Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270105027484/fa1149sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270105027484/fa1149Isup2.hkl |
CCDC reference: 288618
Single crystals of triaquabenzoatocalcium(II)]monobenzoate suitable for X-ray analysis were obtained by slow evaporation at room temperature of an aqueous solution containing CaCl2 and potassium benzoate.
The structure was solved by direct and difference-Fourier methods, and refined by the full-matrix least-squares method. All H atoms were found in ΔF maps, but those connected to C atoms were placed in calculated positions and refined using a riding model, with C—H = 0.93 Å and Uiso(H) = 1.3Ueq(C). Water H atoms were refined isotropically.
Data collection: IPDS (Stoe & Cie, 1996); cell refinement: IPDS; data reduction: IPDS; program(s) used to solve structure: SHELXS86 (Sheldrick, 1985); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Johnson & Burnett, 1997); software used to prepare material for publication: SHELXL97.
[Ca(C7H5O2)(H2O)3](C7H5O2) | F(000) = 704 |
Mr = 336.35 | Dx = 1.452 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 11074 reflections |
a = 7.3004 (10) Å | θ = 2.5–25.9° |
b = 32.252 (4) Å | µ = 0.44 mm−1 |
c = 6.5364 (7) Å | T = 293 K |
β = 91.145 (15)° | Needles, colourless |
V = 1538.7 (3) Å3 | 0.38 × 0.15 × 0.04 mm |
Z = 4 |
Stoe IPDS diffractometer | 2256 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.038 |
Graphite monochromator | θmax = 25.9°, θmin = 2.5° |
ϕ scans | h = −8→8 |
12022 measured reflections | k = −39→39 |
2838 independent reflections | l = −7→7 |
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)] = 0.027 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.063 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.97 | w = 1/[σ2(Fo2) + (0.036P)2] where P = (Fo2 + 2Fc2)/3 |
2838 reflections | (Δ/σ)max = 0.002 |
223 parameters | Δρmax = 0.25 e Å−3 |
0 restraints | Δρmin = −0.17 e Å−3 |
[Ca(C7H5O2)(H2O)3](C7H5O2) | V = 1538.7 (3) Å3 |
Mr = 336.35 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 7.3004 (10) Å | µ = 0.44 mm−1 |
b = 32.252 (4) Å | T = 293 K |
c = 6.5364 (7) Å | 0.38 × 0.15 × 0.04 mm |
β = 91.145 (15)° |
Stoe IPDS diffractometer | 2256 reflections with I > 2σ(I) |
12022 measured reflections | Rint = 0.038 |
2838 independent reflections |
R[F2 > 2σ(F2)] = 0.027 | 0 restraints |
wR(F2) = 0.063 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.97 | Δρmax = 0.25 e Å−3 |
2838 reflections | Δρmin = −0.17 e Å−3 |
