Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270105024121/sf1008sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270105024121/sf1008Isup2.hkl |
CCDC reference: 285643
Sodium metaborate (10 g) was dehydrated in a domestic microwave oven (1000 W) at full power for 10 min. A sample of the resulting NaBO2 (2.64 g, 0.04 mol) was refluxed in a 2:1 mixture of ethanol and toluene (150 ml), under a nitrogen atmosphere, running the distillate through molecular sieves to remove liberated water. After 8 h, the mixture was filtered and the volume was reduced by distillation. On cooling, the product appeared as platey crystals. These were filtered and dried (yield 7.1 g, 83%).
Friedel pairs were merged after a full data set refinement gave a Flack (1983) parameter that was indeterminate. All H atoms were constrained to their expected geometries (C—H = 0.99 and 0.98 Å) and refined with Uiso (H) vaues of 1.2 times Ueq of their carrier atoms.
Data collection: SMART (Bruker, 2001); cell refinement: SMART; data reduction: SAINT (Bruker, 2001) and SADABS (Sheldrick, 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003) and ORTEP-3 (Farrugia, 1997).
[Na(C8H20BO4)] | F(000) = 232 |
Mr = 214.04 | Dx = 1.062 Mg m−3 |
Orthorhombic, P21212 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2 2ab | Cell parameters from 1438 reflections |
a = 7.633 (3) Å | θ = 2.7–26.0° |
b = 15.272 (6) Å | µ = 0.11 mm−1 |
c = 5.744 (2) Å | T = 98 K |
V = 669.6 (4) Å3 | Plate, colourless |
Z = 2 | 0.57 × 0.23 × 0.07 mm |
Bruker SMART CCD area-detector diffractometer | 829 independent reflections |
Radiation source: fine-focus sealed tube | 648 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.068 |
Detector resolution: 8.192 pixels mm-1 | θmax = 26.3°, θmin = 2.7° |
ϕ and ω scans | h = −9→5 |
Absorption correction: multi-scan (Blessing, 1995) | k = −18→19 |
Tmin = 0.812, Tmax = 0.993 | l = −7→7 |
3881 measured reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.056 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.105 | H-atom parameters constrained |
S = 1.12 | w = 1/[σ2(Fo2) + (0.0421P)2 + 0.1167P] where P = (Fo2 + 2Fc2)/3 |
829 reflections | (Δ/σ)max < 0.001 |
67 parameters | Δρmax = 0.18 e Å−3 |
0 restraints | Δρmin = −0.22 e Å−3 |
[Na(C8H20BO4)] | V = 669.6 (4) Å3 |
Mr = 214.04 | Z = 2 |
Orthorhombic, P21212 | Mo Kα radiation |
a = 7.633 (3) Å | µ = 0.11 mm−1 |
b = 15.272 (6) Å | T = 98 K |
c = 5.744 (2) Å | 0.57 × 0.23 × 0.07 mm |
Bruker SMART CCD area-detector diffractometer | 829 independent reflections |
