.202(6) Å, β = 90.141(6)°, V = 13371(2) Å3 and Z = 4). The crystal structure of complex consists of polymeric chains of {[Ag(L)(CH3CN)]+}n cations and \({\text{ClO}}_{\text{4}}^{-}\) anions. In the cation of 1, each Ag(I) center is coordinated to four N atoms from two symmetry-equivalent L ligands and a CH3CN molecule. The adjacent two Ag(I) ions are linked by L ligands which adopt N3-coordinated bridging mode to form a zig-zag chain.Synthesis and Crystal Structure of a 1D Silver(I) Complex {[Ag (L)(CH3CN)](ClO4)}n [L = 5,6-dicyano-2,3-di(2-pyridyl)pyrazine]Qian Gao, Ya-Bo Xie*, Sha Chen, and Dao Wang