A new polymeric alk­yl/alkoxide magnesium–sodium inverse crown complex

Poly[bis­(μ₃-trimethyl­silyl­methano­lato)tetra­kis­(μ₂-trimethylsilylmeth­yl)dimagnesiumdisodium], [Na₂Mg₂(C₄H₁₁OSi)₂(C₄H₁₁Si)₄]_n, was obtained from the controlled exposure to oxygen of the unsolvated sodium magnesate [NaMg(CH₂SiMe)₃]_n. Exhibiting a centrosymmetric (Z′ = ) dimeric core of a heterobimetallic eight-membered cationic ring, hosting two alkoxide ligands at its core, the title compound forms a two-dimensional coordination polymer in the crystallographic bc plane through Na...Me contacts. These contacts from Na to formally uncharged groups are only 0.06 Å longer than those between Na and the formally charged CH₂R anions. The coordination polymers stack along the a direction to give a layer structure with alternating hydro­phobic and hydro­philic regions.

S1. Comment

Alkali metal organometallic compounds can react violently with moisture and oxygen, hence the exclusion of air during the preparation and employment of these complexes is mandatory, with manipulations carried out under a dry inert atmosphere (Wardell, 1982, and references therein). Having stated that, regulated exposure of metal alkyls to dry oxygen can lead to an interesting array of structures, with oxygen inserting into the metal–carbon bond (Barron, 1993; Kennedy et al., 1999; Forbes et al., 2000; Mulvey, 2001; Bailey et al., 2003). Here, we report an example of controlled deliberate oxygen insertion into the homoleptic trisalkyl sodium magnesiate [{NaMgR₃}]_∞ (R = CH₂SiMe₃), a compound which itself has recently been structurally authenticated as a unique two-dimensional supramolecular network in the solid state (Baillie et al., 2011). A drying tube (containing CaCl₂) was fitted to a Schlenk tube containing a solution of the starting magnesiate complex, to allow oxygen but to disallow moisture from entering the system. Slow cooling of the resulting colourless solution led to the deposition of colourless crystals of [{NaMgR₂(OR)}]_∞, (I), where the alkoxide ligand OR is formed as a result of oxygen insertion into the metal–carbon polar bond of an alkyl group.

Looking at its empirical formulation, (I) can be envisaged as the co-complexation product of the bis-alkyl Mg(CH₂SiMe₃)₂ and the alkoxide NaOCH₂SiMe₃ and, as such, may be considered an alkaline earth metal relation of the Lochmann–Schlosser reagent, LiC-KOR, which pairs n-butyllithium with the heavier alkali metal potassium tert-butoxide (Lochmann, 2000). LiC-KOR can be described as a superbase, due to its dramatic enhancement in reactivity in deprotonation reactions compared with a mixture of an alkyllithium with lithium butoxide. Despite the wide applications of the superbase in synthesis, definitive structural information on the Lochmann–Schlosser reagent has not been forthcoming. However, elucidation of the structure of (I) may provide indirect insight into the structural make up of the alkali metal-rich superbase.

Compound (I) features a dimeric arrangement comprising two {NaMgR₂(OR)} units, giving rise to a face-fused double heterocubane structure with two missing corners. The OR groups face-cap the `top' and `bottom' of the structure, acting as a bridge between two Mg atoms and an Na centre (Fig. 1). Alternatively, the compound can be described as an inverse crown complex consisting of a cationic eight-atom {NaCMgC}₂ heterobimetallic ring hosting two alkoxide ligands at its core (Mulvey, 2001). This cationic ring adopts a pseudo-chair structure, with the Na atoms constituting the `head' and `footrest' of the chair (see the alternative view in Fig. 2).

The Mg atom resides in a four-coordinate environment, with widely varying bond angles [84.77 (5)–138.14 (7)°] and bonds to two alkyl groups and two alkoxide ligands; see Table 1 for more details and for a definition of the symmetry operators. Each Na atom bonds to two bridging alkyl groups within the dimeric unit and also to one alkoxide OCH₂SiMe₃ ligand. In addition, Na also forms a secondary intermolecular interaction with a neighbouring methyl group [Na1···C6ⁱⁱ = 2.7448 (18) Å]. Note that this interaction with a neutral methyl group is only about 0.06 Å longer than the interactions with the formally charged CH₂R anions. The Na atom is thus tetracoordinate, with a wide range of angles observed from 82.79 (5) to 171.69 (6)°.

