metal-organic compounds
Diaquabis(L-lactato)magnesium
aCrystal Engineering Division, Center of Applied Solid State Chemistry Research, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China
*Correspondence e-mail: Zhuhonglin1@nbu.edu.cn
In the title compound, [Mg(C3H4O3)2(H2O)2], the Mg2+ cation is six-coordinated by four O atoms from two lactate anions and two aqua ligands, completing an MgO6 distorted octahedral geometry. The complex molecules are bridged by O—H⋯O hydrogen-bonding interactions into helical chains parallel to the a axis, which are linked by further O—H⋯O interactions, forming a three-dimensional supramolecular architecture.
Related literature
For related compounds, see: Carballo et al. (2007); Chen et al. (2000); Qiu et al. (2010); Zeng et al. (2010).
Experimental
Crystal data
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Refinement
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Data collection: RAPID-AUTO (Rigaku, 1998); cell RAPID-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97.
Supporting information
https://doi.org/10.1107/S1600536812028723/aa2062sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536812028723/aa2062Isup2.hkl
Boric acid (1 mmol) and L-lactic acid (1 mmol) were dissolved in 10 ml distilled water. Magnesium hydroxide (0.5 mmol) was then added. The resulting suspension was stirred for 30 min and subsequently the white insoluble solid was filtered out. The colourless filtrate was finally kept at room temperature. After slow evaporation for two months colourless block-like crystals of the title complex were obtained. According to X-ray
boric acid did not participate in the complex formation.H atoms bonded to C atoms were placed in geometrically calculated position and were refined using a riding model, with Uiso(H) = 1.2 Ueq(C). H atoms attached to O atoms were found in a difference Fourier synthesis and were refined with the O—H distance restrained to 0.83 (2) Å and Uiso(H) = 1.2 Ueq(O).
In the past decades, more attention have been paid to design and rational synthesis of coordination polymers based on self-assemblies of metal ions with lactic acid. The crystal structures of a number of metal lactates and their complexes have been reported (Carballo et al., 2007; Chen et al., 2000; Qiu et al., 2010; Zeng et al., 2010).
In the
of the the title compound, Mg(H2O)2(C3H4O3)2, the Mg2+ cation is chelated by two lactate anions bound through the carboxylate and hydroxyl groups. The other two sites are occupied by water molecules forming MgO6 distorted octahedral geometry (Fig. 1). The complexes greatly favor strong hydrogen bonding in the crystalline state. The hydroxyl group O3—H3D of the lactate ligand forms a hydrogen bond with the carboxylate atom O5i of a symmetry-related lactate anion (Table 1). This hydrogen bonding interaction leads to assemble the complexes into one-dimensional helical chain parallel to the a axis (Fig. 2). Other H-bonds link chains forming the three-dimensional architecture (Fig. 3).For related compounds, see: Carballo et al. (2007); Chen et al. (2000); Qiu et al. (2010); Zeng et al. (2010).
