Skip to main content
NCBI home page
Acta Crystallographica Section E: Crystallographic Communications logoLink to Acta Crystallographica Section E: Crystallographic Communications
. 2023 Nov 2;79(Pt 12):1121–1126. doi: 10.1107/S2056989023009349

Crystal structure of CaSiF6·2H2O(mP2) and reevaluation of the SiIV–F bond-valence parameter R 0

Klemen Motaln a,b, Matic Lozinšek a,b,*
Editor: W T A Harrisonc
PMCID: PMC10833414  PMID: 38313128

The crystal structure of a second polymorph of CaSiF6·2H2O featuring a layered structure connected by hydrogen bonds is presented.

Keywords: calcium hexa­fluorido­silicate, bond-valence parameter, crystal structure, disorder, hydrogen bonding

Abstract

The structure of a second polymorph of CaSiF6·2H2O [calcium hexafluorido­silicate dihydrate; space group P2/c (No. 13), Pearson symbol mP2] was elucidated by single-crystal X-ray diffraction. It arose as an unexpected product when soda-lime glass was attacked by HF. Its crystal structure consists of infinite ∞ 2[Ca(H2O)2/1(SiF6)4/4] layers oriented parallel to the bc-crystallographic plane, a unique motif among structurally characterized hydrated hexa­fluorido­silicates. The crystal structure also exhibits inter- and intra­layer hydrogen bonds, with the inter­layer O—H⋯O hydrogen bonds involving a disordered hydrogen atom. The large deviation between the calculated bond-valence sum for Si and the expected value prompted a redetermination of the empirical SiIV–F bond-valence parameter R 0. Based on a data set of 42 high-quality crystal structures containing 49 independent SiIV coordination environments, a revised value of 1.534 Å was derived for R 0.

1. Chemical context

Calcium hexa­fluorido­silicate (CaSiF6) and its hydrated form, calcium hexa­fluorido­silicate dihydrate (CaSiF6·2H2O), are both commercially available chemicals that have found numerous uses, including as additives for cement manufacture (Smart & Roy, 1979 ▸), improving dentine remediation treatments (Kawasaki et al., 1996 ▸), and as precursors for synthesis of luminescent materials (Kubus & Meyer, 2013 ▸). Although the synthesis of CaSiF6·2H2O and its dehydration to CaSiF6 were investigated more than 90 years ago (Carter, 1932 ▸), their crystal structures were determined relatively recently by laboratory-based powder X-ray diffraction using simulated annealing and Rietveld refinement (Frisoni et al., 2011 ▸). The study revealed that CaSiF6·2H2O crystallizes in the monoclinic crystal system (space group P21/n, Pearson symbol mP4) and exhibits a three-dimensional framework structure. In this work, the crystal structure of a second polymorph of CaSiF6·2H2O (space group P2/c, Pearson symbol mP2) was determined by low-temperature single-crystal X-ray diffraction. The observed discrepancies between the calculated and expected bond-valence sum (BVS) for Si also provided the impetus for a reevaluation of the SiIV–F bond-valence parameter R 0 and an improved value of R 0 was determined.

2. Structural commentary

The crystal structure of CaSiF6·2H2O(mP2) features eight atoms in the asymmetric unit, with one hydrogen atom disordered over two positions. The Ca atom is located on a twofold rotation axis and the Si atom is situated on an inversion centre, whereas the light atoms all lie on general positions. The hexa­fluorido­silicate anion displays a nearly ideal octa­hedral coordination, with the cis-F—Si—F angles ranging from 88.37 (4) to 91.63 (4)°. The average Si—F bond length is 1.6859 Å (Table 1 ▸), with the bond lengths ranging from 1.6808 (9) to 1.6942 (9) Å, which is in good agreement with the Si—F distances observed in the crystal structures of CaSiF6·2H2O(mP4) (Frisoni et al., 2011 ▸) and SrSiF6·2H2O (Golovastikov & Belov, 1982 ▸), which span from 1.648 (4) to 1.701 (3) Å and 1.675 (5) to 1.700 (5) Å, respectively. The Ca atom is coordinated by six fluorine atoms at distances of 2.2965 (9)–2.4105 (9) Å originating from four neighbouring [SiF6]2– octa­hedra, two of which are bound to the metal centre in a bidentate and two in a monodentate manner. In turn, each [SiF6]2– octa­hedron is coordinated to four Ca2+ cations. The primary coordination sphere of the Ca2+ cation is completed by two water mol­ecules, with a Ca—O distance of 2.4331 (13) Å, resulting in a distorted square anti­prismatic coordination (Fig. 1 ▸). Such connectivity leads to the formation of ∞ 2[Ca(H2O)2/1(SiF6)4/4] (Jensen, 1989 ▸) infinite layers, which extend along the bc-crystallographic plane and are stacked along the a-axis (Fig. 2 ▸), a structural motif that differs from all other hydrated hexa­fluorido­silicates. Bond-valence sum calculations (Brown, 2009 ▸) for Ca and Si using the parameters b = 0.37, R 0 = 1.842 Å (Ca–F), R 0 = 1.967 Å (Ca–O), and R 0 = 1.58 Å (Si–F) obtained from the literature (Brown 2020 ▸; Brown & Altermatt, 1985 ▸; Brese & O’Keeffe, 1991 ▸), yielded 2.05 valence units (v.u.) for Ca and 4.51 v.u. for Si (expected values: 2 for Ca, 4 for Si). Similarly inflated values for the bond-valence sum of Si were also observed when other crystal structures of hexa­fluorido­silicates were examined, indicating the need to reevaluate the current SiIV–F parameter R 0 (Section 5).

Table 1. Selected bond lengths (Å).

