Four novel lanthanide(III) coordination polymers with 3D network structures containing 2-fold interpenetration

Four novel lanthanide(III) coordination polymers [Ln(L)_1.5(H₂O)₂]·5H₂O [Ln = Sm (1), Eu (2), Tb (3), Dy (4)] have been hydrothermally synthesized by the reaction of 1,2-bis[4-amino-5-carboxylmethylthio-(1,2,4-triazol-3-yl)]ethane (H₂L) with lanthanide(III) salts, and structurally characterized by single crystal X-ray diffraction. Polymers 1–4 are isostructural, in which all the Ln^III atoms are nine-coordinated and the carboxylate groups adopt three different coordination modes (bidentate chelate, bidentate bridging, bidentate chelate bridging) to connect Ln^III atoms. These polymers exhibit 3D network structures with 2-fold interpenetration, in which intriguing 1D channels are observed. Besides, the spectra properties of the title polymers are investigated, the strong luminescence characteristics of 2–3 are found.     

A novel 3D 2-fold interpenetrated framework assembled via mixed bridging ligands

Hydrothermal reaction of Cd(NO₃)₂, NaH₂SIPA (5-sulfoisophthalalic acid monosodium salt) and pyrazine (Pz) resulted in a new polymeric complex {[Cd₃(SIPA)₂(pyrazine)(H₂O)₆] · 2H₂O}_n. X-ray structure analysis reveals that this complex features a 2-fold parallel interpenetrated 3D → 3D entanglement architecture, in which the single 3D network is constructed from {[Cd₃(SIPA)₂(H₂O)₆]}_n 2D neutral layers interconnected by pyrazine ligands.     

Synthesis and characterization of a novel 3D copper(I) coordination polymer with a ligand generated in situ

Hydrothermal reaction of CuCl₂ · 2H₂O, NaN₃ with 1,4-dicyanobenzene in water/ethanol yielded a novel Cu(I)-tetrazolate, {Cu(cptz)}_n, (1) (Hcptz is 5-(4-cyanophenyl)-tetrazole). The cptz ligand in the complex was generated in situ through the [2 + 3] cycloaddition reaction involving one of the two cyano-groups of the precursor 1,4-dicyanobenzene. The structure characterization shows that 1 possesses a 3D 4-connected SrAl₂ topological network. Additionally, complex 1 exhibits strong yellow fluorescence at room temperature in the solid state.     

Self-assembly of novel supramolecular silver(I) compound based on mixed ligands bipy/TST3−, H3TST = 2,4,6-tris (4-sulfophenylamino)-1,3,5-triazine

The novel supramolecular silver(I) compound with formula [Ag₆(TST)₂(bipy)₆(H₂O)₂]_n · 3nH₂O (1) based on assembly of Ag(I) and mixed ligand bipy/TST³⁻, bipy = 2,2′-bipyridine, H₃TST = 2,4,6-tris(4-sulfophenylamino)-1,3,5-triazine, has been prepared by hydrothermal method. In the solid-state structure of 1, two-dimensional layered polymeric structures extended with subunits [Ag₆(TST)₂(bipy)₆(H₂O)₂] interact each other in the form of π–π attractions between bipy, forming a three-dimensional supramolecular architecture. Compound 1 represents a Ag-containing polymeric compound possessing room-temperature luminescence.     

A novel double-stranded dinuclear copper(I) helicate having a photoluminescent CuI2N8 chromophore

Bis-(pyridinal)-ethylenediimine (L) affords [Cu^I₂L₂]X₂ (X=ClO₄⁻ and PF₆⁻). The X-ray crystal structure of the ClO₄⁻ salt shows that the cation [Cu^I₂L₂]²⁺ is a double-stranded helicate. The PF₆⁻ salt exhibits a single emission band (maxima, 540 nm) in solution at room temperature (quantum yield: 2×10⁻⁵ in methanol, 1×10⁻⁵ in CH₂Cl₂).     

