Hexa-μ₂-isopropoxido-κ¹²O:O-hexa­isopropoxidotetra­aluminium(III)

In the tetra­nuclear title compound, [Al₄(C₃H₇O)₁₂], one Al atom is six-coordinate, with an octa­hedral coordination geometry, whereas the other three are four-coordinate with tetra­hedral geometries. Two of the three symmetry-independent Al atoms lie on special positions of site symmetry 2.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.039
• wR factor = 0.098
• Data-to-parameter ratio = 27.3

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT850_ALERT_2_C Check Flack Parameter Exact Value 0.00 and su ..       0.10

Alert level G
REFLT03_ALERT_4_G  ALERT: MoKa measured Friedel data cannot be used to
                   determine absolute structure in a light-atom
                   study EXCEPT under VERY special conditions.
                   It is preferred that Friedel data is merged in such cases.
           From the CIF: _diffrn_reflns_theta_max           29.16
           From the CIF: _reflns_number_total               6434
           Count of symmetry unique reflns         3772
           Completeness (_total/calc)            170.57%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured      2662
           Fraction of Friedel pairs measured     0.706
           Are heavy atom types Z>Si present         no
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K
PLAT794_ALERT_5_G Check Predicted Bond Valency for Al1         (3)       2.81
PLAT794_ALERT_5_G Check Predicted Bond Valency for Al2         (3)       2.64
PLAT794_ALERT_5_G Check Predicted Bond Valency for Al3         (3)       2.82

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   1 ALERT level C = Check and explain
   6 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   3 ALERT type 5 Informative message, check

---

S1. Comment

Some achiral metal-organic compounds crystallize in one of the eleven pairs of enantiomorphic space groups; however, examples of the same compound belonging to one of each pair are rare. There is a short comment on such examples (Ng, 2007).

Related literature

The crystal structure of the title compound was first described in the enantiomorphic space group P4₁2₁2 [Amma (1963); see Folting et al. (1991), Turova et al. (1979) and Turova et al. (1978) for later reports]. For a comment on the occurrence of compounds crystallizing in pairs of enantiomorphic space groups, see Ng (2007).

S2. Experimental

The aluminium isopropoxide was an unexpected product from reaction of trimethyl aluminium (0.72 g, 0.01 mmol; 5 ml of 2M solution in toluene) and 1-methoxy-2-propanol (0.1 mol, 7.2 g, 10 ml). The solid obtained after removing the excess 1-methoxy-2-propanol under reduced pressure was recrystallized from mixture of hexane and dichloromethane (1:1).

S3. Refinement

Hydrogen atoms were placed in calculated positions (C–H 0.96 – 0.98 Å), and were included in refinement in the riding model approximation, with U(H) set to 1.2 to 1.5 times U_eq(C).

Computing details

Data collection: X-RED32 (Stoe & Cie, 2001); cell refinement: X-AREA (Stoe & Cie, 2005); data reduction: X-AREA (Stoe & Cie, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997\bbr00); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2007).

Figures

Fig. 1. Thermal ellipsoid plot of [(C3H7O)3Al]4. Displacement ellipsoids are drawn at the 50% probablity level, and H atoms are drawn as spheres of arbitrary radii. Symmetry codes are given in Table 1.

Hexa-µ₂-isopropoxido-κ¹²O:O- hexaisopropoxidotetraaluminium(III)

Crystal data

[Al4(C3H7O)12]	Dx = 1.128 Mg m^−3
Mr = 816.95	Mo Kα radiation, λ = 0.71073 Å
Tetragonal, P43212	Cell parameters from 5826 reflections
Hall symbol: P 4nw 2abw	θ = 1.8–29.2°
a = 12.331 (2) Å	µ = 0.15 mm^−1
c = 31.641 (6) Å	T = 293 K
V = 4811.1 (14) Å^3	Irregular block, colorless
Z = 4	0.50 × 0.50 × 0.45 mm
F(000) = 1792

Data collection

Stoe IPDS-II imaging-plate diffractometer	6434 independent reflections
Radiation source: medium-focus sealed tube	5960 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.035
Rotation method scans	θmax = 29.2°, θmin = 1.8°
Absorption correction: analytical (X-SHAPE; Stoe & Cie, 2003)	h = −16→16
Tmin = 0.937, Tmax = 0.955	k = −5→16
15084 measured reflections	l = −35→43

