Synthesis and structure of 3D heterometallic （3d-4f） coordination polymers： {[Ln2Cu（pydc）4（H2O）6]·2H2O}n

Two new 3D heterometallic （3d-4f） coordination polymers {[Ln2Cu（pydc）4（H2O）6]·2H2O}n [Ln = Eu （1） and Gd （2）] have been synthesized by hydrothermal reactions and characterized by elemental analysis, X-ray single-crystal analyses, and IR spectroscopy. X-ray crystal structure analyses show that 1 and 2 possess 3D networks and strong intramolecular hydrogen bonding interactions which was confirmed by thermogravimetric （TG） analysis.     

Structural diversity and reactivity of d^10 metal- （4-pyridylthio）acetate system

The hydrothermal synthesis and crystal structures of four coordination polymers, namely, 2D [Zn（μ3-ta）（pytaH）]n （1）, 2D [Zn（μ3-pyta）Cl]n （2）, 1D [Cd（μ-pyta）2（H2O）]n （3）, and 3D [Cd（μ3-pyta）（μ-Cl）]n （4） （pyta = （4-pyridylthio）acetate, ta = thioglycolate）, are reported. They are based on （4-pyridylthio）acetate and its derived ligand. The ta^2- ligand present in 1 was generated from an in situ C（sp^2）-S bond cleavage of the pyta ligand. In these compounds, versatile intermolecular interactions, such as close S…S interactions and strong （O-H…O/N/S） or weak （C-H…O/S, C-H…Cl） hydrogen bonding interactions, play an important role in the formation of three-dimensional supramolecular networks in the solid state.     

Coordination polymer based on （1,2-bis（2-picolinamido） phenyl）copper

( 1,2-bis(2-pyridinecarboxamido)benzene copper Cu(bpb) was synthesized and employed as a building block to construct supramolecular coordination polymer based on intermolecular coordination and hydrogen bonding interactions. X-ray single-crystal diffraction characterization revealed that intermolecular coordination interactions lead to the formation of one-dimensional infinite molecular columns, which array along the same direction in the crystal resulting in the three-dimensional network. The molecular columns are linked together by hydrogen-bonding interactions, which infinitely extend in bc plane. The one-dimensional coordination bonding and two-dimensional hydrogen-bonding interactions result in the formation of supramolecular coordination polymer.     

A new 3-D Gd–Cu heterometallic polymer [Gd_2Cu_3(bpy)_2-(ip)_6]·6H_2O with a non-interpenetrated α-Po net

A new 3-D porous Gd-Cu heterometallic polymer [Gd2Cu3(bpy)2(ip)6]·6H2O (1) (bpy = 2,2'-bipyridine, H2ip = isophthalic acid) has been hydrothermally synthesized and structurally characterized. Compound 1 crystallizes in the triclinic space group P1and displays a 3-D non-interpenetrated α-Po network with 1-D channels filled transversely by the hexa-nuclear chain-like (H2O)6. The EPR and thermal stability of 1 were investigated.     

Three new zinc（Ⅱ） coordination polymers： Modulation of extended structures driven by assistant ligands

Three new complexes, [Zn（dtb）（4,4′-bipy）]·5H2O （1）, [Zn（dtb）（bpp）]·H2O （2） and [Zn（dtb）（phen）2]·CH3- CH2OH·H2O （3） （dtb = 5,5′-dithiobis（2-nitrobenzoic acid）, 4,4′-bipy = 4,4′-bipyridine, bpp = 1,3-bi（4-pyridyl） propane, phen = 1,10-phenanthroline）, have been constructed by dtb ligand and zinc salt in the presence of different assistant N-containing ligands under hydrothermal conditions. The structures of the complexes were established by single-crystal X-ray diffraction analysis. Although compounds 1 and 2 are both 2D networks, the cavities＇ forms and pitch of helix are different. The structure of compound 3 shows a 1D helical chain, and is extended by the supermolecule interactions into a 2D framework. These neutral polymeric complexes exhibit structural and dimensional diversity due to the different coordination modes of the flexible dtb ligand and the effect of assistant ligands.     

Structure and magnetism of carboxylate/EO-azido-mixed-ligands bridged CuII systems

Using two structurally related benzoates bearing different H-bond acceptors as co-ligands, three new azido-Cu^Ⅱ compounds, [Cu（L^1）（N3）（H2O）]n（1）, [Cu（L^1）（N3）（MeOH）]n （2）, and [CuL^2HL^2（N3）3（H2O）]n（3） （HL^1 = 4-nitrobenzoic acid; HL^2= 2-phenyl-4-quinolinecarboxylic acid）, have been synthesized and structurally characterized. 1 is a carboxylate/EO-azido bridged copper chain, forming 3D structure by H-bonds, and 2 has a similar chain structure as 1 but forming a 2D structure by H-bonds, while 3 is a 3D supramolecular network with ternary center H-bonds. Magnetic study indicates that domain ferromagnetic coupling interactions were found to exist in complexes 1 and 3.     

