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Acta Cryst. (2013). E69, i77-i78    [ doi:10.1107/S1600536813028602 ]

Sodium selenite penta­hydrate, Na2SeO3·5H2O

K. Mereiter

CCDC reference: 967053

Abstract top

In the crystal structure of Na2SeO3·5H2O [disodium selen­ate(IV) penta­hydrate], two Se, two selenite O atoms and one water O atom are located on a mirror plane, and one water O atom is located on a twofold rotation axis. The coordination of one Na+ cation is distorted trigonal bipyramidal, formed by three equatorial H2O ligands and two axial selenite O atoms. The other Na+ cation has an octa­hedral coordination by six water mol­ecules. The two independent SeO3 groups form almost undistorted trigonal pyramids, with Se-O bond lengths in the range 1.6856 (7)-1.7202 (10) Å and O-Se-O angles in the range 101.98 (3)-103.11 (5)°, and both are [mu]2-O:O-bonded to a pair of Na+ cations. Hydrogen bonds involving all water molecules and selenite O atoms consolidate the crystal packing. Although anhydrous Na2SeO3 and Na2TeO3 are isotypic, the title compound is surprisingly not isotypic with Na2TeO3·5H2O. In the tellurite hydrate, all Na+ cations have an octa­hedral coordination and the TeO3 groups are bonded to Na+ only via one of their three O atoms.

Comment top

During an investigation of some simple salt hydrates the question for the crystal structure of the title compound Na2SeO3.5H2O arose. Although this solid is a commercial commodity, nutrition supplement, fertilizer additive, and therapeutic substance (European Pharmacopoeia, 2013), its crystallography turned out to be barren land. In order to close this gap, a crystal structure determination of the title compound was carried out.

Fig. 1 shows a characteristic part of the structure. The atoms Se1, O1, Se2, O3, O5w and its two hydrogen atoms H5a and H5b are located on a mirror plane at x,y,3/4. The water oxygen O8w is located on a twofold axis at x,1/4,1/2. All other atoms are in the general position. There are two independent selenite groups in the structure. Both have point symmetry Cs–m and an almost undistorted trigonal pyramidal geometry with Se—O bond distances of 1.6857 (7) – 1.7202 (10) Å (mean value 1.697 (2) Å) and O—Se—O angles of 101.98 (3) – 103.11 (5)° (mean value 102.4 (5)°; Fig. 1 and Table 1). Comparable dimensions have been reported for anhydrous Na2SeO3 (Wickleder, 2002), MgSeO3.6H2O (Andersen et al., 1984) and numerous other simple selenites. In the title compound the two selenite groups are bonded to a pair of mirror related Na1 atoms, which have a distorted trigonal dipyramidal coordination by three water molecules (O5w, O6w, O7w) in equatorial positions and two selenite oxygen atoms (O2 of Se1 and O4 of Se2) in apical positions. The two pentagonal bipyramids share a common corner via the water molecule O5w. Thus a compact group {(Na1)2(H2O)5(SeO3)2} is formed, which is reinforced by four internal hydrogen bonds donated by O6w and O6wi to O1 and O3 (Fig. 1). The second sodium atom, Na2, has an octahedral coordination by water molecules only. This Na2(H2O)6 octahedron shares a face with a second Na2 octahedron related by a twofold axis through O8w to form a double octahedron {(Na2)2(H2O)9}. The two building blocks of the structure, {(Na1)2(H2O)5(SeO3)2} and {(Na2)2(H2O)9}, are then mutually linked via four common water molecules (two O6w and two O7w) to form corrugated layers of the composition Na2SeO3.5H2O extending at y 1/4 and y 3/4 parallel to (010). A top and a side view of a Na2SeO3.5H2O layer including hydrogen bonds is depicted in Fig. 2. All water molecules have approximately tetrahedral coordination figures, either by two Na and two hydrogen bond acceptors (O5w, O6w, O7w, O8w, O9w) or by one Na, one hydrogen bond donor and two hydrogen bond acceptors (O10w). Hydrogen bond data given in Table 2 show normal values for all water molecules except O5w, which has one weak and one very weak interaction (O···O = 2.9468 (16) and 3.3631 (17) Å) with the selenite oxygen atoms O1 and O3 belonging to the same Na2SeO3.5H2O layer. All other hydrogen bonds have O···O distances in the narrow range of 2.7252 (11) to 2.8660 (11) Å with O—H···O angles between 157 (2)° and 176 (2)°. The water molecules of O5w, O6w, O8w (has two symmetry equivalent H-bonds and therefore only one entry in Table 2), and O9w feature exclusively intra-layer hydrogen bonds. Only O7w and O10w donate four inter-layer hydrogen bonds, which explains the observed good cleavage of the crystals along (010). Figures 3, 4 and 5 show projections of the crystal structure. Fig. 3 gives a view parallel to the a axis, this is parallel to two Na2SeO3.5H2O layers. It reveals that the electron lone-pairs of Se1 and Se2 point to an open space between the layers. The shortest distance between adjacent Se atoms of two different Na2SeO3.5H2O layers is Se1···Se2(1 - x,1/2 - y,3/2 - z) = 3.438 Å and corresponds to a mutual off-set of the two Se by 2.152 Å along [100]. This Se1···Se2 distance is ca 0.2 Å smaller than the sum of the van der Waals radii for two Se (2 × 1.80 Å; Rowland & Taylor, 1996) and might indicate a weak mutual interaction.