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.039	H-atom parameters constrained
wR(F^2) = 0.098	w = 1/[σ^2(Fo^2) + (0.0478P)^2 + 1.3524P] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max = 0.001
6434 reflections	Δρmax = 0.23 e Å^−3
236 parameters	Δρmin = −0.28 e Å^−3
0 restraints	Absolute structure: Flack (Flack, 1983), 2626 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.0 (1)

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

	x	y	z	Uiso*/Ueq
Al1	0.20008 (4)	1.20008 (4)	0.0000	0.02227 (13)
Al2	0.03496 (4)	1.03496 (4)	0.0000	0.01840 (12)
Al3	0.02619 (4)	0.88003 (4)	0.067181 (14)	0.02167 (10)
O1	0.33153 (10)	1.16747 (11)	0.01112 (4)	0.0313 (3)
O2	0.09447 (9)	1.15025 (9)	0.03410 (3)	0.0212 (2)
O3	0.12112 (9)	0.92722 (9)	0.02795 (3)	0.0206 (2)
O4	−0.06114 (9)	0.97909 (9)	0.04264 (3)	0.0213 (2)
O5	0.04236 (11)	0.91991 (11)	0.11805 (4)	0.0333 (3)
O6	0.00240 (11)	0.74607 (10)	0.05657 (4)	0.0314 (3)
C1	0.48650 (17)	1.27513 (19)	−0.00848 (7)	0.0456 (5)
H1A	0.4402	1.3279	−0.0216	0.068*
H1B	0.5086	1.2225	−0.0291	0.068*
H1C	0.5494	1.3106	0.0029	0.068*
C2	0.42514 (14)	1.21869 (15)	0.02697 (6)	0.0319 (4)
H2	0.4033	1.2731	0.0479	0.038*
C3	0.49532 (18)	1.1342 (2)	0.04860 (8)	0.0488 (5)
H3A	0.4546	1.0999	0.0707	0.073*
H3B	0.5583	1.1685	0.0604	0.073*
H3C	0.5175	1.0806	0.0283	0.073*
C4	0.00339 (18)	1.28344 (18)	0.07859 (6)	0.0395 (4)
H4A	−0.0648	1.2659	0.0656	0.059*
H4B	0.0369	1.3420	0.0635	0.059*
H4C	−0.0085	1.3048	0.1074	0.059*
C5	0.07732 (14)	1.18432 (14)	0.07744 (5)	0.0254 (3)
H5	0.0430	1.1251	0.0932	0.031*
C6	0.18536 (16)	1.21142 (16)	0.09791 (6)	0.0346 (4)
H6A	0.2316	1.1488	0.0972	0.052*
H6B	0.1736	1.2328	0.1267	0.052*
H6C	0.2192	1.2698	0.0828	0.052*
C7	0.25561 (15)	0.79397 (15)	0.00599 (6)	0.0322 (4)
H7A	0.2264	0.7945	−0.0221	0.048*
H7B	0.2204	0.7385	0.0223	0.048*
H7C	0.3321	0.7796	0.0048	0.048*
C8	0.23637 (13)	0.90413 (14)	0.02667 (5)	0.0248 (3)
H8	0.2729	0.9603	0.0100	0.030*
C9	0.28248 (15)	0.90408 (17)	0.07120 (6)	0.0341 (4)
H9A	0.2702	0.9736	0.0840	0.051*
H9B	0.3590	0.8898	0.0701	0.051*
H9C	0.2474	0.8488	0.0876	0.051*
C10	−0.19215 (17)	1.0540 (2)	0.09220 (7)	0.0432 (5)
H10A	−0.1545	1.1221	0.0911	0.065*
H10B	−0.1642	1.0113	0.1151	0.065*
H10C	−0.2681	1.0668	0.0965	0.065*
C11	−0.17585 (13)	0.99427 (14)	0.05127 (5)	0.0259 (3)
H11	−0.2068	1.0382	0.0284	0.031*
C12	−0.23402 (17)	0.88716 (19)	0.05205 (7)	0.0443 (5)
H12A	−0.2225	0.8501	0.0257	0.066*
H12B	−0.3102	0.8992	0.0561	0.066*
H12C	−0.2064	0.8437	0.0748	0.066*
C13	0.0016 (2)	0.8282 (2)	0.18290 (7)	0.0537 (6)
H13A	−0.0136	0.7621	0.1680	0.081*
H13B	−0.0641	0.8690	0.1862	0.081*
H13C	0.0309	0.8114	0.2102	0.081*