Unlike related inverse crown structures, where Lewis basic donors such as TMEDA (N,N,N',N'-tetramethylethylenediamine) coordinate to the alkali metal (Barnett et al., 2005) or alternatively where the alkali metal is coordinatively supported through metal–arene contacts from aromatic solvents (Gallagher et al., 2002; Andrikopoulos et al., 2003), no such stabilization is observed in (I). This lack of externally added solvating molecules around Na is compensated for by the additional secondary electrostatic interactions with the methyl groups of SiMe₃ fragments from neighbouring molecules. Of the four alkyl groups present in the ring scaffold of (I), only two alkyl units, diagonally opposite each other and inversion related, interact with the neighbouring dimeric units. This leads to polymerization of the eight-membered rings and results in a two-dimensional coordination sheet propagating in the crystallographic bc plane (Fig. 3). Each plane has a core of polar elements surrounded by organic groups and thus a structure with alternating hydrophilic and hydrophobic layers results.

In the oxygen-free parent compound [{NaMgR₃}]_∞ (Baillie et al., 2011), a very different structure is observed, made up of 12-atom {(NaCMgC)₃} fused rings. However, as in (I), each alkyl group acts as a bridge between an Na and an Mg centre, and similar distances are found in the Na—C bond lengths [2.6708 (19) Å]. In addition, the Mg—O distance in (I) is almost identical to those reported in the closely related inverse crown ether [{NaMg(Bu)₂(O^tBu).(TMEDA)}₂] (Barnett et al., 2005) [compare Mg—O1 and Mg—O1ⁱ in Table 1 with Mg—O distances of 2.028 (4) and 2.033 (4) Å in the TMEDA-solvated structure]. To the best of our knowledge, this analogous structure is the only other inverse crown ether with the eight-membered scaffold constructed exclusively with metal–carbon bonds. In contrast with (I), [{NaMg(Bu)₂(OtBu).(TMEDA)}₂] was formed using a different synthetic approach by the co-complexation of the monometallic components NaO^tBu and MgBu₂ in the presence of TMEDA, which solvates the alkali metal and removes the opportunity for polymeric propagation.

Related literature

For related literature, see: Andrikopoulos et al. (2003); Bailey et al. (2003); Baillie et al. (2011); Barnett et al. (2005); Barron (1993); Forbes et al. (2000); Gallagher et al. (2002); Kennedy et al. (1999); Lochmann (2000); Mulvey (2001); Wardell (1982).

S2. Experimental

To a stirred suspension of NaCH₂SiMe₃ (0.11 g, 1.0 mmol) in hexane (15 ml) was added Mg(CH₂SiMe₃)₂ (0.20 g, 1.0 mmol), and the resulting white suspension was stirred at room temperature for 1 h. The volume of solvent was reduced by approximately half under reduced pressure. Benzene (3 ml) was then introduced and the mixture was gently heated. A CaCl₂ drying tube was fitted and the reaction mixture was exposed to air through this for 1 h before being resealed and stirred overnight. The solvent was removed in vacuo and hexane (5 ml) was added with gentle heating. After being allowed to cool slowly to room temperature, the resulting colourless solution afforded a crop of colourless crystals of (I) (yield 0.03 g, 15%). Spectroscopic analysis: ¹H NMR (400.03 MHz, 298 K, C₆D₆, δ, p.p.m.): -2.12 (4H, s, SiCH₂), -0.04 [9H, s, Si(CH₃)₃], -0.35 [18H, s, OSi(CH₃)₃], 3.43 (2H, s, OCH₂); ¹³C {¹H} NMR (100.62 MHz, 298 K, C₆D₆, δ, p.p.m.): -6.00 (MCH₂), -2.61 [OCH₂Si(CH₃)₃], 4.65 [MCH₂Si(CH₃)₃], 55.37 (OCH₂).

S3. Refinement

The H atoms of the CH₂ groups were found through difference synthesis and refined isotropically. Methyl group H-atom positions were found by allowing the torsion angle about the Si—C bond to refine but with an idealized geometry, with C—H = 0.98 Å and U_iso(H) = 1.5U_eq(C).

Computing details

Data collection: CrysAlis PRO (Oxford Diffraction, 2010); cell refinement: CrysAlis PRO (Oxford Diffraction, 2010); data reduction: CrysAlis PRO (Oxford Diffraction, 2010); program(s) used to solve structure: SIR2004 (Burla et al., 2005); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. The molecular structure of (I), showing the dimeric unit generated by a centre of symmetry. Displacement ellipsoids are drawn at the 50% probability level and H atoms have been omitted for clarity.
	Fig. 2. Detail of the central core of (I), with its pseuodo-chair motif.
	Fig. 3. Na···H3C interactions give a two-dimensional polymeric sheet structure in the bc plane of (I). The SiMe3 groups of the alkoxide and all H atoms have been omitted for clarity.

