•A series of isostructural 3D Ln-MOFs were prepared showing high thermal stabilities.•1, 2, 7 and 8 exhibit strong luminescent emitting, while 5 shows NIR luminescence.•1 displays excellent fluorescence sensing for organic solvent small molecules.•The activated 2 exhibits good adsorption capacity for organic dyes in water.A series of novel isostructural 3D lanthanide metal-organic frameworks {[Ln2(NDC)3(H2O)4]·(DMF)4}n (Ln=Eu(1), Gd(2), Tb(3), Er(4), Yb(5), Dy(6), Y(7), Lu(8), H2NDC =2,6-Naphthalenedicarboxylic acid, DMF=N,N-dimethylformamide) with a rhombic channel along the b axis and high thermal stabilities, have been successfully synthesized under solvothermal conditions. The network can be described as 2, 4, 5-connected net with Schäfli symbol of (42.62.82)2(42.63.85)2(6). Luminescent studies illustrate that 1, 2, 7 and 8 exhibit strong luminescent emitting of the corresponding Ln(III) centers in the visible range, while 5 shows near-infrared range (NIR) luminescence. Further studies of 1 and 2A (activated product of 2) show that 1 displays good stability in different solvents and excellent fluorescence sensing for organic solvent small molecules and 2A ([Gd2(NDC)3(H2O)4]n) exhibits good adsorption capacity for organic dyes in water, especially for crystal violet.A series of novel isostructural 2, 4, 5-connected 3D lanthanide metal-organic frameworks (Ln-MOFs) 1-8 with Schäfli symbol of (42.62.82)2(42.63.85)2(6) have been synthesized under solvothermal conditions, exhibiting a rhombic channel along the b axis. Compound 1 displays excellent fluorescence sensing for organic solvent small molecules and the activated compound 2 exhibits good adsorption capacity for organic dyes in water, especially for crystal violet.Download high-res image (218KB)Download full-size image

Porous carbon-coated CoS1.097 nanocomposites (PC-CoS1.097 NCs) were synthesized by a one-step controlled pyrolysis of the zeolitic imidazolate framework ZIF-9 with sulfur powder. The resulting porous composites contained a high level of nanoparticles of CoS1.097 and exhibited considerable mesoporosity. With remarkable electrocatalytic activity, the nanocomposites provided a four-electron pathway for the oxygen reduction reaction (ORR) in alkaline medium. The advantages of the synthesized composites over commercial Pt/C include a high methanol crossover resistance and superior long-term stability lasting for 10000 s cycles. The cost-effective, stable and highly active PC-CoS1.097 NC electrodes have great potential for application in direct methanol fuel cells (DMFCs). This study lays a foundation for the future development of new cost-effective electrocatalysts.

A novel heterometallic-organic framework(HMOF), namely [ZnBa(1,3-BDC)2(DMA)2]n(1)(DMA=N,Ndimethylacetamide), was synthesized by means of solvothermal method from isophthalic acid(1,3-BDC) ligand and relevant metal salts as raw materials. The single-crystal X-ray diffraction analysis result demonstrates that compound 1 is a three-dimensional(3D) framework including heterometallic tetranuclear [Zn2Ba2(COO)8] clusters as building subunits, which could be simplified into an eight-connected body-centered cubic(bcu) topological net. At room temperature, compound 1 displays strong blue luminescence in solid state. Furthermore, the quantum yield and luminescent lifetime of compound 1 were also measured.