Solvothermal synthesis and crystal structure of a luminescent 2D copper(I) coordination polymer with a (3,4)-connected net

A novel copper(I) coordination polymer, {[Cu(tpt)(MeCN)](ClO₄)}_∞ (1) (tpt = 2,4,6-tris(4-pyridyl)-1,3,5-triazine), was synthesized by solvothermal synthesis method and structurally characterized. Single crystal X-ray diffraction showed that 1 consists of a 2D (3,4)-connected network with a unique (5³)₂(5⁴8²) topology. The luminescent properties of 1 in the solid state at ambient temperature were investigated.     

3D printing of dense and porous alkali-activated refractory wastes via Direct Ink Writing (DIW)

Alkali-activated pastes prepared starting from refractory wastes were successfully 3D-printed via Direct Ink Writing. In particular, as raw powders, two different aluminosilicates were used: chamotte (CH, mainly composed of corundum, mullite and andalusite) and alumina-zirconia-silica (AZS, mainly baddeleyite, corundum and amorphous silica). First, pastes rheological parameters were optimized in terms of liquid-to-solid ratio and polyethylene glycol content. Then, both dense prismatic samples and lattice structures were successfully 3D-printed. Additionally, PMMA beads of 20 and 60 μm diameter were used to generate an additional porosity in both dense and lattice structures, leading to hierarchically porous materials. Indeed, samples were partially sintered up to 800 °C, to decompose PMMA beads, when present, and provide very high mechanical properties: a flexural strength of approx. 45 MPa was obtained for both AZS and CH dense samples. Moreover, the addition of 30 vol% of PMMA beads leads to macroporous samples without affecting mechanical properties.     

Metal-controlled assembly of coordination polymers: Structural variation from 2D parallel interpenetration to 3D CsCl-type topology

Two novel metal-organic frameworks [Cd₂(hdb)₂(1,4-ndc)₂]_n (1) and [Ni₃(Hhdb)₂(1,4-ndc)₄(H₂O)₂]_n (2) have been synthesized under the similar hydrothermal conditions (hdb = 1,1′-(1,6-hexanediyl)bis(imidazole) and 1,4-ndc = 1,4-naphthalenedicarboxylate). The polymers (1) and (2) show 2D parallel interpenetration and 3D CsCl-type topology, respectively, which are mainly affected by the differences of the metal centers.     

Enhancing thermoelectric properties of p-type (Bi,Sb)2Te3 via porous structures

Bismuth telluride is a widely used commercial thermoelectric material with excellent thermoelectric performances near room temperature. Reducing thermal conductivity is one of the most effective ways to improve performances of thermoelectric materials. In this study, the thermal conductivity of the material was reduced by fabricating porous structures. Highly dense NaCl-(Bi,Sb)₂Te₃ composites were fabricated by a high-pressure technology. The NaCl phase was then removed from the composites by ultrasonic washing to produce porous structures. The produced (Bi,Sb)₂Te₃ porous materials possessed excellent thermoelectric properties. The porosity and pore size of the (Bi,Sb)₂Te₃ porous materials increased with the increasing NaCl content, decreasing the thermal conductivity significantly. An ultra-low lattice thermal conductivity of 0.21 Wm^?1K^?1 at 493 K was achieved when the porosity was 39%, almost the lowest lattice thermal conductivity reported for (Bi,Sb)₂Te₃ bulk materials. The figure of merit ZT value was enhanced to 1.05 at 493 K when the porosity was 25%. Compared with the most compacted samples (ZT = 0.79 and porosity of 10%) prepared under the same conditions, the ZT value of the porous samples increased by 33%. This study indicated that porous thermoelectric materials can be prepared simply, quickly and efficiently by high-pressure/ultrasonication washing to improve thermoelectric performances, which has evident reference values for preparing other thermoelectric pore materials with enhancing behaviors.     

Luminescent staircase copper(I) coordination polymer based on planar Cu3I3

Copper(I) coordination polymer [Cu₃I₃L]_n (1) has been synthesized by the reaction of CuI and 1,4-bis((cyclohexylthio)acetyl)piperazine (L). Structural and photophysical studies of 1 in solid state are reported. The bonding of Cu₃I₃ produces staircase polymers interconnected by the sulfur atoms of L.     

