Tetrapotassium dicarbonato­dioxo­peroxo­uranium(VI) 2.5-hydrate, K₄[U(CO₃)₂O₂(O₂)]·2.5H₂O

The title compound was obtained by reacting UO₂ powder in 2 M K₂CO₃ with hydrogen peroxide. The compound contains individual [U(CO₃)₂O₂(O₂)]^4- ions, which are linked via an extended network of K atoms and hydrogen bonding. The U atom is coordinated to two trans-axial O atoms and six O atoms in the equatorial plane, forming distorted hexagonal bipyramids. The carbonate ligands are bound to the U center in a bidentate manner, with U-O bond distances ranging from 2.438 (5) to 2.488 (5) Å. The peroxo group forms a three-membered ring with the U atom, with U-O bond distances of 2.256 (6) and 2.240 (6) Å. The U=O bond distances of 1.806 (5) and 1.817 (5) Å, and an O-U-O angle of 175.3 (3)° are characteristic of the linear uranyl(VI) unit.

S1. Comment

The use of oxidizing alkaline solutions for the successful dissolution of metals has been recognized for many decades. The interaction of oxidizing agents, such as peroxide, with actinide elements has been of great importance, due to the multiple uses of peroxide in plutonium reprocessing (Cleveland et al., 1979). Several research groups have investigated the complexation and precipitation of uranium by peroxide in alkaline media. However, the characterization and identification of major solution species and solid structures remains relatively unexplored.

Gurevich and co-workers suggested about a dozen uranium(VI) peroxo compounds that form under different carbonate or peroxide concentrations, studying both their compositions and their solubilities (Gurevich, 1961; Gurevich & Polozhenskaya, 1960, 1961). Most of the reported compounds were obtained as solid phases and characterized by classical gravimetric and vibrational spectroscopic techniques; only a few structural characterizations of single crystals have been reported which reveal a more detailed picture of coordination geometries and bond lengths in U^VI peroxo complexes. Burns & Hughes (2003) reported a one-dimensional peroxide mineral, [UO₂(O₂)(H₂O)₂](H₂O)₂, with bridging peroxo groups. In addition, Alcock et al. (1968) reported the crystal structure of the layered compound Na₄[UO₂(O₂)₃]·9H₂O, where the U atom is coordinated to three peroxo groups, while Mikhailov et al. (1981) determined the crystal structure of (CN₃H₆)₄[UO₂(O₂)(CO₃)₂]·2H₂O, which to date is the only molecular structure of a mixed U^VI peroxo-carbonate complex. Here, we report the synthesis and structural characterization of the title compound, (I), a structurally different mixed uranyl(VI) peroxo-carbonate compound, K₄[UO₂(O₂)(CO₃)₂]·2.5H₂O. \sch

The structure of (I) consists of [UO₈] polyhedra staggered down the crystallographic b axis and linked by a network of K⁺ ions and interstitial water molecules. These polyhedra are comprised of two axial trans-O atoms [mean U═O 1.81 (1) Å], with an O═U═O angle of 175.3 (3)°, and six O atoms in the equatorial plane, to complete a slightly distorted hexagonal-bipyramidal coordination (Fig. 1). Four O atoms originate from two bidentate carbonate ligands, with U—O bond lengths between 2.438 (5) (U1—O3) and 2.488 (5) Å (U1—O6; Table 1). The peroxo ligand is coordinated through both O atoms, with slightly shorter U—O bond distances of 2.256 (6) Å for U1—O9 and 2.240 (6) Å for U1—O10. These distances are very similar to those in (CN₃H₆)₄[UO₂(O₂)(CO₃)₂]x2H₂O (2.23 Å; Mikhailov et al., 1981) and Na₄[UO₂(O₂)₃]·9H₂O (mean 2.28 Å; Alcock et al., 1968). The distance of 1.495 (8) Å between the two peroxo O atoms agrees well with the O—O distances found in (CN₃H₆)₄[UO₂(O₂)(CO₃)₂]·2H₂O (1.52 Å; Mikhailov et al., 1981), Na₄[UO₂(O₂)₃]·9H₂O (1.51 Å; Alcock et al., 1968) and sodium peroxide (1.49 Å; Tallman et al., 1957).

The [UO₈] polyhedra extend along the b axis, with the equatorial planes being parallel to one another (Fig. 2). In contrast, the [UO₈] polyhedra in the previously reported compound (CN₃H₆)₄[UO₂(O₂)(CO₃)₂]·2H₂O (Mikhailov et al., 1981) are angled towards each other. Interestingly, one of the three crystallographically distinct K atoms, K1, lies within the equatorial planes of adjacent [UO₈] polyhedra and is surrounded by six O atoms from three carbonate groups of three different [UO₂(O₂)(CO₃)₃]⁴⁻ molecules (Fig. 3). The distances between atom K1 and the nearest O atoms range between 2.72 and 2.91 Å.

