Lingling Gao

Two lanthanide metal–organic frameworks constructed from tris(4-carboxyphenyl)phosphane oxide with gas adsorption and magnetic properties

Two lanthanide metal–organic frameworks (LOFs), namely, {[Eu(L3−)(H2O)]·5H2O}n (1) and {[Dy(L3−) (H2O)]·2CH3CN}n (2), have been synthesized based on tris(4-carboxyphenyl)phosphane oxide (H3L) and further characterized by powder X-ray diffraction (PXRD), IR spectroscopy, elemental analyses and thermogravimetric (TG) analyses. X-ray diffraction analyses showed that complexes 1 and 2 are isostructural, and thus the structure and gas adsorption properties of complex 1 and the magnetic properties of 2 were described as a representative in detail. Complex 1 appears to have a 3D 6-connected {412·63} net based on binuclear {Eu2(COO)2} SBUs. Furthermore, the adsorption properties of 1 have been investigated using N2, H2, CO2 and CH4 gases. 1 has high CO2 uptake and exhibits highly selective adsorption of CO2 over CH4 at room temperature, which allows 1 to have a potential application in gas separation and purification. Finally, its full magnetic properties revealed that complex 2 displays antiferromagnetic coupling between DyIII ions and single-molecule magnet (SMM) behavior. According to the Arrhenius law, the anisotropy barrier (Ueff) and pre-exponential factor (τ0) were extracted by fitting of the alternating current data, giving the values of 53.5 K and 3.1 × 10−7 s, respectively. The afforded α parameter is less than 0.10, suggesting a single relaxation process.

Gas adsorption, magnetic properties and fluorescent sensing of four coordination polymers based on 1,3,5–Tris(4-carbonylphenyloxy)benzene and bis(imidazole) linkers

Four 3D novel coordination polymers (CPs), formulated as {[Co3(TCPB)2(bibp)2(dioxane)2.5(H2O)2]·(DMF)}n (1), {[Cd6(TCPB)4(bibp)4(dioxane)(H2O)2]·(dioxane)3·DMF·(H2O)0.5}n (2), {[Co1.5(TCPB)(bimb)0.5(DMF)(dioxane)]}n (3), and {[Zn1.5(TCPB)2(bimb)(DMF)(dioxane)2]·dioxane}n (4) (H3TCPB = 1,3,5-tris(4-carbonylphenyloxy)benzene, bibp = 4,4′-bis(imidazol-1-yl)biphenyl, and bimb = 1,4-bis(imidazol-1-ylmethyl)benzene), have been synthesized under solvothermal conditions and characterized by elemental analyses (EA), single-crystal X-ray diffraction analyses, X-ray powder diffraction analyses (PXRD), IR spectra, and thermogravimetric analyses (TGA). The structural analyses reveal that complex 1 can be simplified as a new 2-nodal (3,10)-{3·42}2 {34·410·514·614·72·8}-3,10T3 net, complex 2 has a 3D 2-nodal (3,8)-c network with the point symbols of {42·5}2{44·59·68·73·83·9}, complex 3 exhibits a novel 3D framework with the point symbol of {410·632·7·82}{43}2, and the structure of 4 is a (3,8)-connected {43}2{46·618·84}-tfz-d net. Furthermore, gas sorption behaviors of complex 1 for N2, H2, CH4, and CO2 have been comprehensively studied at varying temperatures: the results reveal that the adsorption capacity of 1 to N2 is stronger than those of other gases. Meanwhile, IAST calculations reveal that 1 exhibits excellent selective separation for CO2/CH4. Magnetic measurements indicate that both 1 and 3 have antiferromagnetic interactions within the trinuclear clusters. In addition, the fluorescent measurements showed that 2 and 4 exhibit highly selective and sensitive detection of Fe3+ and Cr3+ ions.

Synthesis, Structure, and Thermal Stability of Supramolecular Polymers with 1D Chain:

Two supramolecular polymers have been constructed from 2,3,5,6-tetrabromoterephthalic acid (H2TBTA) and 1,3-bis(4-pyridyl)propane (BPP) ligands in water-methanol dissolvant. Single-crystal X-ray and powder diffraction, IR spectroscopy, thermogravimetric analysis, and elemental analysis were employed to characterize all samples. Both of the complex compounds 1 and 2 belong to triclinic crystal system with P-1 space group. The crystal structures analysis indicates that the metal atom coordinated by two carboxylate groups from different TBTA ligands, two BPP, molecules and two H2O molecules formed a slightly distorted octahedral configuration. The compounds of 1 and 2 are 1D chains made with TBTA spacers, BPP molecules, and H2O molecules.

Crystal Structure and Thermal Behavior of Two New Supramolecular Complexes Templated with 1,2,4,5-Benzenetetracarboxylic Acid

Templated coordination polymers [Ni(H2O)4(bipy)](BTA)0.5·H2O (1) and [Co(H2O)4(bipy)](BTA)0.5·H2O (2) (bipy = 4,4′-Bipyridine, H4BTA = 1,2,4,5-Benzenetetracarboxylic Acid) were synthesized and characterized by single-crystal X-ray diffraction, powder diffraction, elemental analysis, IR, and thermogravimetric analysis. Both of complexes 1 and 2 are monoclinic crystal system, C2/c space group, and isostructural. The unit of the structure, the metal ion is coordinated by four water molecules and two bipy molecules, is a slightly distorted octahedral configuration, and the carboxyl group from BTA4- ion doesnt coordinate with the metal ion, the H-bonding interactions further connect the mononuclear molecules to generate a 3D supramolecular complex.