Crystal structure of Rb6[B12O18(OH)6]·2H2O.

The solvothermal reaction of H3BO3, sodium tert-butoxide, Rb2CO3 and pyridine led to a new alkaline metal borate hexa-rubidium hexa-hydroxy-dodeca-borate dihydrate, Rb6[B12O18(OH)6]·2H2O. Its structure contains a large cyclic dodeca-oxoboron cluster, [B12O18(OH)6]6-, formed by six {B3O3} rings. In the crystal, O-H⋯O hydrogen bonds between the components lead to the formation of a three-dimensional supra-molecular framework. © Qiu et al. 2022.

Chemical context

In recent years, borates have made excellent contributions to the development of nonlinear optical (NLO) materials and so they are the focus of material chemists (Bashir et al., 2018 ▸; Qiu et al., 2021a ▸; Wei et al., 2016 ▸). Scientists have found that alkali- and alkaline-earth–metal borates often exhibit a short ultraviolet cut-off edge due to no d–d and f–f electron transition in the ultraviolet region with wide transparency ranges (Shi et al., 2019 ▸; Tang et al., 2019 ▸). Generally, boron has two kinds of coordination modes: either BO3 trigonal or BO4 tetra­hedral, and they further bond to each other through common O atoms forming different oxoboron clusters, which can further polymerize into isolated clusters, one-dimensional chains, two-dimensional layers or three-dimensional frameworks. Here, single crystals of Rb6[B12O18(OH)6]·2H2O with alkali metal atoms and isolated oxoboron clusters have been obtained under solvothermal conditions.

Structural commentary

There are 13.5 independent atoms in the asymmetric unit of the title compound, including 3 B, 9/2 O, 3/2 OH, 3/2 Rb, and 1/2 H2O. It should be noted that the Rb1, Rb2, B2, B4, O4, O6 and O8 atoms are located on special positions with occupancy of 0.25 or 0.5, while the remaining Rb, B and O atoms are located at general positions with an occupancy of 1. Bond-valence-sum calculations show that Rb and B are consistent with the expected oxidation states (Brown & Altermatt, 1985 ▸; Brese & O’Keeffe, 1991 ▸). Six trigonal BO2(OH) units [B—O(av.) = 1.360 Å] and six tetra­hedral BO4 units [B—O(av.) = 1.474 Å] are linked by vertex sharing. Each BO4 unit provides two terminal oxygen atoms to connect with two neighboring BO4 units and shares the other two corners with the BO2(OH) unit to form a [B12O18(OH)6]6− cluster (Fig. 1 ▸). Each Rb atom is six-coordinate, with Rb—O distances in the range of 2.793 (5)-3.359 (5) Å.

Figure 1

The asymmetric unit of the oxoboron cluster of [B12O18(OH)6]6− [symmetry codes: (i) 2 − x, 2 − y, z; (ii) x, y, 2 − z]. Displacement ellipsoids are drawn at the 50% probability level.

Supra­molecular features

In the title compound, each [B12O18(OH)6]6− cluster is connected to other clusters by O1—H1⋯O6, and O6—H6⋯O1 hydrogen bonds, resulting in a three-dimensional supra­molecular framework (Fig. 2 ▸, Table 1 ▸). Water mol­ecules are also attached to supra­molecular structure via O—H⋯O hydrogen bonds. The title structure is different from those of previously reported analogues K7{(BO3)Mn[B12O18(OH)6]}·H2O (Zhang et al., 2004 ▸), and Na2Cs4Ba2[B12O18(OH)6]·4OH (Zhang et al., 2016 ▸). Both compounds crystallize in the non-centrosymmetric Pmn21 space group and their supra­molecular structures are different from that of the title compound. Therefore, the use of different alkali metals as templates may affect the crystallization of the oxoboron supra­molecular structure.

Figure 2

View of the three-dimensional supra­molecular framework along the [010] direction. All of the Rb—O bonds are omitted for clarity and blue dashed lines represent O—H⋯O hydrogen bonds.

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O8—H8B⋯O7i	0.85	2.25	3.046 (6)	155
O8—H8B⋯O4i	0.85	1.68	2.224 (7)	119
O8—H8A⋯O7ii	0.85	1.70	2.231 (5)	118
O8—H8A⋯O4ii	0.85	2.17	2.958 (7)	155
O6—H6⋯O1iii	0.82	1.86	2.670 (5)	167
O1—H1⋯O6iv	0.94	1.91	2.670 (5)	136

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) .

