Tripotassium tris­(oxalato-κ²O,O′)­aluminate bis(hydrogen peroxide) hydrate, the first example of a cyclic hydrogen-bonded H₂O₂ dimer

In addition to associating into cyclic hydrogen-bonded dimers [O...O = 2.663 (1) and 2.914 (1) Å], each hydrogen peroxide mol­ecule in the title structure, K₃[Al(C₂O₄)₃]·1.75H₂O₂·0.25H₂O, hydrogen bonds to a neighbouring oxalate ligand [O...O = 2.700 (1) and 2.730 (1) Å] and coordinates to two K⁺ ions [K...O = 2.6620 (9)–2.8380 (7) Å].

S1. Comment

Several oxyacid salts form perhydrates on recrystallization from aqueous hydrogen peroxide. These include the commercially important bleaches, Na₂CO₃·1.5H₂O₂ (sodium percarbonate) (Adams & Pritchard, 1977; Carrondo et al., 1977; Adams et al., 1979) and Na₉(SO₄)₄Cl·2H₂O₂ (Adams et al., 1978, 1981; Adams & Pritchard 1978).

As the hydrogen peroxide molecules are disordered in the above compounds, accurate geometries for H₂O₂ solvate molecules are usually obtained from other perhydrates, notably the alkali metal oxalate monoperhydrates (Table 3). Even in these structures the hydrogen peroxide geometry is variable, particularly the torsion angle, which adapts to the local environment. The title structure, (I), is the first example of an oxalate perhydrate containing a higher valency main group metal and consists of a racemic mixture of Λ- and Δ-trisoxalatoaluminium anions interspersed with potassium cations and hydrogen peroxide solvate molecules (Fig. 1). Hydrogen bonds link the two crystallographically independent hydrogen peroxide molecules into novel cyclic dimers, which use their two remaining H atoms to associate into chains with the trans O atoms (O10 and O11) of an oxalate ligand (Fig. 2). Each hydrogen peroxide molecule also uses one of its O atoms to coordinate to two K⁺ ions at K···O distances ranging from 2.6620 (9) to 2.8380 (7) Å (selected data are given in Tables 1 and 2). This arrangement leads to H—O—O—H torsion angles of 119 (1) and 124 (1)°, which correspond to low-energy conformations (Hunt et al., 1965).

In 25% of their sites, hydrogen peroxide atoms O15 and O16 have been replaced by a single water O atom, O15B. Both hydrogen peroxide and water molecules share the same H atoms and, although the water geometry is somewhat distorted, [O—H = 1.15 (2) and 1.34 (2) Å, and H—O—H = 117 (1)°[, it clearly shows that a water molecule could replace hydrogen peroxide in the hydrogen-bonding scheme. Also, with distances of 2.799 (3) and 2.881 (3) Å, the water K···O distances make a satisfactory substitute for the corresponding distances to hydrogen peroxide.

The non-solvate part of the structure is isostructural with the analogous trihydrate K₃[Al(C₂O₄)₃]·3H₂O, which itself forms an isostructural series with the Cr (Taylor, 1978), Fe and V trihydrates (Gillard et al., 1969). Two water molecules are located in peroxide sites O13 and O15, thereby maintaining the four K···O bridging bonds, which range from 2.683 (6) to 2.958 (8) Å in the trihydrate. This leaves sufficient space for an additional water molecule, which coordinates to K3 at a distance of 2.995 (7) Å. Although disorder prevents the H atoms being located in the trihydrate it is possible to deduce a hydrogen-bonding scheme from short non-bonded O···O contacts (range 2.753–2.785 Å). These indicate that the two hydrogen bonds to the oxalate ligand are maintained and that the only other hydrogen bond is between the additional water molecule coordinated to K3 and the one replacing O13. The complicated relationship between the title compound and its trihydrate contrasts with the more straightforward situation in the alkali metal oxalate monoperhydrates K₂(C₂O₄)·H₂O₂ and Rb₂(C₂O₄)·H₂O₂. These are isostructural with their monohydrates; however, in their case, a C₂-symmetric site can accomodate either a hydrogen peroxide or water solvate molecule (Pedersen, 1967).

S2. Experimental

K₃[Al(C₂O₄)₃]·3H₂O was prepared by reacting aluminium turnings (1 g) with KOH (6 g) in water (50 ml), heating and adding oxalic acid crystals (14 g). The solution was then filtered and cooled to room temperature before ethanol (50 ml) was added and the solution cooled to 273 K to induce crystallization. Crystals of (I) were prepared by dissolving the above hydrate in a 30% w/w aqueous H₂O₂ solution and then evaporating to dryness at room temperature.

