Guo-Li Zheng

Engineering white light-emitting Eu-doped ZnO urchins by biopolymer-assisted hydrothermal method

With the presence of biopolymer-sodium alginate as additive, Eu-doped ZnO (zinc oxide) urchins consisting of nanorods were synthesized through a hydrothermal route. X-ray diffraction pattern makes evident the absence of phase other than wurtzite ZnO. Upon excited by 325nm xenon laser, such nanostructured Eu-doped ZnO urchins emit white light, which originates from the luminescence of ZnO and the intra-4f transitions of Eu3+ ions. Besides acting as stabilizing agent, sodium alginate may also sensitize the Eu3+ ions in the nanostructures and facilitate the energy transfer from the host to Eu3+ ions.

Synthesis and optical properties of europium-complex-doped inorganic/organic hybrid materials built from oxo-hydroxo organotin nano building blocks.

Hybrid materials doped with novel europium complexes were synthesized using PMMA-co-Sn(12)Clusters (copolymers from oxohydroxo-organotin dimethacrylate and methylmethacrylate) as the matrix material. Two types of hybrid materials were obtained: the physically doped product, PMMA-co-Sn(12)Cluster/Eu(TTA)(3)phen, and the grafted product, PMMA-co-Sn(12)Cluster-co-[EuAA(TTA)(2)phen] (TTA = 2-thenoyltrifluoroacetone, phen = phenanthroline and AA = acrylic acid). The hybrid materials exhibited characteristic luminescence of the Eu(3+) ions, and also showed relative especial optical properties compared with samples just using PMMA as the matrix material. The PMMA-co-Sn(12)Cluster matrix exhibited a high physical doping quantity of [Eu(TTA)(3)phen], which can be attributed to the special structure of this kind of hybrid material. GPC (gel-permeation chromatography), TGA (thermogravimetric analysis), SEM, (1)H NMR, ICP (inductively coupled plasma), (119)Sn NMR, FTIR, and diffuse reflectance techniques were employed to characterize the structures and properties of these hybrid materials.

Entangled metal–organic frameworks modulated by N-donor ligands of different conformations

Based on the aromatic dicarboxylic acid and N-donor ligands with different conformations, four Zn(II) metal–organic frameworks, namely [Zn(mfda)(L1)] (1), [Zn2(mfda)2(L2)]·DMF·H2O (2), [Zn2(mfda)2(L3)(H2O)]·DMF (3) and [Zn2(mfda)2(L4)] (4) have been synthesized (mfda = 9,9- dimethylfluorene-2,7-dicarboxylate anion, L1 = 1,10-phenanthroline, L2 = 4,4′-bipyridine, L3 = 2,5-bis(4-pyridyl)-1,3,4-ocadiazole and L4 = 1,4-bis(imidazol-1-ylmethyl)benzene). Single-crystal X-ray diffraction has revealed that all compounds exhibit entangled structures. Compound 1 is composed of 1D zigzag chains that are entangled through the π–π stacking interactions to generate a three-fold interpenetrating diamond-like networks. 2 exhibits a two-fold interpenetrating (α-Po) net, which leaves 1D channels with high free volume. In 3, parallel mutual polythreadings of 2D layers are connected by hydrogen bonds into a self-penetrating framework with (44·610·7)(4·5·6)(46·52·616·73·9) topology. For 4, the interpenetrating 2D layers are connected into a self-interpenetrating net with (49·66) topology. The potential of N-donor ligands to produce interesting metal–organic frameworks is investigated. Luminescent studies show that 1–4 exhibit strong blue fluorescent emissions.

Near-infrared luminescent copolymerized hybrid materials built from tin nanoclusters and PMMA

Novel near-infrared (NIR) luminescent copolymerized hybrid materials were prepared by covalently grafting and physically doping Ln complexes (Ln = Er, Sm, Yb, and Nd) into a copolymer matrix built from nanobuilding blocks. The structures of the obtained hybrid materials were investigated by Fourier transform infrared (FTIR) spectra, nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), and thermogravimetric analysis (TGA). In the photoluminescence studies, the hybrid materials showed characteristic NIR luminescence of corresponding Ln(3+) ions through intramolecular energy transfer from ligands to Ln(3+) ions. Transparent films of these materials can be easily prepared through spin-coating on indium tin oxide (ITO) glasses taking advantage of the matrix nature.

The first ladder structure containing three different squares: the structure of barium 3-carboxy-4-hydroxybenzenesulfonate

Abstract Barium sulfonate [Ba2L4(H2O)10] (HL=3-carboxy-4-hydroxybenzenesulfonic acid) was obtained by the reaction of BaCl2·2H2O with NaL in water. X-ray structural analysis reveals that the compound has an undulating ladder structure which is the first ladder structure containing three different kinds of squares.

Guest inducing p-sulfonatocalix[4] arene into three-dimensional capsule architecture and a mixed A-B double layer framework

The reactions of sodium p-sulfonatocalix[4]arene (Na5L) and terbium/europium(III) chloride in the presence of pyrazine-N,N′-dioxide (PNNO) in aqueous solutions gave the crystalline complexes 1 and 2. Both structures contain molecular capsules of p-sulfonatocalix[4]arene with PNNO as guest molecules in the cavity of the calix[4]arenes. The molecular capsules are connected through sodium and terbium (or europium) centers forming a three-dimensional framework. The yellow crystals from an aqueous solution containing Na5L and lanthanum(III) chloride reacted with PNNO in aqueous solutions, giving crystals of complex 3. Compound 3 is a special mixed A–B type layer framework of p-sulfonatocalix[4]arene. The structure of compound 3 is made up of two types of bilayered p-sulfonatocalix[4]arene with opposite charges. The two types of layers (in presence or absence of sodium centers) alternate with each other forming a mixed A–B type double bi-layer framework which is uncommon in the layer structure of p-sulfonatocalix[4]arene.

Self-assembly of guest-induced calix[4]arene nanocapsules into three-dimensional molecular architecture

In the presence of NH3-Ag+-NH3, the calix[4]arenes can be induced into dimeric nanocapsules, which can be used as building units constructing a 3D molecular architecture with the appropriate secondary ligands and metal ions.

Synthesis and crystal structure of a novel cobalt phosphonate containing the [Co(H2O)6]2+ cation

Reaction of hexamethylenediaminetetrakis(methylphosphonic acid), [(H2O3PCH2)2N(CH2)6N(CH2PO3H2)2] (H8L), with cobalt nitrate affords a novel phosphonate, [Co(H2O)6][Co(H2O)4(H6L)2]·12H2O (1), and its structure was determined by X-ray diffraction analysis.

Ammonium 4-nitrophenylarsonate.

In the crystal structure of the title compound, (NH(4))[AsO(2)(OH)(C(6)H(4)NO(2))], the 4-nitrophenylarsonate anions and ammonium cations are linked through hydrogen bonds to form infinite chains along the b axis. The hydroxyl O atom of the 4-nitrophenylarsonate anion acts as both an acceptor and a donor of hydrogen bonds. All atoms are located in general positions.