Database survey

A search of the Cambridge Structural Database (CSD, version 5.43, update June 2022; Groom et al., 2016 ▸) for the cyclic dodeca-oxoboron unit {B12O24} ring gave eight hits. In the crystals of Li7Na2KRb2B12O24, Li7.35Na2.36K1.50Cs0.78B12O24, Li6.97Na2.63K1.24Cs1.15B12O24, and Li7.27Na2.67Rb2.06B12O24 (refcodes: JOGBIT, JOGBOZ, JOFNEA, JOFNIE, trigonal, R space group; Baiheti et al., 2019 ▸), the terminal oxygens of this type of the {B12O24} ring can be completely deprotonated [B12O24]12− and fail to extend to high-dimensional structures through covalent bonds and hydrogen bonds. In the crystal of Na8[B12O20(OH)4] (refcode: ETIJAU, monoclinic, P21/c space group; Menchetti et al., 1979 ▸), the partially protonated [B12O20(OH)4]8− unit also fails to extend to a higher dimensional structure through O—B—O bonds. While KNa8[Li@B12O18(OH)6](CO3)2 (refcode: EBUCAJ, trigonal, R space group; Qiu et al., 2021b ▸) is a borate carbonate with the isolated [Li@B12O18(OH)6]5− cluster and inter­esting layers formed by Na+ and CO3 2− ions, thus forming a two-dimensional supra­molecular structure. After changing the synthetic conditions, the isolated [Li@B12O18(OH)6]5− cluster was successfully extended to a layered structure via B—O—B bonds in Cs5[Li@B12O20(OH)2]·3H2O (refcode: EBUCIR, monoclinic, Pc space group; Qiu et al., 2021b ▸), by condensation reactions with the elimination of water mol­ecules between oxoboron clusters.

Synthesis and crystallization

A mixture of H3BO3 (0.618 g, 10 mmol), sodium tert-butoxide (0.096 g, 1 mmol) and Rb2CO3 (0.231 g, 1 mmol) was added into pyridine (3.0 mL). After stirring for 15 min, the resulting mixture was sealed in a 25 mL Teflon-lined stainless steel autoclave, heated at 483 K for 7 days, and then slowly cooled to room temperature. Colorless block-shaped crystals of Rb6[B12O18(OH)6]·2H2O were obtained (yield 51% based on H3BO3). Infrared (KBr pallet, cm−1): 3445vs, 1639m, 1427s, 1320m, 1003m, 939w, 873m, 721m, 622w, 542m. The thermogravimetric curve of the title compound is shown in Fig. 3 ▸ a. The weight loss of 8.6% (cal. 8.4%) in the temperature range 350–950 K for the compound is attributed to the loss of the water mol­ecules and the removal of dehydration of the hydroxyl groups. The compound has almost no weight loss after 950 K. The ultraviolet visible diffuse reflectance spectrum of the title compound is shown in Fig. 3 ▸ b. The band gap obtained by extrapolating the linear part of the rising curve to zero for the compound is 5.59 eV.

Figure 3

(a) Thermogravimetric curve and (b) ultraviolet visible diffuse reflectance spectrum of the title compound. Inset: plots of α/S versus E.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2 ▸. Hydrogen-atom coordinates were refined without any constraints or restraints. Their U iso values were set to 1.2U eq of the parent atoms.

Table 2

Experimental details

Crystal data
Chemical formula	Rb6[B12O18(OH)6]·2H2O
M r	1068.62
Crystal system, space group	Orthorhombic, P n n m
Temperature (K)	296
a, b, c (Å)	13.395 (4), 9.251 (2), 12.368 (4)
V (Å3)	1532.7 (7)
Z	2
Radiation type	Mo Kα
μ (mm−1)	9.60
Crystal size (mm)	0.08 × 0.07 × 0.07
Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Krause et al., 2015 ▸)
T min, T max	0.452, 0.746
No. of measured, independent and observed [I > 2σ(I)] reflections	17510, 1980, 1523
R int	0.057
(sin θ/λ)max (Å−1)	0.667
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.061, 0.173, 1.07
No. of reflections	1980
No. of parameters	110
H-atom treatment	H-atom parameters constrained
Δρmax, Δρmin (e Å−3)	1.57, −1.16

Computer programs: APEX2 and SAINT (Bruker, 2014 ▸), SHELXT2018/3 (Sheldrick, 2015a ▸), SHELXL2018/3 (Sheldrick, 2015b ▸) and SHELXTL (Sheldrick, 2008 ▸).