The crystal structure of anhydrous Na2SeO3 is known (Wickleder, 2002). This monoclinic structure can be seen as a distorted NaCl lattice (Masse et al., 1980), where Se replacing one out of three Na is shifted along a body diagonal of the NaCl lattice so that it has only three facial instead of six octahedral Se—O bonds while two Na atoms maintain their octahedral NaO6 coordination of the NaCl lattice. In reality the oxygen atoms are shifted more than Na and Se because they compensate arising voids and bond length differences between <Na—O> = 2.48 Å and <Se—O> = 1.70 Å. Anhydrous Na2TeO3 (Masse et al., 1980) is isostructural with Na2SeO3 but is more regular because of the larger size of Te (<Te—O> = 1.88 Å) within the host lattice of the NaO6 octahedra with <Na—O> = 2.50 Å. Both salts furnish on crystallization from water pentahydrates, namely the title compound Na2SeO3.5H2O and Na2TeO3.5H2O. In view of the isomorphism of the anhydrous couple it is somewhat unexpected that Na2TeO3.5H2O does not adopt the crystal structure of the title compound or vice versa. The tellurite hydrate crystallizes in the monoclinic space group C2/c (Philippot et al., 1979). It features a framework structure of the composition Na4(H2O)10(TeO3)2 containing three different kinds of Na. Two of these Na have relative regular octahedral coordination figures by water molecules and form infinite chains Na3(H2O)10 (H2O)3Na1(H2O)3Na2(H2O)3Na1 with two face- and one edge-sharing links per section. A third kind of Na with a strongly deformed centrosymmetric octahedral coordination by four H2O and two O bridges the chains via four corner-sharing links and carries simultaneously two TeO3 groups bonded to it η1-O-mode, i.e. via only one of their three O atoms. A reasonable alternative for the structures of Na2SeO3.5H2O and Na2TeO3.5H2O could be the structure of Na2(HPO3).5H2O, a phosphonate with a layered structure of Na(H2O)5 square pyramids, Na(H2O)5(O) octahedra, and η1-O-bonded HPO3 groups linked together only via shared edges and corners (Brodalla et al., 1978). In it the P-bonded phosphonate H atom occupies that space which the electron lone-pair lobes of Se or Te would favour. A proof for this concept and good example for a single common structure type of four different pyramidal XO32- anions is the series MgSO3.6H2O (Andersen & Lindqvist, 1984), MgSeO3.6H2O (Andersen et al., 1984), MgTeO3.6H2O (Andersen et al., 1984), and Mg(HPO3).6H2O (Powell et al., 1994) consisting of Mg(H2O)6 octahedra and XO3 pyramids (disregarding the H in HPO3) bound together by an elastic system of hydrogen bonds into a trigonal lattice of space group R3.

