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Article

Press to Success: Gd5FW3O16—The First Gadolinium(III) Fluoride Oxidotungstate(VI)

by
Katharina V. Dorn
1,2 and
Ingo Hartenbach
1,*
1
Institute of Inorganic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
2
Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16 C, 106 91 Stockholm, Sweden
*
Author to whom correspondence should be addressed.
Crystals 2019, 9(8), 424; https://0-doi-org.brum.beds.ac.uk/10.3390/cryst9080424
Submission received: 21 June 2019 / Revised: 9 August 2019 / Accepted: 12 August 2019 / Published: 16 August 2019
(This article belongs to the Special Issue Rare-Earth Metal Compounds)
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Abstract

:
The gadolinium(III) fluoride oxidotungstate(VI), with the formula Gd5FW3O16, represents the first published fluoride-derivative of a rare-earth metal oxidotungstate. It is synthesized by a mixture of GdF3, Gd2O3, and WO3 at 800 °C and a pressure of 2 GPa with the help of a belt press. The title compound crystallizes in the monoclinic space group P21/c (no. 14) with four formula units per unit cell and the following lattice parameters: a = 539.29 (4), b = 1556.41 (12), c = 1522.66 (11) pm, and β = 93.452 (4). The crystal structure comprises five crystallographically distinguishable Gd3+ cations, which are surrounded by either oxide and fluoride anions (Gd1–3) or by oxide anions only (Gd4, Gd5), with coordination numbers ranging between seven and nine. The fluoride anions are trigonal non-planar coordinated by three Gd3+ cations (Gd1–3). The distorted [WO6]6− octahedra in this structure form isolates edge- and vertex-connected entities of the compositions [W2O10]8− and [W2O11]10−, respectively. According to the presented units, a structured formula can be written as Gd4[FGd3]2[W2O10][W2O11]2. The single-crystal Raman spectrum reveals the typical symmetric stretching vibration mode of octahedral oxidotungstate(VI) units at about 871 cm−1.

Graphical Abstract

1. Introduction

Fluoride oxidotungstates (VI), as well as mixed-ligand fluoridooxidotungstates, are known for several alkali, alkaline-earth, and transition metals but not yet for rare-earth elements. Among them, compounds with non-tungsten bonded fluoride, e.g., Ca2NaF[SiO4]-type [1] Na3F[WO4] [2] are known, while Li[W3O9F] [3], Na5[W3O9F5] [4], K2GeF6-type [5], Cs2[WO2F4] [6], Rb2[WO2F4] [7], and Ag[WOF5]2 [8] represent structures, with all F− anions, of the ligand sphere of hexavalent tungsten both in isolated units or in condensed ones, such as in CuWO3F2 [9]. Ba2[WO3F2]F2 [10,11] and Pb5W3O9F10 [12] (≡ Pb10[WO3F3]4(W2O6F4)F4 with units in parentheses being condensed and those in brackets being isolated) exhibit fluoride anions that are both bonded to W6+ and not. Although fluoride-containing rare-earth metal oxidomolybdates with the compositions REF [MoO4] (RE = Y [13], Ce—Nd [14], Sm—Tm [15], and REFMo2O7 (RE = Y [16], Eu—Yb [17]) are well known, the syntheses of the isotypic tungstates is still very challenging. In case of the aforementioned REF[MoO4] representatives, it is possible to utilize molybdenum trioxide both as reactant and as fluxing agent due to its low melting point of 802 °C [18], while in the respective reaction mixture for the tungstates, all components show a melting point above 1200 °C (e.g., GdF3: m.p. = 1232 °C; Gd2O3: m.p. = 2425 °C; WO3: m.p. = 1473 °C) [18], thus a reaction in silica ampoules would only be possible with another compound as flux. Appropriate candidates, such as alkali metal halides, boron oxide, or molybdenum oxide, all result in undesired side products, such as scheelite-type ARE[WO4]2 representatives (e.g., NaGd[WO4]2 [19]) or rare-earth metal borates and molybdates of various compositions, respectively. Experiments following a modified solution route with respect to the one of Naruke and Yamase [20] were tried by Schustereit [21] to obtain rare-earth metal fluoride tungstate derivatives; however, no crystalline products were attained. Inspired by single crystals of two RE(OH)[WO4] derivatives, which occurred during high-pressure experiments to obtain RE3Cl3[WO6] representatives of the smaller rare-earth metals [22,23], the high-pressure synthesis of the formula analogous, and presumably pseudo-isotypic (due to the replacement of OH− by F−) REF[WO4] derivatives, was pursued. Although, the desired products could not be yielded, it was possible to obtain very few single crystals of the gadolinium(III) fluoride oxidotungstate(VI) with the composition Gd5FW3O16 comprising two different ditungstate units as well as [FGd3]8+ entities — a structural motif known also from La3FMo4O16 [24] and other fluoride-containing lanthanoid compounds. Hence, the high-pressure synthesis route opens up a possibility to obtain fluoride-containing rare-earth metal(III) oxidotungstates(VI), which may provide suitable host lattices for luminescent cations, e.g., Eu3+ and Tb3+, as dopants for compounds of the luminescent innocent rare-earth metals yttrium, lanthanum, gadolinium, and lutetium, analogous to the molybdates, e.g., YF[MoO4]:Eu3+ [13].

