Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270101013762/gd1176sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270101013762/gd1176Isup2.hkl |
CCDC reference: 175070
For related literature, see: Albertsson et al. (1973); Archer et al. (1996); Evans et al. (2001); Kennard et al. (1982); Leiserowitz (1976); Mak et al. (1985); Prout et al. (1968, 1971); Smith et al. (1980).
A sample of powdered sodium hydrogen bis(phenoxyacetate) hydrate (Sigma–Aldrich) was dissolved in Edinburgh tap water and single crystals of sodium phenoxyacetate hemihydrate were obtained by slow evaporation of the aqueous solution.
The water H atoms were located in the difference map and their coordinates were freely refined, but their displacement parameters were treated as riding on oxygen (1.2Ueq of the bound atom). H atoms bonded to C atoms were treated as riding, with C—H distances in the range 0.95–0.99 Å.
Data collection: XSCANS (Siemens, 1996); cell refinement: XSCANS; data reduction: SHELXTL (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
Na+·C8H7O3−·0.5H2O | F(000) = 760 |
Mr = 183.13 | Dx = 1.530 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
a = 34.149 (11) Å | Cell parameters from 32 reflections |
b = 7.654 (3) Å | θ = 5.3–12.3° |
c = 6.144 (2) Å | µ = 0.16 mm−1 |
β = 98.02 (3)° | T = 160 K |
V = 1590.2 (10) Å3 | Needle, colourless |
Z = 8 | 0.74 × 0.26 × 0.05 mm |
Bruker P4 diffractometer | 1127 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.069 |
Graphite monochromator | θmax = 25.0°, θmin = 2.4° |
ω scans | h = −40→1 |
Absorption correction: ψ scan (North et al., 1968) | k = −9→1 |
Tmin = 0.719, Tmax = 0.792 | l = −7→7 |
1719 measured reflections | 3 standard reflections every 97 reflections |
1400 independent reflections | intensity decay: none |
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)] = 0.052 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.139 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.04 | w = 1/[σ2(Fo2) + (0.0816P)2 + 1.4634P] where P = (Fo2 + 2Fc2)/3 |
1400 reflections | (Δ/σ)max < 0.001 |
117 parameters | Δρmax = 0.36 e Å−3 |
0 restraints | Δρmin = −0.49 e Å−3 |
Na+·C8H7O3−·0.5H2O | V = 1590.2 (10) Å3 |
Mr = 183.13 | Z = 8 |
Monoclinic, C2/c | Mo Kα radiation |
a = 34.149 (11) Å | µ = 0.16 mm−1 |
b = 7.654 (3) Å | T = 160 K |
c = 6.144 (2) Å | 0.74 × 0.26 × 0.05 mm |
β = 98.02 (3)° |
Bruker P4 diffractometer | 1127 reflections with I > 2σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0.069 |
Tmin = 0.719, Tmax = 0.792 | 3 standard reflections every 97 reflections |
1719 measured reflections | intensity decay: none |
1400 independent reflections |
R[F2 > 2σ(F2)] = 0.052 | 0 restraints |