Related literature top

For the crystal structure of Na2TeO3.5H2O, see: Philippot et al. (1979). For crystal structures of anhydrous Na2SeO3 and Na2TeO3, see: Wickleder (2002); Masse et al. (1980). For the crystal structures of the isomorphous series MgSO3.6H2O, MgSeO3.6H2O, MgTeO3.6H2O, and Mg(HPO3).6H2O, see: Andersen & Lindqvist (1984); Andersen et al. (1984); Powell et al. (1994). For Na2(HPO3).5H2O, see: Brodalla et al. (1978). For pharmaceutical aspects of Na2SeO3.5H2O, see: European Pharmacopoeia (2013). For van der Waals radii, see: Rowland & Taylor (1996).

Experimental top

Na2SeO3 (p.A. Merck) was dissolved in a small amount of deionized water. The solution was then slowly evaporated at T 285 K and gave after seeding colourless prsimatic crystals of Na2SeO3.5H2O, which were placed of filter paper in order to remove adherent mother liquor. A crystal was then immediately mounted under Paratone oil on a MiTeGen MicroLoopTM and transferred to a Bruker SMART APEX diffractometer equipped with a Bruker Kryoflex cooler.

Refinement top

All hydrogen atoms were clearly visible in a difference Fourier synthesis and refined satisfactorily without restraints. In the final refinement all water molecules were restrained to have similar O—H and similar intramolecular H···H distances using two SADI (σ = 0.01 Å) restraints (Sheldrick, 2008). The isotropic Uiso(H) were freely refined.

Computing details top

Data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT (Bruker, 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2012); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. View of a characteristic part of the crystal structure of Na2SeO3.5H2O. Thermal displacement ellipsoids are shown at the 70% probability level. Symmetry operators are given on the lower right.
[Figure 2] Fig. 2. Two perspective representations of one Na2SeO3.5H2O layer parallel to (010) at y ~ 1/4, viewed along [010] (top) and along [100] (bottom). Hydrogen bonds are indicated by blue lines. Symmetry operators are given on the lower right.
[Figure 3] Fig. 3. Projection of the structure of Na2SeO3.5H2O along [100] with hydrogen bonds shown as dashed lines. Symmetry codes and the letter O for oxygen atoms have been omitted for legibility.
[Figure 4] Fig. 4. Projection of the structure of Na2SeO3.5H2O parallel to [010] with hydrogen bonds shown as dashed lines. Some coinciding sites have been labeled as guidance.
[Figure 5] Fig. 5. Projection of the structure of Na2SeO3.5H2O parallel to [001] with hydrogen bonds shown as dashed lines. Symmetry codes and the letter O for oxygen atoms have been omitted for legibility.
Disodium selenate(IV) pentahydrate top
Crystal data top
Na2SeO3·5H2OF(000) = 1040
Mr = 263.02Dx = 2.084 Mg m3
Orthorhombic, PbcmMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2c 2bCell parameters from 7917 reflections
a = 6.5865 (2) Åθ = 2.4–30.0°
b = 17.2263 (6) ŵ = 4.58 mm1
c = 14.7778 (6) ÅT = 100 K
V = 1676.70 (10) Å3Prism, colourless
Z = 80.35 × 0.21 × 0.14 mm
Data collection top
2529 independent reflections
Radiation source: fine-focus sealed tube2435 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.022
ω and ϕ scansθmax = 30.0°, θmin = 2.4°
Absorption correction: multi-scan
(SADABS; Bruker, 2003)
h = 99
Tmin = 0.503, Tmax = 0.746k = 2224
23979 measured reflectionsl = 2016
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.015Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.039All H-atom parameters refined
S = 1.07 w = 1/[σ2(Fo2) + (0.0224P)2 + 0.7143P]
where P = (Fo2 + 2Fc2)/3
2529 reflections(Δ/σ)max = 0.003
150 parametersΔρmax = 0.64 e Å3
70 restraintsΔρmin = 0.58 e Å3
Crystal data top
Na2SeO3·5H2OV = 1676.70 (10) Å3
Mr = 263.02Z = 8
Orthorhombic, PbcmMo Kα radiation
a = 6.5865 (2) ŵ = 4.58 mm1
b = 17.2263 (6) ÅT = 100 K
c = 14.7778 (6) Å0.35 × 0.21 × 0.14 mm
Data collection top
2529 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2003)
2435 reflections with I > 2σ(I)
Tmin = 0.503, Tmax = 0.746Rint = 0.022
23979 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.01570 restraints
wR(F2) = 0.039All H-atom parameters refined
S = 1.07Δρmax = 0.64 e Å3
2529 reflectionsΔρmin = 0.58 e Å3
150 parameters
Special details top