223 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. Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane) - 7.0664 (0.0023) x + 1.8491 (0.0230) y − 1.4714 (0.0048) z = 0.2409 (0.0140) * 0.0020 (0.0011) C1 * −0.0035 (0.0012) C2 * 0.0015 (0.0014) C3 * 0.0019 (0.0014) C4 * −0.0033 (0.0014) C5 * 0.0013 (0.0013) C6 Rms deviation of fitted atoms = 0.0024 − 7.2146 (0.0025) x + 2.4806 (0.0816) y − 0.7344 (0.0047) z = 0.5039 (0.0576) Angle to previous plane (with approximate e.s.d.) = 6.64 (0.06) * 0.0000 (0.0000) C7 * 0.0000 (0.0000) O7A * 0.0000 (0.0000) O7B Rms deviation of fitted atoms = 0.0000 7.2737 (0.0020) x + 0.3814 (0.0896) y + 0.4228 (0.0049) z = 5.4692 (0.0737) * 0.0000 (0.0000) C17 * 0.0000 (0.0000) O17A * 0.0000 (0.0000) O17B 7.0608 (0.0024) x + 2.4048 (0.0246) y + 1.4612 (0.0052) z = 7.3596 (0.0225) Angle to previous plane (with approximate e.s.d.) = 9.91 (0.05) * −0.0038 (0.0012) C11 * 0.0019 (0.0013) C12 * 0.0004 (0.0014) C13 * −0.0008 (0.0015) C14 * −0.0012 (0.0015) C15 * 0.0034 (0.0013) C16 Rms deviation of fitted atoms = 0.0023 7.0664 (0.0023) x + 1.8491 (0.0231) y + 1.4714 (0.0049) z = 3.2684 (0.0207) Angle to previous plane (with approximate e.s.d.) = 0.99 (0.06) * −0.0020 (0.0011) C1 * 0.0035 (0.0012) C2 * −0.0015 (0.0014) C3 * −0.0019 (0.0014) C4 * 0.0033 (0.0014) C5 * −0.0013 (0.0013) C6 Rms deviation of fitted atoms = 0.0024 7.0608 (0.0024) x + 2.4048 (0.0246) y + 1.4612 (0.0052) z = 7.3596 (0.0225) * −0.0038 (0.0012) C11 * 0.0019 (0.0013) C12 * 0.0004 (0.0014) C13 * −0.0008 (0.0015) C14 * −0.0012 (0.0015) C15 * 0.0034 (0.0013) C16 − 3.6193 (0.0025) C1 − 3.6048 (0.0031) C2 − 3.5860 (0.0030) C3 − 3.5716 (0.0027) C4 − 3.5751 (0.0024) C5 − 3.6035 (0.0023) C6 Rms deviation of fitted atoms = 0.0023 |
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 | ||
Ca1 | 0.26210 (4) | 0.726062 (8) | 0.29568 (5) | 0.02316 (9) | |
C1 | 0.17204 (19) | 0.86040 (4) | 0.3124 (2) | 0.0282 (3) | |
C2 | 0.1297 (2) | 0.87945 (5) | 0.4953 (3) | 0.0386 (4) | |
H2 | 0.1107 | 0.8635 | 0.6115 | 0.050* | |
C3 | 0.1157 (3) | 0.92224 (5) | 0.5055 (3) | 0.0531 (5) | |
H3 | 0.0864 | 0.9349 | 0.6284 | 0.069* | |
C4 | 0.1449 (3) | 0.94603 (5) | 0.3351 (4) | 0.0564 (6) | |
H4 | 0.1353 | 0.9747 | 0.3426 | 0.073* | |
C5 | 0.1884 (3) | 0.92741 (5) | 0.1535 (4) | 0.0553 (5) | |
H5 | 0.2090 | 0.9436 | 0.0385 | 0.072* | |
C6 | 0.2016 (2) | 0.88456 (5) | 0.1406 (3) | 0.0411 (4) | |
H6 | 0.2302 | 0.8721 | 0.0171 | 0.053* | |
C7 | 0.18634 (19) | 0.81405 (4) | 0.3002 (2) | 0.0238 (3) | |