Poly[bis(µ₃-trimethylsilylmethanolato)tetrakis(µ₂- trimethylsilylmethyl)dimagnesiumdisodium]

Crystal data

[Na2Mg2(C4H11OSi)2(C4H11Si)4]	F(000) = 712
Mr = 649.91	Dx = 1.030 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 7568 reflections
a = 9.8057 (3) Å	θ = 2.8–30.3°
b = 18.1602 (5) Å	µ = 0.27 mm^−1
c = 11.8234 (3) Å	T = 123 K
β = 95.482 (3)°	Block, colourless
V = 2095.80 (10) Å^3	0.23 × 0.18 × 0.15 mm
Z = 2

Data collection

Oxford Gemini S diffractometer	5052 independent reflections
Radiation source: fine-focus sealed tube	3663 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.046
Detector resolution: 16.0268 pixels mm^-1	θmax = 28.0°, θmin = 2.8°
ω scans	h = −12→12
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2010)	k = −23→23
Tmin = 0.804, Tmax = 1.000	l = −15→15
17871 measured reflections

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) = 0.100	H atoms treated by a mixture of independent and constrained refinement
S = 0.96	w = 1/[σ^2(Fo^2) + (0.0566P)^2] where P = (Fo^2 + 2Fc^2)/3
5052 reflections	(Δ/σ)max < 0.001
196 parameters	Δρmax = 0.46 e Å^−3
0 restraints	Δρmin = −0.28 e Å^−3

Special details

Experimental. Version 1.171.33.66 (release 28-04-2010 CrysAlis171 .NET) (compiled Apr 28 2010,14:27:37) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

