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A new neutral α-Keggin polyoxometalate, [{Cu(phen)2}2SiW12O40] (1) (phen = 1,10-phenanthroline) was hydrothermally synthesized and characterized by IR, TG and single-crystal X-ray diffraction. The compound is monoclinic, space group P21/c with a = 26.065(5), b = 11.867(2), c = 23.385(5) Å, β = 113.78(3)°, V = 6619 Å3, Z = 4. X-ray analysis showed that both [Cu(phen)2]2+ units are supported on the α-Keggin polyoxoanion [SiW12O40]4- via the surface bridging and terminal oxygen atoms of two non-adjacent WO6 octahedra; these show unusual coordination environments. One Cu ion displays distorted trigonal bipyramidal geometry and the other square pyramidal. The unusual coexistence of complexes with different geometries is most likely caused by steric effects involving surface oxygen atoms of the heteropolytungstate and phen, which prevent the presence of a sixth coordinating atom. Weak π-π stacking interactions between phen groups give a 1D chain-like structure and hydrogen bonds are responsible for extended 2D and 3D motifs in the crystal. [ABSTRACT FROM AUTHOR]

Abstract: We demonstrate bulk synthesis of single-crystal Sc-doped ZnO nanowires by using (Sc+Zn) powders at . These mass nanowires are characterized through X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy (TEM), selected area electron diffraction, and high-resolution TEM, which have uniform diameters of about 40nm and microns of several decades in length. The growth of ZnScO nanowires is suggested for self-catalyzed vapor–liquid–solid. In particular, PL spectra of these nanowires show emission peaks that intensely shift to long wavelength with increasing Sc and the doping quantity is found responsible for the different characteristics, in which PL mechanism is explained in detail. [Copyright &y& Elsevier]