S2. Experimental

UO₂ powder (591 mg, 2.2 mmol in U) was suspended in a 2M K₂CO₃ solution (30 ml), followed by the addition of 35% H₂O₂ (1.8 ml). After vigorous stirring for 15 min, the reaction was stopped by filtering the solution through a 45 mm polyamide syringe filter. Subsequently, the resulting deep-red solution (4 ml) was layered with methanol (6 ml). Single crystals of (I), in the form of reddish rectangular plates, grew overnight at the interface of these two layers. After 4 d, some of these crystals reached a size of 1.0 mm x 0.6 mm. Evaporating the solvent over a period of weeks resulted in the subsequent crystallization of yellow K₄[UO₂(CO₃)₃], which has been previously reported by Anderson et al. (1980). This is caused by degradation of the peroxide.

S3. Refinement

Water atom O3W was refined as one-half occupancy, based on a comparison of its displacement parameters with those of other water O atoms in the structure. H-atom positions were not assigned to any of the water O atoms. In the case of water O3W, the O is one-half occupancy. In the cases of atoms O1W and O2W, the displacement parameters, and the presence of more than one set of hydrogen-bond donors at meaningful hydrogen-bonding distances, strongly suggest that these water molecules are disordered. This disorder, when combined with a difference map that suggested too few H-atom positions, precluded including the H-atom positions in the model. The highest residual electron-density peak was 4.376 e Å⁻³ near U1, and the largest hole was 1.927 e Å⁻³ near C2 (2 Å from U1). Both these peaks are most likely to be a combination of uncompensated electron density (from premature truncation of the Fourier map in a heavy-atom structure) and the inability to perform an ideal absorption correction for this highly absorbing crystal.

Computing details

Data collection: Please provide missing information; cell refinement: Please provide missing information; data reduction: Please provide missing information; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: Please provide missing information; software used to prepare material for publication: Please provide missing information.

Figures

	Fig. 1. A view of the anionic [UO2(O2)(CO3)2]^4− unit in the molecular structure of K4[UO2(O2)(CO3)2]·2.5H2O, showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. The packing of the [UO2(O2)(CO3)2]^4− units in K4[UO2(O2)(CO3)2]·2.5H2O, with interstitial K^+ ions and water molecules, viewed along the b axis.
	Fig. 3. The arrangement of K1 atoms in the equatorial planes of three adjacent [UO2(O2)(CO3)2]^4− units.

Tetrapotassium dicarbonatodioxoperoxouranium(VI) 2.5-hydrate

Crystal data

K4[U(O2)O2(CO3)2]·2.5H2O	F(000) = 1140
Mr = 623.49	Dx = 2.978 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 9687 reflections
a = 6.9077 (14) Å	θ = 1.9–28.3°
b = 9.2332 (18) Å	µ = 12.92 mm^−1
c = 21.809 (4) Å	T = 293 K
β = 91.310 (4)°	Plate, red
V = 1390.6 (5) Å^3	0.10 × 0.10 × 0.08 mm
Z = 4

Data collection

Bruker P4 with SMART 1K CCD area-detector diffractometer	3046 independent reflections
Radiation source: fine-focus sealed tube	2616 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.029
ϕ scans	θmax = 28.3°, θmin = 1.9°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −8→8
Tmin = 0.300, Tmax = 0.356	k = −11→11
9687 measured reflections	l = −28→28