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S2056989022008611/tx2056sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989022008611/tx2056Isup3.hkl

CCDC reference: 2192069

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

Rb6[B12O18(OH)6]·2H2O	Dx = 2.316 Mg m−3
Mr = 1068.62	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pnnm	Cell parameters from 3469 reflections
a = 13.395 (4) Å	θ = 2.7–26.1°
b = 9.251 (2) Å	µ = 9.60 mm−1
c = 12.368 (4) Å	T = 296 K
V = 1532.7 (7) Å3	Block, colorless
Z = 2	0.08 × 0.07 × 0.07 mm
F(000) = 1000

Bruker APEXII CCD diffractometer	1523 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube, Bruker (Mo) X-ray Source	Rint = 0.057
φ and ω scans	θmax = 28.3°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Krause et al., 2015)	h = −17→17
Tmin = 0.452, Tmax = 0.746	k = −12→12
17510 measured reflections	l = −16→16
1980 independent reflections

Refinement on F2	0 restraints
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.061	H-atom parameters constrained
wR(F2) = 0.173	w = 1/[σ2(Fo2) + (0.0825P)2 + 9.4675P] where P = (Fo2 + 2Fc2)/3
S = 1.07	(Δ/σ)max < 0.001
1980 reflections	Δρmax = 1.57 e Å−3
110 parameters	Δρmin = −1.16 e Å−3

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.

	x	y	z	Uiso*/Ueq	Occ. (<1)
Rb1	1.000000	1.000000	0.500000	0.0418 (4)
Rb2	1.000000	0.500000	1.000000	0.0529 (5)
Rb3	0.74535 (5)	1.03106 (9)	0.73060 (7)	0.0489 (3)
O1	1.0385 (4)	0.6325 (4)	0.6768 (4)	0.0397 (12)
H1	1.089080	0.687977	0.643718	0.048*
O2	0.9347 (3)	0.7048 (4)	0.8193 (3)	0.0191 (8)
O3	1.0311 (3)	0.8776 (4)	0.7204 (3)	0.0203 (8)
O4	0.9428 (4)	0.7903 (6)	1.000000	0.0204 (11)
O5	0.7857 (3)	0.7944 (4)	0.9032 (3)	0.0194 (8)
O6	0.6357 (4)	0.7801 (7)	1.000000	0.0270 (13)
H6	0.599457	0.797673	0.948224	0.032*	0.5
O7	0.9137 (3)	0.9603 (4)	0.8563 (3)	0.0224 (8)
O8	0.4074 (4)	0.3941 (5)	0.500000	0.0144 (9)
H8A	0.401585	0.483846	0.486660	0.017*	0.5
H8B	0.456785	0.383526	0.542470	0.017*	0.5
B1	0.9999 (4)	0.7413 (6)	0.7399 (4)	0.0193 (11)
B2	1.000000	1.000000	0.7919 (6)	0.0127 (14)
B3	0.8956 (4)	0.8163 (6)	0.8960 (4)	0.0114 (10)
B4	0.7386 (6)	0.7897 (9)	1.000000	0.0176 (15)

	U11	U22	U33	U12	U13	U23
Rb1	0.0586 (9)	0.0472 (8)	0.0196 (6)	0.0159 (6)	0.000	0.000
Rb2	0.0971 (13)	0.0268 (6)	0.0348 (7)	0.0271 (7)	0.000	0.000
Rb3	0.0324 (4)	0.0516 (5)	0.0628 (5)	0.0101 (3)	−0.0090 (3)	0.0248 (4)
O1	0.059 (3)	0.0192 (19)	0.041 (3)	−0.011 (2)	0.036 (2)	−0.0119 (18)
O2	0.0257 (18)	0.0140 (16)	0.0175 (18)	−0.0067 (14)	0.0084 (15)	−0.0047 (13)
O3	0.0296 (18)	0.0153 (16)	0.0158 (17)	−0.0080 (15)	0.0094 (15)	−0.0048 (14)
O4	0.010 (2)	0.036 (3)	0.015 (2)	0.007 (2)	0.000	0.000
O5	0.0110 (15)	0.036 (2)	0.0117 (16)	−0.0044 (15)	−0.0006 (13)	−0.0003 (14)
O6	0.013 (2)	0.052 (4)	0.016 (2)	−0.004 (2)	0.000	0.000
O7	0.0223 (19)	0.0154 (17)	0.029 (2)	0.0031 (14)	0.0108 (16)	0.0055 (15)
O8	0.017 (2)	0.012 (2)	0.013 (2)	0.0099 (18)	0.000	0.000
B1	0.025 (3)	0.018 (3)	0.014 (2)	−0.007 (2)	0.004 (2)	−0.007 (2)
B2	0.016 (3)	0.015 (3)	0.006 (3)	0.002 (3)	0.000	0.000
B3	0.008 (2)	0.014 (2)	0.012 (2)	−0.0031 (18)	−0.0010 (18)	−0.0018 (19)
B4	0.013 (4)	0.024 (4)	0.016 (4)	−0.004 (3)	0.000	0.000

