Search results for "Staggered conformation"
showing 3 items of 3 documents
Comprehensive Uranium Thiophosphate Chemistry: Framework Compounds Based on Pseudotetrahedrally Coordinated Central Metal Atoms
2013
The new ternary compounds UP2S6, UP2S7, U(P2S6)2, and U3(PS4)4 were prepared from uranium metal, phosphorus pentasulfide, and sulfur at 700 °C. The crystal structures were determined by single-crystal X-ray diffraction methods. UP2S6 (I) crystallizes in the ZrP2S6 structure type [tetragonal, P42/m, a = 6.8058(7) A, c = 9.7597(14) A, Z = 2], which consists of central uranium(IV) atoms coordinated by P2S64– anions (staggered conformation). The anions are two-dimensional connectors for four uranium cations arranged in one plane. The structure of UP2S7 (II) [orthorhombic, Fddd, a = 8.9966(15) A, b = 15.2869(2) A, c = 30.3195(5) A, Z = 16] is closely related to the monoclinic ZrP2S7 structure ty…
Loose crystals engineered by mismatched halogen bonds in hexachloroethane
2018
Distortions of the directional requirements in halogen⋯halogen contacts between hexachloroethane (HCE), C2Cl6, molecules lead to a loose crystal under ambient conditions. Single-crystal X-ray diffraction shows that the orthorhombic HCE phase of space group Pnma, with the molecules in the staggered conformation, extends at least from 85 to 305 K and from 0.1 MPa to 5.42 GPa. At ambient pressure, all intermolecular distances are longer than the sum of van der Waals radii, reached only at the pressure of ca. 1.2 GPa.
Tris(1,10-phenanthroline)zinc(II) dichromate tetrahydrate
2002
The title compound, [Zn(C12H8N2)3][Cr2O7]·4H2O, was obtained by mixing 1,10-phenanthroline (phen), potassium chromate and zinc sulfate solutions. The asymmetric unit is composed of a [Zn(phen)3]2+ cation, a Cr2O72− anion and four water molecules. The ZnII ion is in a distorted octahedral environment, coordinated by six N atoms from three phen molecules. The cations are connected to anions by weak C—H⋯O hydrogen bonds, with shortest H⋯O distances of ca 2.27–2.33 A. The Cr2O72− anion is in a staggered conformation. Two of the four crystallographically independent water molecules are ordered, and two others are disordered, each over two sites.