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.095	H-atom parameters not defined
S = 1.56	w = 1/[σ^2(Fo^2) + (0.0388P)^2] where P = (Fo^2 + 2Fc^2)/3
3046 reflections	(Δ/σ)max = 0.001
176 parameters	Δρmax = 4.38 e Å^−3
0 restraints	Δρmin = −1.93 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
U1	0.30151 (4)	0.69810 (3)	0.135628 (13)	0.01418 (11)
K1	−0.0984 (3)	0.70015 (17)	0.29476 (8)	0.0195 (4)
K2	0.7976 (3)	0.8614 (2)	0.13309 (10)	0.0294 (4)
K3	0.0819 (3)	0.37162 (18)	0.21006 (8)	0.0219 (4)
K4	0.3845 (4)	0.3383 (2)	0.04074 (11)	0.0428 (6)
O1	0.1452 (9)	0.7090 (6)	0.2014 (3)	0.0217 (13)
O2	0.4721 (9)	0.6946 (6)	0.0741 (3)	0.0251 (13)
O3	0.4447 (9)	0.4760 (5)	0.1767 (3)	0.0239 (13)
O4	0.7054 (9)	0.4723 (6)	0.2395 (3)	0.0281 (14)
O5	0.5783 (9)	0.6809 (5)	0.2071 (3)	0.0204 (12)
O6	0.4182 (8)	0.9444 (5)	0.1643 (3)	0.0211 (13)
O7	0.2667 (9)	1.1487 (6)	0.1326 (3)	0.0279 (15)
O8	0.1672 (8)	0.9295 (6)	0.1009 (3)	0.0222 (13)
O9	0.0480 (9)	0.6465 (7)	0.0723 (3)	0.0291 (15)
O10	0.1307 (9)	0.5098 (6)	0.0988 (3)	0.0238 (13)
O1W	0.2237 (9)	0.5840 (8)	−0.0373 (3)	0.0372 (16)
O2W	−0.3705 (10)	0.6882 (7)	0.3834 (4)	0.0400 (17)
O3W	0.296 (2)	1.0256 (17)	−0.0121 (8)	0.055 (4)*	0.50
C1	0.5821 (12)	0.5404 (8)	0.2088 (4)	0.0191 (17)
C2	0.2841 (12)	1.0106 (9)	0.1329 (4)	0.0241 (19)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
U1	0.01573 (17)	0.01050 (15)	0.01640 (16)	−0.00146 (11)	0.00252 (11)	−0.00088 (11)
K1	0.0195 (9)	0.0143 (7)	0.0247 (9)	0.0008 (7)	0.0025 (7)	0.0006 (7)
K2	0.0197 (10)	0.0312 (10)	0.0374 (11)	−0.0047 (8)	0.0033 (8)	−0.0025 (8)
K3	0.0223 (10)	0.0214 (9)	0.0221 (9)	−0.0032 (7)	0.0018 (7)	0.0031 (7)
K4	0.0585 (17)	0.0295 (10)	0.0416 (13)	0.0100 (10)	0.0264 (12)	0.0071 (9)
O1	0.027 (3)	0.022 (3)	0.016 (3)	−0.002 (2)	0.013 (2)	−0.003 (2)
O2	0.024 (3)	0.027 (3)	0.025 (3)	−0.004 (3)	0.015 (3)	−0.004 (3)
O3	0.026 (3)	0.010 (2)	0.036 (4)	−0.001 (2)	−0.006 (3)	0.000 (2)
O4	0.025 (3)	0.017 (3)	0.043 (4)	0.001 (2)	−0.012 (3)	0.003 (3)
O5	0.026 (3)	0.010 (2)	0.025 (3)	−0.001 (2)	−0.001 (3)	−0.001 (2)
O6	0.023 (3)	0.015 (3)	0.025 (3)	−0.003 (2)	−0.003 (3)	0.004 (2)
O7	0.035 (4)	0.009 (2)	0.039 (4)	−0.003 (2)	−0.009 (3)	0.000 (2)
O8	0.021 (3)	0.014 (3)	0.031 (3)	−0.003 (2)	−0.004 (3)	0.002 (2)
O9	0.030 (4)	0.030 (3)	0.026 (4)	−0.001 (3)	−0.004 (3)	−0.002 (3)
O10	0.032 (4)	0.014 (3)	0.026 (3)	0.000 (2)	−0.003 (3)	0.000 (2)
O1W	0.028 (4)	0.054 (4)	0.030 (4)	−0.006 (3)	−0.002 (3)	0.004 (3)
O2W	0.030 (4)	0.040 (4)	0.051 (4)	0.001 (3)	0.014 (3)	−0.001 (3)
C1	0.018 (4)	0.015 (3)	0.024 (4)	0.001 (3)	0.003 (3)	0.000 (3)
C2	0.018 (5)	0.017 (4)	0.038 (5)	0.001 (3)	0.005 (4)	0.006 (4)

Geometric parameters (Å, º)