O7A | 0.17715 (15) | 0.79293 (3) | 0.46184 (16) | 0.0315 (2) | |
O7B | 0.20950 (15) | 0.79679 (3) | 0.13105 (16) | 0.0329 (3) | |
C11 | 0.6858 (2) | 0.88771 (4) | 0.2591 (3) | 0.0305 (3) | |
C12 | 0.6439 (2) | 0.91208 (5) | 0.4256 (3) | 0.0413 (4) | |
H12 | 0.6227 | 0.8997 | 0.5514 | 0.054* | |
C13 | 0.6329 (3) | 0.95486 (5) | 0.4071 (4) | 0.0557 (5) | |
H13 | 0.6040 | 0.9709 | 0.5202 | 0.072* | |
C14 | 0.6644 (3) | 0.97351 (6) | 0.2235 (4) | 0.0614 (6) | |
H14 | 0.6570 | 1.0022 | 0.2116 | 0.080* | |
C15 | 0.7070 (3) | 0.94980 (6) | 0.0565 (4) | 0.0606 (6) | |
H15 | 0.7281 | 0.9625 | −0.0686 | 0.079* | |
C16 | 0.7187 (3) | 0.90682 (5) | 0.0738 (3) | 0.0450 (4) | |
H16 | 0.7487 | 0.8909 | −0.0395 | 0.059* | |
C17 | 0.69162 (19) | 0.84098 (4) | 0.2786 (2) | 0.0269 (3) | |
O17A | 0.70218 (15) | 0.82019 (3) | 0.11567 (18) | 0.0361 (3) | |
O17B | 0.68227 (16) | 0.82526 (3) | 0.45358 (18) | 0.0364 (3) | |
O1 | 0.51237 (15) | 0.75169 (3) | 0.53670 (17) | 0.0302 (2) | |
O2 | 0.45748 (17) | 0.66682 (3) | 0.2878 (2) | 0.0333 (3) | |
O3 | −0.05469 (19) | 0.70475 (6) | 0.2976 (3) | 0.0579 (4) | |
H1A | 0.581 (3) | 0.7723 (6) | 0.503 (3) | 0.052 (6)* | |
H1B | 0.579 (3) | 0.7328 (6) | 0.574 (3) | 0.050 (6)* | |
H2A | 0.519 (3) | 0.6651 (6) | 0.186 (4) | 0.053 (6)* | |
H2B | 0.535 (3) | 0.6655 (6) | 0.385 (4) | 0.063 (7)* | |
H3A | −0.108 (3) | 0.6995 (7) | 0.399 (4) | 0.073 (8)* | |
H3B | −0.111 (4) | 0.7006 (8) | 0.196 (5) | 0.094 (10)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Ca1 | 0.03273 (15) | 0.02336 (14) | 0.01341 (16) | 0.00075 (12) | 0.00124 (10) | 0.00002 (11) |
C1 | 0.0278 (7) | 0.0283 (7) | 0.0284 (10) | −0.0040 (6) | −0.0013 (6) | 0.0014 (6) |
C2 | 0.0475 (10) | 0.0328 (8) | 0.0354 (11) | −0.0058 (7) | −0.0014 (7) | 0.0059 (7) |
C3 | 0.0600 (12) | 0.0398 (9) | 0.0593 (15) | −0.0069 (8) | −0.0058 (10) | 0.0219 (9) |
C4 | 0.0613 (12) | 0.0249 (8) | 0.0827 (19) | −0.0007 (8) | −0.0102 (11) | 0.0044 (9) |
C5 | 0.0669 (13) | 0.0324 (9) | 0.0667 (17) | 0.0032 (8) | 0.0004 (10) | −0.0145 (9) |
C6 | 0.0504 (10) | 0.0343 (8) | 0.0386 (12) | −0.0021 (7) | 0.0037 (8) | −0.0046 (7) |
C7 | 0.0245 (7) | 0.0268 (7) | 0.0200 (9) | −0.0042 (5) | 0.0003 (5) | 0.0001 (6) |
O7A | 0.0481 (6) | 0.0299 (5) | 0.0165 (6) | −0.0079 (4) | 0.0008 (4) | −0.0024 (4) |
O7B | 0.0509 (7) | 0.0315 (5) | 0.0163 (6) | −0.0058 (5) | 0.0044 (5) | 0.0030 (4) |
C11 | 0.0306 (7) | 0.0275 (7) | 0.0333 (10) | 0.0038 (6) | −0.0022 (6) | −0.0021 (6) |
C12 | 0.0485 (10) | 0.0324 (8) | 0.0431 (12) | −0.0020 (7) | 0.0006 (8) | 0.0008 (7) |