C14	0.08284 (16)	0.89431 (16)	0.15819 (5)	0.0315 (4)
H14	0.1498	0.8523	0.1550	0.038*
C15	0.1084 (2)	0.99959 (18)	0.18109 (6)	0.0459 (5)
H15A	0.1598	1.0407	0.1649	0.069*
H15B	0.1386	0.9836	0.2084	0.069*
H15C	0.0430	1.0409	0.1845	0.069*
C16	−0.0992 (2)	0.58198 (18)	0.05267 (8)	0.0489 (5)
H16A	−0.1571	0.6202	0.0389	0.073*
H16B	−0.1287	0.5242	0.0694	0.073*
H16C	−0.0510	0.5525	0.0318	0.073*
C17	−0.03744 (16)	0.65919 (14)	0.08080 (6)	0.0314 (4)
H17	−0.0874	0.6881	0.1021	0.038*
C18	0.05522 (19)	0.60221 (18)	0.10331 (7)	0.0442 (5)
H18A	0.0930	0.6532	0.1209	0.066*
H18B	0.1044	0.5727	0.0828	0.066*
H18C	0.0268	0.5447	0.1205	0.066*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Al1	0.02132 (19)	0.02132 (19)	0.0242 (3)	−0.0026 (2)	−0.00022 (18)	0.00022 (18)
Al2	0.01869 (17)	0.01869 (17)	0.0178 (3)	0.0004 (2)	−0.00008 (16)	0.00008 (16)
Al3	0.0245 (2)	0.0214 (2)	0.01904 (19)	0.00060 (17)	0.00050 (17)	0.00200 (16)
O1	0.0229 (6)	0.0323 (6)	0.0386 (7)	−0.0037 (5)	−0.0041 (5)	−0.0029 (5)
O2	0.0237 (5)	0.0206 (5)	0.0193 (5)	−0.0019 (4)	0.0000 (4)	−0.0022 (4)
O3	0.0198 (5)	0.0209 (5)	0.0213 (5)	0.0022 (4)	−0.0011 (4)	0.0016 (4)
O4	0.0204 (5)	0.0225 (5)	0.0209 (5)	0.0007 (4)	0.0025 (4)	0.0013 (4)
O5	0.0397 (7)	0.0402 (7)	0.0201 (5)	0.0037 (6)	−0.0025 (5)	0.0009 (5)
O6	0.0410 (7)	0.0237 (6)	0.0295 (6)	−0.0027 (5)	0.0033 (5)	0.0044 (5)
C1	0.0304 (10)	0.0500 (12)	0.0562 (12)	−0.0068 (8)	0.0108 (9)	−0.0115 (10)
C2	0.0215 (8)	0.0356 (9)	0.0384 (9)	−0.0017 (7)	−0.0023 (7)	−0.0119 (7)
C3	0.0353 (11)	0.0579 (14)	0.0533 (12)	0.0062 (10)	−0.0174 (9)	−0.0117 (11)
C4	0.0455 (11)	0.0412 (10)	0.0319 (9)	0.0118 (9)	0.0003 (8)	−0.0096 (8)
C5	0.0306 (8)	0.0250 (8)	0.0208 (6)	−0.0008 (6)	0.0015 (6)	−0.0030 (6)
C6	0.0366 (10)	0.0387 (10)	0.0285 (8)	−0.0056 (8)	−0.0045 (7)	−0.0086 (7)
C7	0.0305 (9)	0.0298 (9)	0.0364 (9)	0.0072 (7)	0.0019 (7)	−0.0021 (7)
C8	0.0206 (7)	0.0262 (8)	0.0275 (7)	0.0027 (6)	−0.0006 (6)	0.0025 (6)
C9	0.0282 (9)	0.0410 (10)	0.0330 (8)	0.0067 (7)	−0.0070 (7)	−0.0021 (7)
C10	0.0310 (10)	0.0516 (13)	0.0471 (11)	−0.0002 (8)	0.0100 (8)	−0.0193 (9)
C11	0.0194 (7)	0.0303 (8)	0.0279 (7)	0.0029 (6)	0.0030 (6)	0.0045 (6)
C12	0.0323 (10)	0.0462 (12)	0.0545 (12)	−0.0112 (9)	0.0162 (9)	−0.0144 (10)
C13	0.0759 (17)	0.0562 (14)	0.0289 (9)	−0.0167 (12)	0.0121 (10)	0.0010 (9)
C14	0.0403 (10)	0.0345 (9)	0.0197 (7)	0.0013 (7)	−0.0013 (7)	0.0020 (6)
C15	0.0611 (14)	0.0456 (11)	0.0311 (8)	−0.0035 (10)	−0.0083 (9)	−0.0058 (8)
C16	0.0571 (14)	0.0316 (10)	0.0581 (13)	−0.0116 (10)	−0.0023 (11)	0.0011 (10)
C17	0.0388 (10)	0.0233 (8)	0.0319 (8)	−0.0007 (7)	0.0063 (7)	0.0046 (6)
C18	0.0532 (13)	0.0340 (10)	0.0454 (11)	0.0064 (9)	0.0025 (10)	0.0110 (9)