U1—O2	1.806 (5)	K3—K1^ix	3.695 (3)
U1—O1	1.817 (5)	K4—O10	2.699 (6)
U1—O10	2.240 (6)	K4—O2^x	2.731 (6)
U1—O9	2.256 (6)	K4—O7^viii	2.796 (6)
U1—O3	2.438 (5)	K4—O1W^x	2.803 (7)
U1—O5	2.445 (6)	K4—O1W	3.032 (7)
U1—O8	2.443 (5)	K4—O3W^viii	3.163 (16)
U1—O6	2.488 (5)	K4—O3	3.244 (7)
U1—C1	2.878 (9)	K4—O2	3.421 (6)
U1—C2	2.888 (8)	K4—K4^x	3.841 (4)
U1—K2	3.745 (2)	K4—K1^iii	4.054 (3)
U1—K3	3.7599 (17)	O1—K3^i	3.061 (6)
K1—O1	2.673 (5)	O1—K2^ii	3.131 (7)
K1—O4^i	2.719 (6)	O2—K4^x	2.731 (6)
K1—O2W	2.729 (7)	O3—C1	1.310 (10)
K1—O4^ii	2.764 (6)	O3—K1^iii	2.824 (6)
K1—O7^iii	2.797 (7)	O4—C1	1.242 (10)
K1—O6^iii	2.806 (6)	O4—K1^iii	2.719 (6)
K1—O3^i	2.824 (6)	O4—K1^v	2.764 (6)
K1—O5^ii	2.912 (6)	O4—K3^v	2.848 (7)
K1—C1^i	3.145 (8)	O4—K2^xi	2.962 (7)
K1—C2^iii	3.180 (9)	O5—C1	1.298 (9)
K1—C1^ii	3.221 (9)	O5—K3^i	2.771 (6)
K1—K3^iv	3.695 (3)	O5—K1^v	2.912 (6)
K2—O8^v	2.737 (6)	O6—C2	1.293 (10)
K2—O5	2.791 (6)	O6—K1^i	2.806 (6)
K2—O6	2.829 (6)	O6—K3^i	2.821 (6)
K2—O3W^vi	2.896 (17)	O7—C2	1.280 (10)
K2—O4^vii	2.962 (7)	O7—K4^xii	2.796 (6)
K2—O9^v	2.965 (7)	O7—K1^i	2.797 (6)
K2—O2	2.991 (7)	O7—K3^xii	2.970 (6)
K2—O2W^i	3.082 (7)	O8—C2	1.294 (10)
K2—O1^v	3.131 (7)	O8—K2^ii	2.737 (6)
K2—K1^i	3.775 (3)	O9—O10	1.496 (8)
K2—U1^v	3.793 (2)	O9—K2^ii	2.965 (7)
K3—O10	2.769 (6)	O1W—K4^x	2.803 (7)
K3—O5^iii	2.771 (6)	O2W—K3^iv	3.004 (8)
K3—O3	2.797 (6)	O2W—K2^iii	3.082 (7)
K3—O6^iii	2.821 (6)	O3W—K2^vi	2.896 (17)
K3—O4^ii	2.848 (7)	O3W—K4^xii	3.163 (16)
K3—O7^viii	2.970 (6)	C1—K1^iii	3.145 (8)
K3—O2W^ix	3.004 (8)	C1—K1^v	3.221 (9)
K3—O1^iii	3.061 (6)	C2—K1^i	3.180 (9)
K3—O1	3.152 (5)
O2—U1—O1	175.3 (3)	O4^ii—K3—O2W^ix	84.54 (19)
O2—U1—O10	93.8 (2)	O7^viii—K3—O2W^ix	55.36 (18)
O1—U1—O10	90.5 (2)	O10—K3—O1^iii	133.89 (17)
O2—U1—O9	93.0 (3)	O5^iii—K3—O1^iii	61.73 (17)
O1—U1—O9	91.6 (3)	O3—K3—O1^iii	77.92 (16)
O10—U1—O9	38.9 (2)	O6^iii—K3—O1^iii	61.17 (15)
O2—U1—O3	89.5 (2)	O4^ii—K3—O1^iii	124.75 (17)
O1—U1—O3	90.0 (2)	O7^viii—K3—O1^iii	75.67 (16)
O10—U1—O3	71.6 (2)	O2W^ix—K3—O1^iii	115.75 (18)
O9—U1—O3	110.5 (2)	O10—K3—O1	58.14 (15)
O2—U1—O5	87.6 (3)	O5^iii—K3—O1	136.49 (16)
O1—U1—O5	88.3 (2)	O3—K3—O1	61.14 (15)
O10—U1—O5	125.19 (18)	O6^iii—K3—O1	79.98 (15)
O9—U1—O5	164.1 (2)	O4^ii—K3—O1	79.61 (16)
O3—U1—O5	53.59 (18)	O7^viii—K3—O1	126.07 (16)
O2—U1—O8	92.0 (2)	O2W^ix—K3—O1	125.63 (19)
O1—U1—O8	88.2 (2)	O1^iii—K3—O1	115.99 (11)