Ca1—F1 2.2965 (9) Si1—F1 1.6809 (9)
Ca1—F2i 2.3783 (9) Si1—F2 1.6827 (9)
Ca1—F3i 2.4105 (9) Si1—F3 1.6942 (9)
Ca1—O1 2.4331 (13)    
Open in a new tab

Symmetry code: (i) Inline graphic .

Figure 1.

Figure 1

Open in a new tab

The distorted square anti­prismatic coordination environment of the Ca2+ cation in the crystal structure of CaSiF6·2H2O(mP2). Displacement ellipsoids are drawn at the 50% probability level and hydrogen atoms shown as spheres of arbitrary radius. Hydrogen atom H2 is disordered over two sites with occupancies 0.49 (5) and 0.51 (5) [Symmetry codes: (i) −x, y, −z +  Inline graphic ; (ii) x, −y + 1, z −  Inline graphic ; (iii) −x, −y + 1, −z + 1.]

Figure 2.

Figure 2

Open in a new tab

A single ∞ 2[Ca(H2O)2/1(SiF6)4/4] layer viewed along [100], with the intra­layer O—H⋯F hydrogen bonds depicted as dashed lines.

3. Supra­molecular features

The crystal structure of CaSiF6·2H2O(mP2) exhibits both intra­layer O—H⋯F and inter­layer O—H⋯O hydrogen bonds (Table 2 ▸, Fig. 3 ▸). The intra­layer hydrogen bonds are formed between the F3 atom and the non-disordered hydrogen atom H1, with an O1⋯F3 distance of 2.9042 (14) Å and a graph-set motif of S(6) (Etter et al., 1990 ▸). The oxygen atom O1 is involved in two further hydrogen bonds with the disordered hydrogen atoms H2A and H2B, forming O1—H2A⋯O1 and O1—H2B⋯O1 hydrogen bonds, with O⋯O distances of 2.902 (3) and 2.856 (3) Å, respectively, that link the adjacent ∞ 2[Ca(H2O)2/1(SiF6)4/4] layers.

Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A D—H H⋯A D⋯A D—H⋯A
O1—H1⋯F3ii 0.78 (3) 2.19 (3) 2.9042 (14) 153 (3)
O1—H2B⋯O1iii 0.90 (5) 1.98 (5) 2.856 (3) 167 (4)
O1—H2A⋯O1iv 0.77 (5) 2.17 (5) 2.902 (3) 159 (4)
Open in a new tab

Symmetry codes: (ii) Inline graphic ; (iii) Inline graphic ; (iv) Inline graphic .

Figure 3.

Figure 3

Open in a new tab

Selected fragment of the crystal structure of CaSiF6·2H2O(mP2) displaying intra- and inter­layer hydrogen bonds, which connect the adjacent layers. Some of the disordered hydrogen atoms have been omitted for clarity.

4. Database survey

A search of the Inorganic Crystal Structure Database (ICSD, version January 2023; Bergerhoff et al., 1983 ▸; Zagorac et al., 2019 ▸) revealed that in addition to the aforementioned mP4 polymorph of CaSiF6·2H2O, twelve other hydrated hexa­fluorido­silicates of divalent cations have been crystallographically characterized to date. Most of them form hexa­hydrates with the general formula MSiF6·6H2O, where M = Mg (Syoyama & Osaki, 1972 ▸; Cherkasova et al., 2004 ▸), Cr (Cotton et al., 1992 ▸), Mn (Torii et al., 1997 ▸), Fe (Hamilton, 1962 ▸; Chevrier et al., 1981 ▸), Co (Lynton & Siew; 1973 ▸; Ray et al., 1973a ▸; Ray & Mostafa, 1996 ▸), Ni (Ray et al., 1973a ▸), Cu (Ray et al., 1973b ▸), and Zn (Ray et al., 1973a ▸). The aforementioned compounds all exhibit a similar structural motif composed of alternating discrete [M(H2O)6]2+ and [SiF6]2– octa­hedra, connected via O—H⋯F hydrogen bonds into a three-dimensional network. The only examples of tetra­hydrated metal(II) hexa­fluorido­silicates are the isostructural CrSiF6·4H2O (Cotton et al., 1993 ▸) and CuSiF6·4H2O (Clark et al., 1969 ▸; Schnering & Vu, 1983 ▸; Troyanov et al., 1992 ▸; Cotton et al., 1993 ▸). In their crystal structures, infinite zigzag chains are formed by the coordination of two [SiF6]2– octa­hedra to the apical positions of the square-planar [M(H2O)4]2+ units. The resulting highly distorted octa­hedral coordination surrounding the metal centre is characteristic of the Jahn–Teller active cations. The individual chains in the structures are connected by O—H⋯F hydrogen bonds that link the terminal fluorine atoms of the [SiF6]2– units to the water mol­ecules coordinating the metal centres of the adjacent chains. Lastly there are three examples of metal(II) hexa­fluorido­silicate dihydrates, the isostructural pair CaSiF6·2H2O(mP4) (Frisoni et al., 2011 ▸) and SrSiF6·2H2O (Golovastikov & Belov, 1982 ▸), and PbSiF6·2H2O (Golubev et al., 1991 ▸). All three compounds feature an extended three-dimensional framework structure and display water mol­ecules bridging the metal centres, giving rise to dimeric [(H2O)M(μ-H2O)2 M(OH2)]4+ units for M = Ca, Sr and the more complex [Pb4(H2O)6]8+ units in the structure of PbSiF6·2H2O, which contain both μ- and μ3-water mol­ecules. The Ca2+ cation in CaSiF6·2H2O(mP4) is coordinated by five fluorine and three oxygen atoms arranged in a distorted square-anti­prismatic coordination. Each of the five fluorine atoms coordinated to the Ca2+ ion belongs to a separate [SiF6]2– octa­hedron, which contrasts with the structure of the newly discovered mP2 polymorph, where both monodentate and bidentate coord­ination of the [SiF6]2– anions to the Ca2+ cations is observed (Fig. 4 ▸). Conversely, each [SiF6]2– anion in the structure of CaSiF6·2H2O(mP4) coordinates five neighbouring Ca2+ cations, leaving one terminal fluorine atom, which in turn accepts O—H⋯F hydrogen bonds from two water ligands.

