Zhiping Bai

The crystal structure, equilibrium and spectroscopic studies of bis(dialkyldithiocarbamate) copper(II) complexes [Cu2(R2dtc)4] (dtc=dithiocarbamate)

Abstract Four copper(II) complexes of bis(dialkyldithiocarbamate) [Cd(R2dtc)2] (R=Me, Et, Pr, i-Pr; dtc=dithiocarbamate) have been prepared and characterized by elemental analysis, IR and ESR spectra studies. Their equilibrium constants (K), determined by a UV–vis spectrometry in EtOH, were influenced by the alkyl groups in the following order: i-Pr>n-Pr≈Et>Me. The single crystal structures of complex [Cu2(R2dtc)4] have been determined using X-ray diffraction methods. The compounds [Cu2(Et2dtc)4] and [Cu2(Pr2dtc)4] are built of centrosymmetric neutral dimeric [Cu2(R2dtc)4] entities. The copper atom lies in a distorted square–pyramidal environment. The four equatorial donors are two bidentate chelate sulfur atoms from two dtc ligands. One of the sulfur atoms from the third dtc ligand acts as a bridging ligand occupying the apical position of the symmetry-related copper atom in the dimer structure, which is viewed as two edge-sharing distorted square–pyramids. The structure of [Cu2(i-Pr2dtc)4] is square planar with an exactly planar CuS4 unit and nearly planar NCS2 moieties. The Cu–S distances shows small decreases along the series n-Pr>Et>i-Pr, the biggest change being for the diisopropyl complex. The alkyl substituents at the nitrogen atom affect their coordination number and Cu⋯Cu distance. In the solid, [Cu2(n-Pr2dtc)4] has the shortest Cu⋯Cu distance and [Cu(i-Pr2dtc)2] has the longest one.

Naked-eye detection of fluoride ion in water: a remarkably selective easy-to-prepare test paper

A test paper for high-selectivity detecting fluoride ion in natural aqueous environments without any spectroscopic instrumentation was achieved by using Ru-bipy based quinonehydrazone as a chromo- and fluorogenic hybrid chemosensor.

A sugar-quinoline fluorescent chemosensor for selective detection of Hg2+ ion in natural water

A selective and sensitive fluorescent sensor for detection of Hg2+ in natural water was achieved by incorporating the well-known fluorophore quinoline group and a water-soluble D-glucosamine group within one molecule.

Opto-electronic multifunctional chiral diamondoid-network coordination polymer: bis{4-[2-(4-pyridyl)ethenyl]benzoato}zinc with high thermal stability

A novel 8-fold interpenetration diamondoid-like chiral condensed neutral coordination polymer, bis{4-[2-(4-pyridyl)ethenyl]benzoato}zinc [Zn(PEBA)2] 1, synthesized by the hydrothermal reaction between Zn(ClO4)2·6H2O and 4-[2-(4-pyridylethenyl)]benzenecarbonitrile (PEBC), displays very strong blue fluorescent emission and SHG response (ca. 1.5 × that of urea) as well as high thermal stability (up to ca. 430 °C).

Structure of bis(dipropyldithiocarbamate) cadmium(II), [Cd2(n-Pr2dtc)4] (dtc = dithiocarbamate)

The cadmium complex of bis(dipropyldithiocarbamate), [Cd2(n-Pr2dtc)4] (dtc = dithiocarbamate) was crystallized from ethylether. It crystallizes in the monoclinic system, space group P2I/c, with lattice parameters, a = 8.2532(1), b = 19.4519(1), c = 13.4163(2) Å, β = 99.243(1)°, and Z = 4. The X-ray single-crystal structure of [Cd2(n-Pr2dtc)4] reveals that the complex is binuclear in the solid state and the Cd atom has a distorted square-pyramidal coordination environment and four equatorial donors are the two bidentate chelate sulfur atoms from two dtc ligands, of which the sulfur atom from the bridging dtc ligand occupies the apical position of the symmetry-related Cd atom in the dimer structure.