Absorption correction: multi-scan (Blessing, 1995) | 648 reflections with I > 2σ(I) |
Tmin = 0.812, Tmax = 0.993 | Rint = 0.068 |
3881 measured reflections |
R[F2 > 2σ(F2)] = 0.056 | 0 restraints |
wR(F2) = 0.105 | H-atom parameters constrained |
S = 1.12 | Δρmax = 0.18 e Å−3 |
829 reflections | Δρmin = −0.22 e Å−3 |
67 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
Na1 | 1.0000 | 0.0000 | 0.7432 (3) | 0.0265 (5) | |
O1 | 0.8763 (3) | 0.04140 (13) | 0.4048 (3) | 0.0203 (5) | |
O2 | 1.0828 (3) | 0.06180 (14) | 0.0814 (3) | 0.0210 (6) | |
C1 | 0.7310 (4) | 0.0866 (2) | 0.3100 (6) | 0.0274 (9) | |
H1A | 0.6456 | 0.0442 | 0.2459 | 0.033* | |
H1B | 0.7702 | 0.1253 | 0.1821 | 0.033* | |
C2 | 0.6462 (6) | 0.1400 (3) | 0.4980 (8) | 0.0613 (14) | |
H2A | 0.6009 | 0.1010 | 0.6193 | 0.074* | |
H2B | 0.5495 | 0.1740 | 0.4316 | 0.074* | |
H2C | 0.7329 | 0.1799 | 0.5658 | 0.074* | |
C3 | 1.1704 (5) | 0.1349 (2) | 0.1787 (6) | 0.0280 (9) | |
H3A | 1.2417 | 0.1159 | 0.3136 | 0.034* | |
H3B | 1.0835 | 0.1782 | 0.2341 | 0.034* | |
C4 | 1.2874 (5) | 0.1763 (3) | −0.0024 (7) | 0.0424 (10) | |
H4A | 1.3758 | 0.1339 | −0.0528 | 0.051* | |
H4B | 1.3456 | 0.2277 | 0.0646 | 0.051* | |
H4C | 1.2167 | 0.1944 | −0.1365 | 0.051* | |
B1 | 1.0000 | 0.0000 | 0.2435 (9) | 0.0197 (10) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Na1 | 0.0350 (11) | 0.0397 (11) | 0.0048 (8) | −0.0007 (10) | 0.000 | 0.000 |
O1 | 0.0203 (12) | 0.0283 (12) | 0.0123 (11) | 0.0020 (9) | 0.0014 (10) | −0.0010 (10) |
O2 | 0.0277 (13) | 0.0237 (12) | 0.0115 (11) | −0.0053 (10) | 0.0010 (10) | 0.0016 (9) |
C1 | 0.0231 (19) | 0.034 (2) | 0.0248 (18) | 0.0023 (17) | 0.0014 (15) | 0.0014 (15) |
C2 | 0.046 (3) | 0.088 (4) | 0.050 (2) | 0.036 (3) | −0.005 (2) | −0.021 (3) |
C3 | 0.034 (2) | 0.0269 (19) | 0.0229 (17) | −0.0074 (17) | 0.0014 (16) | −0.0015 (14) |
C4 | 0.048 (3) | 0.044 (2) | 0.035 (2) | −0.016 (2) | 0.003 (2) | 0.0068 (19) |
B1 | 0.025 (3) | 0.024 (3) | 0.010 (2) | 0.001 (3) | 0.000 | 0.000 |
Na1—O2i | 2.250 (3) | C2—H2A | 0.9800 |
Na1—O2ii | 2.250 (3) | C2—H2B | 0.9800 |
Na1—O1 | 2.252 (3) | C2—H2C | 0.9800 |
Na1—O1iii | 2.252 (3) | C3—C4 | 1.510 (5) |
O1—C1 | 1.415 (4) | C3—H3A | 0.9900 |
O1—B1 | 1.466 (4) | C3—H3B | 0.9900 |
O2—C3 | 1.416 (4) | C4—H4A | 0.9800 |
O2—B1 | 1.469 (4) | C4—H4B | 0.9800 |
O2—Na1iv | 2.250 (3) | C4—H4C | 0.9800 |
C1—C2 | 1.500 (5) | B1—O1iii | 1.466 (4) |
C1—H1A | 0.9900 | B1—O2iii | 1.469 (4) |
C1—H1B | 0.9900 | ||
O2i—Na1—O2ii | 60.64 (11) | C1—C2—H2C | 109.5 |
O2i—Na1—O1 | 138.18 (8) | H2A—C2—H2C | 109.5 |