Rb1—O3	2.980 (4)	Rb3—O5	3.105 (4)
Rb1—O3i	2.980 (4)	Rb3—O3ii	3.114 (4)
Rb1—O3ii	2.980 (4)	Rb3—O1xi	3.359 (5)
Rb1—O3iii	2.980 (4)	Rb3—B3	3.491 (5)
Rb1—O6iv	3.166 (6)	Rb3—B2	3.5061 (19)
Rb1—O6v	3.166 (6)	Rb3—B3v	3.603 (5)
Rb1—B2iii	3.610 (7)	Rb3—B4v	3.729 (5)
Rb1—B2	3.610 (7)	O1—B1	1.374 (7)
Rb1—Rb3	4.4556 (12)	O1—H1	0.9433
Rb1—Rb3i	4.4556 (12)	O2—B1	1.357 (6)
Rb1—Rb3ii	4.4556 (12)	O2—B3	1.495 (6)
Rb1—Rb3iii	4.4556 (12)	O3—B1	1.350 (7)
Rb2—O4vi	2.793 (5)	O3—B2	1.496 (5)
Rb2—O4	2.793 (5)	O4—B3vii	1.453 (5)
Rb2—O2vii	3.058 (4)	O4—B3	1.453 (5)
Rb2—O2viii	3.058 (4)	O5—B4	1.354 (5)
Rb2—O2vi	3.058 (4)	O5—B3	1.490 (6)
Rb2—O2	3.058 (4)	O6—B4	1.381 (9)
Rb2—B3	3.488 (5)	O6—H6	0.8200
Rb2—B3vii	3.488 (5)	O6—H6vii	0.8200
Rb2—B3viii	3.488 (5)	O7—B3	1.441 (6)
Rb2—B3vi	3.488 (5)	O7—B2	1.452 (5)
Rb2—Rb3ix	4.3609 (11)	O8—H8A	0.8500
Rb2—Rb3x	4.3609 (11)	O8—H8B	0.8500
Rb3—O7	2.816 (4)	O8—H8Ai	0.8500
Rb3—O2v	2.963 (4)	O8—H8Bi	0.8500
Rb3—O5v	2.974 (4)
O3—Rb1—O3i	132.24 (13)	O3ii—Rb3—O1xi	158.35 (10)
O3—Rb1—O3ii	47.76 (13)	O7—Rb3—B3	23.42 (11)
O3i—Rb1—O3ii	180.00 (5)	O2v—Rb3—B3	154.19 (11)
O3—Rb1—O3iii	180.0	O5v—Rb3—B3	150.79 (11)
O3i—Rb1—O3iii	47.76 (13)	O5—Rb3—B3	25.25 (10)
O3ii—Rb1—O3iii	132.24 (13)	O3ii—Rb3—B3	67.90 (10)
O3—Rb1—O6iv	66.97 (7)	O1xi—Rb3—B3	91.11 (11)
O3i—Rb1—O6iv	66.97 (7)	O7—Rb3—B2	23.45 (12)
O3ii—Rb1—O6iv	113.03 (7)	O2v—Rb3—B2	151.80 (8)
O3iii—Rb1—O6iv	113.03 (7)	O5v—Rb3—B2	108.86 (9)
O3—Rb1—O6v	113.03 (7)	O5—Rb3—B2	67.94 (10)
O3i—Rb1—O6v	113.03 (7)	O3ii—Rb3—B2	25.24 (9)
O3ii—Rb1—O6v	66.97 (7)	O1xi—Rb3—B2	133.79 (11)
O3iii—Rb1—O6v	66.97 (7)	B3—Rb3—B2	42.74 (11)
O6iv—Rb1—O6v	180.0	O7—Rb3—B3v	146.09 (12)
O3—Rb1—B2iii	156.12 (7)	O2v—Rb3—B3v	23.88 (10)
O3i—Rb1—B2iii	23.88 (7)	O5v—Rb3—B3v	23.81 (10)
O3ii—Rb1—B2iii	156.12 (7)	O5—Rb3—B3v	155.00 (10)
O3iii—Rb1—B2iii	23.88 (7)	O3ii—Rb3—B3v	106.72 (10)
O6iv—Rb1—B2iii	90.0	O1xi—Rb3—B3v	92.62 (11)
O6v—Rb1—B2iii	90.0	B3—Rb3—B3v	166.87 (12)
O3—Rb1—B2	23.88 (7)	B2—Rb3—B3v	131.60 (10)
O3i—Rb1—B2	156.12 (7)	O7—Rb3—B4v	121.68 (14)
O3ii—Rb1—B2	23.88 (7)	O2v—Rb3—B4v	62.59 (13)
O3iii—Rb1—B2	156.12 (7)	O5v—Rb3—B4v	19.43 (12)