2. Materials and Methods

2.1. High-Pressure Synthesis

Single crystals of gadolinium(III) fluoride oxidotungstate(VI), with the formula Gd5FW3O16 (Figure 1), were received in attempts to synthesize the gadolinium(III) fluoride ortho-oxidotungstate(VI) GdF[WO4] comprising isolated [WO4]2− tetrahedra. Therefore, the starting materials gadolinium(III) fluoride (GdF3: 99.9%, ChemPur, Karlsruhe, Germany), gadolinium sesquioxide (Gd2O3: 99.9%, ChemPur, Karlsruhe, Germany), and tungsten trioxide (WO3: 99.9%, Merck, Darmstadt, Germany) were mixed together in a molar ratio of 1:1:3 and finely powdered under argon atmosphere in a glovebox.
The mixture was filled into a homemade gold ampoule (purity 99.99%; Figure 2b, top), which was closed with a gold lid and exposed to a reaction temperature of 800 °C and a maximum pressure of 2 GPa for 12 h in a belt press (Figure 2a). Due to the fluoride-containing starting materials and the high-pressure setting, gold was chosen as the most suitable container material. For the title compound Gd5FW3O16, the following reaction equation assuming a not entirely homogeneous mixture of the starting materials was proposed:
GdF3 + 7 Gd2O3 + 9 WO3 → 3 Gd5FW3O16
Due to the extremely small amount of reaction mixture (approx. 50 mg) within the gold ampoules, only very few single crystals of the title compound were obtained. The identification of expected by-products, such as GdOF or GdF[WO4], was not possible.

2.2. Single-Crystal Structure Determination

Intensity data sets for the title compound Gd5FW3O16 were collected with a Smart Apex II Duo single-crystal diffractometer (Bruker AXS, Karlsruhe, Germany) by using Mo-Kα radiation (λ = 71.07 pm) at a temperature of T = 130(2) K. Data correction was applied by the program SADABS [25], and crystal structure solution and refinement were performed with the program package SHELX-2013 [26]. The crystallographic data are displayed in Table 1, while atomic positions and coefficients of the isotropic thermal displacement parameters are given in Table 2. Due to the high absorption of both gadolinium and tungsten, it was not possible to refine all oxygen atoms anisotropically; hence only isotropic refinements for all 16 crystallographically independent O2− anions were performed. The rather high residual electron density, mainly around (Gd5)3+, results from the quite peculiar surrounding of this cation (see Section 3.1). Attempts to solve the structure with the aforementioned cation at a split position (also to resolve the pronouncedly prolate displacement ellipsoid) were not successful. Furthermore, a variation in the occupation of the (Gd5) site, such as defect, mixed, or single occupation with Au3+ (from the container material), resulted in either a full occupation with gadolinium after refinement or in significantly worse residual values (for the occupation of the aforementioned site with gold).

2.3. Single-Crystal Raman Spectroscopy

The single-crystal Raman spectrum for the title compound Gd5FW3O16 was measured with the help of a Horiba XploRa spectrometer using a LASER device of the wavelength λ = 532 nm. For this purpose, the crystal was placed in a glass capillary and fixed with desiccator grease (Figure 1).