C13 | 0.0633 (12) | 0.0317 (9) | 0.0722 (17) | −0.0067 (8) | 0.0013 (10) | 0.0065 (9) |
C14 | 0.0647 (13) | 0.0295 (9) | 0.0895 (19) | −0.0016 (8) | −0.0059 (12) | −0.0102 (10) |
C15 | 0.0725 (14) | 0.0450 (11) | 0.0642 (17) | 0.0105 (10) | −0.0043 (11) | −0.0254 (10) |
C16 | 0.0543 (11) | 0.0410 (9) | 0.0396 (13) | 0.0104 (8) | −0.0012 (8) | −0.0070 (8) |
C17 | 0.0267 (7) | 0.0285 (7) | 0.0256 (10) | 0.0041 (5) | 0.0025 (6) | 0.0010 (6) |
O17A | 0.0465 (7) | 0.0342 (6) | 0.0278 (7) | 0.0047 (5) | 0.0038 (5) | 0.0057 (5) |
O17B | 0.0523 (7) | 0.0303 (5) | 0.0268 (7) | 0.0023 (5) | 0.0073 (5) | −0.0033 (5) |
O1 | 0.0343 (6) | 0.0258 (5) | 0.0304 (7) | −0.0005 (5) | 0.0006 (5) | 0.0002 (4) |
O2 | 0.0426 (7) | 0.0339 (6) | 0.0233 (8) | 0.0048 (5) | 0.0028 (6) | 0.0003 (5) |
O3 | 0.0386 (8) | 0.1092 (12) | 0.0261 (10) | −0.0179 (7) | 0.0041 (6) | 0.0006 (8) |
Ca1—O7Ai | 2.3383 (11) | C7—O7A | 1.2598 (18) |
Ca1—O7Bii | 2.3516 (11) | C11—C12 | 1.382 (2) |
Ca1—O2 | 2.3855 (12) | C11—C16 | 1.384 (2) |
Ca1—O3 | 2.4129 (14) | C11—C17 | 1.513 (2) |
Ca1—O7A | 2.4985 (10) | C12—C13 | 1.387 (2) |
Ca1—O1 | 2.5275 (12) | C12—H12 | 0.9300 |
Ca1—O7B | 2.5481 (11) | C13—C14 | 1.366 (3) |
Ca1—O1i | 2.6158 (12) | C13—H13 | 0.9300 |
Ca1—Ca1ii | 3.6146 (4) | C14—C15 | 1.373 (3) |
C1—C2 | 1.385 (2) | C14—H14 | 0.9300 |
C1—C6 | 1.387 (2) | C15—C16 | 1.393 (2) |
C1—C7 | 1.5010 (19) | C15—H15 | 0.9300 |
C2—C3 | 1.386 (2) | C16—H16 | 0.9300 |
C2—H2 | 0.9300 | C17—O17B | 1.2543 (19) |
C3—C4 | 1.373 (3) | C17—O17A | 1.2619 (19) |
C3—H3 | 0.9300 | O1—H1A | 0.86 (2) |
C4—C5 | 1.373 (3) | O1—H1B | 0.82 (2) |
C4—H4 | 0.9300 | O2—H2A | 0.81 (2) |
C5—C6 | 1.388 (2) | O2—H2B | 0.84 (3) |
C5—H5 | 0.9300 | O3—H3A | 0.79 (3) |
C6—H6 | 0.9300 | O3—H3B | 0.79 (3) |
C7—O7B | 1.2523 (18) | ||
O7Ai—Ca1—O7Bii | 137.96 (4) | C3—C4—H4 | 120.0 |
O7Ai—Ca1—O2 | 85.28 (4) | C4—C5—C6 | 120.36 (18) |
O7Bii—Ca1—O2 | 82.98 (4) | C4—C5—H5 | 119.8 |
O7Ai—Ca1—O3 | 72.17 (5) | C6—C5—H5 | 119.8 |
O7Bii—Ca1—O3 | 74.43 (5) | C1—C6—C5 | 119.88 (17) |
O2—Ca1—O3 | 110.21 (5) | C1—C6—H6 | 120.1 |
O7Ai—Ca1—O7A | 124.63 (4) | C5—C6—H6 | 120.1 |
O7Bii—Ca1—O7A | 79.56 (4) | Ca1i—O7B—Ca1 | 94.99 (3) |
O2—Ca1—O7A | 148.70 (4) | C12—C11—C16 | 118.74 (14) |
O3—Ca1—O7A | 89.85 (5) | C12—C11—C17 | 120.44 (15) |
O7Ai—Ca1—O1 | 147.38 (4) | C16—C11—C17 | 120.81 (15) |
O7Bii—Ca1—O1 | 69.57 (4) | C11—C12—C13 | 120.69 (18) |
O2—Ca1—O1 | 81.39 (4) | C11—C12—H12 | 119.7 |
O3—Ca1—O1 | 140.44 (5) | C13—C12—H12 | 119.7 |
O7A—Ca1—O1 | 68.25 (4) | C14—C13—C12 | 120.3 (2) |