S3. Refinement

Although atom H14 appeared in a chemically reasonable position in the ΔF map, its displacement parameter expanded on least-squares refinement and the atom moved away from O14 to encompass diffuse electron density on the nearby oxalate O atom to which it is hydrogen bonded. This problem has been resolved by fixing the vibrational amplitude of H14 to the average value of the other three H atoms, whilst leaving its positional parameters to refine freely. The 25% occupancy water H atoms attached to O15B are assumed to coincide with the hydrogen peroxide atoms H15 and H16, although it is envisaged that their actual site will be slightly shifted so that hydrogen bonding is maintained and the water geometry is more typical.

Computing details

Data collection: COLLECT (Nonius, 1998); cell refinement: HKL SCALEPACK (Otwinowski & Minor, 1997); data reduction: HKL DENZO and SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. The unit cell of (I), viewed down the a axis.
	Fig. 2. View of (I), showing the atomic labelling scheme (50% probability displacement ellipsoids). Only the boundary ellipse has been drawn for the 25% occupancy water molecule, O15B. The hydrogen peroxide environment in highlighted with primes (') and double primes ('') denoting symmetry codes (x − 1, 1/2 − y, z + 1/2) and (x, 1/2 − y, 1/2 + z), respectively.

(I)

Crystal data

K3[Al(C2O4)3]·1.75H2O2·0.25H2O	F(000) = 944
Mr = 472.37	Dx = 2.157 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 7200 reflections
a = 7.6194 (2) Å	θ = 1.0–27.5°
b = 19.3531 (6) Å	µ = 1.09 mm^−1
c = 10.3668 (4) Å	T = 150 K
β = 107.905 (1)°	Needle, colourless
V = 1454.64 (8) Å^3	0.15 × 0.15 × 0.07 mm
Z = 4

Data collection

Nonius KappaCCD diffractometer	2390 reflections with I > 2σ(I)
CCD rotation images scans	Rint = 0.041
Absorption correction: multi-scan (SORTAV; Blessing, 1995)	θmax = 27.4°, θmin = 2.3°
Tmin = 0.849, Tmax = 0.926	h = −8→9
7571 measured reflections	k = −19→25
3256 independent reflections	l = −11→13

Refinement

Refinement on F^2	All H-atom parameters refined
Least-squares matrix: full	w = 1/[σ^2(Fo^2) + (0.0101P)^2 + 2.2968P] where P = (Fo^2 + 2Fc^2)/3
R[F^2 > 2σ(F^2)] = 0.044	(Δ/σ)max = 0.004
wR(F^2) = 0.088	Δρmax = 0.41 e Å^−3
S = 1.09	Δρmin = −0.49 e Å^−3
3256 reflections	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
256 parameters	Extinction coefficient: 0.00282 (13)
0 restraints

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.