Data collection: RAPID-AUTO (Rigaku, 1998); cell
RAPID-AUTO (Rigaku, 1998); data reduction: CrystalStructure (Rigaku/MSC, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).[Mg(C3H4O3)2(H2O)2] | F(000) = 504 |
Mr = 238.48 | Dx = 1.512 Mg m−3 |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 8276 reflections |
a = 6.0525 (12) Å | θ = 3.3–27.4° |
b = 11.919 (2) Å | µ = 0.19 mm−1 |
c = 14.526 (3) Å | T = 293 K |
V = 1047.9 (4) Å3 | Block, colourless |
Z = 4 | 0.28 × 0.20 × 0.16 mm |
Rigaku R-AXIS RAPID diffractometer | 1401 independent reflections |
Radiation source: fine-focus sealed tube | 1208 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.033 |
Detector resolution: 0 pixels mm-1 | θmax = 27.4°, θmin = 3.3° |
ω scans | h = −7→7 |
Absorption correction: multi-scan (ABSCOR; Higashi, 1995) | k = −15→15 |
Tmin = 0.955, Tmax = 0.970 | l = −18→18 |
10148 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)] = 0.029 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.074 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.14 | w = 1/[σ2(Fo2) + (0.0268P)2 + 0.4768P] where P = (Fo2 + 2Fc2)/3 |
1401 reflections | (Δ/σ)max < 0.001 |
154 parameters | Δρmax = 0.25 e Å−3 |
8 restraints | Δρmin = −0.27 e Å−3 |
[Mg(C3H4O3)2(H2O)2] | V = 1047.9 (4) Å3 |
Mr = 238.48 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 6.0525 (12) Å | µ = 0.19 mm−1 |
b = 11.919 (2) Å | T = 293 K |
c = 14.526 (3) Å | 0.28 × 0.20 × 0.16 mm |
Rigaku R-AXIS RAPID diffractometer | 1401 independent reflections |
Absorption correction: multi-scan (ABSCOR; Higashi, 1995) | 1208 reflections with I > 2σ(I) |
Tmin = 0.955, Tmax = 0.970 | Rint = 0.033 |
10148 measured reflections |
R[F2 > 2σ(F2)] = 0.029 | 8 restraints |
wR(F2) = 0.074 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.14 | Δρmax = 0.25 e Å−3 |
1401 reflections | Δρmin = −0.27 e Å−3 |
154 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 | ||
Mg | 0.21037 (13) | 0.35509 (7) | 0.85604 (5) | 0.02010 (19) | |
O1 | 0.5170 (3) | 0.33271 (14) | 0.79415 (13) | 0.0267 (4) | |
O2 | 0.7174 (3) | 0.21637 (14) | 0.70818 (13) | 0.0317 (4) | |
C1 | 0.5540 (4) | 0.2377 (2) | 0.75825 (17) | 0.0236 (5) | |
C2 | 0.3907 (4) | 0.1430 (2) | 0.77760 (17) | 0.0252 (5) | |
H2A | 0.4712 | 0.0786 | 0.8028 | 0.030* | |
O3 | 0.2403 (3) | 0.18383 (14) | 0.84555 (13) | 0.0295 (4) | |
H3D | 0.146 (4) | 0.1355 (19) | 0.860 (2) | 0.035* | |
C3 | 0.2705 (5) | 0.1069 (2) | 0.6913 (2) | 0.0358 (7) | |
H3A | 0.1694 | 0.0474 | 0.7059 | 0.054* | |
H3B | 0.3756 | 0.0809 | 0.6466 | 0.054* | |
H3C | 0.1901 | 0.1695 | 0.6665 | 0.054* | |
