Li-Ping Xue

Bis(pyridyl) ancillary ligands modulated uninodal 4-, 5- and 6-connected Cd(II) coordination polymers based on 3,4-thiophenedicarboxylate linker

Three new cadmium coordination polymers with formula {[Cd(tdc)(bpe)(H2O)]·2H2O}n (1), [Cd(tdc)(bpp)]n (2), and [Cd(Htdc)2(bipy)]n (3) have been synthesized by hydrothermal reactions of cadmium acetate dihydrate and 3,4-thiophenedicarboxylic acid (H2tdc) in the presence of the corresponding bis(pyridyl) ancillary ligands, namely, 1,2-bis(4-pyridyl)ethylene (bpe), 1,3-bis(4-pyridyl)propane (bpp), and 4,4′-bipyridine (bipy), respectively. Structural analyses reveal that complex 1 exhibits a scarcely reported 4-connected 3D framework with irl (42·63·8) topology, whereas complex 2 features an unprecedented 5-connected 2D framework with (44·53·63) topology. Complex 3 displays a homochiral 3D framework, which can be rationalized as a new 6-connected (510·64·7) topology. The results indicate that H2tdc and bis(pyridyl) ancillary ligands are effective building blocks in constructing polymers with diverse architectures. Solid-state properties for these crystalline materials, such as thermal stability, powder X-ray diffraction have been investigated. Moreover, photoluminescence behaviors of complexes 1–2 are also investigated.

2D lanthanide–organic frameworks constructed from lanthanide acetate skeletons and benzotriazole-5-carboxylic acid connectors: synthesis, structure, luminescence and magnetic properties

Five new two-dimensional (2D) lanthanide–organic frameworks with formula [Ln(Hbtca)2(OAc)(H2O)]n (Ln = Sm 1, Eu 2, Gd 3, Tb 4, Er 5; H2btca = benzotriazole-5-carboxylic acid) have been synthesized by the solvothermal reactions of H2btca and corresponding lanthanide nitrate. X-ray diffraction analysis reveals that these complexes are isostructural and each exhibits a 2D square-grid-type network constructed via Ln2(μ-CH3COO)2 dinuclear secondary building units (SBUs), in which Hbtca− anions adopt two different resonance structures. The 2D networks are further linked by hydrogen-bonding to form a three-dimensional supramolecular network. Compounds 2 and 4 exhibit strong luminescence emission in the visible region. Magnetic susceptibility of 3 reveals weak antiferromagnetic interactions between the Gd(III) ions. Furthermore, infrared (IR), thermogravimetric analysis (TGA), elemental analyses (EA), and powder X-ray diffraction (PXRD) properties of these compounds are also investigated.

Hydrogen bonded-extended lanthanide coordination polymers decorated with 2,3-thiophenedicarboxylate and oxalate: synthesis, structures, and properties

Five new lanthanide coordination polymers, {[Ln2(tdc)2(C2O4)(H2O)4]·(H2O)}n (Ln = Nd (1), Eu (2), Gd (3), Tb (4), Ho (5); H2tdc = 2,3-thiophenedicarboxylic acid), have been synthesized by hydrothermal reactions of H2tdc, sodium oxalate and the corresponding lanthanide nitrate. Crystallographic data show that 1–5 are isomorphous and crystallize in the monoclinic space group C2/c. Each complex contains an oxalate-linked two-dimensional (2D) sql layer structure based on dinuclear [Ln2(tdc)2(H2O)4] building units. Then the 2D layers are further extended by intermolecule hydrogen bonds to form a three-dimensional (3D) supramolecular network with sxb topology. Compounds 2 and 4 display luminescence emission in the visible region, while compounds 1 and 5 exhibit luminescence emission in the near IR region. Dehydrated 1 as a Lewis acid catalyst exhibits high catalytic activity and stability in acetalization reaction under mild conditions. Furthermore, infrared, thermogravimetric analysis, elemental analyses, and powder X-ray diffraction properties of these compounds are also studied.

Three-dimensional pillared layered supramolecular networks comprising polymeric layers and tetrameric {H2O}4 pillars

Three three-dimensional (3D) supramolecular lanthanide complexes, {[Ln2(tdc)3(H2O)](H2O)2}n (Ln = La 1, Ce 2, Pr 3; H2tdc = 3,4-thiophenedicarboxylic acid), have been synthesized by hydrothermal reactions of H2tdc and the corresponding lanthanide nitrate. Crystallographic data show that 1–3 are isomorphous and crystallize in the triclinic P space group. Each of them exhibits an interesting pillared layered supramolecular network comprising polymeric layers and up-up-down-down (uudd) cyclic tetrameric water pillars. Furthermore, in these compounds, tdc2− anions unprecedentedly display three coordination modes in the polymeric layers. Elemental analyses (EA), infrared (IR) spectroscopy, powder X-ray diffraction (PXRD), and thermogravimetric analysis (TGA) were also employed, and the materials exhibit a reversible de- and rehydration behavior.

In Situ Generation of Supported Nano-Palladium on La2O3: An Efficient and Recyclable Catalyst for Heck Cross-Coupling Reaction

The Pd/La2O3 catalyst was simply prepared from readily available reagents. The catalyst exhibited high activities in the Heck cross-coupling reaction and could be reused for several times without activity loss. In addition, the catalyst was characterized by the transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), and inductively coupled plasma (ICP). Supplemental materials are available for this article. Go to the publishers online edition of Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry to view the supplemental file.

Synthesis, Characterization, and Photoluminescent of A New Cadmium(II) Coordination Polymer With 4-Connected irl Topology

A new cadmium(II) coordination polymer with 3,4-thiophe- nedicarboxylic acid (H2tdc) and 1,2-bis(4-pyridyl)ethane (bpa) has been prepared by hydrothermal synthesis and characterized by single-crystal X-ray diffraction, IR, and EA. Compound {[Cd(tdc)(bpa)(H2O)]·2H2O}n (1), is monoclinic, space group C2/c with a = 19.222(9), b = 16.433(8), c = 13.168(6) Å, β = 96.429(2)°, V = 4133 (3) Å3, Z = 8, Mr = 520.82, Dc = 1.674 g/cm3, F(000) = 2096, and μ = 1.20 cm−1. The final refinement gave R = 0.0250 and wR = 0.0657 for 3325 reflections with I > 2σ(I). X-ray diffraction analysis reveals that the title compound exhibits a 4-connected three-dimensional framework with irl topology. Furthermore, the luminescent property of 1 is investigated, which demonstrates that the title compound may be a good candidate as a photoactive material.

A Three-Dimensional Heterometallic CuII–GdIII Coordination Polymer: Hydrothermal Synthesis, Crystal Structure, Thermal and Magnetic Properties

A new 3d-4f coordination polymer, {[Gd2Cu(PDC)2(SO4)2 (H2O)6]·2H2O}n (I), has been synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. The X-ray diffraction analysis reveals that I crystallizes in triclinic system, space group P – 1. Unit cell parameters for I are a = 6.354(2), b = 10.027(2), c = 10.244(3) Å, α = 95.054(2)°, β = 95.098(1)°, γ = 99.818(1)°, V = 637.0(4) Å3, Z = 1. The compound is a three-dimensional network structure in which infinite lanthanide-carboxylate chains are linked by [Cu(SO4)2]2− metalloligands to form a mixed-metal coordination network. The magnetic measurements reveal antiferromagnetic behaviors of the compound.