3. Results and Discussion

3.1. Crystal Structure

The first gadolinium(III) fluoride oxidotungstate(VI), with the empirical formula Gd5FW3O16, crystallizes in the monoclinic space group P21/c (no. 14) with four formula units per unit cell and the lattice parameters a = 539.29(4), b = 1556.41(12), c = 1522.66(11) pm, and β = 93.452(4) (Table 1). The motifs of mutual adjunction [29,30,31], as well as selected interatomic distances (d/pm) and bond angles (∠/°), in the crystal structure of Gd5FW3O16, are summarized in Table 3, Table 4 and Table 5.
The crystal structure of Gd5FW3O16 comprises five crystallographically distinguishable Gd3+ cations (Table 2 and Table 3) with coordination numbers of seven (Gd1), eight (Gd2–Gd4), and nine (Gd5) set up by both oxide and fluoride anions (Gd1–Gd3) and only by oxide anions (Gd4, Gd5), respectively. While the coordination polyhedra of the cations (Gd1)3+, (Gd3)3+, and (Gd5)3+ are irregularly shaped, the ones for (Gd2)3+ and (Gd4)3+ can be described as distorted square antiprisms (Figure 3). Both the Gd3+–O2− distances of 219–295 pm and the Gd3+–F− distances of 230–236 pm (Table 3) are in good accordance to correspondent values found in literature (e.g., in Gd4O3F6 (C.N. (Gd3+) = 9 + 4): d(Gd3+–O2−) = 215–296 pm, d(Gd3+–F−) = 215–278 pm [33]). The fluoride anions are surrounded by three Gd3+ cations (Gd1–Gd3) with a deviation of about 14 pm out of the plane built up by the F− anions (Figure 3, bottom right) and Gd–F–Gd bond angles of 111–130° (Table 4). A very similar environment of the fluoride anions is found in the crystal structure of the lanthanum(III) fluoride oxidomolybdate(VI) of the composition La3FMo4O16 [24], in which the La–F–La bond angles range between 108 and 137° and the deviation of the fluoride atoms out of the plane built up by La3+ cations is about 24 pm. For (Gd5)3+, a rather high and very prolate displacement ellipsoid is noticeable (see Figure 3 bottom left), which can be explained by an anisotropic distribution of the distances between these cations and their surrounding oxide ligands. Although being the gadolinium cation with the highest coordination number, only four O2− anions (O5, O8, O10, O16) are found with distances shorter than 236 pm. These form a belt (or very flat tetrahedron) around (Gd5)3+, roughly situated in the crystallographic (241) layer. Hence, these cations “escape” the stress of a tight, almost two-dimensional surrounding by extending their displacement anisotropically perpendicular to the aforementioned layer. Of the five oxygen atoms with distances longer than 250 pm, the shortest one (O15) also resides within the aforementioned belt, while the four longest ones (O9, O11, O11’, O13) are situated in the direction of the longest principal axis of the displacement ellipsoid of (Gd5)3+.
These findings are also corroborated by both MAPLE [29,30,31] and bond valence calculations [34,35]. The effective coordination numbers (ECoN, [33]) of Gd1–4 are at best about 0.8 less than the real ones (Table 5), whereas (Gd5)3+ exhibits an ECoN value of 6.3, which is only 70% of the nine surrounding oxide anions detected from the crystal structure description, due to this anisotropic distance distribution. The contribution of every single oxygen ligand to the effective coordination number displays a gap from the ideal value of 1 ± 0.2 for the four shortest ones to 0.63 for (O5)2− and between 0.4 and 0.08 for the longest contacts. The same is true for the bond valence calculations, in which Gd1–4 result to an average charge of 3.1, while it amounts for Gd5 to less than 2.9, with the O2− atoms showing the shortest contacts delivering between 0.5 and 0.4 to the overall charge (0.27 for O15 with the median bond length), and the other five provide 0.2 and less (bond-valence parameters for Gd3+−O2− contacts: R0 = 2.065 Å, B = 0.37 [35]). Thus, the coordination number around the (Gd5)3+ cations is better described as five plus four instead of nine.
The crystal structure of Gd5FW3O16 further comprises three crystallographically distinguishable W6+ cations, which are surrounded by six oxide anions each in shape of distorted octahedra (Figure 4). These coordination polyhedra are interconnected via edge- and vertex-sharing to discrete [(W1)2O10]8− and [(W2)(W3)O11]10− entities, respectively (Figure 4). The W6+–O2− distances range from 175 (terminal) to 234 pm (connecting) with the values in between, resembling the overall coordination of the oxygen anion, i.e., the less contact to Gd3+ cations, the shorter the W6+−O2− bond length (Table 4). These values are typical for octahedral oxidotungstates(VI), especially those in Keggin polyhedra comprising both, terminal as well as edge and vertex sharing oxygen atoms (e.g. H3PW12O40: d(W6+–O2−) = 169–245 pm [36]). While the interaction between the oxide anions and the gadolinium cations is of a mainly ionic nature, the bond between oxygen and tungsten can better be described as covalent. Thus, the anionic arrangement is determined by the previously described isolated ditungstate entities, and the Gd3+ cations are arranged in suitable voids (together with the F− anions). However, the voids filled by the (Gd5)3+ cations appear not to be as suitable as those for (Gd1–4)3+; hence the anisotropic distance distribution found for the coordination polyhedra around the (Gd5)3+ cations is explainable.
A view at the expanded unit cell of Gd5FW3O16 is given in Figure 5. Based on the previously mentioned building blocks, namely the two molecular ditungstate units [W2O10]8− and [W2O11]10−, the anionic but non-covalent [FGd3]8+ triangles, and the remaining two Gd3+ cations, Gd4 and Gd5, this first gadolinium fluoride oxidotungstate (VI) can be described with a structured formula according to Gd4[FGd3]2[W2O10][W2O11]2.

