scholarly journals Synthesis, Crystal Structure and Characterization of Cu2 (PO4) (OH)

2009 ◽  
Vol 5 (2) ◽  
pp. 685-694
Author(s):  
R. Ayadi ◽  
Mohamed Boujelbene ◽  
T. Mhiri

This paper reports the hydrothermal synthesis and crystal structure refinement of cuivre phosphate hydroxide,  Cu 2 (PO4) (OH), obtained at 453 K.Its structure consists of chains of edge-sharing, distorted [CuO4 (OH)2] octahedral extending parallel to [001]. These chains are cross linked by isolated PO4 tetrahedra through corner-sharing, forming channels in which dimmers of edge-sharing [CuO4 (OH)] trigonal bipyramids are located. The structure is stabilized by medium to weak O-H…O hydrogen bonds. In contrast to the previous refinement single crystal X-ray and analysis of data from vibrational spectroscopy, all non –H atoms were refined with anisotropic displacement parameters and the H atom was located.

IUCrData ◽  
2021 ◽  
Vol 6 (7) ◽  
Author(s):  
Sergei I. Ivlev ◽  
Florian Kraus

Single crystals of barium bis[tetrafluoridobromate(III)], Ba[BrF4]2, were obtained in the form of tiny blocks. Crystal-structure refinement of Ba[BrF4]2 from single-crystal X-ray diffraction data confirmed the previous model obtained on the basis of powder data [Ivlev et al. (2014). Eur. J. Inorg. Chem. pp. 6261–6267], but with all atoms refined with anisotropic displacement parameters. The crystal structure consists of two symmetry-independent barium cations that are each coordinated by twelve fluorine atoms, forming edge-sharing polyhedra, and an almost square-planar [BrF4]− anion. The compound crystallizes in the Ba[AuF4]2 structure type.


2020 ◽  
Vol 235 (8-9) ◽  
pp. 303-309
Author(s):  
Sven Umlauf ◽  
Markus Weber ◽  
Robert Glaum

AbstractThe monoclinic α-polymorph of (VIVO)(PO3)2 is obtained reproducibly by reaction of V2O5 and H3PO4 (85%) (Au crucible, 380 °C, 4 d). Its crystal structure was refined from X-ray single-crystal data [C2/c, Z = 4, a = 15.1038(7) Å, b = 4.193(2) Å, c = 9.573(9) Å, β = 126.45(3), R1 = 0.052, wR2 = 0.189 for 976 unique reflections with Fo > 4σ(Fo), 48 variables]. A single-phase powder of the β-polymorph is obtained by the reaction of V2O5, H3PO4 (85%) and oxalic acid, evaporating the mixture, and subsequent annealing (porcelain crucible, 800 °C in air, 2 d). Single crystals of β-(VIVO)(PO3)2 were grown in a sealed silica ampoule with chlorine as mineralizer. The crystal structure of the orthorhombic (pseudo-tetragonal) β-polymorph was refined from X-ray single-crystal data [pseudo-merohedral twin, Fdd2, Z = 8, a = 15.536(2) Å, b = 15.586(2) Å, c = 4.2611(5) Å, R1 = 0.032, wR2 = 0.068 for 1072 unique reflections with Fo > 4σ(Fo), 50 variables]. Earlier reports on a tetragonal polymorph with unusual geometric structure of the [(V≡O)O5] polyhedron are corrected.


2005 ◽  
Vol 20 (3) ◽  
pp. 203-206 ◽  
Author(s):  
M. Grzywa ◽  
M. Różycka ◽  
W. Łasocha

Potassium tetraperoxomolybdate (VI) K2[Mo(O2)4] was prepared, and its X-ray powder diffraction pattern was recorded at low temperature (258 K). The unit cell parameters were refined to a=10.7891(2) Å, α=64.925(3)°, space group R−3c (167), Z=6. The compound is isostructural with potassium tetraperoxotungstate (VI) K2[W(O2)4] (Stomberg, 1988). The sample of K2[Mo(O2)4] was characterized by analytical investigations, and the results of crystal structure refinement by Rietveld method are presented; final RP and RWP are 9.79% and 12.37%, respectively.