Figure 4.

Figure 4

Open in a new tab

Comparison of the crystal structures of CaSiF6·2H2O(mP4) (top) and CaSiF6·2H2O(mP2) (bottom), viewed along [010].

5. Redetermination of SiIV–F bond-valence parameter R 0

In order to determine a more accurate value of the SiIV–F bond-valence parameter R 0, the ICSD was searched for all crystal structures containing SiIV in an exclusively fluorine environment. To ensure that only high-quality data were used for the calculation of the R 0 parameter, the data set was limited to crystal structures solved by single-crystal X-ray diffraction at ambient or low-temperature conditions, excluding disordered structures or those with an R 1-value above 0.05. A data set of 42 crystal structures was obtained, containing a total of 49 independent SiIV coordination environments, including the compound presented herein (Table 3 ▸). The R 0i value for each individual Si coordination environment was calculated using formula (A1.3) from the literature (Brown, 2002 ▸), which assumes a fixed value for the b parameter (0.37 Å). An improved value for the R 0 parameter, 1.534 Å, was obtained by averaging the R 0i values, which ranged from 1.508 to 1.562 Å. BVS calculations employing the new empirical parameter yield significantly improved results compared to the calculations performed with the previously reported parameter, as 46 out of 49 evaluated coordination environments give a bond-valence sum within ±0.2 v.u. of the expected value (3.8–4.2 v.u.), in contrast to only a single one when using the old parameter (Table 4 ▸).

Table 3. Crystal structures used for the calculation of the new empirical R 0 bond-valence parameter for SiIV–F.

Compound ICSD number Reference Si—F bond-length range (Å) BVS for Si (R 0 from Brese & O’Keeffe, 1991 ▸) BVS for Si (new R 0)
BaSiF6 60882 (Svensson et al., 1986 ▸) 1.688 (2) 4.481 3.968
(CH3NH3)2SiF6 110673 (Conley et al., 2002 ▸) 1.6810 (12)–1.6828 (17) 4.559 4.037
(CH7N4)2SiF6·2H2O 280103 (Ross et al., 1999 ▸) 1.6797 (9)–1.6808 (9) 4.578 4.054
(CH8N4)SiF6 280102 (Ross et al., 1999 ▸) 1.6684 (9)–1.7043 (9) 4.529 4.010
(C(NH2)2OH)2SiF6 63069 (Gubin et al., 1988 ▸) 1.677 (2)–1.6971 (18) 4.513 3.996
(C(NH2)3)2SiF6 59237 (Waskowska, 1997 ▸) 1.6805 (12)–1.6833 (8) 4.550 4.029
(C4H13N5)SiF6 166449 (Gel’mbol’dt et al., 2009 ▸) 1.657 (3)–1.698 (3) 4.643 4.111
CaSiF6·2H2O(mP2) Present work   1.6808 (9)–1.6942 (9) 4.507 3.991
[Co(NH3)5(NO2)]SiF6 280030 (Naumov et al., 1999 ▸) 1.6769 (18)–1.6899 (13) 4.495 3.981
CrSiF6·4H2O 165384 (Cotton et al., 1993 ▸) 1.6640 (8)–1.6968 (8) 4.546 4.026
CsLiSiF6 142874 (Stoll et al., 2021 ▸) 1.667 (2)–1.699 (2) 4.479 3.966
[Cu(bpy)2(H2O)]SiF6·4H2O 133607 (Nisbet et al., 2021 ▸) 1.6677 (10)–1.6947 (9) 4.574 4.050
[Cu{SC(NH2)2}4]2SiF6 249750 (Bowmaker et al., 2008 ▸) 1.663 (2)–1.696 (2) 4.585 4.060
CuSiF6·4H2O 165385 (Cotton et al., 1993 ▸) 1.6686 (8)–1.6973 (9) 4.510 3.993
CuSiF6·6H2O 34760 (Ray et al., 1973b ▸) 1.679 (5) 4.591 4.066
      1.659 (6)–1.674 (6) 4.765 4.219
H2SiF6·4H2O 40388 (Mootz & Oellers, 1988 ▸) 1.666 (1)–1.696 (1) 4.553 4.031
H2SiF6·6H2O 40389 (Mootz & Oellers, 1988 ▸) 1.677 (1)–1.704 (1) 4.447 3.938
H2SiF6·9.5H2O 40390 (Mootz & Oellers, 1988 ▸) 1.680 (1)–1.697 (1) 4.454 3.944
      1.684 (1)–1.706 (1) 4.448 3.939
K2SiF6(cF4) 420429 (Kutoglu et al., 2009 ▸) 1.6873 (16) 4.490 3.975
K2SiF6(hP2) 158483 (Gramaccioli & Campostrini, 2007 ▸) 1.681 (2)–1.689 (2) 4.518 4.000
K2SiF6·KNO3 417735 (Rissom et al., 2008 ▸) 1.6782 (6) 4.601 4.074
KLiSiF6 142875 (Stoll et al., 2021 ▸) 1.676 (1)–1.701 (1) 4.495 3.980
KNaSiF6 71334 (Fischer & Krämer, 1991 ▸) 1.641 (5)–1.678 (5) 4.860 4.304
K3Na(SiF6)(TaF7) 122403 (Tang et al., 2021 ▸) 1.665 (3)–1.702 (3) 4.558 4.036
K3Na4(BF4)(SiF6)3 121301 (Bandemehr et al., 2020 ▸) 1.650 (2)–1.699 (2) 4.535 4.015
      1.666 (2)–1.700 (1) 4.560 4.038
Li2SiF6 425923 (Hinter­egger et al., 2014 ▸) 1.685 (2) 4.518 4.000
      1.690 (2)–1.690 (8) 4.457 3.947
MgSiF6·6H2O 250196 (Cherkasova et al., 2004 ▸) 1.6888 (9)–1.7465 (10) 4.194 3.714
MnSiF6·6H2O 59274 (Torii et al., 1997 ▸) 1.690 (7) 4.457 3.947
      1.668 (7)–1.693 (7) 4.575 4.051
(NH3OH)2SiF6·2H2O 94567 (Kristl et al., 2002 ▸) 1.6793 (10)–1.6837 (10) 4.570 4.046
(NH4)2SiF6 54724 (Fábry et al., 2001 ▸) 1.695 (1)–1.700 (1) 4.368 3.867
(N2H5)2SiF6 776 (Ouasri et al., 2019 ▸) 1.6777 (4)–1.7101 (4) 4.476 3.963
(N2H6)SiF6 35702 (Cameron et al., 1983 ▸) 1.671 (1)–1.683 (1) 4.596 4.070
Na2SiF6 433134 (Zhang et al., 2017 ▸) 1.6755 (14)–1.6756 (14) 4.635 4.104
      1.6907 (16)–1.6916 (11) 4.443 3.934
PbSiF6·2H2O 39358 (Golubev et al., 1991 ▸) 1.645 (10)–1.707 (10) 4.558 4.036
      1.664 (10)–1.716 (10) 4.411 3.906
Rb2SiF6 136303 (Rienmüller et al., 2021 ▸) 1.693 (3) 4.421 3.915
[RuF(NH3)4(NO)]SiF6 703 (Mikhailov et al., 2019 ▸) 1.661 (1)–1.713 (2) 4.556 4.035
[Ru2(H2O)2(NH4)8S2](SiF6)2 111446 (Woods & Wilson, 2021 ▸) 1.666 (2)–1.7065 (19) 4.552 4.031
SiF4 48147 (Mootz & Korte, 1984 ▸) 1.5401 (6) 4.455 3.945
SrSiF6·2H2O 20552 (Golovastikov & Belov, 1982 ▸) 1.675 (5)–1.700 (5) 4.502 3.987
[Tl2(NH3)6]SiF6·2NH3 144214 (Rudel et al., 2021 ▸) 1.687 (2)–1.6877 (15) 4.488 3.974
Tl2SiF6 136300 (Rienmüller et al., 2021 ▸) 1.686 (6) 4.505 3.989
Tl3F[SiF6] 136302 (Rienmüller et al., 2021 ▸) 1.688 (6)–1.695 (6) 4.439 3.931
Open in a new tab