Geometric parameters (Å, º)

Al1—O1^i	1.7066 (13)	C6—H6B	0.9600
Al1—O1	1.7066 (13)	C6—H6C	0.9600
Al1—O2	1.7994 (12)	C7—C8	1.526 (2)
Al1—O2^i	1.7994 (12)	C7—H7A	0.9600
Al1—Al2	2.8794 (9)	C7—H7B	0.9600
Al2—O3^i	1.9172 (11)	C7—H7C	0.9600
Al2—O3	1.9172 (11)	C8—C9	1.519 (2)
Al2—O4	1.9234 (11)	C8—H8	0.9800
Al2—O4^i	1.9234 (11)	C9—H9A	0.9600
Al2—O2	1.9297 (12)	C9—H9B	0.9600
Al2—O2^i	1.9297 (12)	C9—H9C	0.9600
Al2—Al3^i	2.8601 (7)	C10—C11	1.503 (2)
Al2—Al3	2.8601 (6)	C10—H10A	0.9600
Al3—O5	1.6946 (13)	C10—H10B	0.9600
Al3—O6	1.7110 (14)	C10—H10C	0.9600
Al3—O4	1.8039 (12)	C11—C12	1.503 (3)
Al3—O3	1.8027 (12)	C11—H11	0.9800
O1—C2	1.408 (2)	C12—H12A	0.9600
O2—C5	1.4496 (18)	C12—H12B	0.9600
O3—C8	1.4499 (19)	C12—H12C	0.9600
O4—C11	1.4527 (19)	C13—C14	1.509 (3)
O5—C14	1.4007 (19)	C13—H13A	0.9600
O6—C17	1.406 (2)	C13—H13B	0.9600
C1—C2	1.522 (3)	C13—H13C	0.9600
C1—H1A	0.9600	C14—C15	1.520 (3)
C1—H1B	0.9600	C14—H14	0.9800
C1—H1C	0.9600	C15—H15A	0.9600
C2—C3	1.518 (3)	C15—H15B	0.9600
C2—H2	0.9800	C15—H15C	0.9600
C3—H3A	0.9600	C16—C17	1.509 (3)
C3—H3B	0.9600	C16—H16A	0.9600
C3—H3C	0.9600	C16—H16B	0.9600
C4—C5	1.525 (3)	C16—H16C	0.9600
C4—H4A	0.9600	C17—C18	1.519 (3)
C4—H4B	0.9600	C17—H17	0.9800
C4—H4C	0.9600	C18—H18A	0.9600
C5—C6	1.519 (2)	C18—H18B	0.9600
C5—H5	0.9800	C18—H18C	0.9600
C6—H6A	0.9600
O1^i—Al1—O1	119.34 (9)	H4A—C4—H4B	109.5
O1^i—Al1—O2	106.11 (6)	C5—C4—H4C	109.5
O1—Al1—O2	118.89 (6)	H4A—C4—H4C	109.5
O1^i—Al1—O2^i	118.89 (6)	H4B—C4—H4C	109.5
O1—Al1—O2^i	106.11 (6)	O2—C5—C6	109.83 (14)
O2—Al1—O2^i	82.26 (7)	O2—C5—C4	110.00 (14)
O1^i—Al1—Al2	120.33 (5)	C6—C5—C4	109.74 (15)
O1—Al1—Al2	120.33 (5)	O2—C5—H5	109.1
O2—Al1—Al2	41.13 (4)	C6—C5—H5	109.1
O2^i—Al1—Al2	41.13 (4)	C4—C5—H5	109.1
O3^i—Al2—O3	168.73 (8)	C5—C6—H6A	109.5
O3^i—Al2—O4	95.46 (5)	C5—C6—H6B	109.5