O10—U1—O8	112.0 (2)	O10—K3—K1^ix	107.49 (14)
O9—U1—O8	73.2 (2)	O5^iii—K3—K1^ix	51.12 (13)
O3—U1—O8	175.96 (19)	O3—K3—K1^ix	162.71 (14)
O5—U1—O8	122.72 (18)	O6^iii—K3—K1^ix	96.29 (13)
O2—U1—O6	89.4 (2)	O4^ii—K3—K1^ix	46.93 (12)
O1—U1—O6	86.9 (2)	O7^viii—K3—K1^ix	94.98 (13)
O10—U1—O6	164.7 (2)	O2W^ix—K3—K1^ix	46.69 (13)
O9—U1—O6	126.1 (2)	O1^iii—K3—K1^ix	110.54 (12)
O3—U1—O6	123.38 (19)	O1—K3—K1^ix	123.26 (13)
O5—U1—O6	69.81 (18)	O10—K3—U1	36.28 (12)
O8—U1—O6	52.9 (2)	O5^iii—K3—U1	164.15 (13)
O2—U1—C1	87.7 (3)	O3—K3—U1	40.41 (11)
O1—U1—C1	89.7 (3)	O6^iii—K3—U1	103.73 (12)
O10—U1—C1	98.6 (2)	O4^ii—K3—U1	102.42 (13)
O9—U1—C1	137.4 (2)	O7^viii—K3—U1	97.31 (12)
O3—U1—C1	26.9 (2)	O2W^ix—K3—U1	110.72 (14)
O5—U1—C1	26.67 (19)	O1^iii—K3—U1	114.64 (12)
O8—U1—C1	149.4 (2)	O1—K3—U1	28.80 (9)
O6—U1—C1	96.5 (2)	K1^ix—K3—U1	134.79 (6)
O2—U1—C2	91.7 (2)	O10—K3—K1	96.13 (12)
O1—U1—C2	86.3 (2)	O5^iii—K3—K1	92.90 (12)
O10—U1—C2	138.3 (2)	O3—K3—K1	99.09 (12)
O9—U1—C2	99.6 (2)	O6^iii—K3—K1	47.66 (11)
O3—U1—C2	149.8 (2)	O4^ii—K3—K1	46.76 (12)
O5—U1—C2	96.3 (2)	O7^viii—K3—K1	170.26 (13)
O8—U1—C2	26.4 (2)	O2W^ix—K3—K1	128.62 (15)
O6—U1—C2	26.5 (2)	O1^iii—K3—K1	106.88 (11)
C1—U1—C2	123.0 (2)	O1—K3—K1	44.24 (10)
O2—U1—K2	51.9 (2)	K1^ix—K3—K1	92.87 (5)
O1—U1—K2	123.34 (19)	U1—K3—K1	73.03 (4)
O10—U1—K2	141.42 (15)	O10—K4—O2^x	138.4 (2)
O9—U1—K2	140.68 (16)	O10—K4—O7^viii	80.13 (18)
O3—U1—K2	88.88 (14)	O2^x—K4—O7^viii	134.84 (18)
O5—U1—K2	48.16 (13)	O10—K4—O1W^x	120.0 (2)
O8—U1—K2	89.10 (14)	O2^x—K4—O1W^x	68.5 (2)
O6—U1—K2	49.05 (14)	O7^viii—K4—O1W^x	118.5 (2)
C1—U1—K2	66.85 (16)	O10—K4—O1W	65.83 (18)
C2—U1—K2	68.60 (17)	O2^x—K4—O1W	72.80 (18)
O2—U1—K3	125.67 (17)	O7^viii—K4—O1W	139.64 (19)
O1—U1—K3	56.69 (16)	O1W^x—K4—O1W	97.76 (19)
O10—U1—K3	47.01 (15)	O10—K4—O3W^viii	125.7 (3)
O9—U1—K3	77.27 (16)	O2^x—K4—O3W^viii	68.6 (3)
O3—U1—K3	48.04 (14)	O7^viii—K4—O3W^viii	68.4 (3)
O5—U1—K3	89.43 (12)	O1W^x—K4—O3W^viii	113.8 (3)
O8—U1—K3	132.93 (14)	O1W—K4—O3W^viii	114.4 (3)
O6—U1—K3	139.10 (13)	O10—K4—O3	54.01 (17)
C1—U1—K3	68.18 (16)	O2^x—K4—O3	147.1 (2)
C2—U1—K3	142.46 (16)	O7^viii—K4—O3	67.91 (16)
K2—U1—K3	135.03 (4)	O1W^x—K4—O3	79.65 (19)
O1—K1—O4^i	86.24 (19)	O1W—K4—O3	104.91 (17)
O1—K1—O2W	175.5 (2)	O3W^viii—K4—O3	135.3 (3)
O4^i—K1—O2W	92.6 (2)	O10—K4—O2	56.60 (15)
O1—K1—O4^ii	90.11 (19)	O2^x—K4—O2	103.64 (14)
O4^i—K1—O4^ii	117.13 (8)	O7^viii—K4—O2	120.19 (17)