Table 4. Comparison of the BVS calculation results for SiIV of crystal structures collected in Table 3 ▸ employing the new R 0 parameter and the previously reported parameter.

  R 0 Maximum BVS Minimum BVS Mean BVS Standard deviation % of data within ± 0.2 v.u. % of data within ± 0.1 v.u.
This study 1.534 4.304 3.714 4.005 0.086 93.9 87.8
Brese & O’Keeffe (1991 ▸) 1.58 4.860 4.194 4.522 0.098 2.0 0
Open in a new tab

6. Synthesis and crystallization

Colourless single crystals of the title compound were discovered to have grown serendipitously on a soda-lime watch glass containing a sample of [XeF][SbF6] (Gillespie & Landa, 1973 ▸) frozen under a protective layer of perfluoro­deca­lin at 255 K. It is presumed that CaSiF6·2H2O(mP2) formed when the soda-lime glass was attacked by the HF forming during hydrolysis of the highly oxidizing XeII compound.

7. Raman spectroscopy

A Bruker Senterra II confocal Raman microscope was used to record the Raman spectrum on a randomly oriented single crystal of the title compound. The spectrum was measured at room temperature (297 K) in the 50–4250 cm−1 range with a resolution of 4 cm−1 using the 532 nm laser line operating at 12.5 mW.

In the Raman spectrum of CaSiF6·2H2O(mP2) (Fig. 5 ▸) the bands observed at 677 and 500 cm−1 correspond to the ν1 and ν2 modes of the [SiF6]2– anion, respectively. The bands at 425 and 392 cm−1 can be assigned to the ν5 mode, split due to the distortion of the anion from the ideal O h symmetry (Ouasri et al., 2002 ▸). The Raman bands observed in the 3300–3600 cm−1 region belong to the symmetric ν1 and anti­symmetric ν3 O—H stretching of the coordinated water mol­ecules, whereas the bands at 1649 and 3225 cm−1 could likely be assigned to δ(HOH) (ν2) and 2δ(HOH), respectively (Lacroix et al., 2018 ▸).

Figure 5.

Figure 5

Open in a new tab

Raman spectrum of CaSiF6·2H2O(mP2).

8. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 5 ▸. The positions of the hydrogen atoms, including the disordered one, were located in difference maps and freely refined, including their isotropic thermal parameter U iso (Cooper et al., 2010 ▸). The refinement of the disordered hydrogen atoms’ occupancies, resulted in values of 0.51 (5) and 0.49 (5) for H2A and H2B, respectively.

Table 5. Experimental details.