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
Al1	0.73663 (3)	0.125511 (12)	0.24646 (3)	0.01052 (7)
O1	0.65979 (7)	0.05626 (3)	0.35144 (6)	0.01291 (17)
O2	0.96179 (8)	0.12106 (3)	0.38650 (6)	0.01402 (17)
O3	0.73862 (8)	0.02030 (3)	0.56849 (6)	0.01669 (17)
O4	1.08945 (8)	0.07691 (3)	0.59343 (6)	0.01663 (18)
O5	0.83894 (7)	0.07002 (3)	0.13610 (6)	0.01264 (16)
O6	0.51379 (8)	0.11318 (3)	0.10628 (6)	0.01291 (16)
O7	0.76446 (8)	0.02863 (3)	−0.07688 (6)	0.01748 (18)
O8	0.40017 (8)	0.06610 (3)	−0.09988 (6)	0.01512 (17)
O9	0.61644 (8)	0.18862 (3)	0.32935 (6)	0.01519 (17)
O10	0.81517 (8)	0.20708 (3)	0.17655 (6)	0.01383 (17)
O11	0.55418 (9)	0.30056 (3)	0.33991 (6)	0.02243 (19)
O12	0.79302 (8)	0.32290 (3)	0.18277 (6)	0.02043 (19)
C1	0.77096 (11)	0.05032 (4)	0.47340 (9)	0.0129 (2)
C2	0.96004 (11)	0.08538 (4)	0.49098 (8)	0.0111 (2)
C3	0.72641 (11)	0.05710 (4)	0.01723 (9)	0.0118 (2)
C4	0.52694 (11)	0.08033 (4)	0.00203 (9)	0.0121 (2)
C5	0.63163 (12)	0.25224 (4)	0.30184 (9)	0.0171 (3)
C6	0.75738 (12)	0.26462 (4)	0.21299 (9)	0.0155 (3)
K1	0.03065 (3)	0.421043 (10)	0.33064 (2)	0.01857 (6)
K2	0.47354 (3)	0.087936 (10)	0.664027 (19)	0.01665 (5)
K3	0.26057 (3)	0.413367 (10)	0.75571 (2)	0.01981 (5)
O13	0.29851 (9)	0.18436 (3)	0.45847 (7)	0.0303 (2)
O14	0.39967 (10)	0.24534 (3)	0.51832 (7)	0.0299 (2)
O15	0.13748 (11)	0.33121 (4)	0.54081 (9)	0.0231 (3)	0.75 (1)
O15B	0.0760 (4)	0.32244 (16)	0.5359 (3)	0.0332 (7)*	0.25 (1)
O16	0.01000 (11)	0.27276 (4)	0.49843 (9)	0.0241 (3)	0.75 (1)
H13	0.185 (2)	0.2040 (8)	0.4638 (16)	0.107 (6)*
H14	0.461 (2)	0.2650 (8)	0.4328 (15)	0.095*
H15	0.2218 (18)	0.3026 (7)	0.5439 (14)	0.079 (5)*
H16	−0.041 (2)	0.2771 (8)	0.5636 (16)	0.103 (6)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Al1	0.01066 (10)	0.00961 (11)	0.01151 (11)	−0.00029 (9)	0.00372 (8)	0.00061 (10)
O1	0.0099 (3)	0.0133 (3)	0.0149 (3)	−0.0018 (2)	0.0029 (2)	0.0006 (2)
O2	0.0147 (3)	0.0147 (3)	0.0122 (3)	−0.0034 (2)	0.0034 (2)	0.0021 (2)
O3	0.0216 (3)	0.0156 (3)	0.0166 (3)	0.0013 (2)	0.0115 (2)	0.0046 (3)
O4	0.0130 (3)	0.0202 (3)	0.0165 (3)	0.0031 (2)	0.0042 (2)	0.0010 (3)
O5	0.0112 (3)	0.0131 (3)	0.0134 (3)	0.0000 (2)	0.0035 (2)	−0.0001 (2)
O6	0.0138 (3)	0.0132 (3)	0.0127 (3)	0.0016 (2)	0.0055 (2)	0.0002 (2)
O7	0.0210 (3)	0.0152 (3)	0.0187 (3)	−0.0013 (2)	0.0098 (2)	−0.0031 (3)
O8	0.0134 (3)	0.0165 (3)	0.0143 (3)	−0.0035 (2)	0.0026 (2)	0.0007 (3)
O9	0.0200 (3)	0.0118 (3)	0.0159 (3)	0.0017 (2)	0.0086 (2)	−0.0002 (2)
O10	0.0158 (3)	0.0119 (3)	0.0147 (3)	−0.0005 (2)	0.0061 (2)	−0.0008 (2)
O11	0.0334 (3)	0.0143 (3)	0.0227 (3)	0.0061 (3)	0.0131 (3)	−0.0004 (3)
O12	0.0254 (3)	0.0106 (3)	0.0256 (3)	−0.0020 (2)	0.0083 (3)	0.0016 (3)
C1	0.0124 (4)	0.0094 (4)	0.0167 (4)	0.0030 (3)	0.0042 (3)	−0.0026 (3)
C2	0.0140 (4)	0.0107 (4)	0.0100 (4)	0.0025 (3)	0.0058 (3)	−0.0032 (3)
C3	0.0166 (4)	0.0053 (4)	0.0145 (4)	−0.0022 (3)	0.0064 (3)	0.0003 (3)
C4	0.0138 (4)	0.0086 (4)	0.0137 (4)	−0.0013 (3)	0.0041 (3)	0.0042 (3)
C5	0.0173 (4)	0.0173 (4)	0.0153 (4)	0.0002 (3)	0.0029 (3)	−0.0009 (4)
C6	0.0146 (4)	0.0155 (4)	0.0119 (4)	−0.0005 (3)	−0.0025 (3)	−0.0013 (4)
K1	0.01445 (8)	0.02389 (10)	0.01852 (9)	−0.00209 (7)	0.00676 (7)	−0.00365 (8)
K2	0.01584 (8)	0.01809 (9)	0.01681 (9)	−0.00127 (7)	0.00616 (7)	−0.00223 (8)
K3	0.02105 (9)	0.01956 (9)	0.01971 (9)	−0.00034 (8)	0.00755 (7)	−0.00167 (9)
O13	0.0323 (3)	0.0225 (3)	0.0373 (4)	−0.0102 (3)	0.0126 (3)	−0.0044 (3)
O14	0.0360 (4)	0.0256 (3)	0.0286 (3)	−0.0058 (3)	0.0107 (3)	−0.0070 (3)
O15	0.0222 (4)	0.0145 (4)	0.0332 (5)	−0.0035 (3)	0.0095 (3)	−0.0065 (4)
O16	0.0182 (4)	0.0295 (5)	0.0252 (4)	−0.0112 (4)	0.0078 (3)	−0.0098 (4)