O2W—K1—O4^ii	86.5 (2)	O1W^x—K4—O2	65.99 (19)
O1—K1—O7^iii	85.1 (2)	O1W—K4—O2	57.34 (17)
O4^i—K1—O7^iii	121.79 (18)	O3W^viii—K4—O2	170.8 (3)
O2W—K1—O7^iii	99.2 (2)	O3—K4—O2	53.85 (14)
O4^ii—K1—O7^iii	120.32 (18)	O10—K4—K4^x	92.40 (14)
O1—K1—O6^iii	89.17 (17)	O2^x—K4—K4^x	59.94 (12)
O4^i—K1—O6^iii	168.83 (19)	O7^viii—K4—K4^x	161.67 (18)
O2W—K1—O6^iii	92.77 (19)	O1W^x—K4—K4^x	51.45 (16)
O4^ii—K1—O6^iii	73.00 (18)	O1W—K4—K4^x	46.31 (13)
O7^iii—K1—O6^iii	47.53 (16)	O3W^viii—K4—K4^x	128.3 (3)
O1—K1—O3^i	84.28 (17)	O3—K4—K4^x	94.13 (13)
O4^i—K1—O3^i	47.59 (18)	O2—K4—K4^x	43.71 (10)
O2W—K1—O3^i	98.15 (19)	O10—K4—U1	32.85 (12)
O4^ii—K1—O3^i	163.93 (19)	O2^x—K4—U1	129.19 (13)
O7^iii—K1—O3^i	74.29 (17)	O7^viii—K4—U1	95.90 (13)
O6^iii—K1—O3^i	121.81 (18)	O1W^x—K4—U1	87.17 (16)
O1—K1—O5^ii	89.35 (18)	O1W—K4—U1	67.06 (13)
O4^i—K1—O5^ii	71.12 (17)	O3W^viii—K4—U1	157.8 (3)
O2W—K1—O5^ii	86.1 (2)	O3—K4—U1	37.92 (10)
O4^ii—K1—O5^ii	46.07 (16)	O2—K4—U1	27.06 (9)
O7^iii—K1—O5^ii	165.42 (17)	K4^x—K4—U1	69.89 (6)
O6^iii—K1—O5^ii	119.05 (16)	O10—K4—K1^iii	89.83 (14)
O3^i—K1—O5^ii	118.61 (16)	O2^x—K4—K1^iii	130.09 (16)
O1—K1—C1^i	85.83 (18)	O7^viii—K4—K1^iii	43.54 (13)
O4^i—K1—C1^i	23.0 (2)	O1W^x—K4—K1^iii	76.79 (15)
O2W—K1—C1^i	94.8 (2)	O1W—K4—K1^iii	148.60 (15)
O4^ii—K1—C1^i	140.1 (2)	O3W^viii—K4—K1^iii	95.7 (3)
O7^iii—K1—C1^i	98.9 (2)	O3—K4—K1^iii	43.79 (10)
O6^iii—K1—C1^i	146.4 (2)	O2—K4—K1^iii	93.16 (13)
O3^i—K1—C1^i	24.6 (2)	K4^x—K4—K1^iii	120.46 (12)
O5^ii—K1—C1^i	94.14 (19)	U1—K4—K1^iii	81.71 (5)
O1—K1—C2^iii	87.7 (2)	O10—K4—K3	38.81 (12)
O4^i—K1—C2^iii	145.4 (2)	O2^x—K4—K3	171.91 (17)
O2W—K1—C2^iii	95.7 (2)	O7^viii—K4—K3	43.41 (13)
O4^ii—K1—C2^iii	96.9 (2)	O1W^x—K4—K3	119.59 (16)
O7^iii—K1—C2^iii	23.64 (19)	O1W—K4—K3	104.46 (13)
O6^iii—K1—C2^iii	23.92 (18)	O3W^viii—K4—K3	106.5 (3)
O3^i—K1—C2^iii	97.9 (2)	O3—K4—K3	40.62 (11)
O5^ii—K1—C2^iii	142.85 (18)	O2—K4—K3	80.53 (10)
C1^i—K1—C2^iii	122.5 (2)	K4^x—K4—K3	123.88 (9)
O1—K1—C1^ii	90.3 (2)	U1—K4—K3	53.98 (3)
O4^i—K1—C1^ii	94.87 (19)	K1^iii—K4—K3	55.71 (5)
O2W—K1—C1^ii	85.4 (2)	U1—O1—K1	174.5 (3)
O4^ii—K1—C1^ii	22.33 (18)	U1—O1—K3^i	99.0 (2)
O7^iii—K1—C1^ii	142.53 (19)	K1—O1—K3^i	85.62 (16)
O6^iii—K1—C1^ii	95.33 (19)	U1—O1—K2^ii	96.5 (2)
O3^i—K1—C1^ii	142.3 (2)	K1—O1—K2^ii	83.49 (17)
O5^ii—K1—C1^ii	23.76 (17)	K3^i—O1—K2^ii	122.30 (17)
C1^i—K1—C1^ii	117.88 (16)	U1—O1—K3	94.50 (19)