Crystal data
Chemical formula CaSiF6·2H2O
M r 218.20
Crystal system, space group Monoclinic, P2/c
Temperature (K) 100
a, b, c (Å) 5.96605 (17), 5.13977 (12), 9.9308 (3)
β (°) 107.275 (3)
V (Å3) 290.78 (1)
Z 2
Radiation type Cu Kα
μ (mm−1) 12.29
Crystal size (mm) 0.15 × 0.08 × 0.02
 
Data collection
Diffractometer XtaLAB Synergy-S, Dualflex, Eiger2 R CdTe 1M
Absorption correction Gaussian (CrysAlis PRO; Rigaku OD, 2022 ▸)
T min, T max 0.365, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections 8322, 608, 598
R int 0.051
(sin θ/λ)max (Å−1) 0.628
 
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S 0.025, 0.070, 1.14
No. of reflections 608
No. of parameters 61
H-atom treatment All H-atom parameters refined
Δρmax, Δρmin (e Å−3) 0.32, −0.37
Open in a new tab

Computer programs: CrysAlis PRO (Rigaku OD, 2022 ▸), SUPERFLIP (Palatinus & Chapuis, 2007 ▸), SHELXL2019/2 (Sheldrick, 2015 ▸), OLEX2 (Dolomanov et al., 2009 ▸), DIAMOND (Brandenburg, 2005 ▸) and publCIF (Westrip, 2010 ▸).

Supplementary Material

Crystal structure: contains datablock(s) I. DOI: 10.1107/S2056989023009349/hb8080sup1.cif

e-79-01121-sup1.cif (304KB, cif)

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989023009349/hb8080Isup2.hkl

e-79-01121-Isup2.hkl (50.6KB, hkl)

CCDC reference: 2303630

Additional supporting information: crystallographic information; 3D view; checkCIF report

supplementary crystallographic information

Crystal data

CaSiF6·2H2O F(000) = 216
Mr = 218.20 Dx = 2.492 Mg m−3
Monoclinic, P2/c Cu Kα radiation, λ = 1.54184 Å
a = 5.96605 (17) Å Cell parameters from 5902 reflections
b = 5.13977 (12) Å θ = 7.8–75.3°
c = 9.9308 (3) Å µ = 12.29 mm−1
β = 107.275 (3)° T = 100 K
V = 290.78 (1) Å3 Plate, colourless
Z = 2 0.15 × 0.08 × 0.02 mm
Open in a new tab

Data collection

XtaLAB Synergy-S, Dualflex, Eiger2 R CdTe 1M diffractometer 608 independent reflections
Radiation source: micro-focus sealed X-ray tube, PhotonJet (Cu) X-ray Source 598 reflections with I > 2σ(I)
Mirror monochromator Rint = 0.051
Detector resolution: 13.3333 pixels mm-1 θmax = 75.4°, θmin = 7.8°
ω scans h = −7→7
Absorption correction: gaussian (CrysalisPro; Rigaku OD, 2022) k = −6→6
Tmin = 0.365, Tmax = 1.000 l = −12→12
8322 measured reflections
Open in a new tab

Refinement

Refinement on F2 Primary atom site location: iterative
Least-squares matrix: full Hydrogen site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.025 All H-atom parameters refined
wR(F2) = 0.070 w = 1/[σ2(Fo2) + (0.0516P)2 + 0.0488P] where P = (Fo2 + 2Fc2)/3
S = 1.14 (Δ/σ)max < 0.001
608 reflections Δρmax = 0.32 e Å−3
61 parameters Δρmin = −0.37 e Å−3
0 restraints
Open in a new tab

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
Open in a new tab

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)

x y z Uiso*/Ueq Occ. (<1)
Ca1 0.000000 0.58252 (7) 0.250000 0.01360 (19)
Si1 0.000000 0.000000 0.500000 0.0135 (2)
F1 −0.06447 (16) 0.26688 (17) 0.39793 (9) 0.0187 (3)
F2 0.20424 (15) 0.17052 (18) 0.62125 (9) 0.0178 (2)
F3 −0.19861 (16) 0.09149 (15) 0.58239 (10) 0.0164 (3)
O1 0.3884 (2) 0.4033 (2) 0.36145 (15) 0.0190 (3)
H1 0.378 (5) 0.255 (6) 0.373 (3) 0.035 (7)*
H2B 0.469 (8) 0.483 (9) 0.441 (5) 0.016 (13)* 0.49 (5)
H2A 0.475 (8) 0.419 (7) 0.318 (5) 0.017 (13)* 0.51 (5)
Open in a new tab

Atomic displacement parameters (Å2)

U11 U22 U33 U12 U13 U23
Ca1 0.0176 (3) 0.0092 (3) 0.0144 (3) 0.000 0.00529 (18) 0.000
Si1 0.0181 (3) 0.0090 (3) 0.0140 (3) 0.0000 (2) 0.0059 (2) 0.0000 (2)
F1 0.0251 (5) 0.0124 (4) 0.0201 (5) 0.0025 (4) 0.0091 (4) 0.0041 (3)
F2 0.0189 (5) 0.0155 (4) 0.0190 (5) −0.0010 (3) 0.0056 (4) −0.0037 (3)
F3 0.0201 (5) 0.0120 (5) 0.0185 (5) −0.0003 (3) 0.0080 (4) −0.0020 (3)
O1 0.0199 (6) 0.0145 (6) 0.0224 (6) −0.0008 (4) 0.0058 (5) 0.0006 (4)
Open in a new tab

Geometric parameters (Å, º)