Great diversity in stability of perovskite-type oxides studied by electrochemical hydrogen charging

Single crystals of 0.91Pb(Zn1/3Nb2/3)O3-0.09PbTiO3,SrTiO3 and BaTiO3,and ceramic pellets of CaCu3Ti4O12 and BiFeO3 have been studied and compared through electrochemical hydrogen charging,in which the oxides were coated with silver electrodes to electrolyze water as the cathode.Great diversity has been observed in the stability of the oxides:0.91Pb(Zn1/3Nb2/3)O3-0.09PbTiO3 was quickly decomposed;hydrogen could enter the lattice of the other four oxides,but their properties were influenced at extremely different speeds.Such a great diversity in stability against hydrogen among perovskite-type oxides highlights the importance of reliability study over functional oxides materials.     

Syntheses,structure and photoluminescent properties of lanthanide oxalatosulfocarboxylate coordination polymers

Hydrothermal reactions of oxalic acid(H2ox) and 2-sulfobenzoic acid(H2L) with lanthanide oxide or hydroxide yielded five lanthanide oxalatosulfocarboxylates.They have a general formula [Ln2L2(ox)(H2O)6]n[Ln = La(1),Nd(2),Eu(3),Gd(4),Tb(5)].Their structures were characterized by single crystal X-ray diffraction,powder X-ray diffraction(PXRD),infrared(IR) spectroscopy,elemental analysis(EA),and thermogravimetric analysis(TGA).1-5 are isostructural coordination polymers and feature one-dimensional(1D) chains,which are extended into 3D supramolecular frameworks through inter-chain hydrogen bonds between coordinated H2O donors and oxygen acceptors from carboxylate,sulfonate and oxalate groups.In addition,the solid-state photoluminescence properties of the Nd(2),Eu(3) and Tb(5) derivatives have been measured at room temperature.The Eu and Tb-containing coordination polymers(CPs) exhibit intense red and green luminescence emissions,respectively,with lifetimes in the order of millisecond.     

Reductive smelting of spent lead–acid battery colloid sludge in a molten Na_2CO_3 salt

Lead extraction from spent lead–acid battery paste in a molten Na2CO3 salt containing Zn O as a sulfur-fixing agent was studied. Some influencing factors, including smelting temperature, reaction time, Zn O and salt dosages, were investigated in detail using single-factor experiments. The optimum conditions were determined as follows: T = 880°C; t = 60 min; Na2CO3/paste mass ratio = 2.8:1; and the Zn O dosage is equal to the stoichiometric requirement. Under the optimum conditions, the direct recovery rate of lead reached 98.14%. The results suggested that increases in temperature and salt dosage improved the direct recovery rate of lead. XRD results and thermodynamic calculations indicated that the reaction approaches of lead and sulfur were Pb SO4→Pb and Pb SO4→Zn S, respectively. Sulfur was fixed in the form of Zn S, whereas the molten salt did not react with other components, serving only as a reaction medium.     

Poly(benzyl ether) dendrons without conventional gelation motifs as a new kind of effective organogelators

Two poly(benzyl ether) dendrons,decorated in their periphery with nitrile groups,were divergently synthesized and fully characterized.Their gelation properties were studied by using scanning electron microscopy(SEM),X-ray crystal structure analysis and concentration-and temperature-dependent 1 H NMR spectroscopy.It was found that the gelation capability of these dendrons was highly dependent on dendron generation,and the second-generation dendron G 2-CN proved to be highly efficient organogelator despite the lacking of any conventional gelation motifs,such as amides,long alkyl side chains and steroidal groups.The multiple strong-stacking interactions and hydrogen bonding interactions due to the peripheral isophthalonitrile motifs were proved to be the main driving forces to form the self-assembled gel.     

First-principle study of interaction of H2 and H2O molecules with (ZnO)n(n=3?6) ring clusters

A density functional calculation was performed to investigate the impact of hydrogen and water molecules on zinc oxide clusters (ZnO)n=3–6 ··· X, where X=H2 and H2O. The calculated binding energies were corrected for the basis set superposition error (BSSE). The structural parameters and chemical hardness were calculated for the complexes of zinc oxide clusters and guest molecules. The strength values of the interaction between the clusters and the guest molecules were analyzed based on the topological properties of atoms in molecules (AIM) theory of Bade r. The stereo electronic interact ions inside the ZnO clusters were analyzed in detail using the natural bond orbital (NBO) analysis.     