wR(F2) = 0.139 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.04 | Δρmax = 0.36 e Å−3 |
1400 reflections | Δρmin = −0.49 e Å−3 |
117 parameters |
Experimental. Collimator size 1.5 mm |
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 | 0.46847 (3) | 0.17124 (13) | 0.03367 (15) | 0.0158 (3) | |
O1 | 0.40157 (5) | 0.2474 (2) | 0.1427 (3) | 0.0191 (5) | |
O2 | 0.46095 (5) | 0.1196 (2) | 0.4207 (3) | 0.0176 (4) | |
O3 | 0.44708 (5) | 0.2918 (3) | 0.6954 (3) | 0.0193 (5) | |
O4 | 0.5000 | 0.4255 (4) | 0.2500 | 0.0225 (6) | |
H4 | 0.5200 (9) | 0.492 (5) | 0.247 (5) | 0.027* | |
C2 | 0.44134 (7) | 0.2340 (3) | 0.5031 (4) | 0.0142 (5) | |
C3 | 0.40562 (7) | 0.3153 (3) | 0.3616 (4) | 0.0165 (6) | |
H3A | 0.3814 | 0.2896 | 0.4273 | 0.020* | |
H3B | 0.4089 | 0.4437 | 0.3578 | 0.020* | |
C10 | 0.36439 (7) | 0.2537 (3) | 0.0232 (4) | 0.0149 (5) | |
C11 | 0.35837 (8) | 0.1527 (3) | −0.1669 (4) | 0.0192 (6) | |
H11A | 0.3796 | 0.0877 | −0.2116 | 0.023* | |
C12 | 0.32123 (8) | 0.1475 (4) | −0.2904 (4) | 0.0239 (6) | |
H12A | 0.3171 | 0.0784 | −0.4199 | 0.029* | |
C13 | 0.29003 (8) | 0.2417 (4) | −0.2277 (4) | 0.0244 (6) | |
H13A | 0.2645 | 0.2352 | −0.3115 | 0.029* | |
C14 | 0.29651 (8) | 0.3456 (4) | −0.0413 (4) | 0.0225 (6) | |
H14A | 0.2753 | 0.4118 | 0.0014 | 0.027* | |
C15 | 0.33357 (8) | 0.3539 (4) | 0.0838 (4) | 0.0194 (6) | |
H15A | 0.3379 | 0.4273 | 0.2095 | 0.023* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Na1 | 0.0206 (6) | 0.0161 (6) | 0.0109 (5) | 0.0006 (4) | 0.0027 (4) | −0.0010 (4) |
O1 | 0.0202 (9) | 0.0267 (10) | 0.0107 (9) | 0.0048 (8) | 0.0037 (7) | −0.0033 (8) |
O2 | 0.0210 (9) | 0.0157 (9) | 0.0170 (9) | 0.0031 (7) | 0.0062 (7) | 0.0026 (7) |
O3 | 0.0238 (10) | 0.0225 (10) | 0.0114 (9) | −0.0012 (8) | 0.0016 (7) | 0.0004 (7) |
O4 | 0.0324 (15) | 0.0138 (14) | 0.0232 (14) | 0.000 | 0.0107 (12) | 0.000 |
C2 | 0.0162 (12) | 0.0127 (12) | 0.0147 (12) | −0.0044 (10) | 0.0060 (10) | 0.0021 (10) |
C3 | 0.0211 (13) | 0.0178 (13) | 0.0114 (12) | 0.0019 (10) | 0.0047 (10) | −0.0009 (10) |
C10 | 0.0186 (12) | 0.0150 (12) | 0.0115 (12) | −0.0019 (10) | 0.0035 (9) | 0.0036 (10) |
C11 | 0.0261 (14) | 0.0184 (13) | 0.0142 (12) | 0.0009 (11) | 0.0067 (10) | 0.0002 (11) |
C12 | 0.0325 (15) | 0.0264 (15) | 0.0128 (13) | −0.0080 (12) | 0.0029 (11) | −0.0013 (11) |
C13 | 0.0206 (13) | 0.0323 (16) | 0.0194 (14) | −0.0057 (12) | −0.0003 (11) | 0.0037 (12) |
C14 | 0.0214 (13) | 0.0254 (15) | 0.0218 (14) | 0.0026 (11) | 0.0067 (11) | 0.0036 (12) |
C15 | 0.0228 (13) | 0.0215 (14) | 0.0139 (12) | 0.0012 (11) | 0.0033 (10) | 0.0002 (11) |
Na1—O3i | 2.298 (2) | C2—C3 | 1.528 (3) |
Na1—O2ii | 2.335 (2) | C3—H3A | 0.9900 |