3.2. Single-Crystal Raman Spectrum

The single-crystal Raman spectrum (Figure 6) shows the band of the symmetric vibration mode of the distorted octahedral [WO6]6− entities in the crystal structure of Gd5FW3O16 at a Raman shift of 871 cm−1. This shift is in good accordance with data from both, compounds consisting of vertex-sharing octahedra like russelite (Bi2WO6) [37] and minerals comprising edge-connected octahedral units, such as hübnerite (MnWO4) [37], ferberite (FeWO4) [37], and raspite (α-PbWO4) [37], with their symmetric vibration modes ranging between 800 and 885 cm−1. Due to the large background caused by the desiccator grease (also responsible for the modes between 1000 and 1500 cm−1, as well as between 2600 and 3100 cm−1 [38,39]) in combination with the very small single crystal (Figure 1), the less intense antisymmetric stretching, as well as the deformation vibrations, can only be adumbrated in the area below 850 cm−1 (inset of Figure 6). Other than preliminary experiments using a belt press, in which a contamination with H2O lead to hydroxide containing products, the absence of OH groups in the presented compound is proved by the missing vibration mode at about 3500 cm−1 [40,41], which is a crucial point for the corroboration of the overall composition since F− and OH− groups behave isosteric and the single crystals have proven to be too small for a reliable microprobe analysis.

4. Conclusions

The new gadolinium (III) fluoride oxidotungstate (VI), Gd5FW3O16 (≡Gd4[FGd3]2 [W2O10] [W2O11]2), was synthesized via high-pressure methods in gold ampoules using a belt press and GdF3, Gd2O3, and WO3 as starting materials. The characterization was carried out in single-crystal diffraction and Raman spectroscopy. This fluoride derivative of a rare-earth metal oxidotungstate marks the first success in the syntheses of this class of compounds, while numerous synthesis attempts with both solid-state and solvochemical methods failed to yield crystalline products. Although the high-pressure synthesis has proven to be successful, a high yield of the product could not be established due to the small sample size. However, since elevated pressure appears to have a positive effect on the formation of rare-earth metal fluoride tungstates, there is a good chance to produce a larger amount with hydrothermal methods. Appropriate experiments are already underway, and if a single-phase synthesis has proven to be successful, these materials are rather promising for doping with active cations for luminescence purposes.

Author Contributions

Conceptualization, K.V.D. and I.H.; investigation, K.V.D.; resources, I.H.; writing—original draft preparation, K.V.D.; writing—review and editing, I.H.; supervision, I.H.

