Ping Zhang

Construction of 2-D lanthanide coordination frameworks: syntheses, structures and luminescent property

A series of layered lanthanide coordination frameworks [Ln4(NIPH)6(H2O)4]·(4,4′-bipy) [Ln = La (1), Pr (2)], [La(NIPH)2(H2O)2]·0.5(4,4′-H2bipy) (3), Ln(NIPH)2(H2O)2]·0.5(4,4′-H2bipy)·2H2O [Ln =Pr (4), Nd (5)], and [Ln(NIPH)2]·0.5(4,4′-H2bipy) [Ln = Sm (6), Eu (7), Tb (8), Ho (9), Yb (10)] (NIPH = 5-nitroisophthalate and 4,4′-bipy = 4,4′-bipyridine) have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. All the coordination frameworks display identical crystal system (triclinic) and space group (P). Compounds 1 and 2 are isostructural, their coordination sheets are constructed by polynuclear helical-like chains. Compounds 3–5 are extremely similar in structure, in which Ln atoms are bridged into rod-shaped chains by carboxylate groups. For compounds 6–10, the coordination layers are built up from 1-D zig-zag chains. The 3-D supramolecular frameworks of 1–10 are finally formed through the alternate stack of Ln coordination layers and 4,4′-bipy layers based on hydrogen bonding interactions. Compound 7 displays luminescent property.

Porous lanthanide–copper coordination frameworks exhibiting reversible single-crystal-to-single-crystal transformation based on variable coordination number and geometry

Two serial heterometallic Ln–Cu coordination polymers [Ln2Cu(NIPH)4(H2O)4]·6H2O (Ln = Gd (1a), Nd (2a), Sm (3a), Eu (4a), Tb (5a), Dy (6a), Ho (7a) and Er (8a)) and [Ln2Cu(NIPH)4(H2O)2] (Ln = Gd (1b), Nd (2b), Sm (3b), Eu (4b), Tb(5b), Dy (6b), Ho (7b) and Er (8b) (NIPH = 5-nitroisophthalate) have been successfully synthesized and exhibit reversible single-crystal-to-single-crystal transformation behavior based on a dehydration and rehydration process involving coordinated and uncoordinated water molecules. The coordination polymers 1a–8a and 1b–8b belong to two sets of isomorphous coordination frameworks respectively; their 3D frameworks are constructed by different heterometallic polynuclear chains. For the serial crystals 1a–8a, the Ln3+ and Cu2+ ions are 8-coordinate and 4-coordinate respectively. While for the other serial crystals, 1b–8b, the Ln3+ and Cu2+ ions are 9-coordinate and 6-coordinate respectively. La3+, Ce3+ and Pr3+ were also employed to construct Ln–Cu coordination frameworks [LaCu(NIPH)2(HNIPH)(H2O)2]·2H2O (La-1), [La2Cu(NIPH)4(H2O)2] (La-2), [Ce2Cu(NIPH)4(H2O)6] (Ce-1) and [Pr2Cu(NIPH)4(H2O)4]·6H2O (Pr-a), which do not display the crystal-to-crystal transformation characteristic.

Incorporation of luminescent tris(bipyridine)ruthenium(II) complex in mesoporous silica spheres and their spectroscopic and oxygen-sensing properties

Abstract Tris(bipyridine)ruthenium(II) ([Ru(bpy) 3 ] 2+ ) has been assembled into mesoporous SiO 2 spheres. The assembly material, [Ru(bpy) 3 ] 2+ /sphere, was investigated by UV–VIS adsorption and emission spectra. The emission spectra shown that the wavelength of maximum intensity ( λ max ) of [Ru(bpy) 3 ] 2+ increases with the increasing of [Ru(bpy) 3 ] 2+ loading level. The luminescence of [Ru(bpy) 3 ] 2+ /sphere is easily quenched by oxygen. The oxygen-sensing property of [Ru(bpy) 3 ] 2+ /sphere was investigated. It was demonstrated that [Ru(bpy) 3 ] 2+ /sphere can be used to develop oxygen-sensing material.

Adsorption and protection of plasmid DNA on mesoporous silica nanoparticles modified with various amounts of organosilane.

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.

Amino-functionalized mesoporous silica nanoparticles: adsorption and protection for pcDNA3.1(+)-PKB-HA

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.

Recycle adsorption of Cu 2+ on amine-functionalized mesoporous silica monolithic

Abstract3-Aminopropyltriethoxysilane functionalized worm-like mesoporous silica monolithic(WMSM-NH2) was prepared and used as a new regenerable adsorbent for the removal of Cu2+ ions. The analysis results show that the WMSM-NH2 monolithic had a high efficiency value of 99.3% for Cu2+ remediation when the Cu2+ solution was at an initial concentration of 10.32 mg/L. The regeneration study of the WMSM-NH2 monolithic presented that the adsorption efficiency of 89.0% was remained and a mass of 92.0% was left after seven adsorption-desorption cycles were executed. The monolithic material with high resistance to the acid and good mechanical stability can facilitate the operations of adsorption and regeneration of the adsorbent.

Two lead coordination polymers with nitrilotriacetic acid and oxydiacetic acid: synthesis, characterization, and crystal structure

Two lead coordination compounds [Pb2(nta)]NO3 (1) and [Pb(oda)] (2) have been synthesized by slow evaporation or hydrothermal conditions using nitrilotriacetic acid (nta) and 2,2′-oxydiacetic acid (oda) as ligands, respectively. Their structures were determined by single-crystal X-ray diffraction and further characterized by X-ray powder diffraction, infrared absorption spectrum, and thermogravimetric analysis. Compound 1 is a 2-D honeycomb-like layer structure with (6,3) topology. When the bonding limit of Pb–O extends from 2.76 to 2.90 Å, potential weak Pb–O bonds can be found in 1, and the 2-D layer structure can be further linked to generate a 3-D 4-connected supramolecular sra net with the (42.63.8) Schläfli symbol. Compound 2 contains a 1-D infinite Pb–O chain which is connected through µ3-, µ4-, and µ5-coordination modes of oda to form a new 3-D structure.

catena-Poly[[aqua­dioxidouranium(VI)]-μ3-4,4′-oxydibenzoato]

The title compound, [UO2(C14H8O5)(H2O)]n, is a polymeric UO2 complex bridged by 4,4′-oxydibenzoate ligands. One carboxylate group of the bridging ligand chelates a uranyl cation while the other carboxylate group of the ligand bridges two other two uranyl cations, forming a double-chain polymeric structure. The central UVI atom is seven-coordinated in a distorted UO7 pentagonal-bipyramidal geometry. In the crystal structure, O—H⋯O hydrogen bonding links the polymeric chains into a three-dimensional supramolecular framework. Within the bridging ligand, the two benzene rings are oriented at a dihedral angle of 59.0 (2)°.

Synthesis and structural characterisation of a new layered aluminophosphate [C3H12N2][Al2P2O8(OH)2]·H2O

A new layered aluminophosphate [C3H12N2][Al2P2O8(OH)2]·H2O has been synthesized hydrothermally by using racemic 1,2-diaminopropane as the structure-directing agent. Its structure, solved by single-crystal X-ray diffraction analysis, consists of [Al2P2O8(OH)2]2− macroanionic sheets stacked in an ABAB sequence, and diprotonated racemic 1,2-diaminopropane cations lying between the inorganic sheets. Hydrogen bonds exist between the oxygen atoms in the sheets and nitrogen atoms of the diprotonated 1,2-diaminopropane molecules. The as-synthesized product has also been characterised by powder X-ray diffraction, inductive coupled plasma analysis, IR spectroscopy, TGA and DTA.