O3—Al2—O4	76.68 (5)	H6A—C6—H6B	109.5
O3^i—Al2—O4^i	76.68 (5)	C5—C6—H6C	109.5
O3—Al2—O4^i	95.46 (5)	H6A—C6—H6C	109.5
O4—Al2—O4^i	92.91 (7)	H6B—C6—H6C	109.5
O3^i—Al2—O2	96.50 (5)	C8—C7—H7A	109.5
O3—Al2—O2	92.40 (5)	C8—C7—H7B	109.5
O4—Al2—O2	96.08 (5)	H7A—C7—H7B	109.5
O4^i—Al2—O2	169.22 (5)	C8—C7—H7C	109.5
O3^i—Al2—O2^i	92.40 (5)	H7A—C7—H7C	109.5
O3—Al2—O2^i	96.50 (5)	H7B—C7—H7C	109.5
O4—Al2—O2^i	169.22 (5)	O3—C8—C9	109.93 (13)
O4^i—Al2—O2^i	96.08 (5)	O3—C8—C7	109.82 (14)
O2—Al2—O2^i	75.67 (7)	C9—C8—C7	109.82 (14)
O3^i—Al2—Al3^i	38.30 (3)	O3—C8—H8	109.1
O3—Al2—Al3^i	133.38 (4)	C9—C8—H8	109.1
O4—Al2—Al3^i	95.53 (4)	C7—C8—H8	109.1
O4^i—Al2—Al3^i	38.38 (3)	C8—C9—H9A	109.5
O2—Al2—Al3^i	134.23 (4)	C8—C9—H9B	109.5
O2^i—Al2—Al3^i	95.21 (4)	H9A—C9—H9B	109.5
O3^i—Al2—Al3	133.38 (4)	C8—C9—H9C	109.5
O3—Al2—Al3	38.30 (3)	H9A—C9—H9C	109.5
O4—Al2—Al3	38.38 (3)	H9B—C9—H9C	109.5
O4^i—Al2—Al3	95.53 (4)	C11—C10—H10A	109.5
O2—Al2—Al3	95.21 (3)	C11—C10—H10B	109.5
O2^i—Al2—Al3	134.23 (4)	H10A—C10—H10B	109.5
Al3^i—Al2—Al3	120.12 (3)	C11—C10—H10C	109.5
O3^i—Al2—Al1	95.63 (4)	H10A—C10—H10C	109.5
O3—Al2—Al1	95.63 (4)	H10B—C10—H10C	109.5
O4—Al2—Al1	133.55 (4)	O4—C11—C10	110.79 (14)
O4^i—Al2—Al1	133.55 (4)	O4—C11—C12	110.76 (14)
O2—Al2—Al1	37.83 (3)	C10—C11—C12	110.65 (16)
O2^i—Al2—Al1	37.83 (3)	O4—C11—H11	108.2
Al3^i—Al2—Al1	119.938 (16)	C10—C11—H11	108.2
Al3—Al2—Al1	119.938 (15)	C12—C11—H11	108.2
O5—Al3—O6	119.13 (7)	C11—C12—H12A	109.5
O5—Al3—O4	106.41 (6)	C11—C12—H12B	109.5
O6—Al3—O4	117.83 (6)	H12A—C12—H12B	109.5
O5—Al3—O3	118.94 (7)	C11—C12—H12C	109.5
O6—Al3—O3	106.72 (6)	H12A—C12—H12C	109.5
O4—Al3—O3	82.69 (5)	H12B—C12—H12C	109.5
O5—Al3—Al2	120.50 (5)	C14—C13—H13A	109.5
O6—Al3—Al2	120.36 (5)	C14—C13—H13B	109.5
O4—Al3—Al2	41.45 (4)	H13A—C13—H13B	109.5
O3—Al3—Al2	41.24 (4)	C14—C13—H13C	109.5
