•Three isomorphic 2D layered Ln-MOFs were constructed by flexible tricarboxylic acid.•A series of Eu3+/Tb3+ doped Ln-MOF 4 were fabricated and showed tunable luminescence.•Ln-MOF 2 exhibited excellent fluorescence sensing for small molecules.Three isomorphic lanthanide metal-organic frameworks (Ln-MOFs) [LnL(H2O)2]·2H2O (Ln=Tb for 1, Eu for 2, Gd for 3) have been constructed from flexible organic ligand 4-(2-carboxyphenoxy)benzene-1,3-dioic acid (H3L). They exhibit two-dimensional (2D) layered structure with the rhombus windows along the b axis. This network can be described as a shubnikov plane net with Schäfli symbol of (43)2(46.66.83). Solid state luminescent studies indicate that 1 and 2 show the characteristic red, and green emissions of the corresponding Ln3+ ions, respectively, while 3 exhibits blue emission arising from the organic ligand. Then by adjusting the relative amounts of different luminescent components into the well-defined host framework, a series of new co-doped Ln-MOF, Tb1−xEuxL (4) (x refers to the molar ratios of Eu3+ and Tb3+), with tunable luminescence have been fabricated. The luminescent color of 4 can be tuned from green to red due to the energy transfer from the Tb3+ to Eu3+ ions by changing the doping concentration of the Eu3+ ions. In addition, 2 exhibits good stability in different solvents and excellent fluorescence sensing for small molecules, especially for CH3CN and nitrobenzene.A series of isomorphic 2D layered Ln-MOFs have been constructed from flexible tricarboxylic ligand, showing tunable luminescence and excellent fluorescence sensing for small molecules, respectively.

Using the rigid 3,3-bis(4-hydroxyphenyl)-2-(4-tritylphenyl)isoindolin-1-one with polar functional groups as a building block and formaldehyde dimethyl acetal(FDA) as a crossinglinker, a new hyper-crosslinked polymer (HCP) was synthesized via Friedel-Crafts alkylation reaction promoted by anhydrous FeCl3. The synthesized HCP is insoluble in boiled water and common organic solvents. Moreover, it shows a good CO2 capture capacity even if its surface area is not very high, and the absolute CO2 uptake capacity of it is 3.05 mmol/g. This can be attributed to the introduction of polar hydroxyl and lactam groups into the skeleton of the polymer which provides effective adsorption sites for CO2. In addition, the synthesized HCP also exhibits good adsorption capacity for organic dyes in water, especially for crystal violet.

•The supramolecular layers constructed by left- or right-handed helical chains in 1.•An interesting {[(H2O)10Cl]−}n layer formed via hydrogen bonding interactions in 2.•The {[(H2O)10Cl]−}n layers were pillared to form a 3D supramolecular network.•The fluorescence properties of compound 3 was investigated.Three new supramolecular compounds, [Cu(o-HPIDC)(bpy)(H2O)]·2H2O 1, [Cu(o-H2PIDC)(phen)Cl]·[Cu(phen)2Cl]·10H2O·Cl 2 and {[Cd(o-H2PIDC)(H2O)2Cl]·H2O}2 3 (o-H3PIDC = 2-(pyridine-2-yl)-1H-imidazole-4,5-dicarboxylic acid, bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline), were hydrothermally synthesized and characterized. In compound 1, the adjacent two supramolecular layers are constructed from different types of helical chains with the same pitch. In compound 2, the adjacent 2D water-chloride layers, {[(H2O)10Cl]−}n, are pillared by [Cu(o-H2PIDC)(phen)Cl] units to form the overall 3D supramolecular network with 1D channels through OH⋯O hydrogen bond interactions. In compound 3, two Cd(II) are linked into a binuclear [Cd2(o-H2PIDC)2(H2O)4Cl2] with a ten-membered ring by two o-H2PIDC− ligands. The three compounds self-assemble into 3D supramolecular structures via hydrogen bond and π-π stacking interactions. The fluorescence properties of compound 3 was also investigated.Download high-res image (406KB)Download full-size image

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.

