Ab initiostructure determination of Zr(OH)₂SO₄.3H₂O using the conventional monochromatic X-ray powder diffraction

Abstract

The structure of Zr(OH)2SO4.3H2O has been determined ab initio by conventional powder diffractometry using monochromatic X‐rays. The pattern was indexed using the successive‐dichotomy method yielding cell dimensions a = 8.3645 (4), b = 15.1694 (9), c = 5.4427 (3) Å, and β = 103.145 (5)°. The space group is P21/c with Z = 2. 519 integrated intensities were extracted by whole‐pattern fitting and these were used to calculate the heavy‐atom positions by the Patterson method. Successive Fourier syntheses located the nine O atoms. Rietveld refinement was carried out over an angular range of 15 to 135°(2θ) and this converged with RF = 0.030, RB = 0.066, Rp = 0.085 and Rwp = 0.109. The structure consists of zigzag chains in the direction of [001] formed by edge‐sharing eightfold‐coordinated zirconium polyhedra in the shape of a bicapped trigonal prism. Sulfate tetrahedra bridge within chains whilst a network of hydrogen bonding stabilizes interchain interactions to form `corrugated sheets' parallel to the (100) plane; between these sheets lie `free' water molecules that do not take part in the polyhedra but do play a major role in the hydrogen‐bonding network. The ICDD Powder Diffraction File No. is 44–1493.

Ab Initio Structure Determination of New Mixed Zirconium Hydroxide Nitrates ZrM(OH)2(NO3)3 (M=K, Rb) from X-Ray Powder Diffraction Data

“…Zr distances between the bridged Zr atoms. As already reported for known zirconium basic salts containing [Zr(OH) ]L> L chains(18,19,20,32,35), the common values for Zr . .…”

Structural Analysis of Zirconium Hydroxide Nitrate Monohydrates by X-Ray Powder Diffraction

“…5), in accordance with the notation of Hoard and Silverton for the 4 2m symmetry of the ideal Mo(CN)\ coordination (18). This specific description allows the evaluation of the deviation from the ideal shape (18) and then makes easier the comparison between close dodecahedral coordinations, as those found in the structure of reported zirconium hydroxide nitrates (5-7) and other related basic salts (1,21 Fig. 5), i.e., those which are responsible for the polymerization through the OH-OH bridges and those involving a chemical function such as the bidentate nitrate group.…”

“…Similar to the variety of zirconium hydroxide sulfates reported in literature (1,2), the related family of hydroxide nitrates exhibits a number of phases, which have been clearly identified from temperature-dependent X-ray powder diffraction (TDXD) (3). These phases are generally obtained in a powder form and the application of the developments occurred in the past 10 years in ab initio structure determination (see, for example, Ref.…”

Solution‐Processed HafSOx and ZircSOx Inorganic Thin‐Film Dielectrics and Nanolaminates

“…Several structures have been characterized as simple hydrates, e.g., Hf(SO 4 ) 2 · nH 2 O or Zr(SO 4 ) 2 · nH 2 O, [12] exhibiting variations in the degree of hydration and in the structural dimensionality associated with the condensation of the metal atom, sulfate groups, and water. Materials rich in metal relative to sulfate are known, and they include Zr 2 (OH) 2 (SO 4 ) 3 · 4H 2 O; [13] Hf(OH) 2 SO 4 , Zr(OH) 2 SO 4 , and their hydrates; [14][15][16][17][18] [19,20] and Zr 3 O 5 SO 4 and its hydrate. [21] Additional, largely uncharacterized phases have also been reported.…”