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
Mg1	−0.00426 (6)	0.05122 (3)	−0.09983 (4)	0.01719 (13)
Na1	0.00110 (7)	0.11740 (3)	0.14529 (5)	0.02509 (17)
Si1	0.34964 (5)	0.11136 (3)	0.12990 (4)	0.02460 (13)
Si2	−0.22055 (5)	0.19736 (3)	−0.17790 (4)	0.02400 (13)
Si3	−0.18934 (6)	−0.05907 (3)	0.33618 (4)	0.02845 (13)
O1	0.11632 (11)	0.03426 (5)	0.04690 (9)	0.0169 (2)
C1	0.26296 (17)	0.03189 (9)	0.05188 (14)	0.0193 (3)
C2	0.3087 (2)	0.11026 (13)	0.28116 (17)	0.0492 (6)
H2A	0.3420	0.0643	0.3173	0.074*
H2B	0.2093	0.1138	0.2837	0.074*
H2C	0.3533	0.1522	0.3217	0.074*
C3	0.5377 (2)	0.10166 (12)	0.12316 (18)	0.0381 (5)
H3A	0.5579	0.1014	0.0436	0.057*
H3B	0.5691	0.0554	0.1595	0.057*
H3C	0.5851	0.1431	0.1629	0.057*
C4	0.2891 (2)	0.19933 (10)	0.0612 (2)	0.0446 (6)
H4A	0.3337	0.2409	0.1027	0.067*
H4B	0.1896	0.2033	0.0624	0.067*
H4C	0.3122	0.2001	−0.0177	0.067*
C5	−0.11609 (19)	0.15148 (9)	−0.06267 (14)	0.0215 (4)
C6	−0.1122 (2)	0.26732 (10)	−0.24626 (16)	0.0311 (4)
H6A	−0.0900	0.3080	−0.1932	0.047*
H6B	−0.1630	0.2864	−0.3155	0.047*
H6C	−0.0274	0.2440	−0.2655	0.047*
C7	−0.3707 (2)	0.24875 (12)	−0.1311 (2)	0.0486 (6)
H7A	−0.4260	0.2155	−0.0887	0.073*
H7B	−0.4267	0.2677	−0.1978	0.073*
H7C	−0.3380	0.2899	−0.0821	0.073*
C8	−0.2894 (2)	0.13150 (11)	−0.29098 (18)	0.0433 (5)
H8A	−0.2135	0.1039	−0.3188	0.065*
H8B	−0.3377	0.1589	−0.3540	0.065*
H8C	−0.3530	0.0972	−0.2594	0.065*
C9	−0.09097 (19)	−0.00313 (10)	0.24275 (14)	0.0235 (4)
C10	−0.3040 (3)	−0.00285 (15)	0.42114 (19)	0.0592 (7)
H10A	−0.2480	0.0285	0.4747	0.089*
H10B	−0.3601	−0.0358	0.4633	0.089*
H10C	−0.3639	0.0281	0.3698	0.089*
C11	−0.3025 (3)	−0.12490 (13)	0.2498 (2)	0.0577 (7)
H11A	−0.3607	−0.0977	0.1922	0.087*
H11B	−0.3602	−0.1514	0.2995	0.087*
H11C	−0.2460	−0.1602	0.2124	0.087*
C12	−0.0731 (2)	−0.11256 (10)	0.44100 (16)	0.0362 (5)
H12A	−0.0129	−0.1440	0.4002	0.054*
H12B	−0.1281	−0.1433	0.4874	0.054*
H12C	−0.0175	−0.0784	0.4902	0.054*
H1A	0.2966 (18)	−0.0126 (9)	0.0897 (14)	0.020 (4)*
H1B	0.2951 (18)	0.0301 (9)	−0.0295 (15)	0.025 (5)*
H5A	−0.181 (2)	0.1348 (10)	−0.0094 (18)	0.040 (6)*
H5B	−0.065 (2)	0.1868 (11)	−0.0281 (17)	0.041 (6)*
H9A	−0.022 (2)	0.0234 (9)	0.2927 (15)	0.028 (5)*
H9B	−0.160 (2)	0.0311 (10)	0.2058 (16)	0.032 (5)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Mg1	0.0198 (3)	0.0154 (3)	0.0169 (3)	−0.0005 (2)	0.0042 (2)	0.0013 (2)
Na1	0.0311 (4)	0.0207 (3)	0.0243 (3)	0.0029 (3)	0.0073 (3)	−0.0031 (3)
Si1	0.0194 (3)	0.0288 (3)	0.0262 (3)	−0.0044 (2)	0.0053 (2)	−0.0080 (2)
Si2	0.0227 (3)	0.0233 (2)	0.0263 (2)	0.0017 (2)	0.0043 (2)	0.00898 (19)
Si3	0.0277 (3)	0.0373 (3)	0.0212 (2)	−0.0048 (2)	0.0070 (2)	0.0047 (2)
O1	0.0157 (6)	0.0163 (5)	0.0190 (5)	−0.0004 (4)	0.0029 (4)	0.0001 (4)
C1	0.0175 (8)	0.0188 (8)	0.0217 (8)	0.0000 (7)	0.0027 (7)	0.0008 (7)
C2	0.0394 (13)	0.0782 (17)	0.0312 (11)	−0.0185 (12)	0.0099 (10)	−0.0194 (11)
C3	0.0229 (10)	0.0477 (12)	0.0440 (12)	−0.0044 (9)	0.0043 (9)	−0.0120 (10)
C4	0.0436 (13)	0.0230 (10)	0.0670 (15)	−0.0028 (9)	0.0042 (12)	−0.0077 (9)
C5	0.0253 (10)	0.0158 (8)	0.0236 (8)	−0.0005 (7)	0.0032 (7)	0.0020 (7)
C6	0.0338 (11)	0.0287 (10)	0.0317 (10)	−0.0007 (8)	0.0079 (8)	0.0097 (8)
C7	0.0359 (13)	0.0507 (13)	0.0620 (15)	0.0190 (10)	0.0188 (11)	0.0279 (11)
C8	0.0449 (14)	0.0482 (12)	0.0349 (11)	−0.0146 (11)	−0.0062 (10)	0.0091 (9)
C9	0.0248 (10)	0.0268 (9)	0.0194 (8)	−0.0033 (8)	0.0044 (7)	−0.0006 (7)
C10	0.0529 (16)	0.0884 (18)	0.0410 (12)	0.0210 (14)	0.0291 (12)	0.0210 (13)
C11	0.0580 (16)	0.0684 (16)	0.0438 (13)	−0.0359 (13)	−0.0104 (12)	0.0235 (12)
C12	0.0417 (13)	0.0393 (11)	0.0280 (10)	−0.0021 (9)	0.0059 (9)	0.0048 (8)

Geometric parameters (Å, º)