O6iv—Rb1—B2	90.0	O5—Rb3—B4v	165.50 (14)
O6v—Rb1—B2	90.0	O3ii—Rb3—B4v	74.88 (13)
B2iii—Rb1—B2	180.0	O1xi—Rb3—B4v	126.70 (14)
O3—Rb1—Rb3	63.01 (7)	B3—Rb3—B4v	141.27 (14)
O3i—Rb1—Rb3	135.79 (7)	B2—Rb3—B4v	99.31 (15)
O3ii—Rb1—Rb3	44.21 (7)	B3v—Rb3—B4v	39.47 (14)
O3iii—Rb1—Rb3	116.99 (7)	O7—Rb3—Rb2v	161.66 (8)
O6iv—Rb1—Rb3	119.50 (7)	O2v—Rb3—Rb2v	44.45 (7)
O6v—Rb1—Rb3	60.50 (7)	O5v—Rb3—Rb2v	65.47 (7)
B2iii—Rb1—Rb3	129.799 (15)	O5—Rb3—Rb2v	122.29 (7)
B2—Rb1—Rb3	50.201 (15)	O3ii—Rb3—Rb2v	135.72 (7)
O3—Rb1—Rb3i	135.79 (7)	O1xi—Rb3—Rb2v	64.64 (7)
O3i—Rb1—Rb3i	63.01 (7)	B3—Rb3—Rb2v	141.29 (9)
O3ii—Rb1—Rb3i	116.99 (7)	B2—Rb3—Rb2v	150.36 (11)
O3iii—Rb1—Rb3i	44.21 (7)	B3v—Rb3—Rb2v	50.87 (8)
O6iv—Rb1—Rb3i	119.50 (7)	B4v—Rb3—Rb2v	65.52 (11)
O6v—Rb1—Rb3i	60.50 (7)	O7—Rb3—Rb1	74.06 (8)
B2iii—Rb1—Rb3i	50.202 (15)	O2v—Rb3—Rb1	121.65 (7)
B2—Rb1—Rb3i	129.798 (15)	O5v—Rb3—Rb1	78.67 (7)
Rb3—Rb1—Rb3i	79.60 (3)	O5—Rb3—Rb1	105.16 (7)
O3—Rb1—Rb3ii	44.21 (7)	O3ii—Rb3—Rb1	41.86 (7)
O3i—Rb1—Rb3ii	116.99 (7)	O1xi—Rb3—Rb1	145.17 (7)
O3ii—Rb1—Rb3ii	63.01 (7)	B3—Rb3—Rb1	84.08 (9)
O3iii—Rb1—Rb3ii	135.79 (7)	B2—Rb3—Rb1	52.28 (12)
O6iv—Rb1—Rb3ii	60.50 (7)	B3v—Rb3—Rb1	99.81 (8)
O6v—Rb1—Rb3ii	119.50 (7)	B4v—Rb3—Rb1	60.50 (11)
B2iii—Rb1—Rb3ii	129.798 (14)	Rb2v—Rb3—Rb1	98.86 (3)
B2—Rb1—Rb3ii	50.202 (14)	B1—O1—Rb3xii	116.5 (4)
Rb3—Rb1—Rb3ii	100.40 (3)	B1—O1—H1	96.8
Rb3i—Rb1—Rb3ii	180.0	Rb3xii—O1—H1	78.5
O3—Rb1—Rb3iii	116.99 (7)	B1—O2—B3	120.9 (4)
O3i—Rb1—Rb3iii	44.21 (7)	B1—O2—Rb3x	120.5 (3)
O3ii—Rb1—Rb3iii	135.79 (7)	B3—O2—Rb3x	102.8 (2)
O3iii—Rb1—Rb3iii	63.01 (7)	B1—O2—Rb2	119.9 (3)
O6iv—Rb1—Rb3iii	60.50 (7)	B3—O2—Rb2	93.7 (3)
O6v—Rb1—Rb3iii	119.50 (7)	Rb3x—O2—Rb2	92.81 (9)
B2iii—Rb1—Rb3iii	50.202 (14)	B1—O3—B2	121.0 (4)
B2—Rb1—Rb3iii	129.798 (14)	B1—O3—Rb1	118.4 (3)
Rb3—Rb1—Rb3iii	180.0	B2—O3—Rb1	102.4 (3)
Rb3i—Rb1—Rb3iii	100.40 (3)	B1—O3—Rb3ii	122.9 (3)
Rb3ii—Rb1—Rb3iii	79.60 (3)	B2—O3—Rb3ii	92.20 (15)
O4vi—Rb2—O4	180.0	Rb1—O3—Rb3ii	93.93 (9)
O4vi—Rb2—O2vii	132.41 (6)	B3vii—O4—B3	124.6 (5)
O4—Rb2—O2vii	47.59 (6)	B3vii—O4—Rb2	106.2 (3)
O4vi—Rb2—O2viii	47.59 (6)	B3—O4—Rb2	106.2 (3)
O4—Rb2—O2viii	132.41 (6)	B4—O5—B3	121.2 (4)