A series of new lanthanide metal–organic frameworks (Ln-MOFs) [Ln2(L)3(H2O)4]·2H2O (1) (Ln = Eu, Tb, Gd), and [Gd2(H2O)4(L)(C2O4)2]·3H2O (2) were synthesized based on 4-hydroxypyridine-2,6-dicarboxylic acid (H2L) under hydrothermal conditions. 1 exhibits isomorphous 2D wave-like networks constructed by paddle-wheel [Ln(L)3] units and LnO4(H2O)4 polyhedra. 2 shows a (4,4)-connected 3D framework with a Schlafli symbol of 66. Oxalic acid in the resulting framework of 2 is formed in situ under hydrothermal conditions. Luminescence studies indicate that 1-Eu and 1-Tb show characteristic red and green emissions of the corresponding Ln3+ ions, respectively, while 1-Gd and 2 exhibit blue emission arising from the H2L ligand. Then, by adjusting the co-doping ratio of three different Ln3+ ions into the same framework as that of 1, a novel doped Ln-MOF, [(Eu0.0073Tb0.0007Gd0.992)2(H2O)4(L)3]·2H2O (3), is successfully designed and synthesized, which shows white light emission upon excitation at 340 nm and its emission can also be switched between different colors. In addition, 1-Gd shows weak ferromagnetic interactions.

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 indium MOFs based on rigid 1,4-naphthalenedicarboxylate (1,4-NDC) ligand have been successfully prepared under different solvothermal conditions and characterized by single crystal X-ray diffraction, powder X-ray diffraction, IR spectroscopy, TGA, elemental analyses and luminescence spectrum. In these two compounds, In(OH)(1,4-NDC)·2H2O (1) and HIn(1,4-NDC)2·2H2O·1.5DMF (2), (DMF = N, N′-dimethylformamide), 1,4-NDC exhibits two different coordination modes, constructing disparate architectures by bridging the different building units. Compound 1 exhibits a 3D framework with two kinds of square shape channels that built up from the infinite chains of corner-sharing In(OH)2O4 octahedra with 1,4-NDC ligands. Compound 2 possesses a 3D anion framework with twofold interpenetrating diamond topology which is accomplished by connecting four linear 1,4-NDC ligands to the four-connected In(III) nodes. Moreover, compounds 1 and 2 exhibit strong solid-state luminescence emissions at room temperature.Graphical abstractHighlights► Two new porous In-MOFs are synthesized based on same rigid carboxylate ligand. ► Solvent plays an important role on the formation of In-MOFs. ► Two In-MOFs exhibit strong solid-state luminescence emissions at room temperature.

Two new three-dimensional indium phosphite and indium phosphite–phosphate [In3(H2PO3)3(HPO3)4]·(trans-C6N2H16) 1 and [In6(HPO3)8(H2PO3)5(H2PO4)]·(C3N2H12)22 have been synthesized under hydrothermal conditions using 1,2-diaminocyclohexane (1,2-DACH) and 1,3-diaminopropane (1,3-DAP) as structure directing agents, respectively and further characterized by powder X-ray diffraction, single crystal X-ray diffraction, IR spectroscopy, TGA, ICP-AES and elemental analyses. These two compounds have the similar 3D inorganic framework structures with intersecting 8-membered ring (8-MR) channels. In compound 1, the diprotonated trans-1,2-DACH cations occupy the 8-MR channels along the [0 0 1] direction even though a mix of trans- and cis-isomers of 1,2-DACH molecules are added in the reaction mixture. Moreover, the chirality of trans-1,2-DACH alternates along the channels. It is noted that compound 2 is the first indium phosphite–phosphate compound. Crystal data: compound 1, monoclinic, C2/c (No. 15), a = 18.675(4) Å, b = 10.220(2) Å, c = 13.419(3) Å, β = 98.29(3)°, V = 2534.4(9) Å3, and Z = 4. Compound 2, orthorhombic, Pna21 (No. 33), a = 26.7974(9) Å, b = 9.8459(3) Å, c = 18.5441(6) Å, V = 4892.8(3) Å3, and Z = 4.

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.

A new metal–organic framework [In2(OH)2(1,3-BDC)2(2,2′-bipy)2] 1 (1,3-benzenedicarboxylate = 1,3-BDC, 2,2′-bipyridine = 2,2′-bipy) has been hydrothermally synthesized from the reaction of In(NO3)3, 1,3-BDC and 2,2′-bipy. Single-crystal X-ray diffraction analysis reveals that compound 1 crystallizes in the triclinic space group P-1 (No. 2), a = 8.6461 Å, b = 9.9234 Å, c = 10.1799 Å, α = 78.1801°, β = 75.1646°, γ = 72.7427°, V = 798.40 Å3, Z = 2. Compound 1 contains double-chain-like ribbons which are constructed by In2(OH)2(2,2′-bipy)2∞2+ units and 1,3-BDC ligands. The adjacent ribbons are packed and exhibit interesting 3D supramolecular networks. The further characterizations of compound 1 have been performed by fluorescent spectroscopy, powder X-ray diffraction, IR spectroscopy, thermogravimetric analysis (TGA), ICP-AES and elemental analyses.