Two crown-ether-coordinated caesium halogen salts.

The crystal structures of two crown-ether-coordinated caesium halogen salt hydrates, namely di-μ-bromido-bis[aqua(1,4,7,10,13,16-hexaoxacyclooctadecane)caesium(I)] dihydrate, [Cs2Br2(C12H24O6)2(H2O)2]·2H2O, (I), and poly[[diaquadi-μ-chlorido-μ-(1,4,7,10,13,16-hexaoxacyclooctadecane)dicaesium(I)] dihydrate], {[Cs2Cl2(C12H24O6)(H2O)2]·2H2O}n, (II), are reported. In (I), all atoms are located on general positions. In (II), the Cs(+) cation is located on a mirror plane perpendicular to the a axis, the chloride anion is located on a mirror plane perpendicular to the c axis and the crown-ether ring is located around a special position with site symmetry 2/m, with two opposite O atoms exactly on the mirror plane perpendicular to the a axis; of one water molecule, only the O atom is located on a mirror plane perpendicular on the a axis, while the other water molecule is completely located on a mirror plane perpendicular to the c axis.

Mono-, di-, and oligonuclear complexes of Cu(II) ions and p-hydroquinone ligands: syntheses, electrochemical properties, and magnetic behavior.

Four highly soluble square-planar Cu(II) and Ni(II) complexes of siloxy-salens (2SiCu, 2SiNi) and hydroxy-salens (2Cu, 2Ni) have been synthesized. An X-ray crystal structure analysis was performed on 2SiCu, 2SiNi, and 2Ni. The compounds have been investigated by cyclic voltammetry, UV-vis-NIR spectroelectrochemistry, and EPR spectroscopy.

Synchrotron-radiation study of the two-leg spin-ladder (VO)2P2O7 at 120 K.

The crystal structure of the ambient-pressure phase of vanadyl pyrophosphate, (VO)2P2O7, has been precisely determined at 120 K from synchrotron X-ray diffraction data measured on a high-quality single crystal. The structure refinement unambiguously establishes the orthorhombic space group Pca2(1) as the true crystallographic symmetry. Moreover, it improves the accuracy of previously published atomic coordinates by one order of magnitude, and provides reliable anisotropic displacement parameters for all atoms.