scholarly journals Crystal structure of K0.75[FeII3.75FeIII1.25(HPO3)6]·0.5H2O, an open-framework iron phosphite with mixed-valent FeII/FeIIIions

Author(s):  
Edurne S. Larrea ◽  
José Luis Mesa ◽  
Estibaliz Legarra ◽  
Andrés Tomás Aguayo ◽  
Maria Isabel Arriortua

Single crystals of the title compound, potassium hexaphosphitopentaferrate(II,III) hemihydrate, K0.75[FeII3.75FeIII1.25(HPO3)6]·0.5H2O, were grown under mild hydrothermal conditions. The crystal structure is isotypic with Li1.43[FeII4.43FeIII0.57(HPO3)6]·1.5H2O and (NH4)2[FeII5(HPO3)6] and exhibits a [FeII3.75FeIII1.25(HPO3)6]0.75−open framework with disordered K+(occupancy 3/4) as counter-cations. The anionic framework is based on (001) sheets of two [FeO6] octahedra (one with point group symmetry 3.. and one with point group symmetry .2.) linked along [001] through [HPO3]2−oxoanions. Each sheet is constructed from 12-membered rings of edge-sharing [FeO6] octahedra, giving rise to channels with a radius ofca3.1 Å where the K+cations and likewise disordered water molecules (occupancy 1/4) are located. O...O contacts between the water molecule and framework O atoms of 2.864 (5) Å indicate hydrogen-bonding interactions of medium strength. The infrared spectrum of the compound shows vibrational bands typical for phosphite and water groups. The Mössbauer spectrum is in accordance with the presence of FeIIand FeIIIions.

2014 ◽  
Vol 70 (11) ◽  
pp. 309-311 ◽  
Author(s):  
Teresa Berrocal ◽  
Jose Luis Mesa ◽  
Edurne Larrea ◽  
Juan Manuel Arrieta

Diammonium hexaphosphitopentaferrate(II), (NH4)2[Fe5(HPO3)6], was synthesized under mild hydrothermal conditions and autogeneous pressure, yielding twinned crystals. The crystal structure exhibits an [FeII5(HPO3)6]2−open framework with NH4+groups as counter-cations. The anionic skeleton is based on (001) sheets of [FeO6] octahedra (one with point-group symmetry 3.. and one with .2.) linked along [001] through [HPO3]2−oxoanions. Each sheet is constructed from 12-membered rings of edge-sharing [FeO6] octahedra, giving rise to channels with a radius ofca3.1 Å in which the disordered NH4+cations are located. The IR spectrum shows vibrational bands typical for phosphite and ammonium groups.


2014 ◽  
Vol 70 (12) ◽  
pp. 477-479 ◽  
Author(s):  
Erik Hennings ◽  
Horst Schmidt ◽  
Wolfgang Voigt

Since the discovery of perchlorate salts on Mars and the known occurrence of ferric salts in the regolith, there is a distinct possibility that the title compound could form on the surface of Mars. [Fe(H2O)6](ClO4)3·3H2O was crystallized from aqueous solutions at low temperatures according to the solid–liquid phase diagram. It consists of Fe(H2O)6octahedra (point group symmetry -3.) and perchlorate anions (point group symmetry .2) as well as non-coordinating water molecules, as part of a second hydrogen-bonded coordination sphere around the cation. The perchlorate appears to be slightly disordered, with major–minor component occupancies of 0.773 (9):0.227 (9).


2014 ◽  
Vol 70 (10) ◽  
pp. 235-237 ◽  
Author(s):  
Peter Held

In the title salt, (C2H10N2)3[Pr2(SO4)6]·6H2O, the PrIIIcation is surrounded ninefold by five sulfate groups (two monodentate and three chelating) and by one water molecule [range of Pr—O bond lengths 2.383 (3) to 2.582 (3) Å]. The [Pr(SO4)5(H2O)] groups are arranged in sheets parallel to (010). Two crystal water molecules and two ethylenediammonium cations (one with point group symmetry -1) connect the sheetsviaO—H...O and N—H...O hydrogen bonds from weak up to medium strength into a three-dimensional framework structure.