O7Ai—Ca1—O7B | 78.79 (4) | C14—C13—H13 | 119.9 |
O7Bii—Ca1—O7B | 130.41 (4) | C12—C13—H13 | 119.9 |
O2—Ca1—O7B | 142.48 (4) | C13—C14—C15 | 119.86 (17) |
O3—Ca1—O7B | 96.94 (5) | C13—C14—H14 | 120.1 |
O7A—Ca1—O7B | 51.26 (3) | C15—C14—H14 | 120.1 |
O1—Ca1—O7B | 94.09 (4) | C14—C15—C16 | 120.3 (2) |
O7Ai—Ca1—O1i | 69.12 (4) | C14—C15—H15 | 119.9 |
O7Bii—Ca1—O1i | 144.93 (4) | C16—C15—H15 | 119.9 |
O2—Ca1—O1i | 77.30 (4) | C11—C16—C15 | 120.16 (19) |
O3—Ca1—O1i | 139.76 (5) | C11—C16—H16 | 119.9 |
O7A—Ca1—O1i | 103.13 (4) | C15—C16—H16 | 119.9 |
O1—Ca1—O1i | 78.93 (3) | O17B—C17—O17A | 124.06 (13) |
O7B—Ca1—O1i | 65.32 (3) | O17B—C17—C11 | 118.51 (13) |
Ca1ii—Ca1—Ca1i | 129.422 (16) | O17A—C17—C11 | 117.41 (14) |
C2—C1—C6 | 119.40 (14) | Ca1—O1—H1A | 120.5 (14) |
C2—C1—C7 | 120.30 (14) | Ca1ii—O1—H1A | 111.7 (13) |
C6—C1—C7 | 120.30 (14) | Ca1—O1—H1B | 111.4 (14) |
C1—C2—C3 | 120.08 (17) | Ca1ii—O1—H1B | 115.6 (15) |
C1—C2—H2 | 120.0 | H1A—O1—H1B | 107.9 (19) |
C3—C2—H2 | 120.0 | Ca1—O2—H2A | 114.4 (14) |
C4—C3—C2 | 120.33 (19) | Ca1—O2—H2B | 114.6 (15) |
C4—C3—H3 | 119.8 | H2A—O2—H2B | 104 (2) |
C2—C3—H3 | 119.8 | Ca1—O3—H3A | 123.3 (19) |
C5—C4—C3 | 119.96 (16) | Ca1—O3—H3B | 122 (2) |
C5—C4—H4 | 120.0 | H3A—O3—H3B | 115 (3) |
Symmetry codes: (i) x, −y+3/2, z−1/2; (ii) x, −y+3/2, z+1/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1A···O17B | 0.86 (2) | 1.89 (2) | 2.7370 (15) | 165.9 (18) |
O1—H1B···O17Aii | 0.82 (2) | 1.95 (2) | 2.7445 (15) | 165.8 (19) |
O2—H2B···O17Aii | 0.84 (3) | 1.98 (3) | 2.7939 (19) | 163 (2) |
O2—H2A···O17Bi | 0.81 (2) | 1.97 (2) | 2.7705 (18) | 166.4 (19) |
O3—H3A···O17Aiii | 0.79 (3) | 2.10 (3) | 2.875 (2) | 166 (3) |
O3—H3B···O17Biv | 0.79 (3) | 2.32 (3) | 3.083 (2) | 164 (3) |
Symmetry codes: (i) x, −y+3/2, z−1/2; (ii) x, −y+3/2, z+1/2; (iii) x−1, −y+3/2, z+1/2; (iv) x−1, −y+3/2, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | [Ca(C7H5O2)(H2O)3](C7H5O2) |
Mr | 336.35 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 293 |
a, b, c (Å) | 7.3004 (10), 32.252 (4), 6.5364 (7) |
β (°) | 91.145 (15) |
V (Å3) | 1538.7 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.44 |
Crystal size (mm) | 0.38 × 0.15 × 0.04 |
Data collection | |
Diffractometer | Stoe IPDS diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 12022, 2838, 2256 |
Rint | 0.038 |
(sin θ/λ)max (Å−1) | 0.615 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.027, 0.063, 0.97 |
No. of reflections | 2838 |
No. of parameters | 223 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.25, −0.17 |