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

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
Na10.51942 (7)0.40815 (3)0.62757 (3)0.01543 (9)
Na20.00865 (7)0.34328 (2)0.49775 (3)0.01121 (8)
Se10.36729 (2)0.233898 (8)0.75000.00946 (4)
O10.13882 (15)0.28182 (7)0.75000.01128 (19)
O20.48606 (11)0.27444 (4)0.66069 (5)0.01294 (14)
Se20.30596 (2)0.578291 (8)0.75000.00853 (4)
O30.08542 (15)0.52480 (6)0.75000.01135 (19)
O40.43189 (11)0.54110 (4)0.66066 (5)0.01209 (14)
O5W0.7537 (2)0.41001 (7)0.75000.0182 (2)
H5A0.840 (3)0.4453 (11)0.75000.051 (9)*
H5B0.821 (4)0.3692 (10)0.75000.112 (17)*
O6W0.16164 (12)0.40116 (4)0.62475 (6)0.01327 (15)
H6A0.149 (3)0.3651 (7)0.6612 (9)0.030 (5)*
H6B0.142 (3)0.4410 (6)0.6550 (10)0.038 (5)*
O7W0.73311 (12)0.43467 (5)0.50608 (5)0.01336 (14)
H7A0.682 (2)0.4442 (10)0.4557 (8)0.030 (4)*
H7B0.783 (2)0.4762 (7)0.5234 (10)0.030 (4)*
O8W0.27783 (17)0.25000.50000.0132 (2)
H8AB0.3565 (17)0.2526 (12)0.5444 (5)0.035 (5)*
O9W0.12523 (11)0.24467 (5)0.60772 (6)0.01310 (15)
H9A0.053 (2)0.2498 (10)0.6531 (9)0.030 (5)*
H9B0.2434 (15)0.2472 (11)0.6262 (11)0.035 (5)*
O10W0.17400 (12)0.42733 (5)0.39277 (6)0.01412 (15)
H10A0.2910 (15)0.4283 (10)0.3722 (11)0.031 (5)*
H10B0.099 (2)0.4383 (11)0.3494 (9)0.030 (5)*
Atomic displacement parameters (Å2) top
Na10.0141 (2)0.0175 (2)0.0148 (2)0.00088 (16)0.00163 (16)0.00129 (16)
Na20.01154 (18)0.01093 (18)0.01114 (19)0.00028 (14)0.00033 (14)0.00044 (14)
Se10.00905 (7)0.01022 (7)0.00911 (7)0.00145 (4)0.0000.000
O10.0073 (4)0.0151 (5)0.0114 (5)0.0017 (4)0.0000.000
O20.0110 (3)0.0179 (4)0.0099 (3)0.0010 (3)0.0022 (3)0.0016 (3)
Se20.00845 (7)0.00848 (7)0.00867 (7)0.00085 (4)0.0000.000
O30.0080 (4)0.0127 (5)0.0133 (5)0.0022 (4)0.0000.000
O40.0111 (3)0.0150 (3)0.0101 (3)0.0005 (3)0.0018 (3)0.0014 (3)
O5W0.0184 (5)0.0175 (6)0.0186 (6)0.0028 (5)0.0000.000
O6W0.0166 (4)0.0106 (4)0.0126 (4)0.0008 (3)0.0011 (3)0.0007 (3)
O7W0.0151 (3)0.0140 (3)0.0110 (3)0.0005 (3)0.0004 (3)0.0001 (3)
O8W0.0116 (5)0.0181 (5)0.0099 (5)0.0000.0000.0010 (4)
O9W0.0092 (3)0.0189 (4)0.0112 (3)0.0001 (3)0.0004 (3)0.0018 (3)