O2ii—Na1—O1 | 138.17 (8) | H2B—C2—H2C | 109.5 |
O2i—Na1—O1iii | 138.17 (8) | O2—C3—C4 | 109.7 (3) |
O2ii—Na1—O1iii | 138.18 (8) | O2—C3—H3A | 109.7 |
O1—Na1—O1iii | 60.62 (12) | C4—C3—H3A | 109.7 |
C1—O1—B1 | 118.2 (2) | O2—C3—H3B | 109.7 |
C1—O1—Na1 | 142.90 (19) | C4—C3—H3B | 109.7 |
B1—O1—Na1 | 98.88 (19) | H3A—C3—H3B | 108.2 |
C3—O2—B1 | 117.4 (3) | C3—C4—H4A | 109.5 |
C3—O2—Na1iv | 143.51 (19) | C3—C4—H4B | 109.5 |
B1—O2—Na1iv | 99.02 (19) | H4A—C4—H4B | 109.5 |
O1—C1—C2 | 109.1 (3) | C3—C4—H4C | 109.5 |
O1—C1—H1A | 109.9 | H4A—C4—H4C | 109.5 |
C2—C1—H1A | 109.9 | H4B—C4—H4C | 109.5 |
O1—C1—H1B | 109.9 | O1iii—B1—O1 | 101.6 (3) |
C2—C1—H1B | 109.9 | O1iii—B1—O2iii | 113.63 (12) |
H1A—C1—H1B | 108.3 | O1—B1—O2iii | 113.60 (13) |
C1—C2—H2A | 109.5 | O1iii—B1—O2 | 113.60 (13) |
C1—C2—H2B | 109.5 | O1—B1—O2 | 113.63 (12) |
H2A—C2—H2B | 109.5 | O2iii—B1—O2 | 101.3 (3) |
O2i—Na1—O1—C1 | −52.1 (4) | Na1—O1—B1—O1iii | 0.0 |
O2ii—Na1—O1—C1 | 46.3 (4) | C1—O1—B1—O2iii | −55.6 (3) |
O1iii—Na1—O1—C1 | 177.1 (4) | Na1—O1—B1—O2iii | 122.4 (2) |
O2i—Na1—O1—B1 | 130.78 (12) | C1—O1—B1—O2 | 59.6 (3) |
O2ii—Na1—O1—B1 | −130.80 (12) | Na1—O1—B1—O2 | −122.4 (2) |
O1iii—Na1—O1—B1 | 0.0 | C3—O2—B1—O1iii | −60.7 (3) |
B1—O1—C1—C2 | −167.3 (3) | Na1iv—O2—B1—O1iii | 122.2 (2) |
Na1—O1—C1—C2 | 15.9 (5) | C3—O2—B1—O1 | 54.8 (3) |
B1—O2—C3—C4 | 164.5 (2) | Na1iv—O2—B1—O1 | −122.2 (2) |
Na1iv—O2—C3—C4 | −20.5 (5) | C3—O2—B1—O2iii | 177.0 (3) |
C1—O1—B1—O1iii | −178.0 (3) | Na1iv—O2—B1—O2iii | 0.0 |
Symmetry codes: (i) x, y, z+1; (ii) −x+2, −y, z+1; (iii) −x+2, −y, z; (iv) x, y, z−1. |
Experimental details
Crystal data | |
Chemical formula | [Na(C8H20BO4)] |
Mr | 214.04 |
Crystal system, space group | Orthorhombic, P21212 |
Temperature (K) | 98 |
a, b, c (Å) | 7.633 (3), 15.272 (6), 5.744 (2) |
V (Å3) | 669.6 (4) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.57 × 0.23 × 0.07 |
Data collection | |
Diffractometer | Bruker SMART CCD area-detector diffractometer |
Absorption correction | Multi-scan (Blessing, 1995) |
Tmin, Tmax | 0.812, 0.993 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3881, 829, 648 |
Rint | 0.068 |
(sin θ/λ)max (Å−1) | 0.624 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.056, 0.105, 1.12 |
No. of reflections | 829 |
No. of parameters | 67 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.18, −0.22 |
Computer programs: SMART (Bruker, 2001), SMART, SAINT (Bruker, 2001) and SADABS (Sheldrick, 1996), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), PLATON (Spek, 2003) and ORTEP-3 (Farrugia, 1997).