Computer programs: IPDS (Stoe & Cie, 1996), IPDS, SHELXS86 (Sheldrick, 1985), SHELXL97 (Sheldrick, 1997), ORTEPIII (Johnson & Burnett, 1997), SHELXL97.
Ca1—O7Ai | 2.3383 (11) | Ca1—O7B | 2.5481 (11) |
Ca1—O7Bii | 2.3516 (11) | Ca1—O1i | 2.6158 (12) |
Ca1—O2 | 2.3855 (12) | C7—O7B | 1.2523 (18) |
Ca1—O3 | 2.4129 (14) | C7—O7A | 1.2598 (18) |
Ca1—O7A | 2.4985 (10) | C17—O17B | 1.2543 (19) |
Ca1—O1 | 2.5275 (12) | C17—O17A | 1.2619 (19) |
O7Ai—Ca1—O7Bii | 137.96 (4) | O7A—Ca1—O1 | 68.25 (4) |
O7Ai—Ca1—O2 | 85.28 (4) | O7Ai—Ca1—O7B | 78.79 (4) |
O7Bii—Ca1—O2 | 82.98 (4) | O7Bii—Ca1—O7B | 130.41 (4) |
O7Ai—Ca1—O3 | 72.17 (5) | O2—Ca1—O7B | 142.48 (4) |
O7Bii—Ca1—O3 | 74.43 (5) | O3—Ca1—O7B | 96.94 (5) |
O2—Ca1—O3 | 110.21 (5) | O7A—Ca1—O7B | 51.26 (3) |
O7Ai—Ca1—O7A | 124.63 (4) | O1—Ca1—O7B | 94.09 (4) |
O7Bii—Ca1—O7A | 79.56 (4) | O7Ai—Ca1—O1i | 69.12 (4) |
O2—Ca1—O7A | 148.70 (4) | O7Bii—Ca1—O1i | 144.93 (4) |
O3—Ca1—O7A | 89.85 (5) | O2—Ca1—O1i | 77.30 (4) |
O7Ai—Ca1—O1 | 147.38 (4) | O3—Ca1—O1i | 139.76 (5) |
O7Bii—Ca1—O1 | 69.57 (4) | O7A—Ca1—O1i | 103.13 (4) |
O2—Ca1—O1 | 81.39 (4) | O1—Ca1—O1i | 78.93 (3) |
O3—Ca1—O1 | 140.44 (5) | O7B—Ca1—O1i | 65.32 (3) |
Symmetry codes: (i) x, −y+3/2, z−1/2; (ii) x, −y+3/2, z+1/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1A···O17B | 0.86 (2) | 1.89 (2) | 2.7370 (15) | 165.9 (18) |
O1—H1B···O17Aii | 0.82 (2) | 1.95 (2) | 2.7445 (15) | 165.8 (19) |
O2—H2B···O17Aii | 0.84 (3) | 1.98 (3) | 2.7939 (19) | 163 (2) |
O2—H2A···O17Bi | 0.81 (2) | 1.97 (2) | 2.7705 (18) | 166.4 (19) |
O3—H3A···O17Aiii | 0.79 (3) | 2.10 (3) | 2.875 (2) | 166 (3) |
O3—H3B···O17Biv | 0.79 (3) | 2.32 (3) | 3.083 (2) | 164 (3) |
Symmetry codes: (i) x, −y+3/2, z−1/2; (ii) x, −y+3/2, z+1/2; (iii) x−1, −y+3/2, z+1/2; (iv) x−1, −y+3/2, z−1/2. |
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This study is part of a systematic structural investigation of complexes of aromatic carboxylic acids and alkaline earth metals (Ca, Sr and Ba) in aqueous solution. A wide variety of coordination modes, polymeric arrangements and molecular topologies have been observed, depending on the metal, pH and other synthetic conditions. For calcium with the benzoate anion, three compounds have been reported, namely [Ca(C6H5COO)2]·3H2O (from neutral solution), [Ca(C6H5COO)2]·0.5C6H5COO·2H2O (from acid solution; Cherkezova et al., 1987) and [Ca(C6H5COO)2] (hydrothermal conditions; Keli et al., 1999).