O2vii—Rb2—O2viii	180.0	B4—O5—Rb3x	113.6 (4)
O4vi—Rb2—O2vi	47.59 (6)	B3—O5—Rb3x	102.5 (3)
O4—Rb2—O2vi	132.41 (6)	B4—O5—Rb3	123.3 (4)
O2vii—Rb2—O2vi	86.08 (13)	B3—O5—Rb3	92.0 (3)
O2viii—Rb2—O2vi	93.92 (13)	Rb3x—O5—Rb3	99.83 (10)
O4vi—Rb2—O2	132.41 (6)	B4—O6—Rb1x	128.7 (5)
O4—Rb2—O2	47.59 (6)	B4—O6—H6	125.4
O2vii—Rb2—O2	93.92 (13)	Rb1x—O6—H6	79.7
O2viii—Rb2—O2	86.08 (13)	B4—O6—H6vii	125.35 (13)
O2vi—Rb2—O2	180.0	Rb1x—O6—H6vii	79.74 (6)
O4vi—Rb2—B3	156.42 (9)	H6—O6—H6vii	102.7
O4—Rb2—B3	23.58 (9)	B3—O7—B2	123.7 (3)
O2vii—Rb2—B3	68.60 (11)	B3—O7—Rb3	105.6 (3)
O2viii—Rb2—B3	111.40 (11)	B2—O7—Rb3	106.0 (3)
O2vi—Rb2—B3	154.67 (10)	H8A—O8—H8B	107.7
O2—Rb2—B3	25.33 (10)	H8A—O8—H8Ai	22.4
O4vi—Rb2—B3vii	156.42 (9)	H8B—O8—H8Ai	93.7
O4—Rb2—B3vii	23.58 (9)	H8A—O8—H8Bi	93.7
O2vii—Rb2—B3vii	25.33 (10)	H8B—O8—H8Bi	76.3
O2viii—Rb2—B3vii	154.67 (10)	H8Ai—O8—H8Bi	107.7
O2vi—Rb2—B3vii	111.40 (11)	O3—B1—O2	124.1 (5)
O2—Rb2—B3vii	68.60 (11)	O3—B1—O1	117.8 (5)
B3—Rb2—B3vii	43.27 (17)	O2—B1—O1	118.1 (5)
O4vi—Rb2—B3viii	23.58 (9)	O7ii—B2—O7	113.4 (6)
O4—Rb2—B3viii	156.42 (9)	O7ii—B2—O3ii	110.79 (19)
O2vii—Rb2—B3viii	154.67 (10)	O7—B2—O3ii	107.1 (2)
O2viii—Rb2—B3viii	25.33 (10)	O7ii—B2—O3	107.1 (2)
O2vi—Rb2—B3viii	68.60 (11)	O7—B2—O3	110.79 (19)
O2—Rb2—B3viii	111.40 (11)	O3ii—B2—O3	107.5 (5)
B3—Rb2—B3viii	136.73 (17)	O7ii—B2—Rb3	150.8 (3)
B3vii—Rb2—B3viii	180.0	O7—B2—Rb3	50.53 (19)
O4vi—Rb2—B3vi	23.58 (9)	O3ii—B2—Rb3	62.57 (15)
O4—Rb2—B3vi	156.42 (9)	O3—B2—Rb3	101.8 (2)
O2vii—Rb2—B3vi	111.40 (11)	O7ii—B2—Rb3ii	50.52 (19)
O2viii—Rb2—B3vi	68.60 (11)	O7—B2—Rb3ii	150.8 (3)
O2vi—Rb2—B3vi	25.33 (10)	O3ii—B2—Rb3ii	101.8 (2)
O2—Rb2—B3vi	154.67 (10)	O3—B2—Rb3ii	62.57 (15)
B3—Rb2—B3vi	180.00 (9)	Rb3—B2—Rb3ii	155.0 (2)
B3vii—Rb2—B3vi	136.73 (17)	O7ii—B2—Rb1	123.3 (3)
B3viii—Rb2—B3vi	43.27 (17)	O7—B2—Rb1	123.3 (3)
O4vi—Rb2—Rb3ix	74.33 (8)	O3ii—B2—Rb1	53.8 (3)
O4—Rb2—Rb3ix	105.67 (8)	O3—B2—Rb1	53.8 (3)
O2vii—Rb2—Rb3ix	77.20 (7)	Rb3—B2—Rb1	77.52 (12)
O2viii—Rb2—Rb3ix	102.80 (7)	Rb3ii—B2—Rb1	77.52 (12)
O2vi—Rb2—Rb3ix	42.74 (7)	O7—B3—O4	112.5 (4)
O2—Rb2—Rb3ix	137.26 (7)	O7—B3—O5	108.2 (4)
B3—Rb2—Rb3ix	126.76 (8)	O4—B3—O5	110.8 (4)