Geometric parameters (Å, º)

Al1—O1	1.9274 (7)	C5—C6	1.5383 (14)
Al1—O2	1.8780 (5)	C5—K2^i	3.4643 (9)
Al1—O5	1.9022 (7)	C6—K2^i	3.5217 (9)
Al1—O6	1.8801 (5)	K1—O4^ix	2.6319 (7)
Al1—O9	1.8849 (7)	K1—O7^x	2.6790 (7)
Al1—O10	1.9084 (7)	K1—O8^xi	2.6946 (6)
Al1—K3^i	3.7345 (4)	K1—O15	2.7096 (9)
O1—K2^ii	2.9572 (6)	K1—O12^xii	2.7440 (6)
O1—K3^i	2.9541 (6)	K1—O15B	2.799 (3)
O1—C1	1.2926 (9)	K1—O5^xiii	3.0344 (6)
O2—K3^iii	3.0599 (7)	K1—O3^ix	3.1475 (6)
O2—C2	1.2881 (11)	K1—O7^xiii	3.2922 (6)
O3—K2	2.8290 (7)	K1—C3^xiii	3.3244 (8)
O3—K3^iv	2.7564 (6)	K1—O16	3.3844 (9)
O3—K1^v	3.1475 (6)	K1—C2^ix	3.3969 (9)
O3—K2^ii	3.2274 (6)	K2—O8^xiv	2.7061 (7)
O3—C1	1.2326 (11)	K2—O11^xi	2.7695 (6)
O4—K1^v	2.6319 (7)	K2—O4^xii	2.7980 (6)
O4—K2^vi	2.7980 (6)	K2—O13	2.8380 (7)
O4—C2	1.2179 (9)	K2—O12^xi	2.9411 (7)
O5—C3	1.2910 (9)	K2—O1^ii	2.9573 (6)
O5—K1^vii	3.0344 (6)	K2—O7^xiv	3.1280 (6)
O5—K3^iii	3.0842 (6)	K2—O3^ii	3.2274 (6)
O6—C4	1.2840 (11)	K2—C1^ii	3.3208 (8)
O6—K3^i	2.8677 (7)	K2—O14	3.3698 (7)
O7—C3	1.2302 (11)	K2—C4^xiv	3.4043 (9)
O7—K1^iii	2.6790 (7)	K3—O15	2.6620 (9)
O7—K3^vii	2.8691 (6)	K3—O3^xv	2.7564 (6)
O7—K2^viii	3.1280 (6)	K3—O13^xi	2.7759 (7)
O7—K1^vii	3.2922 (6)	K3—O6^xi	2.8677 (7)
O8—C4	1.2237 (9)	K3—O7^xiii	2.8691 (6)
O8—K1^i	2.6946 (6)	K3—O15B	2.881 (3)
O8—K2^viii	2.7061 (7)	K3—O1^xi	2.9541 (6)
O9—C5	1.2770 (10)	K3—O2^x	3.0599 (7)
O9—K3^i	3.2493 (6)	K3—O5^x	3.0842 (6)
O10—C6	1.2957 (11)	K3—O9^xi	3.2493 (6)
O11—C5	1.2336 (11)	K3—Al1^xi	3.7345 (4)
O11—K2^i	2.7695 (6)	K3—K1^xvi	3.8436 (3)
O12—C6	1.2233 (11)	K3—H15	3.018 (14)
O12—K1^vi	2.7440 (6)	O13—O14	1.4415 (9)
O12—K2^i	2.9411 (7)	O13—K3^i	2.7759 (7)
C1—C2	1.5517 (12)	O13—H13	0.963 (17)
C1—K2^ii	3.3208 (8)	O14—H14	1.183 (17)
C1—K2	3.5106 (10)	O15—O16	1.4675 (12)
C2—K1^v	3.3969 (9)	O15—H15	0.842 (14)
C3—C4	1.5459 (12)	O16—H16	0.881 (18)
C3—K1^vii	3.3244 (8)	O15B—H15	1.154 (15)
C3—K1^iii	3.4715 (10)	O15B—H16	1.344 (17)
C4—K2^viii	3.4042 (9)
O2—Al1—O6	170.07 (3)	O3^ix—K1—C2^ix	43.411 (19)
O2—Al1—O9	97.68 (3)	O7^xiii—K1—C2^ix	135.490 (19)
O6—Al1—O9	89.13 (3)	C3^xiii—K1—C2^ix	114.10 (2)
O2—Al1—O5	89.61 (3)	O16—K1—C2^ix	118.96 (2)
O6—Al1—O5	84.44 (3)	O8^xiv—K2—O11^xi	65.916 (19)
O9—Al1—O5	170.55 (3)	O8^xiv—K2—O4^xii	74.595 (18)