Ca1—Si1i 3.2815 (3) Si1—F1vi 1.6808 (9)
Ca1—Si1ii 3.2815 (3) Si1—F1 1.6809 (9)
Ca1—F1 2.2965 (9) Si1—F2vi 1.6826 (9)
Ca1—F1iii 2.2965 (9) Si1—F2 1.6827 (9)
Ca1—F2iv 2.3783 (9) Si1—F3 1.6942 (9)
Ca1—F2v 2.3783 (9) Si1—F3vi 1.6942 (9)
Ca1—F3iv 2.4105 (9) O1—H1 0.78 (3)
Ca1—F3v 2.4105 (9) O1—H2B 0.90 (5)
Ca1—O1 2.4331 (13) O1—H2A 0.77 (5)
Ca1—O1iii 2.4331 (13)
Si1ii—Ca1—Si1i 98.328 (10) O1—Ca1—Si1i 112.20 (3)
F1iii—Ca1—Si1i 86.58 (2) O1iii—Ca1—Si1ii 112.20 (3)
F1—Ca1—Si1i 169.60 (2) O1iii—Ca1—Si1i 96.74 (3)
F1iii—Ca1—Si1ii 169.60 (2) O1iii—Ca1—O1 135.49 (6)
F1—Ca1—Si1ii 86.58 (2) Ca1vii—Si1—Ca1v 180.0
F1—Ca1—F1iii 90.11 (4) F1—Si1—Ca1v 82.60 (3)
F1—Ca1—F2iv 158.57 (3) F1—Si1—Ca1vii 97.40 (3)
F1—Ca1—F2v 79.82 (3) F1vi—Si1—Ca1v 97.40 (3)
F1iii—Ca1—F2iv 79.82 (3) F1vi—Si1—Ca1vii 82.60 (3)
F1iii—Ca1—F2v 158.57 (3) F1vi—Si1—F1 180.0
F1—Ca1—F3iv 142.32 (3) F1vi—Si1—F2vi 89.65 (5)
F1—Ca1—F3v 100.99 (3) F1—Si1—F2vi 90.35 (5)
F1iii—Ca1—F3v 142.32 (3) F1—Si1—F2 89.65 (5)
F1iii—Ca1—F3iv 100.99 (3) F1vi—Si1—F2 90.35 (5)
F1—Ca1—O1 76.07 (4) F1—Si1—F3 89.83 (4)
F1iii—Ca1—O1iii 76.07 (4) F1—Si1—F3vi 90.17 (4)
F1iii—Ca1—O1 72.88 (4) F1vi—Si1—F3 90.17 (4)
F1—Ca1—O1iii 72.88 (4) F1vi—Si1—F3vi 89.83 (4)
F2v—Ca1—Si1ii 29.44 (2) F2—Si1—Ca1v 44.00 (3)
F2v—Ca1—Si1i 99.95 (3) F2—Si1—Ca1vii 136.00 (3)
F2iv—Ca1—Si1i 29.44 (2) F2vi—Si1—Ca1v 136.00 (3)
F2iv—Ca1—Si1ii 99.95 (3) F2vi—Si1—Ca1vii 44.00 (3)
F2iv—Ca1—F2v 115.49 (5) F2vi—Si1—F2 180.0
F2iv—Ca1—F3v 77.00 (3) F2—Si1—F3vi 91.63 (4)
F2v—Ca1—F3v 58.87 (3) F2vi—Si1—F3 91.63 (4)
F2v—Ca1—F3iv 77.00 (3) F2—Si1—F3 88.37 (4)
F2iv—Ca1—F3iv 58.87 (3) F2vi—Si1—F3vi 88.37 (4)
F2v—Ca1—O1iii 82.87 (4) F3—Si1—Ca1v 45.25 (3)
F2iv—Ca1—O1iii 121.89 (4) F3vi—Si1—Ca1v 134.75 (3)
F2iv—Ca1—O1 82.87 (4) F3—Si1—Ca1vii 134.75 (3)
F2v—Ca1—O1 121.89 (4) F3vi—Si1—Ca1vii 45.25 (3)
F3v—Ca1—Si1ii 29.94 (2) F3—Si1—F3vi 180.0
F3v—Ca1—Si1i 87.56 (2) Si1—F1—Ca1 155.57 (5)
F3iv—Ca1—Si1i 29.94 (2) Si1—F2—Ca1v 106.56 (4)
F3iv—Ca1—Si1ii 87.56 (2) Si1—F3—Ca1v 104.81 (4)
F3v—Ca1—F3iv 91.93 (4) Ca1—O1—H1 110 (2)
F3v—Ca1—O1 75.09 (4) Ca1—O1—H2B 115 (3)
F3v—Ca1—O1iii 141.61 (4) Ca1—O1—H2A 114 (3)
F3iv—Ca1—O1 141.61 (4) H1—O1—H2B 111 (3)
F3iv—Ca1—O1iii 75.09 (4) H1—O1—H2A 107 (3)
O1—Ca1—Si1ii 96.74 (3)
Ca1v—Si1—F1—Ca1 115.56 (12) F2vi—Si1—F1—Ca1 −108.01 (13)
Ca1vii—Si1—F1—Ca1 −64.44 (12) F2—Si1—F1—Ca1 71.99 (13)
Ca1vii—Si1—F2—Ca1v 180.000 (1) F2vi—Si1—F3—Ca1v −170.07 (5)
Ca1vii—Si1—F3—Ca1v 180.000 (1) F2—Si1—F3—Ca1v 9.93 (5)
F1vi—Si1—F2—Ca1v −100.32 (4) F3vi—Si1—F1—Ca1 −19.64 (13)
F1—Si1—F2—Ca1v 79.69 (4) F3—Si1—F1—Ca1 160.36 (13)
F1—Si1—F3—Ca1v −79.72 (4) F3vi—Si1—F2—Ca1v 169.84 (5)
F1vi—Si1—F3—Ca1v 100.28 (4) F3—Si1—F2—Ca1v −10.16 (5)
Open in a new tab

Symmetry codes: (i) −x, y+1, −z+1/2; (ii) x, y+1, z; (iii) −x, y, −z+1/2; (iv) x, −y+1, z−1/2; (v) −x, −y+1, −z+1; (vi) −x, −y, −z+1; (vii) x, y−1, z.