B3vii—Rb2—Rb3ix	96.67 (8)	O7—B3—O2	111.3 (4)
B3viii—Rb2—Rb3ix	83.33 (8)	O4—B3—O2	107.2 (4)
B3vi—Rb2—Rb3ix	53.24 (8)	O5—B3—O2	106.9 (4)
O4vi—Rb2—Rb3x	105.67 (8)	O7—B3—Rb2	146.6 (3)
O4—Rb2—Rb3x	74.33 (8)	O4—B3—Rb2	50.3 (3)
O2vii—Rb2—Rb3x	102.80 (7)	O5—B3—Rb2	105.1 (3)
O2viii—Rb2—Rb3x	77.20 (7)	O2—B3—Rb2	61.0 (2)
O2vi—Rb2—Rb3x	137.26 (7)	O7—B3—Rb3	51.0 (2)
O2—Rb2—Rb3x	42.74 (7)	O4—B3—Rb3	149.7 (3)
B3—Rb2—Rb3x	53.24 (8)	O5—B3—Rb3	62.7 (2)
B3vii—Rb2—Rb3x	83.33 (8)	O2—B3—Rb3	102.9 (3)
B3viii—Rb2—Rb3x	96.67 (8)	Rb2—B3—Rb3	157.61 (16)
B3vi—Rb2—Rb3x	126.76 (8)	O7—B3—Rb3x	128.1 (3)
Rb3ix—Rb2—Rb3x	180.0	O4—B3—Rb3x	119.4 (3)
O7—Rb3—O2v	153.22 (11)	O5—B3—Rb3x	53.7 (2)
O7—Rb3—O5v	127.55 (10)	O2—B3—Rb3x	53.3 (2)
O2v—Rb3—O5v	47.64 (10)	Rb2—B3—Rb3x	75.88 (10)
O7—Rb3—O5	46.94 (10)	Rb3—B3—Rb3x	81.95 (10)
O2v—Rb3—O5	131.85 (10)	O5—B4—O5vii	124.3 (6)
O5v—Rb3—O5	169.84 (10)	O5—B4—O6	117.8 (3)
O7—Rb3—O3ii	46.81 (9)	O5vii—B4—O6	117.8 (3)
O2v—Rb3—O3ii	128.83 (9)	O5—B4—Rb3x	47.0 (3)
O5v—Rb3—O3ii	83.65 (10)	O5vii—B4—Rb3x	132.1 (5)
O5—Rb3—O3ii	92.98 (9)	O6—B4—Rb3x	90.9 (3)
O7—Rb3—O1xi	111.56 (10)	O5—B4—Rb3xiii	132.1 (5)
O2v—Rb3—O1xi	69.14 (10)	O5vii—B4—Rb3xiii	47.0 (3)
O5v—Rb3—O1xi	116.34 (10)	O6—B4—Rb3xiii	90.9 (3)
O5—Rb3—O1xi	65.88 (10)	Rb3x—B4—Rb3xiii	99.8 (2)
B2—O3—B1—O2	4.2 (8)	Rb2—O4—B3—O5	92.7 (4)
Rb1—O3—B1—O2	−123.3 (5)	B3vii—O4—B3—O2	−147.0 (4)
Rb3ii—O3—B1—O2	120.5 (5)	Rb2—O4—B3—O2	−23.6 (4)
B2—O3—B1—O1	−174.3 (5)	B3vii—O4—B3—Rb2	−123.5 (7)
Rb1—O3—B1—O1	58.2 (6)	B3vii—O4—B3—Rb3	40.4 (11)
Rb3ii—O3—B1—O1	−58.1 (6)	Rb2—O4—B3—Rb3	163.9 (5)
B3—O2—B1—O3	−3.0 (8)	B3vii—O4—B3—Rb3x	−89.9 (6)
Rb3x—O2—B1—O3	127.7 (5)	Rb2—O4—B3—Rb3x	33.5 (3)
Rb2—O2—B1—O3	−118.4 (5)	B4—O5—B3—O7	−107.7 (6)
B3—O2—B1—O1	175.6 (5)	Rb3x—O5—B3—O7	124.4 (3)
Rb3x—O2—B1—O1	−53.8 (6)	Rb3—O5—B3—O7	23.9 (3)
Rb2—O2—B1—O1	60.1 (6)	B4—O5—B3—O4	15.9 (7)
Rb3xii—O1—B1—O3	91.4 (5)	Rb3x—O5—B3—O4	−111.9 (4)
Rb3xii—O1—B1—O2	−87.2 (5)	Rb3—O5—B3—O4	147.5 (4)
B3—O7—B2—O7ii	−87.0 (4)	B4—O5—B3—O2	132.3 (5)
Rb3—O7—B2—O7ii	151.1 (2)	Rb3x—O5—B3—O2	4.5 (4)
B3—O7—B2—O3ii	150.5 (4)	Rb3—O5—B3—O2	−96.0 (3)
