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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′ = 1 \over 2) 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.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270111023134/em3041sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270111023134/em3041Isup2.hkl
Contains datablock I

CCDC reference: 838137

Comment top

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(OtBu).(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 NaOtBu and MgBu2 in the presence of TMEDA, which solvates the alkali metal and removes the opportunity for polymeric propagation.

Related literature top

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).

Experimental top

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).

Refinement top

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 Uiso(H) = 1.5Ueq(C).

Computing details top

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 top
[Figure 1] 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.
[Figure 2] Fig. 2. Detail of the central core of (I), with its pseuodo-chair motif.
[Figure 3] 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] top
Crystal data top
[Na2Mg2(C4H11OSi)2(C4H11Si)4]F(000) = 712
Mr = 649.91Dx = 1.030 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 7568 reflections
a = 9.8057 (3) Åθ = 2.8–30.3°
b = 18.1602 (5) ŵ = 0.27 mm1
c = 11.8234 (3) ÅT = 123 K
β = 95.482 (3)°Block, colourless
V = 2095.80 (10) Å30.23 × 0.18 × 0.15 mm
Z = 2
Data collection top
Oxford Gemini S
diffractometer
5052 independent reflections
Radiation source: fine-focus sealed tube3663 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.046
Detector resolution: 16.0268 pixels mm-1θmax = 28.0°, θmin = 2.8°
ω scansh = 1212
Absorption correction: multi-scan
(CrysAlis PRO; Oxford Diffraction, 2010)
k = 2323
Tmin = 0.804, Tmax = 1.000l = 1515
17871 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.039Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.100H atoms treated by a mixture of independent and constrained refinement
S = 0.96 w = 1/[σ2(Fo2) + (0.0566P)2]
where P = (Fo2 + 2Fc2)/3
5052 reflections(Δ/σ)max < 0.001
196 parametersΔρmax = 0.46 e Å3
0 restraintsΔρmin = 0.28 e Å3
Crystal data top
[Na2Mg2(C4H11OSi)2(C4H11Si)4]V = 2095.80 (10) Å3
Mr = 649.91Z = 2
Monoclinic, P21/cMo Kα radiation
a = 9.8057 (3) ŵ = 0.27 mm1
b = 18.1602 (5) ÅT = 123 K
c = 11.8234 (3) Å0.23 × 0.18 × 0.15 mm
β = 95.482 (3)°
Data collection top
Oxford Gemini S
diffractometer
5052 independent reflections
Absorption correction: multi-scan
(CrysAlis PRO; Oxford Diffraction, 2010)
3663 reflections with I > 2σ(I)
Tmin = 0.804, Tmax = 1.000Rint = 0.046
17871 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0390 restraints
wR(F2) = 0.100H atoms treated by a mixture of independent and constrained refinement
S = 0.96Δρmax = 0.46 e Å3
5052 reflectionsΔρmin = 0.28 e Å3
196 parameters
Special details top