C2—O1—Al1	138.27 (12)	H13A—C13—H13C	109.5
C5—O2—Al1	125.02 (10)	H13B—C13—H13C	109.5
C5—O2—Al2	133.39 (10)	O5—C14—C13	110.79 (17)
Al1—O2—Al2	101.03 (5)	O5—C14—C15	108.29 (16)
C8—O3—Al3	126.32 (10)	C13—C14—C15	110.60 (17)
C8—O3—Al2	131.78 (10)	O5—C14—H14	109.0
Al3—O3—Al2	100.46 (6)	C13—C14—H14	109.0
C11—O4—Al3	125.99 (10)	C15—C14—H14	109.0
C11—O4—Al2	133.27 (9)	C14—C15—H15A	109.5
Al3—O4—Al2	100.18 (5)	C14—C15—H15B	109.5
C14—O5—Al3	146.90 (13)	H15A—C15—H15B	109.5
C17—O6—Al3	133.51 (12)	C14—C15—H15C	109.5
C2—C1—H1A	109.5	H15A—C15—H15C	109.5
C2—C1—H1B	109.5	H15B—C15—H15C	109.5
H1A—C1—H1B	109.5	C17—C16—H16A	109.5
C2—C1—H1C	109.5	C17—C16—H16B	109.5
H1A—C1—H1C	109.5	H16A—C16—H16B	109.5
H1B—C1—H1C	109.5	C17—C16—H16C	109.5
O1—C2—C3	108.66 (16)	H16A—C16—H16C	109.5
O1—C2—C1	110.51 (16)	H16B—C16—H16C	109.5
C3—C2—C1	111.28 (17)	O6—C17—C16	109.60 (16)
O1—C2—H2	108.8	O6—C17—C18	110.21 (16)
C3—C2—H2	108.8	C16—C17—C18	111.36 (17)
C1—C2—H2	108.8	O6—C17—H17	108.5
C2—C3—H3A	109.5	C16—C17—H17	108.5
C2—C3—H3B	109.5	C18—C17—H17	108.5
H3A—C3—H3B	109.5	C17—C18—H18A	109.5
C2—C3—H3C	109.5	C17—C18—H18B	109.5
H3A—C3—H3C	109.5	H18A—C18—H18B	109.5
H3B—C3—H3C	109.5	C17—C18—H18C	109.5
C5—C4—H4A	109.5	H18A—C18—H18C	109.5
C5—C4—H4B	109.5	H18B—C18—H18C	109.5
O1^i—Al1—Al2—O3^i	13.79 (6)	Al1—Al2—O2—C5	−171.47 (17)
O1—Al1—Al2—O3^i	−166.21 (6)	O3^i—Al2—O2—Al1	−90.82 (6)
O2—Al1—Al2—O3^i	93.36 (6)	O3—Al2—O2—Al1	96.10 (5)
O2^i—Al1—Al2—O3^i	−86.64 (6)	O4—Al2—O2—Al1	172.95 (5)
O1^i—Al1—Al2—O3	−166.21 (6)	O4^i—Al2—O2—Al1	−40.7 (3)
O1—Al1—Al2—O3	13.79 (6)	O2^i—Al2—O2—Al1	0.0
O2—Al1—Al2—O3	−86.64 (6)	Al3^i—Al2—O2—Al1	−83.23 (6)
O2^i—Al1—Al2—O3	93.36 (6)	Al3—Al2—O2—Al1	134.39 (4)
O1^i—Al1—Al2—O4	−89.25 (7)	O5—Al3—O3—C8	63.16 (14)
O1—Al1—Al2—O4	90.75 (7)	O6—Al3—O3—C8	−75.17 (13)