•In situ acylation of two ortho-position carboxylic groups with N2H4 can produce acylhydrazide molecule.•Structural characterization of three acylhydrazidate-coordinated complexes is reported.•Structural characterization of two acylhydrazide molecules is reported.•Character of acylhydrazide molecule is revealed.By utilizing the hydrothermal in situ acylation of organic acids with N2H4, three acylhydrazidate-coordinated compounds [Mn(L1)2(H2O)2] (L1 = 2,3-quinolinedicarboxylhydrazidate; HL1 = 2,3-dihydropyridazino[4,5-b] quinoline-1,4-dione) 1, [Mn2(ox)(L2)2(H2O)6]·2H2O (L2 = benzimidazolate-5,6-dicarboxylhydrazide; HL2 = 6,7-dihydro-1H-imidazo[4,5-g]phthalazine-5,8-dione; ox = oxalate) 2, and [Cd(HL3)(bpy)] (L3 = 4,5-di(3′-carboxylphenyl)phthalhydrazidate; H3L3 = 6,7-dihydro-1H-imidazo[4,5-g]phthalazine-5,8-dione; bpy = 2,2′-bipyridine) 3, as well as two acylhydrazide molecules L4 (L4 = oxepino[2,3,4-de:7,6,5-d′e′]diphthalazine-4,10(5H,9H)-dione) 4 and L5 (L5 = 4,5-dibromophthalhydrazide; L5 = 6,7-dibromo-2,3-dihydrophthalazine-1,4-dione) 5 were obtained. X-ray single-crystal diffraction analysis reveals that (i) 1 only possesses a mononuclear structure, but it self-assembles into a 2-D supramolecular network via the NhydrazineH ⋯ Nhydrazine and OwH ⋯ Ohydroxylimino interactions; (ii) 2 exhibits a dinuclear structure. Ox acts as the linker, while L2 just serves as a terminal ligand; (iii) In 3, L3 acts as a 3-connected node to propagate the 7-coordinated Cd2 + centers into a 1-D double-chain structure; (iv) 4 is a special acylhydrazide molecule. Two OH groups for the intermediates 3,3′-biphthalhydrazide further lose one water molecule to form 4; (v) 5 is a common monoacylhydrazide molecule. Via the NhydrazineH ⋯ Ohydrazine, OhydroxyliminoH ⋯ Oacylamino and the π ⋯ π interactions, it self-assembles into a 2-D supramolecular network. The photoluminescence analysis reveals that 4 emits light with the maxima at 510 nm.By employing IR spectrum, TG curve, powder XRD pattern, X-ray single-crystal diffraction analysis, and photoluminescence analysis, structural characterization of three acylhydrazidate-coordinated complexes and two acylhydrazide molecules is revealed.

Under hydrothermal conditions, the reactions of Ba2+/Zn2+, aromatic polycarboxylic acids and N2H4 with or without oxalic acid were carried out, affording four new acylhydrazidate-extended metal–organic frameworks (MOFs) [Ba(pmdh)] (pmdh = pyromellitdihydrazidate) 1, [Ba(sdpth)(H2O)2]·0.5H2O (sdpth = 4,4′-sulfoyldiphthalhydrazidate) 2, [Ba2(cpth)2(H2O)2] (cpth = 4-carboxylphthalhydrazidate) 3 and [Zn2(pdh)2(ox)]·H2O (ox = oxalate, pdh = pyridine-2,3-dicarboxylhydrazidate) 4. The acylhydrazidate molecules pmdh, sdpth, cpth and pdh in compounds 1–4 derived from the hydrothermal in situ acylation of N2H4 with aromatic polycarboxylic acids. X-ray single-crystal diffraction analysis revealed that (i) in compound 1, the pmdh I molecules link the Ba2+ ions into a two-dimensional (2D) layer with a (4,4) topology, and then the pmdh II molecules extend these layers into a three-dimensional (3D) network; (ii) in compound 2, the sdpth molecules link the Ba2+ ions to form a one-dimensional (1D) square tube. Interestingly, the tubes are further linked into a 3D supramolecular network via the N–H⋯O interactions, creating synchronously big channels; (iii) in compound 3, the cpth I molecules link the Ba1 ions into a 3D network with a (10,3) topology. Ba2 and cpth II are distributed on the channels; (iv) in compound 4, Zn2+ and pdh aggregate to form two types of Zn4(pdh)4 clusters. The ox molecules act as the secondary linkers, extending the Zn4(pdh)4 secondary building units (SBUs) into a 3D network with a 66 topology. The photoluminescence analysis indicates that compounds 3 and 4 emit green light with maxima at 495 nm for 3 (λex = 397 nm), and 522 nm for 4 (λex = 395 nm), respectively. At 77 K, the activated 2 and 4 can adsorb N2 in amounts of 58.31 cm3 g−1 for 2 and 38.38 cm3 g−1 for 4, respectively.