C2^iii—K1—C1^ii	119.2 (2)	K1—O1—K3	80.40 (14)
O1—K1—K3^iv	123.34 (15)	K3^i—O1—K3	122.1 (2)
O4^i—K1—K3^iv	49.94 (14)	K2^ii—O1—K3	111.51 (19)
O2W—K1—K3^iv	53.20 (16)	U1—O2—K4^x	160.0 (3)
O4^ii—K1—K3^iv	83.11 (14)	U1—O2—K2	99.7 (2)
O7^iii—K1—K3^iv	144.82 (14)	K4^x—O2—K2	99.61 (18)
O6^iii—K1—K3^iv	139.80 (13)	U1—O2—K4	93.4 (2)
O3^i—K1—K3^iv	87.42 (13)	K4^x—O2—K4	76.36 (14)
O5^ii—K1—K3^iv	47.80 (11)	K2—O2—K4	135.6 (2)
C1^i—K1—K3^iv	66.68 (16)	C1—O3—U1	95.6 (4)
C2^iii—K1—K3^iv	148.90 (16)	C1—O3—K3	131.3 (5)
C1^ii—K1—K3^iv	64.71 (14)	U1—O3—K3	91.55 (19)
O8^v—K2—O5	143.86 (19)	C1—O3—K1^iii	91.6 (5)
O8^v—K2—O6	150.98 (18)	U1—O3—K1^iii	170.8 (3)
O5—K2—O6	60.29 (16)	K3—O3—K1^iii	88.08 (16)
O8^v—K2—O3W^vi	82.7 (4)	C1—O3—K4	138.0 (5)
O5—K2—O3W^vi	129.0 (4)	U1—O3—K4	87.23 (18)
O6—K2—O3W^vi	86.2 (4)	K3—O3—K4	90.34 (17)
O8^v—K2—O4^vii	100.83 (18)	K1^iii—O3—K4	83.55 (15)
O5—K2—O4^vii	69.40 (17)	C1—O4—K1^iii	98.1 (5)
O6—K2—O4^vii	69.76 (17)	C1—O4—K1^v	100.0 (5)
O3W^vi—K2—O4^vii	136.4 (4)	K1^iii—O4—K1^v	161.9 (3)
O8^v—K2—O9^v	58.79 (17)	C1—O4—K3^v	131.4 (5)
O5—K2—O9^v	100.89 (18)	K1^iii—O4—K3^v	83.13 (17)
O6—K2—O9^v	147.37 (19)	K1^v—O4—K3^v	84.59 (17)
O3W^vi—K2—O9^v	87.3 (3)	C1—O4—K2^xi	131.4 (5)
O4^vii—K2—O9^v	131.87 (19)	K1^iii—O4—K2^xi	86.01 (17)
O8^v—K2—O2	134.78 (18)	K1^v—O4—K2^xi	82.41 (18)
O5—K2—O2	61.90 (17)	K3^v—O4—K2^xi	97.16 (19)
O6—K2—O2	63.36 (16)	C1—O5—U1	95.6 (5)
O3W^vi—K2—O2	69.2 (4)	C1—O5—K3^i	128.7 (5)
O4^vii—K2—O2	124.06 (17)	U1—O5—K3^i	93.23 (19)
O9^v—K2—O2	84.48 (17)	C1—O5—K2	127.0 (5)
O8^v—K2—O2W^i	65.74 (17)	U1—O5—K2	91.10 (18)
O5—K2—O2W^i	138.11 (18)	K3^i—O5—K2	103.17 (17)
O6—K2—O2W^i	85.27 (17)	C1—O5—K1^v	91.6 (5)
O3W^vi—K2—O2W^i	64.8 (4)	U1—O5—K1^v	172.6 (2)
O4^vii—K2—O2W^i	77.04 (19)	K3^i—O5—K1^v	81.09 (16)
O9^v—K2—O2W^i	120.30 (19)	K2—O5—K1^v	85.70 (17)
O2—K2—O2W^i	125.2 (2)	C2—O6—U1	94.3 (5)
O8^v—K2—O1^v	61.01 (16)	C2—O6—K1^i	94.5 (5)
O5—K2—O1^v	82.94 (16)	U1—O6—K1^i	171.2 (3)
O6—K2—O1^v	135.40 (16)	C2—O6—K3^i	127.7 (5)
O3W^vi—K2—O1^v	138.4 (4)	U1—O6—K3^i	91.11 (16)
O4^vii—K2—O1^v	74.39 (16)	K1^i—O6—K3^i	84.35 (16)
O9^v—K2—O1^v	57.51 (16)	C2—O6—K2	131.0 (5)
O2—K2—O1^v	122.28 (17)	U1—O6—K2	89.33 (17)
O2W^i—K2—O1^v	111.72 (19)	K1^i—O6—K2	84.13 (16)
O8^v—K2—U1	162.86 (14)	K3^i—O6—K2	100.95 (19)
O5—K2—U1	40.73 (13)	C2—O7—K4^xii	126.7 (5)
O6—K2—U1	41.62 (11)	C2—O7—K1^i	95.2 (5)
O3W^vi—K2—U1	88.5 (3)	K4^xii—O7—K1^i	92.94 (19)