2014 ◽  
Vol 70 (12) ◽  
pp. 480-482 ◽  
Author(s):  
Erik Hennings ◽  
Horst Schmidt ◽  
Wolfgang Voigt

The title compound, [SnCl4(H2O)2]·6H2O, was crystallized according to the solid–liquid phase diagram at lower temperatures. It is built-up of SnCl4(H2O)2octahedral units (point group symmetry 2) and lattice water molecules. An intricate three-dimensional network of O—H...O and O—H...Cl hydrogen bonds between the complex molecules and the lattice water molecules is formed in the crystal structure.


Author(s):  
Bougar Sarr ◽  
Abdou Mbaye ◽  
Cheikh Abdoul Khadir Diop ◽  
Mamadou Sidibe ◽  
Yoann Rousselin

The organic–inorganic title salt, (C6H16N)2[Sn(C2O4)2Cl2] or ( i Pr2NH2)2[Sn(C2O4)2Cl2], was obtained by reacting bis(diisopropylammonium) oxalate with tin(IV) chloride dihydrate in methanol. The SnIV atom is coordinated by two chelating oxalate ligands and two chloride ions in cis positions, giving rise to an [Sn(C2O4)2Cl2]2− anion (point group symmetry 2), with the SnIV atom in a slightly distorted octahedral coordination. The cohesion of the crystal structure is ensured by the formation of N—H...O hydrogen bonding between (iPr2NH2)+ cations and [SnCl2(C2O4)2]2− anions. This gives rise to an infinite chain structure extending parallel to [101]. The main inter-chain interactions are van der Waals forces. The electronic spectrum of the title compound displays only one high intensity band in the UV region assignable to ligand–metal ion charge-transfer (LMCT) transitions. An IR spectrum was also recorded and is discussed.


Author(s):  
Maksym Seredyuk ◽  
M. Carmen Muñoz ◽  
José A. Real ◽  
Turganbay S. Iskenderov

The title complex, poly[dodeca-μ-cyanido-diiron(III)triplatinum(II)], [FeIII2{PtII(CN)4}3], has a three-dimensional polymeric structure. It is built-up from square-planar [PtII(CN)4]2−anions (point group symmetry 2/m) bridging cationic [FeIIIPtII(CN)4]+∞layers extending in thebcplane. The FeIIatoms of the layers are located on inversion centres and exhibit an octahedral coordination sphere defined by six N atoms of cyanide ligands, while the PtIIatoms are located on twofold rotation axes and are surrounded by four C atoms of the cyanide ligands in a square-planar coordination. The geometrical preferences of the two cations for octahedral and square-planar coordination, respectively, lead to a corrugated organisation of the layers. The distance between neighbouring [FeIIIPtII(CN)4]+∞layers corresponds to the lengtha/2 = 8.0070 (3) Å, and the separation between two neighbouring PtIIatoms of the bridging [PtII(CN)4]2−groups corresponds to the length of thecaxis [7.5720 (2) Å]. The structure is porous with accessible voids of 390 Å3per unit cell.


Author(s):  
Nataliia Yu. Strutynska ◽  
Marina A. Bondarenko ◽  
Ivan V. Ogorodnyk ◽  
Vyacheslav N. Baumer ◽  
Nikolay S. Slobodyanik

Potassium rubidium cobalt(II)/titanium(IV) tris(orthophosphate), Rb0.743K0.845Co0.293Ti1.707(PO4)3, has been obtained using a high-temperature crystallization method. The obtained compound has a langbeinite-type structure. The three-dimensional framework is built up from mixed-occupied (Co/TiIV)O6octahedra (point group symmetry .3.) and PO4tetrahedra. The K+and Rb+cations are statistically distributed over two distinct sites (both with site symmetry .3.) in the large cavities of the framework. They are surrounded by 12 O atoms.