A novel 3D structure of Ag-1,4-cyclohexanedicarboxylate coordination framework

A novel 3D polymeric complex, [Ag(chdc)_0.5]_n (1), (H₂chdc = 1,4-cyclohexanedicarboxylate acid), was synthesized by self-assembly reaction of H₂chdc with Ag(I) ions. The most interesting characteristic of 1 is that the distribution of Ag(I) ions in the crystal is similar to the carbon atoms in a layer of graphite.     

新法简易制备单相NaZr_2(PO_4)_3纳米晶

以ZrOCl2.8H2O和Na3PO4.12H2O为原料,在表面活性剂聚乙二醇(PEG)-400的存在下,先通过在室温下充分研磨反应混合物进行固相反应,然后将混合物在60℃下保温4 h,接着用去离子水洗去混合物中的可溶性无机盐并于100℃下干燥,即得纳米晶NaZr2(PO4)3的前驱体,将前驱体煅烧可得NaZr2(PO4)3纳米晶。前驱体和它的煅烧产物通过TG/DTA,IR,XRD和UV-vis表征。结果表明,500℃下煅烧2 h得到的产物为无定形结构,700℃下煅烧2 h得到具有高结晶度的六方晶系结构的NaZr2(PO4)3[空间群R-3c(167)],其平均一次粒径为39 nm。     

Hydrothermal synthesis and characterization of a copper(I) halide coordination polymer with isonicotinic acid (IN) ligand as a template possessing three-dimensional supramolecular network structure

The title compound [CuBr(IN)]_n 1 was hydrothermally synthesized from a simple reaction of CuBr₂–IN–KBr–NaOH–H₂O. X-ray analysis revealed that it is a new example containing extended one-dimensional staircase chain in copper(I) halide family. Its structure can be better described as a three-dimensional supramolecular network assembled via a combination of coordinate–covalent bonds and intermolecular hydrogen bonds. Moreover, compound 1 was characterized by elemental analysis, IR spectrum and TGA analysis.     

自组装法制备载有阿奇霉素的聚己内酯纳米微球的研究

在没有表面活性剂存在的条件下,通过微相逆转法,阿奇霉素与聚己内酯自组装形成了载有阿奇霉素的聚己内酯纳米微球.采用动态激光光散射、扫描电镜观察、原子力显微镜观察、紫外分光光度法等手段表征了纳米微球的大小、形态以及包封率和载药量,并探讨了纳米微球的形成机理.研究结果表明,采用微相逆转法可以成功制得高包封率和高载药量的载药纳米微球,且其水分散液在低温下十分稳定.     

A novel luminescent 3D metal–organic framework possessing 4-fold interpenetrating (3,4)-connected net

A novel 3D polymer [Zn(L¹)(1,4-BDC)_0.5] (1) (HL¹ = 3,5-bis(pyridin-4-ylmethoxy)benzoic acid, 1,4-BDC = 1,4-benzenedicarboxylate anion) has been isolated under hydrothermal condition and characterized by single crystal X-ray diffraction. Compound 1 displays a 3D 4-fold interpenetrating (3,4)-connected net with (4 · 8²)(4 · 8⁵) topology. In addition, powder X-ray diffraction, photoluminescent property and thermogravimetric analysis for 1 are investigated in detail.     

A new nickel metal organic framework (Ni-MOF) porous nanostructure as a potential novel electrochemical sensor for detecting glucose

Journal of Porous Materials - A Ni-MOF-based novel electrochemical sensor was synthesized with high surface area of 1381 m2/g, significant porosity of 1.14–9.6 nm and average...     

A highly novel dinickel complex: A hydrogen-bonded anti-skew carboxylate bridge and a 2D supramolecular structure

Reaction of the tridentate Schiff base ligands obtained from 2,4-dihydroxybenzaldehyde and either l-isoleucine or l-tert-leucine with Ni(NO₃)₂ in methanol/water solution in the presence of base afforded dinickel complexes. The crystal structure of the product derived from l-tert-leucine has been determined by X-ray crystallography. The octahedrally coordinated two Ni centers were found to be bridged by a single carboxylate group in an extremely unusual non-planar fashion. A 2D supramolecular structure, constructed by infinite hydrogen-bonded complex sheets parallel to the ab-plane of the unit cell, arises from intermolecular O–H?O hydrogen bonds.