Na1—O2iii | 2.420 (2) | C3—H3B | 0.9900 |
Na1—O2 | 2.459 (2) | C10—C11 | 1.392 (4) |
Na1—O4 | 2.513 (2) | C10—C15 | 1.394 (4) |
Na1—O1 | 2.537 (2) | C11—C12 | 1.385 (4) |
Na1—Na1iii | 3.179 (2) | C11—H11A | 0.9500 |
Na1—Na1iv | 3.454 (2) | C12—C13 | 1.385 (4) |
Na1—Na1ii | 4.0384 (16) | C12—H12A | 0.9500 |
O1—C10 | 1.376 (3) | C13—C14 | 1.387 (4) |
O1—C3 | 1.431 (3) | C13—H13A | 0.9500 |
O2—C2 | 1.251 (3) | C14—C15 | 1.388 (4) |
O3—C2 | 1.251 (3) | C14—H14A | 0.9500 |
O4—H4 | 0.85 (3) | C15—H15A | 0.9500 |
O3i—Na1—O2ii | 96.08 (7) | O3—C2—O2 | 127.4 (2) |
O3i—Na1—O2iii | 110.87 (7) | O3—C2—C3 | 113.6 (2) |
O2ii—Na1—O2iii | 86.86 (7) | O2—C2—C3 | 119.0 (2) |
O3i—Na1—O2 | 151.19 (7) | O1—C3—C2 | 110.6 (2) |
O2ii—Na1—O2 | 96.45 (6) | O1—C3—H3A | 109.5 |
O2iii—Na1—O2 | 95.65 (7) | C2—C3—H3A | 109.5 |
O3i—Na1—O4 | 103.07 (7) | O1—C3—H3B | 109.5 |
O2ii—Na1—O4 | 156.46 (7) | C2—C3—H3B | 109.5 |
O2iii—Na1—O4 | 73.67 (6) | H3A—C3—H3B | 108.1 |
O2—Na1—O4 | 73.01 (6) | O1—C10—C11 | 116.4 (2) |
O3i—Na1—O1 | 87.83 (7) | O1—C10—C15 | 123.5 (2) |
O2ii—Na1—O1 | 103.40 (7) | C11—C10—C15 | 120.1 (2) |
O2iii—Na1—O1 | 157.84 (7) | C12—C11—C10 | 119.5 (2) |
O2—Na1—O1 | 64.04 (6) | C12—C11—H11A | 120.3 |
O4—Na1—O1 | 91.01 (6) | C10—C11—H11A | 120.3 |
C10—O1—C3 | 116.72 (18) | C11—C12—C13 | 121.0 (3) |
C10—O1—Na1 | 131.72 (14) | C11—C12—H12A | 119.5 |
C3—O1—Na1 | 111.06 (14) | C13—C12—H12A | 119.5 |
C2—O2—Na1v | 126.13 (15) | C12—C13—C14 | 119.2 (3) |
C2—O2—Na1iii | 114.81 (16) | C12—C13—H13A | 120.4 |
Na1v—O2—Na1iii | 93.14 (7) | C14—C13—H13A | 120.4 |
C2—O2—Na1 | 114.37 (15) | C13—C14—C15 | 120.8 (3) |
Na1v—O2—Na1 | 114.75 (8) | C13—C14—H14A | 119.6 |
Na1iii—O2—Na1 | 81.32 (7) | C15—C14—H14A | 119.6 |
C2—O3—Na1vi | 134.45 (17) | C14—C15—C10 | 119.4 (2) |
Na1—O4—Na1iii | 78.48 (10) | C14—C15—H15A | 120.3 |
Na1—O4—H4 | 137 (2) | C10—C15—H15A | 120.3 |
Na1iii—O4—H4 | 101 (2) | ||
O3i—Na1—O1—C10 | 33.2 (2) | O4—Na1—O2—Na1iii | −52.29 (5) |
O2ii—Na1—O1—C10 | −62.6 (2) | O1—Na1—O2—Na1iii | −152.04 (7) |
O2iii—Na1—O1—C10 | −178.4 (2) | Na1iv—Na1—O2—Na1iii | 61.42 (7) |
O2—Na1—O1—C10 | −153.3 (2) | Na1ii—Na1—O2—Na1iii | 104.16 (5) |
O4—Na1—O1—C10 | 136.2 (2) | Na1v—Na1—O2—Na1iii | 89.47 (8) |
Na1iii—Na1—O1—C10 | −175.07 (19) | O3i—Na1—O4—Na1iii | −159.36 (7) |
Na1iv—Na1—O1—C10 | −86.3 (2) | O2ii—Na1—O4—Na1iii | −15.73 (13) |
Na1ii—Na1—O1—C10 | −29.5 (2) | O2iii—Na1—O4—Na1iii | −51.12 (5) |
Na1v—Na1—O1—C10 | −125.5 (2) | O2—Na1—O4—Na1iii | 50.23 (5) |
O3i—Na1—O1—C3 | −138.19 (16) | O1—Na1—O4—Na1iii | 112.64 (6) |
O2ii—Na1—O1—C3 | 126.07 (16) | Na1iv—Na1—O4—Na1iii | −41.18 (4) |
O2iii—Na1—O1—C3 | 10.2 (3) | Na1ii—Na1—O4—Na1iii | −92.96 (10) |
