Hans-Lothar Keller

Hydrothermalsynthese und Kristallstruktur der Münzmetall‐Quecksilber‐Chalkogenidhalogenide CuHgSeBr, AgHgSBr und AgHgSI

CuHgSeBr wird aus CuBr und HgSe in konzentrierter wassriger HBr durch hydrothermale Umsetzung bei 285 °C in Form von roten Kristallen, AgHgSBr und AgHgSI werden aus AgX (X = Br, I) und HgS in halbkonzentrierter wassriger HX (X = Br, I) durch hydrothermale Umsetzung bei 300 °C bzw. 400 °C in Form von hellgelben Kristallen erhalten. Die Substanzen kristallisieren isotyp (orthorhombisch, Pmma, a = 1020,1(3) pm, b = 431,2(1) pm, c = 925,6(3) pm fur CuHgSeBr, a = 964,8(8) pm, b = 466,1(4) pm, c = 942,6(6) pm fur AgHgSBr und a = 1015,9(2) pm, b = 464,77(5) pm, c = 984,9(2) pm fur AgHgSI, Z = 4). Die Strukturen bestehen aus ebenen, gefalteten Hg–Y-Ketten, die durch Y2X2-Tetraederdoppel miteinander verknupft sind. Die Atome der Sorte M (M = Cu, Ag; X = Br, I; Y = S, Se) sind stark verzerrt tetraedrisch von zwei Halogen- und zwei Chalkogenatomen umgeben. Der neue Strukturtyp unterscheidet sich im Aufbau der Hg–Y-Ketten von der bekannten Struktur des CuHgSeCl, entspricht jedoch der gemittelten Struktur der Order-Disorder-Phase γ-Hg3S2Cl2. Hydrothermal Synthesis and Crystal Structure of the Coinage Metal Mercury Chalcogenide Halides CuHgSeBr, AgHgSBr, and AgHgSI The hydrothermal reaction of CuBr and HgSe in concentrated aqueous HBr as solvent at 285 °C yields red crystals of CuHgSeBr, the hydrothermal reaction of AgX (X = Br, I) and HgS in half-concentrated aqueous HX (X = Br, I) as solvent at 300/400 °C yields yellow crystals of AgHgSBr and AgHgSI. The compounds crystallize isotypically (orthorhombic, Pmma, a = 1020.1(3) pm, b = 431.2(1) pm, c = 925.6(3) pm for CuHgSeBr, a = 964.8(8) pm, b = 466.1(4) pm, c = 942.6(6) pm for AgHgSBr und a = 1015.9(2) pm, b = 464.77(5) pm, c = 984.9(2) pm for AgHgSI, Z = 4). The structures consist of plane folded Hg–Y chains connected by pairs of distorted Y2X2 terahedra sharing the X–X-edge (M = Cu, Ag; X = Br, I; Y = S, Se). Atoms of the monovalent metals M have a strongly distorted tetrahedral coordination of two halogen and two chalcogen atoms. The new structure type shows distinct differences in the arrangement of the Hg–Y chains in comparision to the already known CuHgSeCl, but represents the superposition structure of the order-disorder phase γ-Hg3S2Cl2.

Hydrogen position, hydrogen bonding and hydroxide dynamics in the Cd(OH)Cl structure type

Abstract The crystal structure of Cd(OH)Cl crystallizes in its own structure type which is intimately related to the layer structures of cadmium hydroxide and cadmium chloride. The hydrogen position of this structure type, however, is not yet completely clear. We performed single-crystal X-Ray diffraction of Cd(OH)Cl on a modern κ-CCD diffractometer, TOF neutron diffraction experiments with an annular cylindrical sample of Cd(OD)Cl, temperature-dependent 2H-NMR-spectroscopy and quantum mechanical calculations to reinvestigate the crystal structure with full information about the H-position, H-bonding and hydroxide dynamics. The results show that the hydrogen position is near a three-fold axis, that only small angle librations occur and that the amount of hydrogen bonding can be neglected.

CsPdCl3 – eine Verbindung mit [Pd2Cl6]-Baugruppen und anorganischem Kation

Im System CsCl/PdCl2 haben wir eine neue Verbindung der Summenformel CsPdCl3 gefunden. Die Kristallstrukturbestimmung erfolgte mit Hilfe der Rontgenpulvermethode, deren Ergebnis mit dem von Einkristalluntersuchungen an translativ fehlgeordneten Einkristallen ubereinstimmt. CsPdCl3 kristallisiert im orthorhombischen Raumgruppentyp Ibam (Nr. 72), mit a = 13,724(1), b = 10,579(1), c = 8,499(1) A und Z = 8. CsPdCl3 ist die erste Verbindung, die dimere [Pd2Cl6]2–-Baugruppen mit Caesiumkationen enthalt. Solche Einheiten wurden bisher ausschlieslich in Verbindungen mit grosen „organischen” Kationen gefunden. CsPdCl3 – A Compound with Isolated [Pd2Cl6] Groups and an Inorganic Cation The crystal structure of CsPdCl3 has been characterized by X-ray powder diffraction methods. Meanwhile it was possible to isolate single crystals and to confirm the structure by single crystal X-ray investigations. CsPdCl3 crystallizes orthorhombic in space group Ibam (No. 72) with a = 13.724(1), b = 10.579(1), c = 8.499(1) A, and Z = 8. CsPdCl3 is a compound with a dinuclear [Pd2Cl6]2– group and a cesium cation. Formerly such groups are only found in combination with large “organic” cations so far.

Solvothermal synthesis, phase transition and crystal structure of β- and γ-CuPb3Br7

Abstract Single crystals of CuPb3Br7 were solvothermally synthesized starting with CuBr and PbBr2 in diethylene glycol at a temperature of 453 K. Two reversible phase transitions were observed with the DSC method at temperatures of 156 K and 433 K. The crystal structures of the low and medium temperature modifications were determined with single crystal X-ray diffraction method. Both modifications can be derived from the Sr7Pt3 type structure and can be differentiated by minor atomic displacements and partial occupation of the additional copper positions.