Two new compounds [Zn2L(OH)H2O]n (1) and [Cd(HL)]n (2) have been assembled from a semirigid V-shape ligand under hydrothermal conditions. The two compounds were determined by single-crystal X-ray diffraction analyses and further characterized by solid state emission spectra, IR spectra, and thermogravimetric analyses. Single crystal X-ray diffraction analyses show that both of the two compounds crystallize in space group P1¯ and display a three-dimensional (3D) structure with different topologies of fluorite topology for 1 and Au4Ho topology for 2. It is noteworthing that 1 has a novel Zn2 dinuclear unit containing only one bridging oxygen atom between two Zn atoms. Studies of photophysical properties reveal that 1 and 2 present luminescence, which can be ascribed to the emission of intraligand transition.Graphical abstractUsing ligand 5-(4′-(tetrazol-5″-yl)phenoxy) isophthalic acid, two new 3D coordination polymers, [Zn2L(OH)H2O] (1) and [Cd(HL)] (2), have been synthesized. Compound 1 is a 3D fluorite network. Compound 2 possesses a 3D Au4Ho topology.Highlights► New compounds 1 and 2 are based on 5-(4′-(tetrazol-5″-yl)phenoxy) isophthalic acid. ► Compound 1 is a 3D network with fluorite topology. ► In compound 1, zinc adopts a novel dinuclear mode. ► Compound 2 possesses a 3D framework with Au4Ho topology. ► Luminescence can be ascribed to the emission of intraligand transition.

•Hollow CaCO3 was firstly prepared by Ca(CH3COO)2 and NaHCO3 without any templates..•The product of hollow CaCO3 was pure phase of vaterite.•The application of this simple and environmental-friendly method is promising.We describe a simple and green method for synthesizing hollow calcium carbonate (CaCO3) microspheres composed of vaterite via the reaction of Ca(CH3COO)2 with NaHCO3 in the solvent mixture of ethylene glycol (EG) and H2O, without any templates. We show that the reaction rapidly conducts to the formation of microspheres with an average diameter of 800 nm. XRD and FTIR analyses confirm that the hollow CaCO3 microspheres are the characteristic of the vaterite polymorph. SEM and TEM observations reveal that the microspheres have a hollow core of around 500 nm width and are composed of vaterite with an average diameter of 80 nm. A possible growth mechanism for the hollow structure has been proposed, which exhibits that the hollow CaCO3 microspheres are formed by an aggregation mechanism. This work may pave the way for the elaboration of a biomaterial with potential applications in therapy as well as drug delivery.Graphical abstract

This work evaluated the adsorption and protection capacities of amino-functionalized mesoporous silica nanoparticles (Am-MSNs) for the recombinant DNA (rDNA), pcDNA3.1(+)-PKB-HA. The in vitro biocompatibility of Am-MSNs was also tested on HeLa and A549 cells, respectively. The results reveal that the MSNs modified with 3-aminopropyltriethoxysilane exhibit good adsorption capacity for pcDNA3.1(+)-PKB-HA at physiological conditions and the adsorption amount is higher than that of other silica nanoparticles. Moreover, the material can also protect pcDNA3.1(+)-PKB-HA from enzymatic degradation completely and presents high in vitro biocompatibility. This demonstrates that Am-MSNs may be potential nonviral vector candidates for pcDNA3.1(+)-PKB-HA.

Ordered MCM-41-type mesoporous silica nanoparticles (MSNs) with pore size of 2.6 nm were synthesized and were further modified with various amounts of 3-aminopropyltriethoxysilane (APTES), respectively, by a direct co-condensation method. These amine functionalized mesoporous silica nanoparticles (Am-MSNs) were employed to complex with plasmid DNA (pDNA) to study their adsorption and protection capacities. The results demonstrate the MSNs functionalized with aminopropyl groups present advanced adsorption capacities for pDNA immobilization. And Am-MSNs with high APTES amount lead to high amount of pDNA adsorption. Further investigation of pDNA protection shows that Am-MSNs with moderate APTES amount could completely protect pDNA from enzymatic degradation, while those with smaller and/or higher amount of APTES could partially provide protection of pDNA.Graphical abstractHighlights► Adsorption and protection of pDNA on Am-MSNs with various APTES amounts were studied. ► All the Am-MSNs exhibited good adsorption capacity of pDNA. ► Samples with moderate APTES amount could totally protect pDNA. ► The effect of APTES amount on pDNA protection was addressed. ► The materials might be good candidates for gene carriers.