O2—Na1—O1—C3 | 35.36 (15) | Na1v—Na1—O4—Na1iii | 31.05 (3) |
O4—Na1—O1—C3 | −35.15 (16) | Na1vi—O3—C2—O2 | −35.7 (4) |
Na1iii—Na1—O1—C3 | 13.59 (16) | Na1vi—O3—C2—C3 | 143.41 (18) |
Na1iv—Na1—O1—C3 | 102.40 (18) | Na1v—O2—C2—O3 | 62.3 (3) |
Na1ii—Na1—O1—C3 | 159.13 (14) | Na1iii—O2—C2—O3 | −52.0 (3) |
Na1v—Na1—O1—C3 | 63.18 (15) | Na1—O2—C2—O3 | −143.5 (2) |
O3i—Na1—O2—C2 | −25.2 (3) | Na1v—O2—C2—C3 | −116.7 (2) |
O2ii—Na1—O2—C2 | −140.46 (14) | Na1iii—O2—C2—C3 | 128.97 (19) |
O2iii—Na1—O2—C2 | 132.08 (16) | Na1—O2—C2—C3 | 37.4 (3) |
O4—Na1—O2—C2 | 61.08 (16) | C10—O1—C3—C2 | 156.0 (2) |
O1—Na1—O2—C2 | −38.66 (16) | Na1—O1—C3—C2 | −31.3 (2) |
Na1iii—Na1—O2—C2 | 113.38 (18) | O3—C2—C3—O1 | 178.2 (2) |
Na1iv—Na1—O2—C2 | 174.80 (16) | O2—C2—C3—O1 | −2.6 (3) |
Na1ii—Na1—O2—C2 | −142.46 (15) | C3—O1—C10—C11 | −165.4 (2) |
Na1v—Na1—O2—C2 | −157.2 (2) | Na1—O1—C10—C11 | 23.6 (3) |
O3i—Na1—O2—Na1v | 131.95 (14) | C3—O1—C10—C15 | 14.5 (3) |
O2ii—Na1—O2—Na1v | 16.70 (13) | Na1—O1—C10—C15 | −156.49 (19) |
O2iii—Na1—O2—Na1v | −70.77 (9) | O1—C10—C11—C12 | 177.5 (2) |
O4—Na1—O2—Na1v | −141.76 (9) | C15—C10—C11—C12 | −2.4 (4) |
O1—Na1—O2—Na1v | 118.50 (10) | C10—C11—C12—C13 | 0.1 (4) |
Na1iii—Na1—O2—Na1v | −89.47 (8) | C11—C12—C13—C14 | 1.5 (4) |
Na1iv—Na1—O2—Na1v | −28.04 (10) | C12—C13—C14—C15 | −0.9 (4) |
Na1ii—Na1—O2—Na1v | 14.70 (11) | C13—C14—C15—C10 | −1.3 (4) |
O3i—Na1—O2—Na1iii | −138.58 (13) | O1—C10—C15—C14 | −176.9 (2) |
O2ii—Na1—O2—Na1iii | 106.17 (7) | C11—C10—C15—C14 | 3.0 (4) |
O2iii—Na1—O2—Na1iii | 18.70 (9) |
Symmetry codes: (i) x, y, z−1; (ii) x, −y, z−1/2; (iii) −x+1, y, −z+1/2; (iv) −x+1, −y, −z; (v) x, −y, z+1/2; (vi) x, y, z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
O4—H4···O3vii | 0.85 (3) | 2.00 (3) | 2.809 (3) | 157 (3) |
Symmetry code: (vii) −x+1, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | Na+·C8H7O3−·0.5H2O |
Mr | 183.13 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 160 |
a, b, c (Å) | 34.149 (11), 7.654 (3), 6.144 (2) |
β (°) | 98.02 (3) |
V (Å3) | 1590.2 (10) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 0.16 |
Crystal size (mm) | 0.74 × 0.26 × 0.05 |
Data collection | |
Diffractometer | Bruker P4 diffractometer |
Absorption correction | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.719, 0.792 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 1719, 1400, 1127 |
Rint | 0.069 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.052, 0.139, 1.04 |
No. of reflections | 1400 |
No. of parameters | 117 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.36, −0.49 |
Computer programs: XSCANS (Siemens, 1996), XSCANS, SHELXTL (Bruker, 1999), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL.