2015 ◽  
Vol 71 (9) ◽  
pp. 1109-1113
Author(s):  
Akihiko Nakatsuka ◽  
Kazumasa Sugiyama ◽  
Akira Yoneda ◽  
Keiko Fujiwara ◽  
Akira Yoshiasa

Single crystals of the title compound, the post-perovskite-type CaIrO3[calcium iridium(IV) trioxide], have been grown from a CaCl2flux at atmospheric pressure. The crystal structure consists of an alternate stacking of IrO6octahedral layers and CaO8hendecahedral layers along [010]. Chains formed by edge-sharing of IrO6octahedra (point-group symmetry 2/m..) run along [100] and are interconnected along [001] by sharing apical O atoms to build up the IrO6octahedral layers. Chains formed by face-sharing of CaO8hendecahedra (point-group symmetrym2m) run along [100] and are interconnected along [001] by edge-sharing to build up the CaO8hendecahedral layers. The IrO6octahedral layers and CaO8hendecahedral layers are interconnected by sharing edges. The present structure refinement using a high-power X-ray source confirms the atomic positions determined by Hiraiet al.(2009) [Z. Kristallogr.224, 345–350], who had revised our previous report [Sugaharaet al.(2008).Am. Mineral.93, 1148–1152]. However, the displacement ellipsoids of the Ir and Ca atoms based on the present refinement can be approximated as uniaxial ellipsoids elongating along [100], unlike those reported by Hiraiet al.(2009). This suggests that the thermal vibrations of the Ir and Ca atoms are mutually suppressed towards the Ir...Ca direction across the shared edge because of the dominant repulsion between the two atoms.


Author(s):  
Jamal Khmiyas ◽  
Abderrazzak Assani ◽  
Mohamed Saadi ◽  
Lahcen El Ammari

Single crystals of magnesium copper(II) bis[orthophosphate(V)] monohydrate, Mg1.65Cu1.35(PO4)2·H2O, were grown under hydrothermal conditions. The crystal structure is formed by three types of cationic sites and by two unique (PO4)3−anions. One site is occupied by Cu2+, the second site by Mg2+and the third site by a mixture of the two cations with an Mg2+:Cu2+occupancy ratio of 0.657 (3):0.343 (3). The structure is built up from more or less distorted [MgO6] and [(Mg/Cu)O5(H2O)] octahedra, [CuO5] square-pyramids and regular PO4tetrahedra, leading to a framework structure. Within this framework, two types of layers parallel to (-101) can be distinguished. The first layer is formed by [Cu2O8] dimers linked to PO4tetrahedraviacommon edges. The second, more corrugated layer results from the linkage between [(Cu/Mg)2O8(H2O)2] dimers and [MgO6] octahedra by common edges. The PO4units link the two types of layers, leaving space for channels parallel [101], into which the H atoms of the water molecules protrude. The latter are involved in O—H...O hydrogen-bonding interactions (one bifurcated) with framework O atoms across the channels.


2015 ◽  
Vol 71 (11) ◽  
pp. 1418-1420 ◽  
Author(s):  
Thomas G. Müller ◽  
Florian Kraus

Hexaamminecobalt(II) bis[tetracarbonylcobaltate(-I)], [Co(NH3)6][Co(CO)4]2, was synthesized by reaction of liquid ammonia with Co2(CO)8. The CoIIatom is coordinated by six ammine ligands. The resulting polyhedron, the hexaamminecobalt(II) cation, exhibits point group symmetry -3. The Co-Iatom is coordinated by four carbonyl ligands, leading to a tetracarbonylcobaltate(−I) anion in the shape of a slightly distorted tetrahedron, with point group symmetry 3. The crystal structure is related to that of high-pressure BaC2(space groupR-3m), with the [Co(NH3)6]2+cations replacing the Ba sites and the [Co(CO)4]−anions replacing the C sites. N—H...O hydrogen bonds between cations and anions stabilize the structural set-up in the title compound.


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