Enhancement mechanisms behind exclusive removal and selective recovery of copper from salt solutions with an aminothiazole-functionalized adsorbent

The aminothiazole-functionalized adsorbent (CEAD) could exclusively remove and to selectively recover copper. The adsorption and separation properties of Cu(II) onto CEAD from aqueous media, with or without salts such as NaNO3, Ca(NO3)2 and Ni(NO3)2, were systematically compared by carrying out single, binary and multiple component static and dynamic experiments. In binary systems, the adsorption capacities of Cu(II) were obviously increased by 39.47%, 47.37% and 57.89% with Ni(NO3)2, NaNO3 and Ca(NO3)2, respectively. Besides, simulation study was performed to selectively recover Cu(II) from multi-component aqueous media, with the separation factor of only 54.91 in aqueous media without salts. The separation factor became infinite in the presence of NaNO3 and the enhancement ratio for Cu(II) was raised by 126.31%. Dynamic adsorption could separate Cu(II) and Ni(II) completely and the amount of effluent for pure Ni(II) increased to 127 BV with the help of NaNO3. In the predominant chelating mode simulated by density functional theory calculation, a metal ion coordinated with three nitrogen atoms and formed a chelating complex with two five-membered rings, and Cu(II) showed stronger coordinating ability than Ni(II) did. Meanwhile, anions exerted significant beneficial effects by electrostatic screening, and thus strengthened the exclusive removal and selective recovery of Cu(II).

Synthesis, structural and spectroscopic characterization of the α and β forms of bis(imidazole)copper(II) dibenzoate, [Cu(im)2(OBz)2]

Two modifications of the α and β forms of bis(imidazole)copper(II) dibenzoate, [Cu(im)2(OBz)2], have been obtained by recrystallization from EtOH. X-ray analysis reveals that the two modifications have the same structure with different geometric parameters. The α form crystallizes in the C2/c space group and the β form, in the P2(1)/n space group. The crystal structures of both consist of centrosymmetric monomeric molecules of [Cu(im)2(OBz)2] with a distorted octahedral geometry for the CuN2O2ċO2′ chromophore. The e.s.r. spectra of the α and β forms exhibit a shf structure that consists of 9 lines, and these signals are also different from those of monomeric tetra(imidazole)copper(II) diacetate. Electronic and i.r. spectra are in agreement with the structural data.

2-(2-Hydroxybenzylidene)-1-(2-picoloyl)-hydrazine hemihydrate

In the title compound [2-hydroxybenzaldehyde 2-pyridylcarbonylhydrazone hemihydrate, C 13 H 11 N 3 O 2 .-0.5H 2 O or (1).0.5H 2 O], molecules of (1) are linked pairwise through intermolecular N-N…N hydrogen bonds. These pairs alternate with hydrogen-bonded water molecules to form one-dimensional chains.

The collective flux pinning force in (Sm0.5Eu0.5)Ba2Cu3O7−δ superconductors

We have measured the isothermal magnetization loops of top-seeded melt processed (Sm0.5Eu0.5)Ba2Cu3O7??+10?mol%?(SmEu)BaCuO5+10?wt% Ag crystals in a magnetic field up to 8?T parallel to the c-axis from 50 to 87?K using a vibrating sample magnetometer. All of the isothermal Jc(H) curves show a second peak. The scaling of the Fp?H curves indicates that the flux pinning force Fp comes from the collective pinning of two kinds of pinning centres, Fp = FpH+FpL. One (FpH) is the ?Tc-type pinning centre originating from the RE?Ba and RE?RE substitution responsible for the second peak; the other (FpL) is the normal pinning contributed by the surface and point pins. The Hc2?T diagram implies two critical temperatures. The crossover occurs at about 88.2?K.

Structure of hexakis(imidazole)nickel(II) disalicylate, [Ni(Im)6](Sal)2

The crystal and molecular structures of [Ni(Im)6](Sal)2 (Im = imidazole, Sal = salicylate) have been determined by X-ray crystallography. It crystallizes in the triclinic system, space group P1¯, with lattice parameters a = 8.3125(2), b = 8.7168(1), c = 12.3262(3) Å, α = 90.341(1), β = 96.33(1), γ = 101.544(1)°, and Z = 1. The crystal structure of the title compound is built up of discrete monomeric molecules of [Ni(Im)6](Sal)2. The nickel(II) ions have an octahedral geometry with the NiN6 chromophore. In the solid state, the title compound forms a network through N—H···O hydrogen bonds, the intermolecular hydrogen bonds connect the Ni(Im)2+6 moieties and salicylate molecules.