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 (Å2) top
xyzUiso*/Ueq
Mg10.00426 (6)0.05122 (3)0.09983 (4)0.01719 (13)
Na10.00110 (7)0.11740 (3)0.14529 (5)0.02509 (17)
Si10.34964 (5)0.11136 (3)0.12990 (4)0.02460 (13)
Si20.22055 (5)0.19736 (3)0.17790 (4)0.02400 (13)
Si30.18934 (6)0.05907 (3)0.33618 (4)0.02845 (13)
O10.11632 (11)0.03426 (5)0.04690 (9)0.0169 (2)
C10.26296 (17)0.03189 (9)0.05188 (14)0.0193 (3)
C20.3087 (2)0.11026 (13)0.28116 (17)0.0492 (6)
H2A0.34200.06430.31730.074*
H2B0.20930.11380.28370.074*
H2C0.35330.15220.32170.074*
C30.5377 (2)0.10166 (12)0.12316 (18)0.0381 (5)
H3A0.55790.10140.04360.057*
H3B0.56910.05540.15950.057*
H3C0.58510.14310.16290.057*
C40.2891 (2)0.19933 (10)0.0612 (2)0.0446 (6)
H4A0.33370.24090.10270.067*
H4B0.18960.20330.06240.067*
H4C0.31220.20010.01770.067*
C50.11609 (19)0.15148 (9)0.06267 (14)0.0215 (4)
C60.1122 (2)0.26732 (10)0.24626 (16)0.0311 (4)
H6A0.09000.30800.19320.047*
H6B0.16300.28640.31550.047*
H6C0.02740.24400.26550.047*
C70.3707 (2)0.24875 (12)0.1311 (2)0.0486 (6)
H7A0.42600.21550.08870.073*
H7B0.42670.26770.19780.073*
H7C0.33800.28990.08210.073*
C80.2894 (2)0.13150 (11)0.29098 (18)0.0433 (5)
H8A0.21350.10390.31880.065*
H8B0.33770.15890.35400.065*
H8C0.35300.09720.25940.065*
C90.09097 (19)0.00313 (10)0.24275 (14)0.0235 (4)
C100.3040 (3)0.00285 (15)0.42114 (19)0.0592 (7)
H10A0.24800.02850.47470.089*
H10B0.36010.03580.46330.089*
H10C0.36390.02810.36980.089*
C110.3025 (3)0.12490 (13)0.2498 (2)0.0577 (7)
H11A0.36070.09770.19220.087*
H11B0.36020.15140.29950.087*
H11C0.24600.16020.21240.087*
C120.0731 (2)0.11256 (10)0.44100 (16)0.0362 (5)
H12A0.01290.14400.40020.054*
H12B0.12810.14330.48740.054*
H12C0.01750.07840.49020.054*
H1A0.2966 (18)0.0126 (9)0.0897 (14)0.020 (4)*
H1B0.2951 (18)0.0301 (9)0.0295 (15)0.025 (5)*
H5A0.181 (2)0.1348 (10)0.0094 (18)0.040 (6)*
H5B0.065 (2)0.1868 (11)0.0281 (17)0.041 (6)*
H9A0.022 (2)0.0234 (9)0.2927 (15)0.028 (5)*
H9B0.160 (2)0.0311 (10)0.2058 (16)0.032 (5)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Mg10.0198 (3)0.0154 (3)0.0169 (3)0.0005 (2)0.0042 (2)0.0013 (2)
Na10.0311 (4)0.0207 (3)0.0243 (3)0.0029 (3)0.0073 (3)0.0031 (3)
Si10.0194 (3)0.0288 (3)0.0262 (3)0.0044 (2)0.0053 (2)0.0080 (2)
Si20.0227 (3)0.0233 (2)0.0263 (2)0.0017 (2)0.0043 (2)0.00898 (19)
Si30.0277 (3)0.0373 (3)0.0212 (2)0.0048 (2)0.0070 (2)0.0047 (2)
O10.0157 (6)0.0163 (5)0.0190 (5)0.0004 (4)0.0029 (4)0.0001 (4)
C10.0175 (8)0.0188 (8)0.0217 (8)0.0000 (7)0.0027 (7)0.0008 (7)
C20.0394 (13)0.0782 (17)0.0312 (11)0.0185 (12)0.0099 (10)0.0194 (11)
C30.0229 (10)0.0477 (12)0.0440 (12)0.0044 (9)0.0043 (9)0.0120 (10)
C40.0436 (13)0.0230 (10)0.0670 (15)0.0028 (9)0.0042 (12)0.0077 (9)