A Novel Degradation Pathway of Zn（dmid） （ phen）2 in Pyridine

The light-oxidation degradation processes of Zn(dmid)(phen)2(dmid = 4, 5-dimercapto-1,3-dithiole-2 one, phen = 1,10-phenanthroaline) in pyridine solvent has been monitored, h has been found under the light, dmid^2- of Zn(dmid)(phen)2 in pyridine solution could generate NCS^- and NCS^-replaces dmid^2- to form Zn(NCS)2 (phen)2 simultaneously. The crystal structure of Zn(NCS)2 (phen)2 has been determined. In the crystal of Zn(NCS)2 (phen)2. two NCS^- ligands are arranged in syn-configuration, and there is strong π-π interaction between the two adjacent parallel phen.     

Low-temperature densification sintering and properties of CaAl_2Si_2O_8 ceramics with MeO·2B_2O_3(Me=Ca,Sr,Ba)

Dense CaAl2Si2O8 ceramics were prepared via a two-step sintering process at temperatures below 1000°C. First, pre-sintered Ca Al2Si2O8 powders containing small amounts of other crystal phases were obtained by sintering a mixture of calcium hydroxide and kaolin powders at 950°C for 6 h. Subsequently, the combination of the pre-sintered ceramic powders with Me O·2B2O3(Me = Ca, Sr, Ba) flux agents enabled the low-temperature densification sintering of the CaAl2Si2O8 ceramics at 950°C. The sintering behavior and phase formation of the CaAl2Si2O8 ceramics were investigated in terms of the addition of the three MeO·2B2O3 flux agents. Furthermore, alumina and quartz were introduced into the three flux agents to investigate the sintering behaviors, phase evolvements, microstructures, and physical properties of the resulting CaAl2Si2O8 ceramics. The results showed that, because of their low-melting characteristics, the MeO·2B2O3(Me = Ca, Sr, Ba) flux agents facilitated the formation of the CaAl2Si2O8 ceramics with a dense microstructure via liquid-phase sintering. The addition of alumina and quartz to the flux agents also strongly affected the microstructures, phase formation, and physical properties of the CaAl2Si2O8 ceramics.     

Synthesis and crystal structure of tetranuclear zinc benzoate

A tetranuclear zinc benzoate Zr4O(C6H5CO2)6 was synthesized and characterized by X-ray single crystal determination. It crystallizes in cubic, space group Ia-3d. Its crystal cell is very large, α=4.10063(18)nm, V=68.953(5)nm^3 and Z=48. The structure is composed of discrete Zr4O(C6H5CO2)6 molecules. In each molecule, four zinc atoms are held together by a central oxygen atom, which results in the formation of a regular tetrahedron. All benzoate ligands coordinate to zinc atoms in a bidentate bridging mode. Each zinc atom is in a slightly distorted tetrahedral geometry, coordinated by three benzoate oxygen atoms and the central oxygen atom. The intermolecular interactions result in the formation of a three-dimensional supramolecular framework, with non-intersecting parallel channels.     

Investigation of the interfacial water structure on poly[2-（dimethylamino）ethyl methacrylate] at the air/water interface by sum frequency generation vibrational spectroscopy

The effect of pH on the conformation of surface alkyl groups and the structure of interfacial water molecules on poly[2-(dime-thylamino)ethyl methacrylate](PDEM) at the air/water interface were investigated with sum frequency generation vibrational spectroscopy(SFG-VS).At pH 4.1,the hydrogen bonding SFG spectra were similar to that of the air/pure water interface.As the pH increased from 5.4 to 9.6,the SFG intensities of both highly ordered hydrogen bonding(3200 cm-1 band) and less-ordered hydrogen bonding(3400 cm-1 band) were enhanced because of the charge-induced effect of deprotonated PDEM.The free OH peak disappeared completely because it was replaced by interfacial PDEM molecules.At pH 11.5,a new spectral band appeared at about 3580 cm-1 in the ppp and sps spectra,and this could be assigned to the C2v asymmetric stretching mode of the water molecules through molecular symmetry simulation.These hydrogen bonding structures are fully consistent with the conformational change of PDEM alkyl groups,and PDEM molecules act as a Hofmeister solvent.PDEM molecules are kosmotropic when they are charged and become more chaotropic as the pH increases.     

Crystal structure and photoelectricity property of Fe(Ⅱ/Ⅲ) coordination supermolecules

Three new mixed-ligand Fe(Ⅱ/Ⅲ) complexes [Fe2(μ2–btec)( μ2–H2btec)(phen)2(H2O)2]n (1), [Fe2(btec) (phen)2(H2O)4] (2), and {[Fe(o-pha)(phen)(H2O)]·H2O}n (3) (phen=1,10-phenanthroline, o-H2pha=o-phthalic acid, H4btec=1,2,4,5-benzenetetracarboxylic acid) have been hydrothermally synthesized and detected by single crystal X-ray diffraction, showing that complexes (1) and (2) are both bridged by the betc4? ligands to form 1D chain and dinuclear structure and complex (3) is bridged by the o-pha groups to form 1D ...     