Author(s):  
Gohil S. Thakur ◽  
Hans Reuter ◽  
Claudia Felser ◽  
Martin Jansen

The crystal structure redetermination of Sr2PdO3 (distrontium palladium trioxide) was carried out using high-quality single-crystal X-ray data. The Sr2PdO3 structure has been described previously in at least three reports [Wasel-Nielen & Hoppe (1970). Z. Anorg. Allg. Chem. 375, 209–213; Muller & Roy (1971). Adv. Chem. Ser. 98, 28–38; Nagata et al. (2002). J. Alloys Compd. 346, 50–56], all based on powder X-ray diffraction data. The current structure refinement of Sr2PdO3, as compared to previous powder data refinements, leads to more precise cell parameters and fractional coordinates, together with anisotropic displacement parameters for all sites. The compound is confirmed to have the orthorhombic Sr2CuO3 structure type (space group Immm) as reported previously. The structure consists of infinite chains of corner-sharing PdO4 plaquettes interspersed by SrII atoms. A brief comparison of Sr2PdO3 with the related K2NiF4 structure type is given.


Author(s):  
Paolo Ballirano ◽  
Beatrice Celata ◽  
Alessandro Pacella ◽  
Ferdinando Bosi

A detailed description of the structure of the amphibole-supergroup minerals is very challenging owing to their complex chemical composition that renders the process of cation partition extremely difficult, particularly because of the occurrence of multivalent elements. Since amphiboles naturally occur under a fibrous morphology and have largely been used to produce asbestos, there is a growing demand for detailed and accurate structural data in order to study the relationships between structure, composition and toxicity. The present study proposes a recommended refinement procedure for both X-ray single-crystal structure refinement (SREF) and Rietveld analysis for tremolite, selected as a test case. The corresponding structural results are compared to estimate the `degree of confidence' of the Rietveld refinement with regard to SREF. In particular, it is shown that the interpretation of the electron density of the tremolite structure by SREF is model dependent. By assuming that the site-scattering values from SREF should be as close as possible to those from electron microprobe analysis, as a crucial constraint for the correct description of the final crystal-chemical model, it is found that it is best satisfied by using partially ionized scattering curves (SCs) for O and Si, and neutral SCs (neutral oxygen curves or NOCs) for other atoms. This combination leads to the best fit to the diffraction data. Moreover, it is found that Rietveld refinement using NOCs produces the best structural results, in excellent agreement with SREF. It is worth noting that, due to the complexity of the diffraction pattern and the fairly large number of freely refinable parameters, refinements with different combinations of SCs produce results almost indistinguishable from a statistical point of view, albeit showing significant differences from a structural point of view.


2013 ◽  
Vol 634-638 ◽  
pp. 451-455
Author(s):  
Yan Yang ◽  
Liu Ting Yan ◽  
Rong Huan Qin ◽  
Wen Gui Duan

The lead(II) Complex constructed with 5-hydroxyisophthalic acid, [Pb3(5-hipa)2]n•4H2O(1), (5-hipa = 5-hydro- xyisophthalic acid) has been synthesized by hydrothermal methods and structurally characterized by elemental analysis, IR and X-ray single crystal diffraction. In trinuclear symmetrical complex 1, Pb1 is four-coordinated, Pb2 and Pb3 are three-coordinated by 5-nitroisophthalic acid groups, respectively, which is further connected through intermolecular hydrogen bonds resulting in a three-dimensional (3D) network.


2008 ◽  
Vol 63 (5) ◽  
pp. 543-547 ◽  
Author(s):  
Inés Viera ◽  
Laura Domínguez ◽  
Javier Ellena ◽  
María H. Torre

This work reports the synthesis and characterization of a new copper complex with nadolol, a betablocker aminoalcohol. The stoichiometry found was Na[Cu(nadololate)(CO3)] · H2O. Electronic and vibrational spectroscopy analysis was performed, and the crystal structure of Na[Cu(nadololate)-(CO3)] · H2O was determined by X-ray diffraction.


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