Acknowledgments

We are indebted to Adrian Geyer for measuring the single-crystal Raman spectrum with the Raman microscope of Hans-Joachim Massonne (Institute of Mineralogy and Crystal Chemistry, University of Stuttgart, Germany), and Graham McNally, Frank Falkenberg, and Hidenori Takagi for the opportunity to use the belt press at the Max-Planck-Institute for Solid-State Research (Stuttgart, Germany). Furthermore, we thank Wolfgang Frey (Institute for Organic Chemistry, University of Stuttgart, Germany) for the collection of the single-crystal data. Finally, the financial support from the State of Baden-Württemberg (Stuttgart, Germany) and the Open Access Publishing Fund of the University of Stuttgart is gratefully acknowledged.

Conflicts of Interest

The authors declare no conflict of interest.

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Crystals 09 00424 g001 550
Figure 1. Photos of a single crystal of gadolinium(III) fluoride oxidotungstate(VI) (Gd5FW3O16) in a glass capillary taken by the optics of a Raman microscope at different magnifications [22].
Figure 1. Photos of a single crystal of gadolinium(III) fluoride oxidotungstate(VI) (Gd5FW3O16) in a glass capillary taken by the optics of a Raman microscope at different magnifications [22].
Crystals 09 00424 g001
Crystals 09 00424 g002 550
Figure 2. Schematic cross-section (a) of the high-pressure die and the pressure cell of the belt press at the Max-Planck-Institute for Solid State Research (Stuttgart, Germany), and the gold ampoule after treatment ((b), top).
Figure 2. Schematic cross-section (a) of the high-pressure die and the pressure cell of the belt press at the Max-Planck-Institute for Solid State Research (Stuttgart, Germany), and the gold ampoule after treatment ((b), top).
Crystals 09 00424 g002
Crystals 09 00424 g003 550
Figure 3. Coordination environments of the five crystallographically distinguishable Gd3+ cations (red) and trigonal non-planar coordination polyhedra of the fluoride anions (green) in the crystal structure of Gd5FW3O16 (ellipsoid representation at 95% probability).
Figure 3. Coordination environments of the five crystallographically distinguishable Gd3+ cations (red) and trigonal non-planar coordination polyhedra of the fluoride anions (green) in the crystal structure of Gd5FW3O16 (ellipsoid representation at 95% probability).
Crystals 09 00424 g003
Crystals 09 00424 g004 550
Figure 4. Distorted [WO6]6− octahedra in the crystal structure of Gd5FW3O16 (ellipsoid representation at 95% probability), which are connected via common edges to discrete [(W1)2O10]8− units comprising an inversion center ○ (left) and by sharing vertices to also discrete [(W2)(W3)O11]10− entities (right).
Figure 4. Distorted [WO6]6− octahedra in the crystal structure of Gd5FW3O16 (ellipsoid representation at 95% probability), which are connected via common edges to discrete [(W1)2O10]8− units comprising an inversion center ○ (left) and by sharing vertices to also discrete [(W2)(W3)O11]10− entities (right).
Crystals 09 00424 g004
Crystals 09 00424 g005 550