Two new zinc-triazole-biphenyldicarboxylate frameworks based on secondary building units (SBUs), namely, Zn4(μ4-O)(trz)2(4,4′-bpdc)2 (1) and Zn2(trz)2(2,4′-bpdc) (2), [Htrz = 1,2,4-triazole, H2bpdc = biphenyldicarboxylate] have been synthesized by hydrothermal reactions and characterized by single-crystal X-ray diffraction analyses, X-ray power diffraction, elemental analyses, infrared absorption spectra, and thermogravimetric analyses. Compound 1 is a 2-fold interpenetrating diamond topology constructed from [Zn4(μ4-O)(trz)2]4+ SBUs with tetrahedral [Zn4(μ4-O)] core and two trz ligands. Compound 2 is a 2D 6-connected hxl network based on [Zn2(trz)2]2+ SBUs. Additionally, these two compounds show emission properties at room temperature in the solid state.Structural views of two new coordination polymers Zn4(μ4-O)(trz)2(4,4′-bpdc)2 (1) and Zn2(trz)2(2,4′-bpdc) (2) based on secondary building units (SBUs), 1 is a 2-fold interpenetrating diamond topology constructed from [Zn4(μ4-O)(trz)2]4+ SBUs, and 2 is a 2D 6-connected hxl network based on [Zn2(trz)2]2+ SBUs.Research Highlights► Two new compounds were synthesized under hydrothermal conditions. ► 1 exhibits a 4-connected porous 2-fold interpenetrating diamond network. ► 2 is a 6-connected hxl net. ► The two compounds show emission properties at room temperature in the solid state.

A family of lamellar mesostructured hydroxyapatites are synthesized using five terminal linear aliphatic carboxylic acids (capric acid, lauric acid, myristic acid, palmitic acid, and stearic acid with the general formula of Cn−1H2n−1CO2H, n = 10, 12, 14, 16, 18). The study of X-ray diffraction shows that the hydroxyapatite samples exhibit similar multi-lamellar mesostructure and their interlamellar spacing is proportional to the carbon numbers of carboxylic acids. The transmission electron microscopic images on the products prove the parallel aligned configuration. Fourier transform infrared spectra displays the characteristic components of hydroxyapatite in as-prepared samples. Thermogravimetric analysis, elemental analysis (C, H), and inductively coupled plasma analysis were further used to confirm the organic and inorganic composition of the products.

Two new zinc–triazole–carboxylate frameworks constructed from secondary building units (SBUs), [Zn5(trz)4(btc)2(DMF)2(H2O)2]·2H2O·DMF (1) and [Zn4(trz)3(btc)2(CH3CN)(H2O)]·5H2O·(Bu4N) (2), [Htrz = 1,2,4-triazole, H3btc = 1,2,4-benzenetricarboxylate, Bu4N = tetrabutylammonium], have been synthesized by solvothermal reactions and characterized by single-crystal X-ray diffraction analyses, X-ray power diffraction, elemental analyses, infrared spectra and thermogravimetric analyses. Both compounds 1 and 2 exhibit 3D (3,8)-connected tfz-d nets with {43}2{46.618.84} topology symbol built from rod-shaped {[Zn5(trz)4]6+}n SBUs (1) and {[Zn4(trz)3]5+}n SBUs (2). In two compounds, rodlike units are connected by btc ligands via different modes. Additionally, solid state fluorescent emission spectra of two compounds show fluorescent properties at room temperature.Both compounds 1 and 2 exhibit 3D (3,8)-connected tfz-d nets, 1 consists of [Zn3(trz)4] cores linked through two Zn atoms to form rod-shaped {[Zn5(trz)4]6+}n SBUs, and 2 contains 3-fold paddle-wheels [Zn2(trz)3] cores which are connected by Zn to generate rod-shaped {[Zn4(trz)3]5+}n SBUs.

Four novel zinc(II) metal-organic frameworks, {[Zn7(trz)6(1,3-bdc)4(H2O)2]·2H2O}n (1), {[Zn7(trz)6(hip)4(H2O)2]·8H2O}n (2), [Zn4(trz)4(Hnip)2(nip)]n (3), and [Zn5(trz)2(Hbtc)4(H2O)4]n (4) (Htrz = 1,2,4-triazole, 1,3-H2bdc = 1,3-benzenedicarboxylic acid, H2hip = 5-hydroxyisophthalic acid, H2nip = 5-nitroisophthalic acid, and H3btc = 1,3,5-benzenetricarboxylic acid), have been hydrothermally synthesized by reaction of Zn salt and Htrz with four different aromatic acids, respectively. Their structures were determined by single-crystal X-ray diffraction analyses and further characterized by X-ray powder diffraction, elemental analyses, IR spectra, and TG analyses. The structures of compounds 1 and 2 are isostructural and feature the 3D structure containing multidimensional intersecting ring channels formed by the interconnection of 2D layers {[Zn7(trz)6]8+}n with 1,3-bdc (1) or hip (2). Compound 3 consists of {[Zn4(trz)4]4+}n layers with (4, 82) topology arranged in the −ABAB− stacking sequence, which are connected by nip pillars to generate a novel 3D open framework. Compound 4 is also in a 3D structure containing 2D layer motifs, which are further linked by btc ligands to complete the structure. There are two different building units [Zn2(trz)2]2+ and [ZnO6] within the 2D layers of 4. All of the compounds 1−4 exhibit the 3D pillared-layer structures. In the 2D layer motifs of these four compounds, trz ligands connect Zn ions in different coordination modes, which reflect the tendency of the trz ligand to bridge multiple metal sites, and the aromatic carboxylate ligands in compounds 1−4 serve as the pillar between the 2D layers, creating the 3D open frameworks. Moreover, these four compounds exhibit emission properties at room temperature in the solid state.

