catena-Poly[[disilver(I)(Ag-Ag)-bis[mu-1,1'-(butane-1,4-diyl)diimidazole-kappa2N(3):N3']] bis(perchlorate)]: a double helix stabilized by ligand-unsupported argentophilic interactions.

The title compound, {[Ag(2)(C(10)H(14)N(4))(2)](ClO(4))(2)}(n), is a one-dimensional coordination polymer formed by Ag(I) atoms linearly bridged by 1,1'-(butane-1,4-diyl)diimidazole molecules. The chains have a helical arrangement and pairs of chains are held together by the rarely reported ligand-unsupported Ag-Ag interaction [2.966 (1) A], which results in a double-helix structure. The double helix contains twisted 24-membered metallomacrocycles, which are composed of four Ag atoms and two ligands. The Ag atoms lie on twofold axes.

catena-Poly[[(2,2'-bipyridyl)oxidovanadium]-di-mu2-oxido-[(2,2'-bipyridyl)oxidovanadium]-mu3-selenito-bis[(2,2'-bipyridyl)dioxidovanadium]-mu3-selenito].

In the title compound, [V(4)O(8)(SeO(3))(2)(C(10)H(8)N(2))(4)], there are two distinct vanadium coordination environments. Alternating corner-shared VO(4)N(2) octahedra and SeO(3) pyramids result in eight-membered centrosymmetric V(2)Se(2)O(4) rings. In addition, pairs of V centres form centrosymmetric V(2)O(6)N(4) clusters via edge-sharing. These two kinds of secondary building units are linked in an ABABAB fashion to give an infinite chain whose nature is unprecedented in Se-V-O systems.

Bis(mu-4-carboxy-2-sulfonatobenzoato)bis[aqua(2,2'-bipyridyl)manganese(II)].

In the title compound, [Mn(2)(C(8)H(4)O(7)S)(2)(C(10)H(8)N(2))(2)(H(2)O)(2)], pairs of hexacoordinated manganese(II) centres are bridged by 2-sulfonatoterephthalate(2-) anions to form cyclic centrosymmetric dimers, which are linked into sheets by O-H...O hydrogen bonds.

A facile synthesis to Zn(2)SiO(4):Mn(2+) phosphor with controllable size and morphology at low temperature.

Sphere- and rod-shaped Zn(2)SiO(4):Mn(2+) phosphor nanocrystals were synthesized at 230 degrees C. The process consists of tuning the surfactant concentration in the oil/surfactant/ethanol system. Powder X-ray (XRD) and transmission electron microscopy (TEM) were used to characterize the phase purity, size and morphology. Photoluminescent (PL) spectra were collected and analyzed. Fourier transform infrared (FT-IR) spectra of the samples indicate the removal of surfactant in the phosphor nanoparticles. As a result, the sphere-shaped phosphor nanoparticles of 100 nm in size can be redispersed in ethanol ultrasonically. The suspension maintain stable for over 48 h.

Highly sensitive WO3 hollow-sphere gas sensors.

In this paper, we describe how WO(3) hollow spheres have been synthesized in solution phase by the controlled hydrolysis of WCl(6) using novel carbon microspheres as the templates. All of the products were characterized by X-ray powder diffraction (XRD), scanning electronic microscopy (SEM), and transmission electron microscopy (TEM). The as-synthesized spheres had large diameters of about 400 nm and thin shells of about 30 nm composed of numerous small nanocrystals. Prompted by the porous structure and small crystal size of the shell wall, we constructed WO(3) hollow-sphere gas sensors and found that these sensors had good sensitivity to alcohol, acetone, CS(2), and other organic gases.