C50.0253 (10)0.0158 (8)0.0236 (8)0.0005 (7)0.0032 (7)0.0020 (7)
C60.0338 (11)0.0287 (10)0.0317 (10)0.0007 (8)0.0079 (8)0.0097 (8)
C70.0359 (13)0.0507 (13)0.0620 (15)0.0190 (10)0.0188 (11)0.0279 (11)
C80.0449 (14)0.0482 (12)0.0349 (11)0.0146 (11)0.0062 (10)0.0091 (9)
C90.0248 (10)0.0268 (9)0.0194 (8)0.0033 (8)0.0044 (7)0.0006 (7)
C100.0529 (16)0.0884 (18)0.0410 (12)0.0210 (14)0.0291 (12)0.0210 (13)
C110.0580 (16)0.0684 (16)0.0438 (13)0.0359 (13)0.0104 (12)0.0235 (12)
C120.0417 (13)0.0393 (11)0.0280 (10)0.0021 (9)0.0059 (9)0.0048 (8)
Geometric parameters (Å, º) top
Mg1—O12.0274 (12)C2—H2A0.9800
Mg1—O1i2.0347 (11)C2—H2B0.9800
Mg1—C52.1915 (17)C2—H2C0.9800
Mg1—C9i2.1890 (17)C3—H3A0.9800
Mg1—Mg1i3.0004 (10)C3—H3B0.9800
Mg1—Na1i3.1096 (8)C3—H3C0.9800
Mg1—Na13.1332 (8)C4—H4A0.9800
Na1—O12.2716 (12)C4—H4B0.9800
Na1—C52.6850 (18)C4—H4C0.9800
Na1—C92.6706 (18)C5—H5A0.98 (2)
Na1—C6ii2.7448 (18)C5—H5B0.89 (2)
Na1—Mg1i3.1096 (8)C6—H6A0.9800
Na1—Si13.4416 (9)C6—H6B0.9800
Na1—H5A2.45 (2)C6—H6C0.9800
Na1—H5B2.44 (2)C7—H7A0.9800
Na1—H9A2.466 (17)C7—H7B0.9800
Na1—H9B2.385 (18)C7—H7C0.9800
Si1—C31.862 (2)C8—H8A0.9800
Si1—C41.864 (2)C8—H8B0.9800
Si1—C21.870 (2)C8—H8C0.9800
Si1—C11.8725 (17)C9—Mg1i2.1890 (17)
Si2—C51.8257 (18)C9—H9A0.979 (19)
Si2—C71.871 (2)C9—H9B0.991 (19)
Si2—C81.871 (2)C10—H10A0.9800
Si2—C61.8868 (17)C10—H10B0.9800
Si3—C91.8401 (17)C10—H10C0.9800
Si3—C111.868 (2)C11—H11A0.9800
Si3—C121.873 (2)C11—H11B0.9800
Si3—C101.879 (2)C11—H11C0.9800
O1—C11.4342 (19)C12—H12A0.9800
O1—Mg1i2.0347 (11)C12—H12B0.9800
C1—H1A0.966 (17)C12—H12C0.9800
C1—H1B1.041 (17)
O1—Mg1—O1i84.77 (5)C9—Si3—C11110.08 (9)
O1—Mg1—C9i110.06 (6)C9—Si3—C12111.27 (9)
O1i—Mg1—C9i102.46 (6)C11—Si3—C12108.79 (10)
O1—Mg1—C5102.52 (6)C9—Si3—C10113.32 (10)
O1i—Mg1—C5106.08 (6)C11—Si3—C10106.58 (13)
C9i—Mg1—C5138.14 (7)C12—Si3—C10106.58 (10)
O1—Mg1—Mg1i42.48 (3)C1—O1—Mg1122.69 (9)
O1i—Mg1—Mg1i42.29 (3)C1—O1—Mg1i122.22 (9)
C9i—Mg1—Mg1i112.22 (5)Mg1—O1—Mg1i95.23 (5)
C5—Mg1—Mg1i109.53 (5)C1—O1—Na1123.01 (9)
O1—Mg1—Na1i89.07 (3)Mg1—O1—Na193.40 (5)
O1i—Mg1—Na1i46.88 (3)Mg1i—O1—Na192.29 (5)
C9i—Mg1—Na1i57.43 (5)O1—C1—Si1113.78 (11)
C5—Mg1—Na1i150.02 (6)O1—C1—H1A109.9 (10)
Mg1i—Mg1—Na1i61.67 (2)Si1—C1—H1A107.3 (10)
O1—Mg1—Na146.36 (3)O1—C1—H1B110.7 (10)
O1i—Mg1—Na188.28 (3)Si1—C1—H1B108.4 (9)
C9i—Mg1—Na1153.69 (6)H1A—C1—H1B106.4 (13)
C5—Mg1—Na157.34 (5)Si1—C2—H2A109.5
Mg1i—Mg1—Na160.88 (2)Si1—C2—H2B109.5
Na1i—Mg1—Na1122.550 (19)H2A—C2—H2B109.5
O1—Na1—C983.19 (5)Si1—C2—H2C109.5
O1—Na1—C582.79 (5)H2A—C2—H2C109.5
C9—Na1—C5116.83 (6)H2B—C2—H2C109.5
O1—Na1—C6ii171.69 (6)Si1—C3—H3A109.5
C9—Na1—C6ii104.77 (6)Si1—C3—H3B109.5