A new molybdenum complex (C4H12N2)2[(MoV2O4)(MoVIO4)(C2O4)2]·2H2O, was solvothermally synthesized and characterized by single-crystal X-ray diffraction. The structure of the compound consists of oxalate acid-coordinated mixed-valent [MoV2O4][MoVIO4] helical chains and protonated piperazine cations. The helical chains are built up from the [MoV2O4] units and [MoVIO4] tetrahedral. The central axis about helical chain is a 2-fold screw axis. The compound crystallizes in the space group P21/n of monoclinic system with a = 11.396(2) Å, b = 14.107(3) Å, c = 15.805(3) Å, β = 102.09(3)°, V = 2484.6(9) Å3, Z = 4. Other characterizations by elemental analysis, IR, and thermal analysis for this compound are also given.A molybdenum complex (C4H12N2)2[(MoV2O4)(MoVIO4)(C2O4)2]·2H2O, was solvothermally synthesized and characterized by single-crystal X-ray diffraction. The structure of the compound consists of oxalate acid-coordinated mixed-valent [MoV2O4][MoVIO4] helical chains and protonated piperazine cations.

A new copper molybdenum phosphate with a three-dimensional supramolecular framework has been prepared by hydrothermal synthesis and characterised by single crystal X-ray analysis.

Under hydrothermal conditions, the reactions of Ba2+/Zn2+, aromatic polycarboxylic acids and N2H4 with or without oxalic acid were carried out, affording four new acylhydrazidate-extended metal–organic frameworks (MOFs) [Ba(pmdh)] (pmdh = pyromellitdihydrazidate) 1, [Ba(sdpth)(H2O)2]·0.5H2O (sdpth = 4,4′-sulfoyldiphthalhydrazidate) 2, [Ba2(cpth)2(H2O)2] (cpth = 4-carboxylphthalhydrazidate) 3 and [Zn2(pdh)2(ox)]·H2O (ox = oxalate, pdh = pyridine-2,3-dicarboxylhydrazidate) 4. The acylhydrazidate molecules pmdh, sdpth, cpth and pdh in compounds 1–4 derived from the hydrothermal in situ acylation of N2H4 with aromatic polycarboxylic acids. X-ray single-crystal diffraction analysis revealed that (i) in compound 1, the pmdh I molecules link the Ba2+ ions into a two-dimensional (2D) layer with a (4,4) topology, and then the pmdh II molecules extend these layers into a three-dimensional (3D) network; (ii) in compound 2, the sdpth molecules link the Ba2+ ions to form a one-dimensional (1D) square tube. Interestingly, the tubes are further linked into a 3D supramolecular network via the N–H⋯O interactions, creating synchronously big channels; (iii) in compound 3, the cpth I molecules link the Ba1 ions into a 3D network with a (10,3) topology. Ba2 and cpth II are distributed on the channels; (iv) in compound 4, Zn2+ and pdh aggregate to form two types of Zn4(pdh)4 clusters. The ox molecules act as the secondary linkers, extending the Zn4(pdh)4 secondary building units (SBUs) into a 3D network with a 66 topology. The photoluminescence analysis indicates that compounds 3 and 4 emit green light with maxima at 495 nm for 3 (λex = 397 nm), and 522 nm for 4 (λex = 395 nm), respectively. At 77 K, the activated 2 and 4 can adsorb N2 in amounts of 58.31 cm3 g−1 for 2 and 38.38 cm3 g−1 for 4, respectively.