O2—Al1—Al2—O4	−9.69 (7)	O4—Al3—O3—C8	167.90 (12)
O2^i—Al1—Al2—O4	170.31 (7)	Al2—Al3—O3—C8	167.58 (15)
O1^i—Al1—Al2—O4^i	90.75 (7)	O5—Al3—O3—Al2	−104.43 (7)
O1—Al1—Al2—O4^i	−89.25 (7)	O6—Al3—O3—Al2	117.25 (6)
O2—Al1—Al2—O4^i	170.31 (7)	O4—Al3—O3—Al2	0.32 (5)
O2^i—Al1—Al2—O4^i	−9.69 (7)	O3^i—Al2—O3—C8	146.61 (13)
O1^i—Al1—Al2—O2	−79.57 (7)	O4—Al2—O3—C8	−166.87 (13)
O1—Al1—Al2—O2	100.43 (7)	O4^i—Al2—O3—C8	101.43 (13)
O2^i—Al1—Al2—O2	180.0	O2—Al2—O3—C8	−71.19 (13)
O1^i—Al1—Al2—O2^i	100.43 (7)	O2^i—Al2—O3—C8	4.65 (13)
O1—Al1—Al2—O2^i	−79.57 (7)	Al3^i—Al2—O3—C8	108.15 (13)
O2—Al1—Al2—O2^i	180.0	Al3—Al2—O3—C8	−166.57 (16)
O1^i—Al1—Al2—Al3^i	45.23 (5)	Al1—Al2—O3—C8	−33.39 (13)
O1—Al1—Al2—Al3^i	−134.77 (5)	O3^i—Al2—O3—Al3	−46.8 (2)
O2—Al1—Al2—Al3^i	124.80 (6)	O4—Al2—O3—Al3	−0.30 (5)
O2^i—Al1—Al2—Al3^i	−55.20 (6)	O4^i—Al2—O3—Al3	−92.01 (6)
O1^i—Al1—Al2—Al3	−134.77 (5)	O2—Al2—O3—Al3	95.38 (6)
O1—Al1—Al2—Al3	45.23 (5)	O2^i—Al2—O3—Al3	171.22 (5)
O2—Al1—Al2—Al3	−55.20 (6)	Al3^i—Al2—O3—Al3	−85.28 (6)
O2^i—Al1—Al2—Al3	124.80 (6)	Al1—Al2—O3—Al3	133.17 (4)
O3^i—Al2—Al3—O5	−90.94 (8)	O5—Al3—O4—C11	−69.86 (13)
O3—Al2—Al3—O5	100.37 (8)	O6—Al3—O4—C11	66.96 (13)
O4—Al2—Al3—O5	−80.11 (8)	O3—Al3—O4—C11	172.05 (12)
O4^i—Al2—Al3—O5	−167.81 (7)	Al2—Al3—O4—C11	172.37 (15)
O2—Al2—Al3—O5	13.10 (7)	O5—Al3—O4—Al2	117.77 (7)
O2^i—Al2—Al3—O5	88.15 (8)	O6—Al3—O4—Al2	−105.41 (7)
Al3^i—Al2—Al3—O5	−136.51 (6)	O3—Al3—O4—Al2	−0.32 (5)
Al1—Al2—Al3—O5	43.49 (6)	O3^i—Al2—O4—C11	0.60 (14)
O3^i—Al2—Al3—O6	88.04 (8)	O3—Al2—O4—C11	−171.21 (14)
O3—Al2—Al3—O6	−80.66 (8)	O4^i—Al2—O4—C11	−76.28 (13)
O4—Al2—Al3—O6	98.86 (8)	O2—Al2—O4—C11	97.76 (14)
O4^i—Al2—Al3—O6	11.16 (7)	O2^i—Al2—O4—C11	137.2 (2)
O2—Al2—Al3—O6	−167.92 (7)	Al3^i—Al2—O4—C11	−37.88 (13)
O2^i—Al2—Al3—O6	−92.88 (8)	Al3—Al2—O4—C11	−171.51 (16)