O2—Al1—O10	90.74 (3)	O11^xi—K2—O4^xii	103.54 (2)
O6—Al1—O10	97.21 (3)	O8^xiv—K2—O3	127.779 (18)
O9—Al1—O10	83.69 (3)	O11^xi—K2—O3	123.588 (19)
O5—Al1—O10	90.25 (3)	O4^xii—K2—O3	132.457 (18)
O2—Al1—O1	84.00 (3)	O8^xiv—K2—O13	126.99 (2)
O6—Al1—O1	89.38 (3)	O11^xi—K2—O13	86.556 (19)
O9—Al1—O1	85.33 (3)	O4^xii—K2—O13	68.99 (2)
O5—Al1—O1	101.47 (3)	O3—K2—O13	105.23 (2)
O10—Al1—O1	167.09 (3)	O8^xiv—K2—O12^xi	115.392 (18)
O2—Al1—K3^i	129.39 (2)	O11^xi—K2—O12^xi	59.19 (2)
O6—Al1—K3^i	48.76 (2)	O4^xii—K2—O12^xi	147.130 (18)
O9—Al1—K3^i	60.460 (19)	O3—K2—O12^xi	68.230 (18)
O5—Al1—K3^i	118.853 (19)	O13—K2—O12^xi	81.497 (19)
O10—Al1—K3^i	126.64 (2)	O8^xiv—K2—O1^ii	74.848 (18)
O1—Al1—K3^i	51.637 (17)	O11^xi—K2—O1^ii	140.71 (2)
C1—O1—Al1	113.12 (5)	O4^xii—K2—O1^ii	66.397 (17)
C1—O1—K3^i	130.07 (6)	O3—K2—O1^ii	79.324 (18)
Al1—O1—K3^i	97.59 (2)	O13—K2—O1^ii	120.364 (17)
C1—O1—K2^ii	94.59 (5)	O12^xi—K2—O1^ii	145.165 (18)
Al1—O1—K2^ii	141.67 (3)	O8^xiv—K2—O7^xiv	56.973 (17)
K3^i—O1—K2^ii	82.443 (15)	O11^xi—K2—O7^xiv	76.429 (17)
C2—O2—Al1	115.56 (5)	O4^xii—K2—O7^xiv	127.208 (19)
C2—O2—K3^iii	117.22 (5)	O3—K2—O7^xiv	74.758 (17)
Al1—O2—K3^iii	107.14 (3)	O13—K2—O7^xiv	158.651 (18)
C1—O3—K3^iv	157.26 (6)	O12^xi—K2—O7^xiv	78.752 (17)
C1—O3—K2	113.69 (5)	O1^ii—K2—O7^xiv	80.864 (15)
K3^iv—O3—K2	88.43 (2)	O8^xiv—K2—O3^ii	112.263 (18)
C1—O3—K1^v	104.98 (5)	O11^xi—K2—O3^ii	162.996 (18)
K3^iv—O3—K1^v	80.945 (15)	O4^xii—K2—O3^ii	60.771 (17)
K2—O3—K1^v	85.536 (17)	O3—K2—O3^ii	71.687 (18)
C1—O3—K2^ii	83.45 (5)	O13—K2—O3^ii	81.612 (17)
K3^iv—O3—K2^ii	84.565 (16)	O12^xi—K2—O3^ii	130.128 (19)
K2—O3—K2^ii	108.313 (18)	O1^ii—K2—O3^ii	42.453 (16)
K1^v—O3—K2^ii	159.68 (2)	O7^xiv—K2—O3^ii	117.592 (16)
C2—O4—K1^v	119.21 (6)	O8^xiv—K2—C1^ii	91.01 (2)
C2—O4—K2^vi	135.98 (6)	O11^xi—K2—C1^ii	153.12 (2)
K1^v—O4—K2^vi	102.667 (18)	O4^xii—K2—C1^ii	54.73 (2)
C3—O5—Al1	114.13 (5)	O3—K2—C1^ii	81.01 (2)
C3—O5—K1^vii	91.30 (4)	O13—K2—C1^ii	97.79 (2)
Al1—O5—K1^vii	130.43 (3)	O12^xi—K2—C1^ii	147.65 (2)
C3—O5—K3^iii	135.07 (6)	O1^ii—K2—C1^ii	22.830 (17)
Al1—O5—K3^iii	105.55 (2)	O7^xiv—K2—C1^ii	103.222 (18)
K1^vii—O5—K3^iii	77.828 (14)	O3^ii—K2—C1^ii	21.64 (2)
C4—O6—Al1	115.33 (5)	O8^xiv—K2—O14	119.61 (2)