Mg1—O1	2.0274 (12)	C2—H2A	0.9800
Mg1—O1^i	2.0347 (11)	C2—H2B	0.9800
Mg1—C5	2.1915 (17)	C2—H2C	0.9800
Mg1—C9^i	2.1890 (17)	C3—H3A	0.9800
Mg1—Mg1^i	3.0004 (10)	C3—H3B	0.9800
Mg1—Na1^i	3.1096 (8)	C3—H3C	0.9800
Mg1—Na1	3.1332 (8)	C4—H4A	0.9800
Na1—O1	2.2716 (12)	C4—H4B	0.9800
Na1—C5	2.6850 (18)	C4—H4C	0.9800
Na1—C9	2.6706 (18)	C5—H5A	0.98 (2)
Na1—C6^ii	2.7448 (18)	C5—H5B	0.89 (2)
Na1—Mg1^i	3.1096 (8)	C6—H6A	0.9800
Na1—Si1	3.4416 (9)	C6—H6B	0.9800
Na1—H5A	2.45 (2)	C6—H6C	0.9800
Na1—H5B	2.44 (2)	C7—H7A	0.9800
Na1—H9A	2.466 (17)	C7—H7B	0.9800
Na1—H9B	2.385 (18)	C7—H7C	0.9800
Si1—C3	1.862 (2)	C8—H8A	0.9800
Si1—C4	1.864 (2)	C8—H8B	0.9800
Si1—C2	1.870 (2)	C8—H8C	0.9800
Si1—C1	1.8725 (17)	C9—Mg1^i	2.1890 (17)
Si2—C5	1.8257 (18)	C9—H9A	0.979 (19)
Si2—C7	1.871 (2)	C9—H9B	0.991 (19)
Si2—C8	1.871 (2)	C10—H10A	0.9800
Si2—C6	1.8868 (17)	C10—H10B	0.9800
Si3—C9	1.8401 (17)	C10—H10C	0.9800
Si3—C11	1.868 (2)	C11—H11A	0.9800
Si3—C12	1.873 (2)	C11—H11B	0.9800
Si3—C10	1.879 (2)	C11—H11C	0.9800
O1—C1	1.4342 (19)	C12—H12A	0.9800
O1—Mg1^i	2.0347 (11)	C12—H12B	0.9800
C1—H1A	0.966 (17)	C12—H12C	0.9800
C1—H1B	1.041 (17)
O1—Mg1—O1^i	84.77 (5)	C9—Si3—C11	110.08 (9)
O1—Mg1—C9^i	110.06 (6)	C9—Si3—C12	111.27 (9)
O1^i—Mg1—C9^i	102.46 (6)	C11—Si3—C12	108.79 (10)
O1—Mg1—C5	102.52 (6)	C9—Si3—C10	113.32 (10)
O1^i—Mg1—C5	106.08 (6)	C11—Si3—C10	106.58 (13)
C9^i—Mg1—C5	138.14 (7)	C12—Si3—C10	106.58 (10)
O1—Mg1—Mg1^i	42.48 (3)	C1—O1—Mg1	122.69 (9)
O1^i—Mg1—Mg1^i	42.29 (3)	C1—O1—Mg1^i	122.22 (9)
C9^i—Mg1—Mg1^i	112.22 (5)	Mg1—O1—Mg1^i	95.23 (5)
C5—Mg1—Mg1^i	109.53 (5)	C1—O1—Na1	123.01 (9)
O1—Mg1—Na1^i	89.07 (3)	Mg1—O1—Na1	93.40 (5)
O1^i—Mg1—Na1^i	46.88 (3)	Mg1^i—O1—Na1	92.29 (5)
C9^i—Mg1—Na1^i	57.43 (5)	O1—C1—Si1	113.78 (11)
C5—Mg1—Na1^i	150.02 (6)	O1—C1—H1A	109.9 (10)
Mg1^i—Mg1—Na1^i	61.67 (2)	Si1—C1—H1A	107.3 (10)
O1—Mg1—Na1	46.36 (3)	O1—C1—H1B	110.7 (10)
O1^i—Mg1—Na1	88.28 (3)	Si1—C1—H1B	108.4 (9)
C9^i—Mg1—Na1	153.69 (6)	H1A—C1—H1B	106.4 (13)
C5—Mg1—Na1	57.34 (5)	Si1—C2—H2A	109.5
Mg1^i—Mg1—Na1	60.88 (2)	Si1—C2—H2B	109.5