Figure 5. View at the expanded unit cell of Gd5FW3O16 along [100] emphasizing [(O4)2(W1)2]8+ rhombuses of the [(W1)2O10]8− entities (light blue), [(W2)(W3)O11]10− units (dark blue), and the trigonal non-planar coordination environments of the F− anions (green).
Figure 5. View at the expanded unit cell of Gd5FW3O16 along [100] emphasizing [(O4)2(W1)2]8+ rhombuses of the [(W1)2O10]8− entities (light blue), [(W2)(W3)O11]10− units (dark blue), and the trigonal non-planar coordination environments of the F− anions (green).
Crystals 09 00424 g005
Crystals 09 00424 g006 550
Figure 6. Single-crystal Raman spectrum of Gd5FW3O16 (only visible band at 871 cm−1) embedded in desiccator grease (bands between 1000 and 3100 cm−1) under excitation with a green LASER (λ = 532 nm).
Figure 6. Single-crystal Raman spectrum of Gd5FW3O16 (only visible band at 871 cm−1) embedded in desiccator grease (bands between 1000 and 3100 cm−1) under excitation with a green LASER (λ = 532 nm).
Crystals 09 00424 g006
Table
Table 1. Crystallographic data for gadolinium (III) fluoride oxidotungstate (VI) (Gd5FW3O16).
Table 1. Crystallographic data for gadolinium (III) fluoride oxidotungstate (VI) (Gd5FW3O16).
Crystal SystemMonoclinic
Space groupP21/c (no. 14)
Formula units, Z4
a/pm539.29(4)
b/pm1556.41(12)
c/pm1522.66(11)
β/°93.452(4)
Density, Dx/g·cm−38.397
Molar volume, V/cm3·mol−1192.07
Single-crystal X-ray diffractometerSmart Apex II Duo (Bruker AXS)
Radiation71.07 (Mo-Kα)
Temperature, T/K130(2)
Data correctionsProgram SADABS [25]
Structure solution and refinementProgram package SHELX-2013 [26], scattering factors according to [27]
Index range, ±h/±k/±l8/23/23
2θmax/°66.40
F (000)2716
Absorption coefficient, μ52.64
Reflections collected/unique22613/4758
Refined parameters147
Rint/Rσ0.058/0.059
R1 for (n) reflections with |Fo| ≥ 4σ (Fo)0.033 (3728)
R1/wR2 for all reflections0.052/0.047
Goodness of Fit, S1.005
Extinction, g0.00078 (1)
Residual electron density, ρmin/max/e− 10−6 pm−3−4.98/3.95 at (Gd5)3+
Table
Table 2. Wyckoff positions, fractional atomic coordinates, and equivalent isotropic displacement parameters (Ueq 1) for Gd5FW3O16.
Table 2. Wyckoff positions, fractional atomic coordinates, and equivalent isotropic displacement parameters (Ueq 1) for Gd5FW3O16.
AtomPositionx/ay/bz/cUeq/pm2
Gd14e0.54505(6)0.22505(2)0.86095(2)51.2(8)
Gd24e0.99526(6)0.15440(2)0.22655(2)47.8(7)
Gd34e0.02811(6)0.11780(2)0.47811(2)48.0(8)
Gd44e0.48355(6)0.02332(2)0.12010(2)43.4(8)
Gd54e0.98901(8)0.09537(3)0.72614(3)152.9(10)
F4e0.1920(7)0.1929(3)0.3634(3)67(9)
W14e0.00855(5)0.10733(2)0.97043(2)41.7(7)
W24e0.54455(5)0.21721(2)0.63497(2)42.4(6)
W34e0.56511(5)0.02705(2)0.34505(2)42.7(6)
O14e0.8804(8)0.2125(3)0.9665(3)58(10)
O24e0.1430(9)0.1177(3)0.0836(3)67(10)
O34e0.2830(9)0.1171(3)0.9023(3)67(11)
O44e0.7770(8)0.0232(3)0.0125(3)48(10)
O54e0.8007(8)0.0847(3)0.8614(3)50(10)
O64e0.3607(9)0.2020(3)0.5350(3)80(11)
O74e0.6309(9)0.1708(3)0.1260(3)57(10)
O84e0.8288(9)0.1619(3)0.5964(3)75(11)
O94e0.2937(9)0.2284(3)0.7170(3)85(11)
O104e0.7822(8)0.2219(3)0.7491(3)46(10)
O114e0.5031(9)0.0898(3)0.6852(3)98(11)
O124e0.3689(9)0.0384(3)0.4321(3)80(10)
O134e0.3196(9)0.0591(3)0.2558(3)101(11)