Hydrogen-bond geometry (Å, º)

D—H···A D—H H···A D···A D—H···A
O1—H1···F3vi 0.78 (3) 2.19 (3) 2.9042 (14) 153 (3)
O1—H2B···O1viii 0.90 (5) 1.98 (5) 2.856 (3) 167 (4)
O1—H2A···O1ix 0.77 (5) 2.17 (5) 2.902 (3) 159 (4)
Open in a new tab

Symmetry codes: (vi) −x, −y, −z+1; (viii) −x+1, −y+1, −z+1; (ix) −x+1, y, −z+1/2.

Funding Statement

Funding for this research was provided by: European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant agreement No. 950625); Jožef Stefan Institute Director’s Fund; Slovenian Research and Innovation Agency (N1-0189).

References

  1. Bandemehr, J., Klippstein, J., Ivlev, S., Sachs, M. & Kraus, F. (2020). Z. Kristallogr. 235, 247–254.
  2. Bergerhoff, G., Hundt, R., Sievers, R. & Brown, I. D. (1983). J. Chem. Inf. Comput. Sci. 23, 66–69.
  3. Bowmaker, G. A., Pakawatchai, C., Skelton, B. W., Thanyasirikul, Y. & White, A. H. (2008). Z. Anorg. Allg. Chem. 634, 2583–2588.
  4. Brandenburg, K. (2005). DIAMOND. Crystal Impact GbR, Bonn, Germany.
  5. Brese, N. E. & O’Keeffe, M. (1991). Acta Cryst. B47, 192–197.
  6. Brown, I. D. (2002). The Chemical Bonding in Inorganic Chemistry: The Bond Valence Model. Oxford: Oxford University Press.
  7. Brown, I. D. (2009). Chem. Rev. 109, 6858–6919. [DOI] [PMC free article] [PubMed]
  8. Brown, I. D. (2020). bvparam2020.cif, Accumulated Table of Bond Valence Parameters, (IUCr) Bond valence parameters, http://www.iucr.org/resources/data/datasets/bond-valence-parameters. Brockhouse Institute for Materials Research, McMaster University, Hamilton, ON, Canada.
  9. Brown, I. D. & Altermatt, D. (1985). Acta Cryst. B41, 244–247.
  10. Cameron, T. S., Knop, O. & MacDonald, L. A. (1983). Can. J. Chem. 61, 184–188.
  11. Carter, R. H. (1932). J. Econ. Entomol. 25, 707–709.
  12. Cherkasova, T. G., Tatarinova, E. S. & Cherkasova, E. V. (2004). Zh. Neorg. Khim. 49, 1161–1164.
  13. Chevrier, G., Hardy, A. & Jéhanno, G. (1981). Acta Cryst. A37, 578–584.
  14. Clark, M. J. R., Fleming, J. E. & Lynton, H. (1969). Can. J. Chem. 47, 3859–3861.
  15. Conley, B. D., Yearwood, B. C., Parkin, S. & Atwood, D. A. (2002). J. Fluorine Chem. 115, 155–160.
  16. Cooper, R. I., Thompson, A. L. & Watkin, D. J. (2010). J. Appl. Cryst. 43, 1100–1107.
  17. Cotton, F. A., Daniels, L. M. & Murillo, C. A. (1993). Inorg. Chem. 32, 4868–4870.
  18. Cotton, F. A., Falvello, L. R., Murillo, C. A. & Quesada, J. F. (1992). J. Solid State Chem. 96, 192–198.
  19. Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341.
  20. Etter, M. C., MacDonald, J. C. & Bernstein, J. (1990). Acta Cryst. B46, 256–262. [DOI] [PubMed]
  21. Fábry, J., Chval, J. & Petříček, V. (2001). Acta Cryst. E57, i90–i91.
  22. Fischer, J. & Krämer, V. (1991). Mater. Res. Bull. 26, 925–930.
  23. Frisoni, S., Brenna, S. & Masciocchi, N. (2011). Powder Diffr. 26, 308–312.
  24. Gel’mbol’dt, V. O., Minacheva, L. Kh., Ganin, E. V., Sergienko, V. S. & Botoshansky, M. S. (2009). Zh. Neorg. Khim. 54, 1974.
  25. Gillespie, R. J. & Landa, B. (1973). Inorg. Chem. 12, 1383–1389.
  26. Golovastikov, N. I. & Belov, N. V. (1982). Kristallografiya, 27, 1084–1086.
  27. Golubev, A. M., Ilinets, A. M., Tsvigunov, A. N. & Makarevich, L. G. (1991). Kristallografiya, 36, 214–216.
  28. Gramaccioli, C. M. & Campostrini, I. (2007). Can. Mineral. 45, 1275–1280.
  29. Gubin, A. I., Buranbaev, M. Zh., Nurakhmetov, N. N., Suyundikova, F. O. & Tashenov, A. (1988). Kristallografiya, 33, 509–510.
  30. Hamilton, W. C. (1962). Acta Cryst. 15, 353–360.
  31. Hinteregger, E., Wurst, K., Niederwieser, N., Heymann, G. & Huppertz, H. (2014). Z. Kristallogr. 229, 77–82.
  32. Jensen, W. B. (1989). Cohesion and Structure, Vol. 2, The Structures of Binary Compounds, edited by F. R. de Boer and D. G. Pettifor, pp. 105–146. Amsterdam: North-Holland
  33. Kawasaki, A., Ishikawa, K., Suge, T., Yoshiyama, M., Asaoka, K. & Ebisu, S. (1996). J. Dent. 24, 429–434. [DOI] [PubMed]