Na1^i—Mg1—Na1	122.550 (19)	H2A—C2—H2B	109.5
O1—Na1—C9	83.19 (5)	Si1—C2—H2C	109.5
O1—Na1—C5	82.79 (5)	H2A—C2—H2C	109.5
C9—Na1—C5	116.83 (6)	H2B—C2—H2C	109.5
O1—Na1—C6^ii	171.69 (6)	Si1—C3—H3A	109.5
C9—Na1—C6^ii	104.77 (6)	Si1—C3—H3B	109.5
C5—Na1—C6^ii	95.46 (6)	H3A—C3—H3B	109.5
O1—Na1—Mg1^i	40.83 (3)	Si1—C3—H3C	109.5
C9—Na1—Mg1^i	43.69 (4)	H3A—C3—H3C	109.5
C5—Na1—Mg1^i	94.54 (4)	H3B—C3—H3C	109.5
C6^ii—Na1—Mg1^i	147.46 (5)	Si1—C4—H4A	109.5
O1—Na1—Mg1	40.24 (3)	Si1—C4—H4B	109.5
C9—Na1—Mg1	96.21 (4)	H4A—C4—H4B	109.5
C5—Na1—Mg1	43.41 (4)	Si1—C4—H4C	109.5
C6^ii—Na1—Mg1	138.84 (5)	H4A—C4—H4C	109.5
Mg1^i—Na1—Mg1	57.450 (19)	H4B—C4—H4C	109.5
O1—Na1—Si1	53.61 (3)	Si2—C5—Mg1	119.04 (9)
C9—Na1—Si1	112.03 (5)	Si2—C5—Na1	161.64 (9)
C5—Na1—Si1	107.41 (4)	Mg1—C5—Na1	79.25 (5)
C6^ii—Na1—Si1	119.83 (5)	Si2—C5—H5A	105.5 (12)
Mg1^i—Na1—Si1	86.17 (2)	Mg1—C5—H5A	103.8 (11)
Mg1—Na1—Si1	82.41 (2)	Na1—C5—H5A	65.7 (12)
O1—Na1—H5A	93.8 (5)	Si2—C5—H5B	105.4 (13)
C9—Na1—H5A	100.1 (5)	Mg1—C5—H5B	115.0 (13)
C5—Na1—H5A	21.5 (5)	Na1—C5—H5B	64.7 (13)
C6^ii—Na1—H5A	87.2 (5)	H5A—C5—H5B	107.3 (17)
Mg1^i—Na1—H5A	91.0 (4)	Si2—C6—H6A	109.5
Mg1—Na1—H5A	54.0 (5)	Si2—C6—H6B	109.5
Si1—Na1—H5A	128.4 (5)	H6A—C6—H6B	109.5
O1—Na1—H5B	91.1 (5)	Si2—C6—H6C	109.5
C9—Na1—H5B	135.4 (5)	H6A—C6—H6C	109.5
C5—Na1—H5B	19.2 (5)	H6B—C6—H6C	109.5
C6^ii—Na1—H5B	84.9 (5)	Si2—C7—H7A	109.5
Mg1^i—Na1—H5B	111.7 (5)	Si2—C7—H7B	109.5
Mg1—Na1—H5B	56.0 (5)	H7A—C7—H7B	109.5
Si1—Na1—H5B	99.1 (5)	Si2—C7—H7C	109.5
H5A—Na1—H5B	35.9 (6)	H7A—C7—H7C	109.5
O1—Na1—H9A	89.2 (4)	H7B—C7—H7C	109.5
C9—Na1—H9A	21.5 (5)	Si2—C8—H8A	109.5
C5—Na1—H9A	138.3 (5)	Si2—C8—H8B	109.5
C6^ii—Na1—H9A	97.4 (4)	H8A—C8—H8B	109.5
Mg1^i—Na1—H9A	56.2 (4)	Si2—C8—H8C	109.5
Mg1—Na1—H9A	113.2 (4)	H8A—C8—H8C	109.5
Si1—Na1—H9A	100.1 (4)	H8B—C8—H8C	109.5
H5A—Na1—H9A	120.4 (7)	Si3—C9—Mg1^i	122.00 (9)
H5B—Na1—H9A	156.3 (7)	Si3—C9—Na1	158.38 (9)
O1—Na1—H9B	95.4 (4)	Mg1^i—C9—Na1	78.88 (5)
C9—Na1—H9B	21.7 (5)	Si3—C9—H9A	106.2 (10)
C5—Na1—H9B	100.8 (5)	Mg1^i—C9—H9A	110.1 (10)
C6^ii—Na1—H9B	92.9 (4)	Na1—C9—H9A	67.4 (10)