O10W0.0108 (3)0.0183 (4)0.0132 (4)0.0008 (3)0.0001 (3)0.0022 (3)
Geometric parameters (Å, º) top
Na1—O7W2.3266 (9)Se2—O31.7202 (10)
Na1—O6W2.3600 (9)O5W—Na1iii2.3781 (10)
Na1—O22.3650 (9)O5W—H5A0.831 (10)
Na1—O5W2.3781 (10)O5W—H5B0.833 (10)
Na1—O42.4119 (9)O6W—H6A0.826 (9)
Na2—O9Wi2.3458 (9)O6W—H6B0.830 (9)
Na2—O6W2.3520 (9)O7W—Na2iv2.4057 (9)
Na2—O10W2.3852 (9)O7W—H7A0.833 (9)
Na2—O8W2.3930 (9)O7W—H7B0.829 (9)
Na2—O7Wii2.4056 (9)O8W—Na2i2.3930 (9)
Na2—O9W2.5108 (9)O8W—H8AB0.837 (8)
Se1—O21.6857 (7)O9W—Na2i2.3457 (9)
Se1—O2iii1.6857 (7)O9W—H9A0.825 (9)
Se1—O11.7164 (10)O9W—H9B0.826 (9)
Se2—O41.6856 (7)O10W—H10A0.828 (9)
Se2—O4iii1.6856 (7)O10W—H10B0.829 (9)
O7W—Na1—O6W126.90 (3)Na1—O5W—Na1iii99.06 (5)
O7W—Na1—O2114.03 (3)Na1—O5W—H5A116.9 (10)
O6W—Na1—O282.02 (3)Na1iii—O5W—H5A116.9 (10)
O7W—Na1—O5W101.06 (4)Na1—O5W—H5B109.6 (13)
O6W—Na1—O5W131.46 (4)Na1iii—O5W—H5B109.6 (13)
O2—Na1—O5W85.18 (4)H5A—O5W—H5B104.6 (15)
O7W—Na1—O496.58 (3)Na2—O6W—Na1117.62 (4)
O6W—Na1—O479.24 (3)Na2—O6W—H6A99.2 (11)
O2—Na1—O4149.39 (3)Na1—O6W—H6A97.2 (12)
O5W—Na1—O489.32 (4)Na2—O6W—H6B135.6 (12)
O9Wi—Na2—O6W164.81 (3)Na1—O6W—H6B95.9 (13)
O9Wi—Na2—O10W97.56 (3)H6A—O6W—H6B104.8 (12)
O6W—Na2—O10W93.79 (3)Na1—O7W—Na2iv111.55 (3)
O9Wi—Na2—O8W81.60 (3)Na1—O7W—H7A119.0 (12)
O6W—Na2—O8W87.49 (3)Na2iv—O7W—H7A112.8 (12)
O10W—Na2—O8W94.49 (3)Na1—O7W—H7B99.9 (12)
O9Wi—Na2—O7Wii99.97 (3)Na2iv—O7W—H7B106.4 (12)
O6W—Na2—O7Wii90.29 (3)H7A—O7W—H7B105.4 (12)
O10W—Na2—O7Wii88.88 (3)H8ABi—O8W—Na2i115.7 (11)
O8W—Na2—O7Wii176.07 (3)H8ABi—O8W—Na2118.9 (12)
O9Wi—Na2—O9W82.01 (3)Na2i—O8W—Na284.39 (4)
O6W—Na2—O9W85.46 (3)H8ABi—O8W—H8AB103.5 (14)
O10W—Na2—O9W172.76 (3)Na2i—O8W—H8AB118.9 (12)
O8W—Na2—O9W78.28 (3)Na2—O8W—H8AB115.7 (11)
O7Wii—Na2—O9W98.32 (3)Na2i—O9W—Na282.82 (3)
O2iii—Se1—O2103.06 (5)Na2i—O9W—H9A113.2 (12)
O2iii—Se1—O1101.98 (3)Na2—O9W—H9A104.5 (12)
O2—Se1—O1101.98 (3)Na2i—O9W—H9B127.4 (12)
Se1—O2—Na1127.49 (4)Na2—O9W—H9B120.6 (13)
O4iii—Se2—O4103.11 (5)H9A—O9W—H9B105.5 (12)
O4iii—Se2—O3102.24 (3)Na2—O10W—H10A132.5 (12)
O4—Se2—O3102.24 (3)Na2—O10W—H10B111.7 (12)