O144e0.7181(9)0.1391(3)0.3603(3)83(11)
O154e0.1307(9)0.0152(3)0.5929(3)64(10)
O164e0.7875(8)0.0239(3)0.2326(3)51(10)
1 U e q = 1 3 [ U 22 + 1 sin ( β ) 2 ( U 11 + U 33 − 2 U 13 cos ( β ) ) ] [28].
Table
Table 3. Selected interatomic distances (d/pm) in the crystal structure of Gd5FW3O16.
Table 3. Selected interatomic distances (d/pm) in the crystal structure of Gd5FW3O16.
Distance Distance Distance Distance
Gd1–F229.4(4)Gd2–F235.8(4)Gd3–F232.1(4)Gd4–O2239.1(5)
Gd1–O1235.4(5)Gd2–O2243.0(5)Gd3–O1276.1(5)Gd4–O3255.5(5)
Gd1–O3230.8(5)Gd2–O7243.1(5)Gd3–O6234.4(5)Gd4–O4234.5(5)
Gd1–O5258.3(5)Gd2–O9244.3(5)Gd3–O8225.9(5)Gd4–O4’249.7(5)
Gd1–O9250.8(5)Gd2–O10227.9(5)Gd3–O12235.6(5)Gd4–O5230.3(5)
Gd1–O10219.0(5)Gd2–O13231.6(5)Gd3–O14240.0(5)Gd4–O7242.9(5)
Gd1–O14231.2(5)Gd2–O14260.9(5)Gd3–O15240.8(5)Gd4–O13236.6(5)
Gd2–O16232.4(5)Gd3–O15’246.5(5)Gd4–O16229.8(5)
Gd5–O5235.7(5)W1–O1177.6(5)W2–O6178.2(5)W3–O11190.6(5)
Gd5–O8234.8(5)W1–O2183.6(5)W2–O7181.1(5)W3–O12175.4(5)
Gd5–O9265.2(5)W1–O3186.4(5)W2–O8188.3(5)W3–O13190.5(5)
Gd5–O10230.0(5)W1–O4194.5(5)W2–O9190.4(5)W3–O14193.7(5)
Gd5–O11265.8(5)W1–O4’234.4(5)W2–O10209.8(5)W3–O15195.7(5)
Gd5–O11’287.9(5)W1–O5197.8(5)W2–O11214.3(5)W3–O16215.0(5)
Gd5–O13294.6(5)
Gd5–O15253.9(5)
Gd5–O16228.1(5)
Table
Table 4. Selected bond angles (∠/°) in the crystal structure of Gd5FW3O16.
Table 4. Selected bond angles (∠/°) in the crystal structure of Gd5FW3O16.
Angle
Gd1–F–Gd2(1x)117.2(2)
Gd1–F–Gd3(1x)130.3(2)
Gd2–F–Gd3(1x)111.4(2)
W1–O4–W1(2x)107.3(2)
O4–W1–O4’(2x)72.7(2)
W2–O11–W3(1x)145.0(3)
Table
Table 5. Motifs of mutual adjunction [29,30,31] and effective coordination numbers (ECoN) [32] for the cations in the crystal structure of Gd5FW3O16.
Table 5. Motifs of mutual adjunction [29,30,31] and effective coordination numbers (ECoN) [32] for the cations in the crystal structure of Gd5FW3O16.
AtomGd1Gd2Gd3Gd4Gd5W1W2W3C.N.
F1/11/11/10/00/00/00/00/03
O11/10/01/10/00/01/10/00/03
O20/01/10/01/10/01/10/00/03
O31/10/00/01/10/01/10/00/03
O40/00/00/02/20/02/20/00/04
O51/10/00/01/11/11/10/00/04
O60/00/01/10/00/00/01/10/02
O70/01/10/01/10/00/01/10/03
O80/00/01/10/01/10/01/10/03
O91/11/10/00/01/10/01/10/04
O101/11/10/00/01/10/01/10/04
O110/00/00/00/02/20/01/11/14
O120/00/01/10/00/00/00/01/12
O130/01/10/01/11/10/00/01/14
O141/11/11/10/00/00/00/01/14
O150/00/02/20/01/10/00/01/14
O160/01/10/01/11/10/00/01/14
C.N.78889666
ECoN6.27.47.27.66.34.84.85.0

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Dorn, K.V.; Hartenbach, I. Press to Success: Gd5FW3O16—The First Gadolinium(III) Fluoride Oxidotungstate(VI). Crystals 2019, 9, 424. https://0-doi-org.brum.beds.ac.uk/10.3390/cryst9080424

AMA Style

Dorn KV, Hartenbach I. Press to Success: Gd5FW3O16—The First Gadolinium(III) Fluoride Oxidotungstate(VI). Crystals. 2019; 9(8):424. https://0-doi-org.brum.beds.ac.uk/10.3390/cryst9080424

Chicago/Turabian Style

Dorn, Katharina V., and Ingo Hartenbach. 2019. "Press to Success: Gd5FW3O16—The First Gadolinium(III) Fluoride Oxidotungstate(VI)" Crystals 9, no. 8: 424. https://0-doi-org.brum.beds.ac.uk/10.3390/cryst9080424

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