C5—Na1—C6ii95.46 (6)H3A—C3—H3B109.5
O1—Na1—Mg1i40.83 (3)Si1—C3—H3C109.5
C9—Na1—Mg1i43.69 (4)H3A—C3—H3C109.5
C5—Na1—Mg1i94.54 (4)H3B—C3—H3C109.5
C6ii—Na1—Mg1i147.46 (5)Si1—C4—H4A109.5
O1—Na1—Mg140.24 (3)Si1—C4—H4B109.5
C9—Na1—Mg196.21 (4)H4A—C4—H4B109.5
C5—Na1—Mg143.41 (4)Si1—C4—H4C109.5
C6ii—Na1—Mg1138.84 (5)H4A—C4—H4C109.5
Mg1i—Na1—Mg157.450 (19)H4B—C4—H4C109.5
O1—Na1—Si153.61 (3)Si2—C5—Mg1119.04 (9)
C9—Na1—Si1112.03 (5)Si2—C5—Na1161.64 (9)
C5—Na1—Si1107.41 (4)Mg1—C5—Na179.25 (5)
C6ii—Na1—Si1119.83 (5)Si2—C5—H5A105.5 (12)
Mg1i—Na1—Si186.17 (2)Mg1—C5—H5A103.8 (11)
Mg1—Na1—Si182.41 (2)Na1—C5—H5A65.7 (12)
O1—Na1—H5A93.8 (5)Si2—C5—H5B105.4 (13)
C9—Na1—H5A100.1 (5)Mg1—C5—H5B115.0 (13)
C5—Na1—H5A21.5 (5)Na1—C5—H5B64.7 (13)
C6ii—Na1—H5A87.2 (5)H5A—C5—H5B107.3 (17)
Mg1i—Na1—H5A91.0 (4)Si2—C6—H6A109.5
Mg1—Na1—H5A54.0 (5)Si2—C6—H6B109.5
Si1—Na1—H5A128.4 (5)H6A—C6—H6B109.5
O1—Na1—H5B91.1 (5)Si2—C6—H6C109.5
C9—Na1—H5B135.4 (5)H6A—C6—H6C109.5
C5—Na1—H5B19.2 (5)H6B—C6—H6C109.5
C6ii—Na1—H5B84.9 (5)Si2—C7—H7A109.5
Mg1i—Na1—H5B111.7 (5)Si2—C7—H7B109.5
Mg1—Na1—H5B56.0 (5)H7A—C7—H7B109.5
Si1—Na1—H5B99.1 (5)Si2—C7—H7C109.5
H5A—Na1—H5B35.9 (6)H7A—C7—H7C109.5
O1—Na1—H9A89.2 (4)H7B—C7—H7C109.5
C9—Na1—H9A21.5 (5)Si2—C8—H8A109.5
C5—Na1—H9A138.3 (5)Si2—C8—H8B109.5
C6ii—Na1—H9A97.4 (4)H8A—C8—H8B109.5
Mg1i—Na1—H9A56.2 (4)Si2—C8—H8C109.5
Mg1—Na1—H9A113.2 (4)H8A—C8—H8C109.5
Si1—Na1—H9A100.1 (4)H8B—C8—H8C109.5
H5A—Na1—H9A120.4 (7)Si3—C9—Mg1i122.00 (9)
H5B—Na1—H9A156.3 (7)Si3—C9—Na1158.38 (9)
O1—Na1—H9B95.4 (4)Mg1i—C9—Na178.88 (5)
C9—Na1—H9B21.7 (5)Si3—C9—H9A106.2 (10)
C5—Na1—H9B100.8 (5)Mg1i—C9—H9A110.1 (10)
C6ii—Na1—H9B92.9 (4)Na1—C9—H9A67.4 (10)
Mg1i—Na1—H9B54.7 (4)Si3—C9—H9B103.6 (11)
Mg1—Na1—H9B94.2 (4)Mg1i—C9—H9B103.6 (11)
Si1—Na1—H9B133.3 (5)Na1—C9—H9B62.7 (11)
H5A—Na1—H9B81.5 (7)H9A—C9—H9B111.1 (15)
H5B—Na1—H9B117.4 (7)Si3—C10—H10A109.5
H9A—Na1—H9B39.1 (6)Si3—C10—H10B109.5
C3—Si1—C4109.76 (10)H10A—C10—H10B109.5
C3—Si1—C2110.13 (10)Si3—C10—H10C109.5
C4—Si1—C2109.72 (11)H10A—C10—H10C109.5
C3—Si1—C1108.12 (8)H10B—C10—H10C109.5
C4—Si1—C1109.58 (9)Si3—C11—H11A109.5
C2—Si1—C1109.51 (9)Si3—C11—H11B109.5
C3—Si1—Na1176.36 (7)H11A—C11—H11B109.5
C4—Si1—Na173.68 (7)Si3—C11—H11C109.5
C2—Si1—Na169.18 (7)H11A—C11—H11C109.5
C1—Si1—Na169.16 (5)H11B—C11—H11C109.5
C5—Si2—C7114.08 (9)Si3—C12—H12A109.5
C5—Si2—C8112.33 (9)Si3—C12—H12B109.5
C7—Si2—C8106.86 (11)H12A—C12—H12B109.5
C5—Si2—C6109.16 (9)Si3—C12—H12C109.5
C7—Si2—C6106.38 (9)H12A—C12—H12C109.5
C8—Si2—C6107.69 (9)H12B—C12—H12C109.5
O1i—Mg1—Na1—O184.41 (6)Si1—Na1—O1—Mg1128.08 (5)
C9i—Mg1—Na1—O130.82 (12)C9—Na1—O1—Mg1i12.68 (5)
C5—Mg1—Na1—O1165.20 (8)C5—Na1—O1—Mg1i105.57 (5)