Mg1^i—Na1—H9B	54.7 (4)	Si3—C9—H9B	103.6 (11)
Mg1—Na1—H9B	94.2 (4)	Mg1^i—C9—H9B	103.6 (11)
Si1—Na1—H9B	133.3 (5)	Na1—C9—H9B	62.7 (11)
H5A—Na1—H9B	81.5 (7)	H9A—C9—H9B	111.1 (15)
H5B—Na1—H9B	117.4 (7)	Si3—C10—H10A	109.5
H9A—Na1—H9B	39.1 (6)	Si3—C10—H10B	109.5
C3—Si1—C4	109.76 (10)	H10A—C10—H10B	109.5
C3—Si1—C2	110.13 (10)	Si3—C10—H10C	109.5
C4—Si1—C2	109.72 (11)	H10A—C10—H10C	109.5
C3—Si1—C1	108.12 (8)	H10B—C10—H10C	109.5
C4—Si1—C1	109.58 (9)	Si3—C11—H11A	109.5
C2—Si1—C1	109.51 (9)	Si3—C11—H11B	109.5
C3—Si1—Na1	176.36 (7)	H11A—C11—H11B	109.5
C4—Si1—Na1	73.68 (7)	Si3—C11—H11C	109.5
C2—Si1—Na1	69.18 (7)	H11A—C11—H11C	109.5
C1—Si1—Na1	69.16 (5)	H11B—C11—H11C	109.5
C5—Si2—C7	114.08 (9)	Si3—C12—H12A	109.5
C5—Si2—C8	112.33 (9)	Si3—C12—H12B	109.5
C7—Si2—C8	106.86 (11)	H12A—C12—H12B	109.5
C5—Si2—C6	109.16 (9)	Si3—C12—H12C	109.5
C7—Si2—C6	106.38 (9)	H12A—C12—H12C	109.5
C8—Si2—C6	107.69 (9)	H12B—C12—H12C	109.5
O1^i—Mg1—Na1—O1	84.41 (6)	Si1—Na1—O1—Mg1	−128.08 (5)
C9^i—Mg1—Na1—O1	−30.82 (12)	C9—Na1—O1—Mg1^i	12.68 (5)
C5—Mg1—Na1—O1	−165.20 (8)	C5—Na1—O1—Mg1^i	−105.57 (5)
Mg1^i—Mg1—Na1—O1	50.55 (4)	Mg1—Na1—O1—Mg1^i	−95.38 (5)
Na1^i—Mg1—Na1—O1	50.55 (4)	Si1—Na1—O1—Mg1^i	136.54 (5)
O1—Mg1—Na1—C9	−71.74 (6)	Mg1—O1—C1—Si1	111.87 (10)
O1^i—Mg1—Na1—C9	12.68 (6)	Mg1^i—O1—C1—Si1	−125.95 (9)
C9^i—Mg1—Na1—C9	−102.56 (11)	Na1—O1—C1—Si1	−8.20 (15)
C5—Mg1—Na1—C9	123.06 (8)	C3—Si1—C1—O1	−177.72 (12)
Mg1^i—Mg1—Na1—C9	−21.18 (5)	C4—Si1—C1—O1	−58.12 (14)
Na1^i—Mg1—Na1—C9	−21.18 (5)	C2—Si1—C1—O1	62.27 (14)
O1—Mg1—Na1—C5	165.20 (8)	Na1—Si1—C1—O1	4.84 (9)
O1^i—Mg1—Na1—C5	−110.38 (7)	C7—Si2—C5—Mg1	151.08 (11)
C9^i—Mg1—Na1—C5	134.39 (13)	C8—Si2—C5—Mg1	29.28 (14)
Mg1^i—Mg1—Na1—C5	−144.24 (7)	C6—Si2—C5—Mg1	−90.09 (11)
Na1^i—Mg1—Na1—C5	−144.24 (7)	C7—Si2—C5—Na1	−23.7 (3)
O1—Mg1—Na1—C6^ii	167.32 (9)	C8—Si2—C5—Na1	−145.5 (3)
O1^i—Mg1—Na1—C6^ii	−108.27 (8)	C6—Si2—C5—Na1	95.1 (3)
C9^i—Mg1—Na1—C6^ii	136.50 (13)	O1—Mg1—C5—Si2	170.76 (9)
C5—Mg1—Na1—C6^ii	2.11 (9)	O1^i—Mg1—C5—Si2	−101.14 (10)