Rb3—O7—B2—O3ii	28.6 (4)	B4—O5—B3—Rb2	68.6 (6)
B3—O7—B2—O3	33.5 (6)	Rb3x—O5—B3—Rb2	−59.2 (2)
Rb3—O7—B2—O3	−88.4 (3)	Rb3—O5—B3—Rb2	−159.77 (14)
B3—O7—B2—Rb3	121.9 (5)	B4—O5—B3—Rb3	−131.6 (6)
B3—O7—B2—Rb3ii	−37.2 (9)	Rb3x—O5—B3—Rb3	100.53 (14)
Rb3—O7—B2—Rb3ii	−159.0 (5)	B4—O5—B3—Rb3x	127.9 (6)
B3—O7—B2—Rb1	93.0 (4)	Rb3—O5—B3—Rb3x	−100.53 (14)
Rb3—O7—B2—Rb1	−28.9 (2)	B1—O2—B3—O7	15.5 (6)
B1—O3—B2—O7ii	106.5 (5)	Rb3x—O2—B3—O7	−122.4 (3)
Rb1—O3—B2—O7ii	−119.1 (3)	Rb2—O2—B3—O7	143.9 (3)
Rb3ii—O3—B2—O7ii	−24.6 (3)	B1—O2—B3—O4	−107.8 (5)
B1—O3—B2—O7	−17.7 (6)	Rb3x—O2—B3—O4	114.3 (3)
Rb1—O3—B2—O7	116.7 (4)	Rb2—O2—B3—O4	20.6 (4)
Rb3ii—O3—B2—O7	−148.8 (3)	B1—O2—B3—O5	133.4 (5)
B1—O3—B2—O3ii	−134.4 (5)	Rb3x—O2—B3—O5	−4.5 (4)
Rb1—O3—B2—O3ii	0.000 (2)	Rb2—O2—B3—O5	−98.2 (3)
Rb3ii—O3—B2—O3ii	94.51 (12)	B1—O2—B3—Rb2	−128.3 (5)
B1—O3—B2—Rb3	−69.7 (5)	Rb3x—O2—B3—Rb2	93.72 (13)
Rb1—O3—B2—Rb3	64.69 (18)	B1—O2—B3—Rb3	68.4 (5)
Rb3ii—O3—B2—Rb3	159.20 (13)	Rb3x—O2—B3—Rb3	−69.56 (19)
B1—O3—B2—Rb3ii	131.1 (5)	Rb2—O2—B3—Rb3	−163.28 (12)
Rb1—O3—B2—Rb3ii	−94.51 (12)	B1—O2—B3—Rb3x	137.9 (5)
B1—O3—B2—Rb1	−134.4 (5)	Rb2—O2—B3—Rb3x	−93.72 (13)
Rb3ii—O3—B2—Rb1	94.51 (12)	B3—O5—B4—O5vii	−4.5 (11)
B2—O7—B3—O4	87.7 (6)	Rb3x—O5—B4—O5vii	118.2 (7)
Rb3—O7—B3—O4	−150.2 (3)	Rb3—O5—B4—O5vii	−121.1 (6)
B2—O7—B3—O5	−149.6 (4)	B3—O5—B4—O6	175.2 (6)
Rb3—O7—B3—O5	−27.6 (4)	Rb3x—O5—B4—O6	−62.1 (8)
B2—O7—B3—O2	−32.5 (6)	Rb3—O5—B4—O6	58.6 (8)
Rb3—O7—B3—O2	89.5 (3)	B3—O5—B4—Rb3x	−122.7 (6)
B2—O7—B3—Rb2	36.8 (8)	Rb3—O5—B4—Rb3x	120.7 (4)
Rb3—O7—B3—Rb2	158.8 (4)	B3—O5—B4—Rb3xiii	−64.7 (7)
B2—O7—B3—Rb3	−122.0 (5)	Rb3x—O5—B4—Rb3xiii	58.0 (5)
B2—O7—B3—Rb3x	−91.9 (5)	Rb3—O5—B4—Rb3xiii	178.7 (2)
Rb3—O7—B3—Rb3x	30.1 (4)	Rb1x—O6—B4—O5	90.1 (6)
B3vii—O4—B3—O7	90.4 (7)	Rb1x—O6—B4—O5vii	−90.1 (6)
Rb2—O4—B3—O7	−146.2 (3)	Rb1x—O6—B4—Rb3x	49.90 (10)
B3vii—O4—B3—O5	−30.8 (8)	Rb1x—O6—B4—Rb3xiii	−49.90 (10)

D—H···A	D—H	H···A	D···A	D—H···A
O8—H8B···O7x	0.85	2.25	3.046 (6)	155
O8—H8B···O4x	0.85	1.68	2.224 (7)	119
O8—H8A···O7xiv	0.85	1.70	2.231 (5)	118
O8—H8A···O4xiv	0.85	2.17	2.958 (7)	155
O6—H6···O1xi	0.82	1.86	2.670 (5)	167
O1—H1···O6iv	0.94	1.91	2.670 (5)	136