O4^vii—K2—U1	95.69 (13)	C2—O7—K3^xii	136.8 (5)
O9^v—K2—U1	106.30 (14)	K4^xii—O7—K3^xii	96.29 (18)
O2—K2—U1	28.39 (10)	K1^i—O7—K3^xii	85.25 (17)
O2W^i—K2—U1	123.22 (15)	C2—O8—U1	96.4 (5)
O1^v—K2—U1	120.28 (11)	C2—O8—K2^ii	124.7 (5)
O8^v—K2—K1^i	105.52 (13)	U1—O8—K2^ii	93.97 (18)
O5—K2—K1^i	92.62 (12)	O10—O9—U1	70.0 (3)
O6—K2—K1^i	47.67 (11)	O10—O9—K2^ii	127.9 (4)
O3W^vi—K2—K1^i	90.3 (3)	U1—O9—K2^ii	92.2 (2)
O4^vii—K2—K1^i	46.53 (12)	O9—O10—U1	71.1 (3)
O9^v—K2—K1^i	164.31 (15)	O9—O10—K4	124.1 (4)
O2—K2—K1^i	109.16 (12)	U1—O10—K4	106.3 (2)
O2W^i—K2—K1^i	45.53 (13)	O9—O10—K3	132.4 (4)
O1^v—K2—K1^i	117.19 (12)	U1—O10—K3	96.7 (2)
U1—K2—K1^i	89.14 (5)	K4—O10—K3	103.54 (19)
O8^v—K2—U1^v	39.98 (11)	K4^x—O1W—K4	82.24 (19)
O5—K2—U1^v	105.33 (13)	K1—O2W—K3^iv	80.1 (2)
O6—K2—U1^v	163.60 (13)	K1—O2W—K2^iii	80.79 (17)
O3W^vi—K2—U1^v	109.9 (3)	K3^iv—O2W—K2^iii	123.4 (3)
O4^vii—K2—U1^v	98.62 (13)	K2^vi—O3W—K4^xii	92.3 (4)
O9^v—K2—U1^v	36.47 (12)	O4—C1—O5	122.3 (8)
O2—K2—U1^v	118.83 (12)	O4—C1—O3	122.6 (7)
O2W^i—K2—U1^v	103.80 (14)	O5—C1—O3	115.1 (7)
O1^v—K2—U1^v	28.43 (9)	O4—C1—U1	178.9 (6)
U1—K2—U1^v	132.81 (6)	O5—C1—U1	57.7 (4)
K1^i—K2—U1^v	131.79 (6)	O3—C1—U1	57.5 (4)
O10—K3—O5^iii	157.29 (19)	O4—C1—K1^iii	58.9 (4)
O10—K3—O3	59.02 (18)	O5—C1—K1^iii	176.8 (6)
O5^iii—K3—O3	139.65 (19)	O3—C1—K1^iii	63.8 (4)
O10—K3—O6^iii	138.08 (17)	U1—C1—K1^iii	121.1 (3)
O5^iii—K3—O6^iii	60.62 (16)	O4—C1—K1^v	57.7 (4)
O3—K3—O6^iii	100.99 (18)	O5—C1—K1^v	64.6 (5)
O10—K3—O4^ii	100.21 (19)	O3—C1—K1^v	176.4 (6)
O5^iii—K3—O4^ii	71.36 (18)	U1—C1—K1^v	122.3 (3)
O3—K3—O4^ii	140.73 (17)	K1^iii—C1—K1^v	116.6 (3)
O6^iii—K3—O4^ii	71.52 (18)	O7—C2—O8	121.1 (8)
O10—K3—O7^viii	76.01 (17)	O7—C2—O6	122.6 (8)
O5^iii—K3—O7^viii	96.52 (17)	O8—C2—O6	116.3 (7)
O3—K3—O7^viii	72.03 (16)	O7—C2—U1	176.8 (6)
O6^iii—K3—O7^viii	136.65 (17)	O8—C2—U1	57.2 (4)
O4^ii—K3—O7^viii	139.54 (19)	O6—C2—U1	59.2 (4)
O10—K3—O2W^ix	74.45 (18)	O7—C2—K1^i	61.2 (5)
O5^iii—K3—O2W^ix	83.63 (18)	O8—C2—K1^i	175.5 (6)
O3—K3—O2W^ix	116.24 (19)	O6—C2—K1^i	61.6 (4)
O6^iii—K3—O2W^ix	141.51 (19)	U1—C2—K1^i	120.8 (3)

Symmetry codes: (i) −x+1/2, y+1/2, −z+1/2; (ii) x−1, y, z; (iii) −x+1/2, y−1/2, −z+1/2; (iv) −x−1/2, y+1/2, −z+1/2; (v) x+1, y, z; (vi) −x+1, −y+2, −z; (vii) −x+3/2, y+1/2, −z+1/2; (viii) x, y−1, z; (ix) −x−1/2, y−1/2, −z+1/2; (x) −x+1, −y+1, −z; (xi) −x+3/2, y−1/2, −z+1/2; (xii) x, y+1, z.