Na1—O3i | 2.298 (2) | Na1—Na1iv | 3.454 (2) |
Na1—O2ii | 2.335 (2) | Na1—Na1ii | 4.0384 (16) |
Na1—O2iii | 2.420 (2) | O1—C10 | 1.376 (3) |
Na1—O2 | 2.459 (2) | O1—C3 | 1.431 (3) |
Na1—O4 | 2.513 (2) | O2—C2 | 1.251 (3) |
Na1—O1 | 2.537 (2) | O3—C2 | 1.251 (3) |
Na1—Na1iii | 3.179 (2) | ||
O3i—Na1—O2ii | 96.08 (7) | O2iii—Na1—O4 | 73.67 (6) |
O3i—Na1—O2iii | 110.87 (7) | O2—Na1—O4 | 73.01 (6) |
O2ii—Na1—O2iii | 86.86 (7) | O3i—Na1—O1 | 87.83 (7) |
O3i—Na1—O2 | 151.19 (7) | O2ii—Na1—O1 | 103.40 (7) |
O2ii—Na1—O2 | 96.45 (6) | O2iii—Na1—O1 | 157.84 (7) |
O2iii—Na1—O2 | 95.65 (7) | O2—Na1—O1 | 64.04 (6) |
O3i—Na1—O4 | 103.07 (7) | O4—Na1—O1 | 91.01 (6) |
O2ii—Na1—O4 | 156.46 (7) |
Symmetry codes: (i) x, y, z−1; (ii) x, −y, z−1/2; (iii) −x+1, y, −z+1/2; (iv) −x+1, −y, −z. |
D—H···A | D—H | H···A | D···A | D—H···A |
O4—H4···O3v | 0.85 (3) | 2.00 (3) | 2.809 (3) | 157 (3) |
Symmetry code: (v) −x+1, −y+1, −z+1. |
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The structure of the title compound, (I), was first solved by X-ray photography (R = 0.096; Prout et al., 1971) and has now been redetermined at 160 K (R = 0.052) during an investigation of the impact of impurities on the crystallization of phenoxyacetic acid. The structure consists of a ribbon-like Na–O core, running parallel to the [001] direction, which is bridged above and below by water molecules. As in the acid salt (Evans et al., 2001), the phenyl groups form hydrocarbon layers on the outside of the Na–O ribbon. The ribbon consists of sodium ions surrounded by six O atoms in a distorted octahedral arrangement. The shortest Na···Na bridging distances [range 3.179 (2)–4.0384 (16) Å] are similar to those reported for other bridging systems (Albertsson, 1973).
Hydrates of other metal salts of phenoxyacetate have been determined. Some, like the sodium salt, are oligomeric, namely the lead (Archer et al., 1996; Mak et al., 1985) magnesium and cobalt salts (Smith et al., 1980), whereas the cadmium (Mak et al., 1985) and copper (Prout et al., 1968) derivatives contain discrete units.
Two structural features were identified in the CO2- group in the title compound. First, the distortion of the exo-C1 angles C15–C10–O1 and C11–C10–O1 [123.3 (2) and 116.4 (2)°, respectively], which deviate from the trigonal angle (120°). The distortion is caused by the steric requirements of the side chain and is found throughout the phenoxyalkanoic acid series (Kennard et al., 1982; Evans et al., 2001). Secondly, the C—O distances for both C2—O3 and C2—O2 are identical [1.251 (3) Å], and the former of the O3–C2–C3 and O2–C2–C3 angles [113.6 (2) and 119.0 (2) Å] deviates from the trigonal value. In disordered carboxylic acid groups (Leiserowitz, 1976), both bond lengths are also the same, but the O—C—C angles are both close to 120°. In the title compound, the similarity in C—O distances arises because the CO2- group is delocalized. However, the O2 and O3 atoms do not have similar environments, as O3 is involved in a hydrogen bond with water (see Table 2) and O2 is not. In contrast, O2 has many more contacts with sodium ions (see Table 1) as it is orientated into the NaO core.