O4 | 0.3478 (3) | 0.36013 (14) | 0.98528 (11) | 0.0269 (4) | |
O5 | 0.4302 (4) | 0.46441 (16) | 1.10705 (14) | 0.0414 (6) | |
C4 | 0.3553 (4) | 0.4525 (2) | 1.02739 (18) | 0.0244 (5) | |
C5 | 0.2663 (5) | 0.5563 (2) | 0.97857 (17) | 0.0274 (6) | |
H5A | 0.3796 | 0.6150 | 0.9800 | 0.033* | |
O6 | 0.2256 (3) | 0.52574 (13) | 0.88475 (12) | 0.0253 (4) | |
H6D | 0.236 (5) | 0.5821 (15) | 0.8526 (16) | 0.030* | |
C6 | 0.0595 (6) | 0.6001 (3) | 1.0249 (2) | 0.0517 (9) | |
H6A | 0.0080 | 0.6655 | 0.9929 | 0.078* | |
H6B | 0.0922 | 0.6192 | 1.0876 | 0.078* | |
H6C | −0.0528 | 0.5432 | 1.0235 | 0.078* | |
O7 | 0.0543 (3) | 0.37074 (16) | 0.73217 (12) | 0.0292 (4) | |
H7A | −0.052 (3) | 0.3289 (19) | 0.7204 (19) | 0.035* | |
H7B | 0.062 (5) | 0.4195 (17) | 0.6915 (15) | 0.035* | |
O8 | −0.0981 (3) | 0.33681 (17) | 0.91682 (12) | 0.0295 (4) | |
H8A | −0.210 (3) | 0.346 (2) | 0.8848 (17) | 0.035* | |
H8B | −0.124 (5) | 0.2826 (17) | 0.9512 (16) | 0.035* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Mg | 0.0207 (4) | 0.0195 (4) | 0.0200 (4) | −0.0006 (4) | −0.0010 (3) | 0.0003 (3) |
O1 | 0.0226 (8) | 0.0243 (9) | 0.0332 (9) | −0.0025 (8) | 0.0032 (8) | −0.0066 (8) |
O2 | 0.0251 (9) | 0.0316 (9) | 0.0384 (10) | −0.0039 (9) | 0.0074 (9) | −0.0109 (8) |
C1 | 0.0212 (12) | 0.0265 (12) | 0.0233 (12) | 0.0003 (11) | −0.0038 (10) | −0.0031 (10) |
C2 | 0.0240 (12) | 0.0205 (11) | 0.0309 (13) | 0.0014 (11) | 0.0016 (10) | −0.0019 (11) |
O3 | 0.0334 (10) | 0.0215 (8) | 0.0335 (10) | −0.0048 (8) | 0.0100 (9) | −0.0012 (7) |
C3 | 0.0281 (14) | 0.0378 (14) | 0.0414 (16) | −0.0077 (13) | 0.0019 (13) | −0.0149 (13) |
O4 | 0.0388 (10) | 0.0197 (8) | 0.0222 (8) | 0.0045 (9) | −0.0099 (8) | −0.0029 (7) |
O5 | 0.0630 (14) | 0.0323 (10) | 0.0288 (10) | 0.0164 (11) | −0.0218 (11) | −0.0107 (9) |
C4 | 0.0255 (12) | 0.0252 (12) | 0.0225 (12) | 0.0035 (11) | −0.0037 (10) | −0.0014 (10) |
C5 | 0.0384 (14) | 0.0197 (11) | 0.0242 (12) | −0.0004 (12) | −0.0060 (12) | −0.0035 (9) |
O6 | 0.0352 (10) | 0.0178 (8) | 0.0231 (9) | −0.0014 (9) | −0.0034 (8) | 0.0035 (7) |
C6 | 0.063 (2) | 0.057 (2) | 0.0353 (16) | 0.0379 (19) | −0.0036 (17) | −0.0096 (15) |
O7 | 0.0322 (10) | 0.0312 (10) | 0.0240 (9) | −0.0088 (9) | −0.0071 (8) | 0.0086 (8) |
O8 | 0.0257 (9) | 0.0354 (10) | 0.0275 (10) | −0.0033 (9) | 0.0014 (8) | 0.0076 (8) |
Mg—O7 | 2.0407 (19) | C3—H3C | 0.9600 |
Mg—O4 | 2.0544 (18) | O4—C4 | 1.261 (3) |
Mg—O3 | 2.0549 (19) | O5—C4 | 1.251 (3) |
Mg—O8 | 2.077 (2) | C4—C5 | 1.524 (3) |
Mg—O6 | 2.0784 (18) | C5—O6 | 1.432 (3) |
Mg—O1 | 2.079 (2) | C5—C6 | 1.514 (4) |
O1—C1 | 1.267 (3) | C5—H5A | 0.9800 |
O2—C1 | 1.254 (3) | O6—H6D | 0.821 (10) |