Mg1^i—Mg1—Na1—C6^ii	−142.13 (8)	C9^i—Mg1—C5—Si2	30.01 (17)
Na1^i—Mg1—Na1—C6^ii	−142.13 (8)	Mg1^i—Mg1—C5—Si2	−145.53 (8)
O1—Mg1—Na1—Mg1^i	−50.55 (4)	Na1^i—Mg1—C5—Si2	−78.66 (14)
O1^i—Mg1—Na1—Mg1^i	33.86 (3)	Na1—Mg1—C5—Si2	−178.33 (13)
C9^i—Mg1—Na1—Mg1^i	−81.37 (12)	O1—Mg1—C5—Na1	−10.91 (6)
C5—Mg1—Na1—Mg1^i	144.24 (7)	O1^i—Mg1—C5—Na1	77.19 (5)
Na1^i—Mg1—Na1—Mg1^i	0.0	C9^i—Mg1—C5—Na1	−151.66 (9)
O1—Mg1—Na1—Si1	39.73 (4)	Mg1^i—Mg1—C5—Na1	32.80 (6)
O1^i—Mg1—Na1—Si1	124.15 (4)	Na1^i—Mg1—C5—Na1	99.66 (9)
C9^i—Mg1—Na1—Si1	8.92 (12)	O1—Na1—C5—Si2	−175.1 (3)
C5—Mg1—Na1—Si1	−125.47 (6)	C9—Na1—C5—Si2	106.3 (3)
Mg1^i—Mg1—Na1—Si1	90.29 (2)	C6^ii—Na1—C5—Si2	−3.3 (3)
Na1^i—Mg1—Na1—Si1	90.29 (2)	Mg1^i—Na1—C5—Si2	145.7 (3)
O1^i—Mg1—O1—C1	134.03 (12)	Mg1—Na1—C5—Si2	175.3 (4)
C9^i—Mg1—O1—C1	32.65 (12)	Si1—Na1—C5—Si2	−126.9 (3)
C5—Mg1—O1—C1	−120.63 (11)	O1—Na1—C5—Mg1	9.57 (5)
Mg1^i—Mg1—O1—C1	134.03 (12)	C9—Na1—C5—Mg1	−69.01 (7)
Na1^i—Mg1—O1—C1	87.26 (10)	C6^ii—Na1—C5—Mg1	−178.60 (6)
Na1—Mg1—O1—C1	−133.36 (12)	Mg1^i—Na1—C5—Mg1	−29.61 (5)
O1^i—Mg1—O1—Mg1^i	0.0	Si1—Na1—C5—Mg1	57.79 (5)
C9^i—Mg1—O1—Mg1^i	−101.38 (6)	C11—Si3—C9—Mg1^i	−42.80 (15)
C5—Mg1—O1—Mg1^i	105.34 (6)	C12—Si3—C9—Mg1^i	77.89 (13)
Na1^i—Mg1—O1—Mg1^i	−46.77 (3)	C10—Si3—C9—Mg1^i	−162.03 (12)
Na1—Mg1—O1—Mg1^i	92.61 (5)	C11—Si3—C9—Na1	120.8 (3)
O1^i—Mg1—O1—Na1	−92.61 (5)	C12—Si3—C9—Na1	−118.5 (3)
C9^i—Mg1—O1—Na1	166.01 (6)	C10—Si3—C9—Na1	1.6 (3)
C5—Mg1—O1—Na1	12.72 (6)	O1—Na1—C9—Si3	−177.9 (3)
Mg1^i—Mg1—O1—Na1	−92.61 (5)	C5—Na1—C9—Si3	−99.5 (3)
Na1^i—Mg1—O1—Na1	−139.38 (3)	C6^ii—Na1—C9—Si3	4.6 (3)
C9—Na1—O1—C1	−118.80 (11)	Mg1^i—Na1—C9—Si3	−165.9 (3)
C5—Na1—O1—C1	122.95 (11)	Mg1—Na1—C9—Si3	−139.7 (3)
Mg1^i—Na1—O1—C1	−131.48 (12)	Si1—Na1—C9—Si3	136.0 (3)
Mg1—Na1—O1—C1	133.14 (12)	O1—Na1—C9—Mg1^i	−11.99 (5)
Si1—Na1—O1—C1	5.06 (9)	C5—Na1—C9—Mg1^i	66.36 (7)
C9—Na1—O1—Mg1	108.05 (6)	C6^ii—Na1—C9—Mg1^i	170.45 (6)
C5—Na1—O1—Mg1	−10.19 (5)	Mg1—Na1—C9—Mg1^i	26.17 (6)
Mg1^i—Na1—O1—Mg1	95.38 (5)	Si1—Na1—C9—Mg1^i	−58.13 (6)

Symmetry codes: (i) −x, −y, −z; (ii) x, −y+1/2, z+1/2.