Lithium bond structures of H_nY (n=2, 3; Y=O, S, N)… LiNH_2 and the abnormal blue shift of N―Li bond

The optimized geometries of the complexes between HnY (n=2, 3; Y=O, S, N) and LiNH2 have been calculated at the B3LYP/6-311 G** and MP2/6-311 G** levels. Three stable complexes were obtained. Frequency analysis showed that the enlarged 2N―4Li presents the abnormal blue shift in three complexes. The calculated binding energy with basis set super-position error (BSSE) and zero-point vibrational energy (ZPE) corrections of complex I―III is _58.65, _31.66 and _69.59 kJ·mol-1 (MP2), respectively. Natural bond orbital theory (NBO) analysis has been performed, and the results revealed that the H2O…LiNH2 (complex I) and H3N…LiNH2 (complex III) are formed with coexisting σ-s and n-s type lithium bond interactions, complexⅡis formed with π-s type lithium bond interaction between HnY (n=2,3; Y=O, N) and LiNH2, and H2S…LiNH2 (complex II) is formed with n-s type lithium bond interaction between H2S and LiNH2. Natural resonance theory (NRT) and atom in molecule (AIM) theory have also been studied to investigate the bond order and topological properties of the lithium bond structures.     

Synthesis, structure and superoxide dismutase activity of two self-assembly transition metal complexes containing a tridentate amino-Schiff base deviating from salicylaldehyde with glycine

Two new transition metal （Cu, Ni） complexes with amino-Schiff base ligand, （CgH7NO3）Cu（C14H12N2）.H2O （1） and （C9HTNO3）Ni（C3H4N2）3.H2O （2）, have been designed and synthesized in ethanol solution at room temperature. Both of the complexes have been characterized by elemental analysis, IR spectra, UV-vis spectroscopy and X-ray single crystal diffraction. For complex 1, the coordination environment of the central copper atom is a distorted square pyramid, and one-dimensional chain is formed through the inter-molecular hydrogen bonds （O4-H2W…O3, O4…H2W…O3#1 （#1： -x＋1, y, -z＋3/2）） and weak interactions （∏-∏ stacking interaction） between the phenyl rings. For complex 2, the nickel atom is 6-coordinated and in a distorted octahedral environment, and a discrete hydrogen-bond cluster （four molecules are connected by hydrogen bonds into a group） is formed via two types of intra-molecular hydrogen bonds （O-H...O, N-H...O） and inter-molecular hydrogen bonds （O-H...O, N-H...O）.     

Synthesis, crystal structure and properties of binuclear manganese complex [(bipy)2Mn2(μ-O)(μ-Ac)2(H2O)2](ClO4)2

Binuclear manganese complex [(bipy)2Mn2(μ-O)(μ-Ac)2(H2O)2](ClO4)2 was synthesized by the reaction of MnAc3·2H2O with 2,2′- -bipyridine in the HAc-NaAc buffer (pH = 4.0). X-ray diffraction result for the single crystal shows that the crystal is monoclinic, space group C2/C, with a = 3.408 2(7), b = 0.864 4(2), c = 2.174 9(4) nm, β=105.2°,V =6.186(2) nm3, Z = 8. There are two very strong peaks of UV-Vis spectrum in the range of 400-600 nm, which are similar to those of Mn catalase and Mn ribonuleotide reductase extracted from organisms. Cyclic voltammogram shows that the complex in CH3CN undergoes quasi-reversible one-electron reduction and oxidation at E1/2=1.15 V.     

Studies of Several Systems with Air Electrode Electro-Synthesizing H2O2 on the Spot for Degrading Aniline in Aqueous

A gas diffusion electrode (air electrode) with a high current efficiency of electro-synthesizing H2O2 using O2 in air was prepared. The several systems with air electrode as cathode of electro-synthesizing H2O2 on the reaction spot for degrading aniline in aqueous--electro-Fenton system, photo-excitation electro-H2O2 system and photo-electro-Fenton system, were developed. The rates of decomposition of H2O2 and mineralization of aniline were experimentally measured respectively under different conditions, and the results indicated there has an excellent parallel relation between decomposition rate of H2O2 and mineralization rate of aniline. Especially, photo-electro-Fenton system, where H2O2 is decomposed the fastest, is the best system of oxidizing and degrading organic toxicants. Compared photo-electro-Fenton system with photo-Fenton system, important role is revealed in the interface of air electrode. In this paper, the mineralization mechanism of aniline in the photo-electro-Fenton system was also discussed.