Jian-Hao Zhou

Fabrication of nanocrystalline ZnWO4 with different morphologies and sizes via hydrothermal route

Abstract ZnWO 4 nanocrystals have been prepared via a hydrothermal route, and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy. The size and morphology of ZnWO 4 nanocrystals were found to depend on the reaction temperature and pH. The length of ZnWO 4 nanorod increased with the increase in pH of the hydrothermal solution. An unusual nanoparticle-to-nanorod transformation was observed during the formation of ZnWO 4 nanoparticles at pH 11.0 and 180 °C. Luminescent properties of ZnWO 4 nanocrystals were investigated by photoluminescence (PL) spectroscopy.

Morphology control of MnWO4 nanocrystals by a solvothermal route

A solvothermal route to MnWO4 nanoparticles and nanorods has been developed. These nano-size products have been characterized by X-ray diffraction and transmission electron microscopy. The pressure, pH and temperature of the reaction systems were found to play important roles in determining the morphologies of the MnWO4 nanocrystalline products. Homologous surfactants have also been used to control the formation of MnWO4 nanocrystals. These surfactants were found to play a crucial role in the solvothermal route, and there is apparently a relationship between the molecular weight of the added homologous surfactants and the aspect ratio of the resulting nanorods.

Synthesis, structures and magnetic properties of two copper(II) complexes with pyrazole and pivalate ligands

The copper(II) complexes, [CuII 3(μ3-OH)(μ-pz)3(Hpz)(Me3CCOO)2]·(Me3CCOOH)2 (1) (Hpz = pyrazole) and CuII(Hpz*)2(Me3CCOO)2 (2) (Hpz* = 3,5-dimethylpyrazole), were obtained from the reactions of Cu(NO3)2·3H2O with Me3CCOOK and Hpz/Hpz* in ethanol. The complex 1 is made up of a trinuclear core [Cu3(μ3-OH)]5+ with a nearly isosceles triangle, surrounded by three bidentate bridging pyrazolate ligands. Two adjacent molecules of 1 are connected by hydrogen bonds to form a dimer. The magnetic susceptibility of 1 was studied, showing antiferromagnetic behavior in the 1.8–300 K range. The complex 2 shows a trans-N2O2 square-planar geometry for the Cu(II) center. The crystal structure of 2 exhibits a one-dimensional chain arrangement mediated by intermolecular H-bonds.

Syntheses and crystal structures of two lead complexes containing tricyanomethanide

Two lead complexes [Pb(2,2′-bipy)2(H2O)2(tcm)]2·(tcm)2·2H2O, 1, and [Pb(phen)2(tcm)2], 2, have been prepared by reacting Pb(NO3)2, potassium tricyanomethanide (Ktcm) and 2,2-bipyridine or 10-phenanthroline, respectively. X-ray crystallography studies show that 1 is a dimer formed by two eight-coordinate [Pb(bipy)2(H2O)2] units bridged by tricyanomethanide while 2 is a mononuclear six-coordinate compound with the lead atom surrounded by two phen ligands and two tricyanomethanide ions.

Dibenzyl 2,2′-(ethane-1,2-diyl­idene)dihydrazinecarbodithioate bis(di­methyl­formamide) solvate

The title compound, C(18)H(18)N(4)S(4).2C(3)H(7)NO, crystallizes with the dibenzyl dihydrazinecarbodithioate molecule residing on a crystallographic inversion centre. The molecule adopts a trans conformation with respect to the central C-C single bond. The dihedral angle between the phenyl group and the thiothiosemicarbazone unit is 74.1 (1) degrees.