In spite of the wide application of calcium benzoate (for example, as a preservative in the food industry), the crystal structure of this compound has been poorly investigated. Cherkezova et al. (1987) studied the syntheses and thermal stabilities of Mg, Ca, Sr and Ba benzoates and determined only the space group and cell parameters of [Ca(C6H5COO)2]·3H2O. Here, we describe the crystal structure of [Ca(C6H5COO)](C6H5COO)·3H2O, triaquabenzoatocalcium(II) monobenzoate, (I).
The asymmetric unit of (I) consists of one Ca centre, two benzoate anions and three water molecules. The Ca atom is coordinated in a distorted square-antiprismatic geometry by two monodentate carboxylate groups of different benzoate moieties, one bidentate carboxylate and four water molecules. Indeed, the atoms that form square faces [O2/O7Ai/O3/O7Bi and O1/O1i/O7B/O7A; symmetry code: (i) ? Please provide symmetry code] deviate from a square-planar geometry and the coordination polyhedra could alternatively be described as an irregular trigonal dodecahedron. The coordination geometry around the Ca atom cannot be assigned unequivocally to one of these ideal structures due to strong distortion (Fig. 1). The Ca—O bond lengths vary from 2.338 (1) to 2.616 (1) Å (Table 1).
The independent benzoate entities play distinct structural roles. One type (atoms C1–C7/O7A/O7B) acts as a ligand to two Ca atoms, bridging them to give polymeric [Ca(C6H5COO)(H2O)3]+∞ chains running parallel to the c axis (Fig. 1). The carboxylate group (O7A/C7/O7B) of these anions is almost coplanar with the phenyl ring [dihedral angle 6.64 (6)°].
The second type of benzoate anions (atoms C11–C17/O17A/O17B) is present in an isolated form and is not linked to the chain by covalent bonds (Figs. 1 and 2). These anions are linked to the chain by strong hydrogen bonds between the carboxyl group (O17A/C17/O17B) and water molecules (Table 2). All aqua ligands act as hydrogen-bond donors, and atoms O17A and O17B of the carboxylate group are hydrogen-bond acceptors.
Neighbouring phenyl groups are stacked nearly parallel along the a axis. The interplanar distance between the phenyl rings C1–C6 and C11–C16 is 3.593 (4) Å. The dihedral angle is 0.99 (6)° and the shortest atom-to-atom distance between these two rings is 3.596 (1) Å. This distance lies in the normal range of 3.3–3.8 Å (Janiak, 2000), indicative of π–π interaction.
The combination of these hydrogen bonds, π–π stacking interactions and Ca—O bonds leads to the formation of a two-dimensional network running parallel to the ac plane (Fig 2).