Al3^i—Al2—Al3—O6	42.46 (6)	Al1—Al2—O4—C11	103.72 (13)
Al1—Al2—Al3—O6	−137.54 (6)	O3^i—Al2—O4—Al3	172.12 (5)
O3^i—Al2—Al3—O4	−10.83 (7)	O3—Al2—O4—Al3	0.30 (5)
O3—Al2—Al3—O4	−179.52 (8)	O4^i—Al2—O4—Al3	95.23 (6)
O4^i—Al2—Al3—O4	−87.70 (8)	O2—Al2—O4—Al3	−90.73 (5)
O2—Al2—Al3—O4	93.21 (6)	O2^i—Al2—O4—Al3	−51.3 (3)
O2^i—Al2—Al3—O4	168.26 (8)	Al3^i—Al2—O4—Al3	133.63 (4)
Al3^i—Al2—Al3—O4	−56.40 (5)	Al1—Al2—O4—Al3	−84.77 (6)
Al1—Al2—Al3—O4	123.60 (5)	O6—Al3—O5—C14	35.9 (3)
O3^i—Al2—Al3—O3	168.70 (7)	O4—Al3—O5—C14	172.1 (2)
O4—Al2—Al3—O3	179.52 (8)	O3—Al3—O5—C14	−97.3 (2)
O4^i—Al2—Al3—O3	91.82 (6)	Al2—Al3—O5—C14	−145.1 (2)
O2—Al2—Al3—O3	−87.26 (7)	O5—Al3—O6—C17	21.18 (19)
O2^i—Al2—Al3—O3	−12.22 (7)	O4—Al3—O6—C17	−110.12 (16)
Al3^i—Al2—Al3—O3	123.12 (6)	O3—Al3—O6—C17	159.41 (16)
Al1—Al2—Al3—O3	−56.88 (6)	Al2—Al3—O6—C17	−157.81 (15)
O1^i—Al1—O1—C2	25.16 (16)	Al1—O1—C2—C3	152.14 (16)
O2—Al1—O1—C2	−107.20 (18)	Al1—O1—C2—C1	−85.5 (2)
O2^i—Al1—O1—C2	162.84 (17)	Al1—O2—C5—C6	−32.61 (18)
Al2—Al1—O1—C2	−154.84 (16)	Al2—O2—C5—C6	137.16 (13)
O1^i—Al1—O2—C5	−69.64 (13)	Al1—O2—C5—C4	88.28 (16)
O1—Al1—O2—C5	68.26 (13)	Al2—O2—C5—C4	−101.95 (17)
O2^i—Al1—O2—C5	172.44 (15)	Al3—O3—C8—C9	−37.91 (19)
Al2—Al1—O2—C5	172.44 (15)	Al2—O3—C8—C9	125.61 (13)
O1^i—Al1—O2—Al2	117.92 (6)	Al3—O3—C8—C7	83.03 (15)
O1—Al1—O2—Al2	−104.18 (7)	Al2—O3—C8—C7	−113.45 (14)
O2^i—Al1—O2—Al2	0.0	Al3—O4—C11—C10	77.18 (18)
O3^i—Al2—O2—C5	97.71 (14)	Al2—O4—C11—C10	−113.17 (16)
O3—Al2—O2—C5	−75.37 (14)	Al3—O4—C11—C12	−46.01 (19)
O4—Al2—O2—C5	1.48 (14)	Al2—O4—C11—C12	123.65 (15)
O4^i—Al2—O2—C5	147.8 (2)	Al3—O5—C14—C13	−85.5 (3)
O2^i—Al2—O2—C5	−171.47 (17)	Al3—O5—C14—C15	153.1 (2)
Al3^i—Al2—O2—C5	105.30 (13)	Al3—O6—C17—C16	148.14 (16)
Al3—Al2—O2—C5	−37.08 (14)	Al3—O6—C17—C18	−89.0 (2)

Symmetry code: (i) y−1, x+1, −z.