Mg1i—Mg1—Na1—O150.55 (4)Mg1—Na1—O1—Mg1i95.38 (5)
Na1i—Mg1—Na1—O150.55 (4)Si1—Na1—O1—Mg1i136.54 (5)
O1—Mg1—Na1—C971.74 (6)Mg1—O1—C1—Si1111.87 (10)
O1i—Mg1—Na1—C912.68 (6)Mg1i—O1—C1—Si1125.95 (9)
C9i—Mg1—Na1—C9102.56 (11)Na1—O1—C1—Si18.20 (15)
C5—Mg1—Na1—C9123.06 (8)C3—Si1—C1—O1177.72 (12)
Mg1i—Mg1—Na1—C921.18 (5)C4—Si1—C1—O158.12 (14)
Na1i—Mg1—Na1—C921.18 (5)C2—Si1—C1—O162.27 (14)
O1—Mg1—Na1—C5165.20 (8)Na1—Si1—C1—O14.84 (9)
O1i—Mg1—Na1—C5110.38 (7)C7—Si2—C5—Mg1151.08 (11)
C9i—Mg1—Na1—C5134.39 (13)C8—Si2—C5—Mg129.28 (14)
Mg1i—Mg1—Na1—C5144.24 (7)C6—Si2—C5—Mg190.09 (11)
Na1i—Mg1—Na1—C5144.24 (7)C7—Si2—C5—Na123.7 (3)
O1—Mg1—Na1—C6ii167.32 (9)C8—Si2—C5—Na1145.5 (3)
O1i—Mg1—Na1—C6ii108.27 (8)C6—Si2—C5—Na195.1 (3)
C9i—Mg1—Na1—C6ii136.50 (13)O1—Mg1—C5—Si2170.76 (9)
C5—Mg1—Na1—C6ii2.11 (9)O1i—Mg1—C5—Si2101.14 (10)
Mg1i—Mg1—Na1—C6ii142.13 (8)C9i—Mg1—C5—Si230.01 (17)
Na1i—Mg1—Na1—C6ii142.13 (8)Mg1i—Mg1—C5—Si2145.53 (8)
O1—Mg1—Na1—Mg1i50.55 (4)Na1i—Mg1—C5—Si278.66 (14)
O1i—Mg1—Na1—Mg1i33.86 (3)Na1—Mg1—C5—Si2178.33 (13)
C9i—Mg1—Na1—Mg1i81.37 (12)O1—Mg1—C5—Na110.91 (6)
C5—Mg1—Na1—Mg1i144.24 (7)O1i—Mg1—C5—Na177.19 (5)
Na1i—Mg1—Na1—Mg1i0.0C9i—Mg1—C5—Na1151.66 (9)
O1—Mg1—Na1—Si139.73 (4)Mg1i—Mg1—C5—Na132.80 (6)
O1i—Mg1—Na1—Si1124.15 (4)Na1i—Mg1—C5—Na199.66 (9)
C9i—Mg1—Na1—Si18.92 (12)O1—Na1—C5—Si2175.1 (3)
C5—Mg1—Na1—Si1125.47 (6)C9—Na1—C5—Si2106.3 (3)
Mg1i—Mg1—Na1—Si190.29 (2)C6ii—Na1—C5—Si23.3 (3)
Na1i—Mg1—Na1—Si190.29 (2)Mg1i—Na1—C5—Si2145.7 (3)
O1i—Mg1—O1—C1134.03 (12)Mg1—Na1—C5—Si2175.3 (4)
C9i—Mg1—O1—C132.65 (12)Si1—Na1—C5—Si2126.9 (3)
C5—Mg1—O1—C1120.63 (11)O1—Na1—C5—Mg19.57 (5)
Mg1i—Mg1—O1—C1134.03 (12)C9—Na1—C5—Mg169.01 (7)
Na1i—Mg1—O1—C187.26 (10)C6ii—Na1—C5—Mg1178.60 (6)
Na1—Mg1—O1—C1133.36 (12)Mg1i—Na1—C5—Mg129.61 (5)
O1i—Mg1—O1—Mg1i0.0Si1—Na1—C5—Mg157.79 (5)
C9i—Mg1—O1—Mg1i101.38 (6)C11—Si3—C9—Mg1i42.80 (15)
C5—Mg1—O1—Mg1i105.34 (6)C12—Si3—C9—Mg1i77.89 (13)
Na1i—Mg1—O1—Mg1i46.77 (3)C10—Si3—C9—Mg1i162.03 (12)
Na1—Mg1—O1—Mg1i92.61 (5)C11—Si3—C9—Na1120.8 (3)
O1i—Mg1—O1—Na192.61 (5)C12—Si3—C9—Na1118.5 (3)
C9i—Mg1—O1—Na1166.01 (6)C10—Si3—C9—Na11.6 (3)
C5—Mg1—O1—Na112.72 (6)O1—Na1—C9—Si3177.9 (3)
Mg1i—Mg1—O1—Na192.61 (5)C5—Na1—C9—Si399.5 (3)
Na1i—Mg1—O1—Na1139.38 (3)C6ii—Na1—C9—Si34.6 (3)
C9—Na1—O1—C1118.80 (11)Mg1i—Na1—C9—Si3165.9 (3)
C5—Na1—O1—C1122.95 (11)Mg1—Na1—C9—Si3139.7 (3)
Mg1i—Na1—O1—C1131.48 (12)Si1—Na1—C9—Si3136.0 (3)
Mg1—Na1—O1—C1133.14 (12)O1—Na1—C9—Mg1i11.99 (5)
Si1—Na1—O1—C15.06 (9)C5—Na1—C9—Mg1i66.36 (7)
C9—Na1—O1—Mg1108.05 (6)C6ii—Na1—C9—Mg1i170.45 (6)
C5—Na1—O1—Mg110.19 (5)Mg1—Na1—C9—Mg1i26.17 (6)
Mg1i—Na1—O1—Mg195.38 (5)Si1—Na1—C9—Mg1i58.13 (6)
Symmetry codes: (i) x, y, z; (ii) x, y+1/2, z+1/2.