C4—O6—K3^i	127.27 (5)	O11^xi—K2—O14	64.113 (18)
Al1—O6—K3^i	101.71 (3)	O4^xii—K2—O14	86.248 (18)
C3—O7—K1^iii	120.66 (5)	O3—K2—O14	107.47 (2)
C3—O7—K3^vii	151.12 (6)	O13—K2—O14	25.022 (17)
K1^iii—O7—K3^vii	87.63 (2)	O12^xi—K2—O14	61.315 (17)
C3—O7—K2^viii	103.83 (5)	O1^ii—K2—O14	145.237 (16)
K1^iii—O7—K2^viii	88.504 (18)	O7^xiv—K2—O14	133.886 (16)
K3^vii—O7—K2^viii	80.889 (15)	O3^ii—K2—O14	106.003 (16)
C3—O7—K1^vii	80.76 (4)	C1^ii—K2—O14	122.800 (18)
K1^iii—O7—K1^vii	106.065 (18)	O8^xiv—K2—C4^xiv	19.061 (18)
K3^vii—O7—K1^vii	86.031 (16)	O11^xi—K2—C4^xiv	54.823 (19)
K2^viii—O7—K1^vii	160.02 (2)	O4^xii—K2—C4^xiv	92.89 (2)
C4—O8—K1^i	133.83 (6)	O3—K2—C4^xiv	117.908 (19)
C4—O8—K2^viii	114.71 (6)	O13—K2—C4^xiv	132.94 (2)
K1^i—O8—K2^viii	103.486 (18)	O12^xi—K2—C4^xiv	97.053 (19)
C5—O9—Al1	115.65 (6)	O1^ii—K2—C4^xiv	86.867 (19)
C5—O9—K3^i	131.27 (5)	O7^xiv—K2—C4^xiv	43.229 (19)
Al1—O9—K3^i	89.23 (2)	O3^ii—K2—C4^xiv	127.926 (19)
C6—O10—Al1	115.20 (6)	C1^ii—K2—C4^xiv	106.29 (2)
C5—O11—K2^i	114.28 (6)	O14—K2—C4^xiv	116.815 (19)
C6—O12—K1^vi	130.96 (5)	O15—K3—O3^xv	158.50 (2)
C6—O12—K2^i	108.27 (6)	O15—K3—O13^xi	98.90 (2)
K1^vi—O12—K2^i	91.222 (19)	O3^xv—K3—O13^xi	91.85 (2)
O3—C1—O1	126.31 (8)	O15—K3—O6^xi	64.11 (2)
O3—C1—C2	121.25 (7)	O3^xv—K3—O6^xi	128.795 (19)
O1—C1—C2	112.43 (8)	O13^xi—K3—O6^xi	110.87 (2)
O3—C1—K2^ii	74.91 (4)	O15—K3—O7^xiii	89.27 (2)
O1—C1—K2^ii	62.58 (4)	O3^xv—K3—O7^xiii	80.192 (19)
C2—C1—K2^ii	141.34 (6)	O13^xi—K3—O7^xiii	171.80 (2)
O3—C1—K2	47.56 (4)	O6^xi—K3—O7^xiii	73.282 (18)
O1—C1—K2	100.94 (5)	O15—K3—O15B	9.00 (7)
C2—C1—K2	125.44 (5)	O3^xv—K3—O15B	152.01 (6)
K2^ii—C1—K2	91.98 (2)	O13^xi—K3—O15B	95.44 (6)
O4—C2—O2	126.20 (8)	O6^xi—K3—O15B	73.09 (7)
O4—C2—C1	121.14 (8)	O7^xiii—K3—O15B	92.55 (6)
O2—C2—C1	112.64 (6)	O15—K3—O1^xi	117.48 (2)
O2—C2—K1^v	148.43 (5)	O3^xv—K3—O1^xi	80.545 (18)
C1—C2—K1^v	87.20 (5)	O13^xi—K3—O1^xi	91.401 (19)
O7—C3—O5	126.48 (8)	O6^xi—K3—O1^xi	54.749 (16)
O7—C3—C4	120.90 (7)	O7^xiii—K3—O1^xi	85.377 (17)
O5—C3—C4	112.62 (8)	O15B—K3—O1^xi	126.10 (7)
O7—C3—K1^vii	77.81 (4)	O15—K3—O2^x	97.01 (2)
O5—C3—K1^vii	65.86 (4)	O3^xv—K3—O2^x	73.815 (18)
C4—C3—K1^vii	131.70 (5)	O13^xi—K3—O2^x	55.566 (19)
O5—C3—K1^iii	98.45 (5)	O6^xi—K3—O2^x	156.365 (17)