Na1—O2i | 2.250 (3) | O1—B1 | 1.466 (4) |
Na1—O1 | 2.252 (3) | O2—B1 | 1.469 (4) |
O2i—Na1—O1 | 138.18 (8) | O1ii—B1—O1 | 101.6 (3) |
O1—Na1—O1ii | 60.62 (12) | O1—B1—O2 | 113.63 (12) |
B1—O1—C1—C2 | −167.3 (3) | B1—O2—C3—C4 | 164.5 (2) |
Symmetry codes: (i) x, y, z+1; (ii) −x+2, −y, z. |
This study is part of a programme aimed at investigating boron diolates and alkoxides particularly those containing sodium cations [Cambridge Structural Database (Allen, 2002) refcodes GAKLAG (Gainsford & Kemmitt, 2004) and FEFHOO (Gainsford & Kemmitt, 2005a); Gainsford & Kemmitt, 2005b; Bishop et al., 2000]. Although borates form a range of diolate complexes (Bachelier & Verchere, 1995; Springsteen & Wang, 2002), structural data are sparse. There are no reported structures for tetraethoxyborate salts (Allen, 2002), though there are a large number of tetramethoxyborate salts reported (see Gainsford & Kemmitt, 2005b) [two guanidinium salts have since been reported, viz. FEWJOH and FEWJUN (Abrahams et al., 2005)].
The basic polymeric fragment of the title compound, (I), with asymmetric unit formula [Na0.5(C4H10B0.5O2)], has twofold crystallographic symmetry with the symmetry (c) axis passing through the Na and B atoms. The molecules crystallized in a racemically twinned crystal. Enantiomeric resolution was not expected from the synthesis or from the small anomalous dispersion effects.
The sodium cations are four-coordinate in a highly distorted tetrahedral arrangement, with mean Na—O distances of 2.251 (3) Å, and O—Na—O angles of 138.18 (8) and 60.62 (12)°. This Na—O distance is at the short end of the range of those reported when the bound O atoms are not structurally constrained; one example of the latter case is POGDAQ01 (Caselli et al., 2000), where the Na—O distances range from 2.243 to 2.355 Å in a niobium–tetraoxycalix(4)arene compound. The Na1/O1/O1C/B1 and Na1/O2A/O2B/B1B coordination planes (see Fig. 1) are at right angles [89.98 (12)°]. These parameters are at the extremes of values for four-coordinate O-bound sodium cations, with the inter-planar angles usually in the range 55–80°, for example, bis(µ2-triphenylmethoxo)dihydrido-bis(tetrahydrofuran)aluminiumsodium (JISHIC; Noth et al., 1998) with interplanar angle 64.7° and Na—O distances of 2.289–2.350 Å. When the four-coordinate arrangement approaches square planar because of the constrained O-atom geometry, the Na atoms usually have another one (or more) longer `intramolecular' contacts. making a pseudo-square-pyramidal or octahedral description more appropriate [e.g. in the calix(4)arene–sodium compound DONSAA (Bott et al., 1986), with Na—O = 2.274–2.332 Å and a fifth interaction, Na···C = 2.663 Å.] However, in some cases, the fifth available Na+ site is shielded by parts of the bound molecule, `preserving' the approximate square-planar geometry (e.g. in POGDAQ01).
The B—O and C—O bond lengths average to 1.416 (4) and 1.467 (4) Å, and the mean B—O—C angle is 117.8 (2)°, values that fall within normal ranges as reported in GAKLAG. The O—B—O angles are distorted from pure tetrahedral values (Table 1) and also compared with those in the bis(1,1,1-trihydroxymethylpropane)borate salt (XOCHOM; Zviedre & Belsky, 2001) of 108.6–109.9°. The borate anions bridge the sodium cations, forming one-dimensional polymers running along the twofold-symmetry c axis direction (Fig. 2). This packing mode was also observed in catena-[µ3bis(ethylenedioxy)borato]sodium(I) (GAKLAG), where the polymers were aligned with the 21 screw axis.