  34. Kristl, M., Drofenik, M. & Golič, L. (2002). Acta Chim. Slov. 49, 243–250.
  35. Kubus, M. & Meyer, H.-J. (2013). Z. Anorg. Allg. Chem. 639, 669–671.
  36. Kutoglu, A., Nikolov, V., Petrov, K. & Allmann, R. (2009). ICSD Communication.
  37. Lacroix, M. R., Bukovsky, E. V., Lozinšek, M., Folsom, T. C., Newell, B. S., Liu, Y., Peryshkov, D. V. & Strauss, S. H. (2018). Inorg. Chem. 57, 14983–15000. [DOI] [PubMed]
  38. Lynton, H. & Siew, P. Y. (1973). Can. J. Chem. 51, 227–229.
  39. Mikhailov, A., Vuković, V., Kijatkin, C., Wenger, E., Imlau, M., Woike, T., Kostin, G. & Schaniel, D. (2019). Acta Cryst. B75, 1152–1163. [DOI] [PubMed]
  40. Mootz, D. & Korte, L. (1984). Z. Naturforsch. B, 39, 1295–1299.
  41. Mootz, D. & Oellers, E. J. (1988). Z. Anorg. Allg. Chem. 559, 27–39.
  42. Naumov, D. Yu., Kashcheeva, N. E., Boldyreva, E. V. & Howard, J. A. K. (1999). Acta Cryst. C55, 1205–1208.
  43. Nisbet, M. L., Hiralal, E. & Poeppelmeier, K. R. (2021). Acta Cryst. E77, 158–164. [DOI] [PMC free article] [PubMed]
  44. Ouasri, A., Lambarki, F., Rhandour, A., Saadi, M. & El Ammari, L. (2019). Acta Cryst. E75, 1507–1510. [DOI] [PMC free article] [PubMed]
  45. Ouasri, A., Rhandour, A., Dhamelincourt, M.-C., Dhamelincourt, P., Mazzah, A. & Taibi, M. (2002). J. Raman Spectrosc. 33, 715–719.
  46. Palatinus, L. & Chapuis, G. (2007). J. Appl. Cryst. 40, 786–790.
  47. Ray, S. & Mostafa, G. (1996). Z. Kristallogr. 211, 368–372.
  48. Ray, S., Zalkin, A. & Templeton, D. H. (1973a). Acta Cryst. B29, 2741–2747.
  49. Ray, S., Zalkin, A. & Templeton, D. H. (1973b). Acta Cryst. B29, 2748–2751.
  50. Rienmüller, J., Bandemehr, J. & Kraus, F. (2021). Z. Naturforsch. B, 76, 559–565.
  51. Rigaku OD (2022). CrysAlis PRO. Rigaku Corporation, Wrocław, Poland.
  52. Rissom, C., Schmidt, H. & Voigt, W. (2008). Cryst. Res. Technol. 43, 74–82.
  53. Ross, C. R., Bauer, M. R., Nielson, R. M. & Abrahams, S. C. (1999). Acta Cryst. B55, 246–254. [DOI] [PubMed]
  54. Rudel, S. S., Graubner, T., Karttunen, A. J., Dehnen, S. & Kraus, F. (2021). Inorg. Chem. 60, 15031–15040. [DOI] [PubMed]
  55. Schnering, H. G. von V. & Vu, D. (1983). Angew. Chem. 95, 421.
  56. Sheldrick, G. M. (2015). Acta Cryst. C71, 3–8.
  57. Smart, R. M. & Roy, D. M. (1979). Cem. Concr. Res. 9, 269–273.
  58. Stoll, C., Seibald, M., Baumann, D., Bandemehr, J., Kraus, F. & Huppertz, H. (2021). Eur. J. Inorg. Chem. pp. 62–70. [DOI] [PubMed]
  59. Svensson, G., Albertsson, J., Svensson, C. & Elding, L. I. (1986). Acta Chem. Scand. 40a, 631–633.
  60. Syoyama, S. & Osaki, K. (1972). Acta Cryst. B28, 2626–2627.
  61. Tang, R. L., Lian, X., Yao, W. D., Liu, W. & Guo, S. P. (2021). Dalton Trans. 50, 16562–16567. [DOI] [PubMed]
  62. Torii, A., Ogawa, K., Tamura, H. & Osaki, K. (1997). Acta Cryst. C53, 833–836.
  63. Troyanov, S. I., Morozov, I. V. & Korenev, Yu. M. (1992). Zh. Neorg. Khim. 37, 380–387.
  64. Waskowska, A. (1997). Acta Cryst. C53, 128–130.
  65. Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.
  66. Woods, J. J. & Wilson, J. J. (2021). Angew. Chem. Int. Ed. 60, 1588–1592. [DOI] [PMC free article] [PubMed]
  67. Zagorac, D., Müller, H., Ruehl, S., Zagorac, J. & Rehme, S. (2019). J. Appl. Cryst. 52, 918–925. [DOI] [PMC free article] [PubMed]
  68. Zhang, W., Jing, Q., Fang, Y. & Chen, Z. (2017). Z. Anorg. Allg. Chem. 643, 1739–1743.

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

Crystal structure: contains datablock(s) I. DOI: 10.1107/S2056989023009349/hb8080sup1.cif

e-79-01121-sup1.cif (304KB, cif)

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989023009349/hb8080Isup2.hkl

e-79-01121-Isup2.hkl (50.6KB, hkl)

CCDC reference: 2303630

Additional supporting information: crystallographic information; 3D view; checkCIF report

Articles from Acta Crystallographica Section E: Crystallographic Communications are provided here courtesy of International Union of Crystallography

RESOURCES