C4—C3—K1^iii	135.38 (5)	O7^xiii—K3—O2^x	123.017 (18)
K1^vii—C3—K1^iii	89.49 (2)	O15B—K3—O2^x	88.21 (7)
O8—C4—O6	126.36 (8)	O1^xi—K3—O2^x	136.385 (17)
O8—C4—C3	120.86 (8)	O15—K3—O5^x	70.75 (2)
O6—C4—C3	112.76 (6)	O3^xv—K3—O5^x	88.731 (17)
O8—C4—K2^viii	46.23 (5)	O13^xi—K3—O5^x	103.21 (2)
O6—C4—K2^viii	146.04 (5)	O6^xi—K3—O5^x	126.308 (17)
C3—C4—K2^viii	85.42 (5)	O7^xiii—K3—O5^x	78.758 (17)
O11—C5—O9	125.05 (9)	O15B—K3—O5^x	63.30 (6)
O11—C5—C6	121.38 (8)	O1^xi—K3—O5^x	162.177 (17)
O9—C5—C6	113.57 (8)	O2^x—K3—O5^x	51.387 (16)
O11—C5—K2^i	46.78 (5)	O15—K3—O9^xi	83.55 (2)
O9—C5—K2^i	155.37 (6)	O3^xv—K3—O9^xi	117.948 (16)
C6—C5—K2^i	79.37 (5)	O13^xi—K3—O9^xi	61.52 (2)
O12—C6—O10	126.56 (9)	O6^xi—K3—O9^xi	50.706 (16)
O12—C6—C5	121.68 (8)	O7^xiii—K3—O9^xi	120.598 (19)
O10—C6—C5	111.76 (7)	O15B—K3—O9^xi	89.09 (6)
O12—C6—K2^i	52.47 (5)	O1^xi—K3—O9^xi	48.948 (15)
O10—C6—K2^i	154.55 (5)	O2^x—K3—O9^xi	116.385 (17)
C5—C6—K2^i	75.20 (5)	O5^x—K3—O9^xi	148.063 (16)
O4^ix—K1—O7^x	133.947 (18)	O15—K3—Al1^xi	87.32 (2)
O4^ix—K1—O8^xi	77.547 (19)	O3^xv—K3—Al1^xi	111.315 (14)
O7^x—K1—O8^xi	135.605 (19)	O13^xi—K3—Al1^xi	90.363 (17)
O4^ix—K1—O15	131.73 (3)	O6^xi—K3—Al1^xi	29.536 (11)
O7^x—K1—O15	91.08 (2)	O7^xiii—K3—Al1^xi	90.699 (15)
O8^xi—K1—O15	79.24 (2)	O15B—K3—Al1^xi	95.65 (7)
O4^ix—K1—O12^xii	76.18 (2)	O1^xi—K3—Al1^xi	30.770 (12)
O7^x—K1—O12^xii	90.54 (2)	O2^x—K3—Al1^xi	145.928 (12)
O8^xi—K1—O12^xii	131.99 (2)	O5^x—K3—Al1^xi	155.586 (14)
O15—K1—O12^xii	89.35 (2)	O9^xi—K3—Al1^xi	30.310 (12)
O4^ix—K1—O15B	134.73 (7)	O15—K3—K1^xvi	105.871 (18)
O7^x—K1—O15B	84.60 (7)	O3^xv—K3—K1^xvi	53.967 (12)
O8^xi—K1—O15B	89.15 (6)	O13^xi—K3—K1^xvi	131.505 (18)
O15—K1—O15B	9.96 (6)	O6^xi—K3—K1^xvi	117.364 (13)
O12^xii—K1—O15B	81.88 (6)	O7^xiii—K3—K1^xvi	44.139 (14)
O4^ix—K1—O5^xiii	87.019 (19)	O15B—K3—K1^xvi	102.62 (6)
O7^x—K1—O5^xiii	82.611 (18)	O1^xi—K3—K1^xvi	111.927 (13)
O8^xi—K1—O5^xiii	66.618 (17)	O2^x—K3—K1^xvi	80.205 (12)
O15—K1—O5^xiii	120.75 (2)	O5^x—K3—K1^xvi	50.509 (11)
O12^xii—K1—O5^xiii	149.088 (17)	O9^xi—K3—K1^xvi	160.302 (13)
O15B—K1—O5^xiii	127.00 (6)	Al1^xi—K3—K1^xvi	131.128 (8)
O4^ix—K1—O3^ix	57.729 (18)	O15—K3—H15	15.5 (2)
O7^x—K1—O3^ix	76.459 (18)	O3^xv—K3—H15	173.9 (2)
O8^xi—K1—O3^ix	126.921 (19)	O13^xi—K3—H15	91.8 (3)