Se2—O4—Na1129.59 (4)H10A—O10W—H10B105.2 (12)
Symmetry codes: (i) x, y+1/2, z+1; (ii) x1, y, z; (iii) x, y, z+3/2; (iv) x+1, y, z.
Hydrogen-bond geometry (Å, º) top
O5W—H5A···O3iv0.83 (1)2.12 (1)2.9468 (16)173 (3)
O5W—H5B···O1iv0.83 (1)2.58 (2)3.3631 (17)158 (3)
O6W—H6A···O10.83 (1)1.95 (1)2.7704 (12)176 (2)
O6W—H6B···O30.83 (1)2.05 (1)2.8660 (11)169 (2)
O7W—H7A···O4v0.83 (1)1.89 (1)2.7252 (11)176 (2)
O7W—H7B···O10Wv0.83 (1)2.09 (1)2.8740 (12)157 (2)
O8W—H8AB···O20.84 (1)1.96 (1)2.7744 (9)166 (1)
O9W—H9A···O10.83 (1)1.99 (1)2.8027 (11)168 (2)
O9W—H9B···O2ii0.83 (1)1.91 (1)2.7259 (11)168 (2)
O10W—H10A···O4v0.83 (1)1.96 (1)2.7672 (11)164 (2)
O10W—H10B···O3vi0.83 (1)2.01 (1)2.8374 (11)174 (2)
Symmetry codes: (ii) x1, y, z; (iv) x+1, y, z; (v) x+1, y+1, z+1; (vi) x, y+1, z+1.
Selected bond lengths (Å) top
Na1—O7W2.3266 (9)Na2—O7Wii2.4056 (9)
Na1—O6W2.3600 (9)Na2—O9W2.5108 (9)
Na1—O22.3650 (9)Se1—O21.6857 (7)
Na1—O5W2.3781 (10)Se1—O2iii1.6857 (7)
Na1—O42.4119 (9)Se1—O11.7164 (10)
Na2—O9Wi2.3458 (9)Se2—O41.6856 (7)
Na2—O6W2.3520 (9)Se2—O4iii1.6856 (7)
Na2—O10W2.3852 (9)Se2—O31.7202 (10)
Na2—O8W2.3930 (9)
Symmetry codes: (i) x, y+1/2, z+1; (ii) x1, y, z; (iii) x, y, z+3/2.
Hydrogen-bond geometry (Å, º) top
O5W—H5A···O3iv0.831 (10)2.120 (10)2.9468 (16)173 (3)
O5W—H5B···O1iv0.833 (10)2.576 (16)3.3631 (17)158 (3)
O6W—H6A···O10.826 (9)1.945 (9)2.7704 (12)176.1 (17)
O6W—H6B···O30.830 (9)2.047 (10)2.8660 (11)168.9 (15)
O7W—H7A···O4v0.833 (9)1.893 (9)2.7252 (11)176.3 (17)
O7W—H7B···O10Wv0.829 (9)2.091 (10)2.8740 (12)157.4 (16)
O8W—H8AB···O20.837 (8)1.956 (8)2.7744 (9)165.7 (14)
O9W—H9A···O10.825 (9)1.989 (9)2.8027 (11)168.4 (17)
O9W—H9B···O2ii0.826 (9)1.912 (10)2.7259 (11)168.3 (19)
O10W—H10A···O4v0.828 (9)1.961 (10)2.7672 (11)164.2 (18)
O10W—H10B···O3vi0.829 (9)2.011 (9)2.8374 (11)174.3 (18)
Symmetry codes: (ii) x1, y, z; (iv) x+1, y, z; (v) x+1, y+1, z+1; (vi) x, y+1, z+1.
Acknowledgements top

The X-ray centre of the Vienna University of Technology is acknowledged for providing access to a single-crystal diffractometer and financial support.