Experimental details

Crystal data
Chemical formula[Na2Mg2(C4H11OSi)2(C4H11Si)4]
Mr649.91
Crystal system, space groupMonoclinic, P21/c
Temperature (K)123
a, b, c (Å)9.8057 (3), 18.1602 (5), 11.8234 (3)
β (°) 95.482 (3)
V3)2095.80 (10)
Z2
Radiation typeMo Kα
µ (mm1)0.27
Crystal size (mm)0.23 × 0.18 × 0.15
Data collection
DiffractometerOxford Gemini S
diffractometer
Absorption correctionMulti-scan
(CrysAlis PRO; Oxford Diffraction, 2010)
Tmin, Tmax0.804, 1.000
No. of measured, independent and
observed [I > 2σ(I)] reflections
17871, 5052, 3663
Rint0.046
(sin θ/λ)max1)0.660
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.039, 0.100, 0.96
No. of reflections5052
No. of parameters196
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.46, 0.28

Computer programs: CrysAlis PRO (Oxford Diffraction, 2010), SIR2004 (Burla et al., 2005), SHELXL97 (Sheldrick, 2008), X-SEED (Barbour, 2001).

Selected geometric parameters (Å, º) top
Mg1—O12.0274 (12)Na1—O12.2716 (12)
Mg1—O1i2.0347 (11)Na1—C52.6850 (18)
Mg1—C52.1915 (17)Na1—C92.6706 (18)
Mg1—C9i2.1890 (17)Na1—C6ii2.7448 (18)
O1—Mg1—O1i84.77 (5)O1—Na1—C983.19 (5)
O1—Mg1—C9i110.06 (6)O1—Na1—C582.79 (5)
O1i—Mg1—C9i102.46 (6)C9—Na1—C5116.83 (6)
O1—Mg1—C5102.52 (6)O1—Na1—C6ii171.69 (6)
O1i—Mg1—C5106.08 (6)C9—Na1—C6ii104.77 (6)
C9i—Mg1—C5138.14 (7)C5—Na1—C6ii95.46 (6)
Symmetry codes: (i) x, y, z; (ii) x, y+1/2, z+1/2.
 

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