O15—K1—O3^ix	152.07 (2)	O6^xi—K3—H15	53.9 (3)
O12^xii—K1—O3^ix	66.259 (17)	O7^xiii—K3—H15	96.3 (3)
O15B—K1—O3^ix	142.31 (6)	O15B—K3—H15	22.4 (3)
O5^xiii—K1—O3^ix	82.838 (15)	O1^xi—K3—H15	104.3 (3)
O4^ix—K1—O7^xiii	122.588 (19)	O2^x—K3—H15	104.4 (3)
O7^x—K1—O7^xiii	73.935 (18)	O5^x—K3—H15	85.7 (3)
O8^xi—K1—O7^xiii	61.764 (18)	O9^xi—K3—H15	68.1 (2)
O15—K1—O7^xiii	80.14 (2)	Al1^xi—K3—H15	73.6 (3)
O12^xii—K1—O7^xiii	160.93 (2)	K1^xvi—K3—H15	120.2 (2)
O15B—K1—O7^xiii	85.62 (6)	O14—O13—K3^i	143.24 (6)
O5^xiii—K1—O7^xiii	41.439 (15)	O14—O13—K2	98.60 (4)
O3^ix—K1—O7^xiii	118.831 (16)	K3^i—O13—K2	92.07 (2)
O4^ix—K1—C3^xiii	101.62 (2)	O14—O13—H13	91.4 (9)
O7^x—K1—C3^xiii	85.10 (2)	K3^i—O13—H13	115.2 (9)
O8^xi—K1—C3^xiii	54.30 (2)	K2—O13—H13	116.0 (10)
O15—K1—C3^xiii	98.10 (2)	O13—O14—K2	56.38 (3)
O12^xii—K1—C3^xiii	171.428 (19)	O13—O14—H14	102.8 (7)
O15B—K1—C3^xiii	105.00 (6)	K2—O14—H14	125.2 (7)
O5^xiii—K1—C3^xiii	22.844 (17)	O16—O15—K3	137.85 (7)
O3^ix—K1—C3^xiii	105.467 (18)	O16—O15—K1	104.26 (5)
O7^xiii—K1—C3^xiii	21.42 (2)	K3—O15—K1	103.37 (3)
O4^ix—K1—O16	122.76 (2)	O16—O15—H15	86.0 (9)
O7^x—K1—O16	87.96 (2)	K3—O15—H15	107.1 (9)
O8^xi—K1—O16	98.670 (19)	K1—O15—H15	119.3 (10)
O15—K1—O16	24.85 (2)	O16—O15B—K1	113.07 (19)
O12^xii—K1—O16	64.737 (19)	O16—O15B—K3	150.8 (2)
O15B—K1—O16	17.38 (6)	K1—O15B—K3	95.80 (9)
O5^xiii—K1—O16	144.349 (19)	O16—O15B—H15	93.4 (7)
O3^ix—K1—O16	128.122 (18)	K1—O15B—H15	100.0 (8)
O7^xiii—K1—O16	102.922 (18)	K3—O15B—H15	85.5 (7)
C3^xiii—K1—O16	122.33 (2)	K1—O15B—H16	132.3 (6)
O4^ix—K1—C2^ix	18.236 (18)	K3—O15B—H16	115.1 (7)
O7^x—K1—C2^ix	119.224 (19)	H15—O15B—H16	117.0 (10)
O8^xi—K1—C2^ix	95.74 (2)	O15B—O16—K1	49.55 (16)
O15—K1—C2^ix	136.28 (2)	O15—O16—K1	50.89 (4)
O12^xii—K1—C2^ix	61.87 (2)	O15B—O16—H16	84.7 (10)
O15B—K1—C2^ix	134.92 (7)	O15—O16—H16	96.0 (10)
O5^xiii—K1—C2^ix	95.424 (19)	K1—O16—H16	114.5 (10)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O13—H13···O16	0.963 (17)	1.992 (17)	2.9139 (12)	159.5 (14)
O14—H14···O11	1.183 (17)	1.527 (17)	2.6996 (11)	169.9 (12)
O15—H15···O14	0.842 (14)	1.832 (15)	2.6633 (11)	169.4 (14)
O16—H16···O10^x	0.881 (18)	1.858 (18)	2.7297 (12)	169.6 (14)

Symmetry code: (x) x−1, −y+1/2, z+1/2.