C1—C2 | 1.526 (4) | C6—H6A | 0.9600 |
C2—O3 | 1.428 (3) | C6—H6B | 0.9600 |
C2—C3 | 1.512 (4) | C6—H6C | 0.9600 |
C2—H2A | 0.9800 | O7—H7A | 0.832 (10) |
O3—H3D | 0.836 (10) | O7—H7B | 0.830 (10) |
C3—H3A | 0.9600 | O8—H8A | 0.828 (10) |
C3—H3B | 0.9600 | O8—H8B | 0.832 (10) |
O7—Mg—O4 | 172.11 (8) | H3A—C3—H3B | 109.5 |
O7—Mg—O3 | 93.80 (8) | C2—C3—H3C | 109.5 |
O4—Mg—O3 | 93.50 (8) | H3A—C3—H3C | 109.5 |
O7—Mg—O8 | 88.18 (8) | H3B—C3—H3C | 109.5 |
O4—Mg—O8 | 88.77 (8) | C4—O4—Mg | 118.91 (16) |
O3—Mg—O8 | 90.37 (8) | O5—C4—O4 | 124.1 (2) |
O7—Mg—O6 | 96.20 (8) | O5—C4—C5 | 117.8 (2) |
O4—Mg—O6 | 76.70 (7) | O4—C4—C5 | 118.1 (2) |
O3—Mg—O6 | 169.46 (9) | O6—C5—C6 | 111.6 (2) |
O8—Mg—O6 | 93.28 (9) | O6—C5—C4 | 107.29 (19) |
O7—Mg—O1 | 92.51 (8) | C6—C5—C4 | 111.4 (2) |
O4—Mg—O1 | 92.14 (8) | O6—C5—H5A | 108.8 |
O3—Mg—O1 | 76.23 (7) | C6—C5—H5A | 108.8 |
O8—Mg—O1 | 166.60 (8) | C4—C5—H5A | 108.8 |
O6—Mg—O1 | 99.95 (8) | C5—O6—Mg | 116.59 (13) |
C1—O1—Mg | 116.77 (16) | C5—O6—H6D | 109 (2) |
O2—C1—O1 | 124.0 (2) | Mg—O6—H6D | 134 (2) |
O2—C1—C2 | 117.9 (2) | C5—C6—H6A | 109.5 |
O1—C1—C2 | 118.1 (2) | C5—C6—H6B | 109.5 |
O3—C2—C3 | 111.3 (2) | H6A—C6—H6B | 109.5 |
O3—C2—C1 | 106.8 (2) | C5—C6—H6C | 109.5 |
C3—C2—C1 | 111.7 (2) | H6A—C6—H6C | 109.5 |
O3—C2—H2A | 109.0 | H6B—C6—H6C | 109.5 |
C3—C2—H2A | 109.0 | Mg—O7—H7A | 119.0 (19) |
C1—C2—H2A | 109.0 | Mg—O7—H7B | 131.6 (19) |
C2—O3—Mg | 116.46 (15) | H7A—O7—H7B | 109 (2) |
C2—O3—H3D | 112 (2) | Mg—O8—H8A | 118.8 (19) |
Mg—O3—H3D | 127 (2) | Mg—O8—H8B | 121 (2) |
C2—C3—H3A | 109.5 | H8A—O8—H8B | 106 (2) |
C2—C3—H3B | 109.5 |
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H3D···O5i | 0.84 | 1.83 | 2.668 (2) | 178 |
O6—H6D···O2ii | 0.82 | 1.85 | 2.666 (2) | 174 |
O7—H7A···O2iii | 0.83 | 1.94 | 2.768 (2) | 171 |
O7—H7B···O5iv | 0.83 | 1.85 | 2.678 (2) | 177 |
O8—H8A···O1iii | 0.83 | 2.12 | 2.933 (2) | 167 |
O8—H8B···O4i | 0.83 | 1.94 | 2.765 (2) | 168 |
Symmetry codes: (i) x−1/2, −y+1/2, −z+2; (ii) −x+1, y+1/2, −z+3/2; (iii) x−1, y, z; (iv) −x+1/2, −y+1, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | [Mg(C3H4O3)2(H2O)2] |
Mr | 238.48 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 293 |
a, b, c (Å) | 6.0525 (12), 11.919 (2), 14.526 (3) |
V (Å3) | 1047.9 (4) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.19 |
Crystal size (mm) | 0.28 × 0.20 × 0.16 |
Data collection | |
Diffractometer | Rigaku R-AXIS RAPID |
Absorption correction | Multi-scan (ABSCOR; Higashi, 1995) |
Tmin, Tmax | 0.955, 0.970 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 10148, 1401, 1208 |
Rint | 0.033 |
(sin θ/λ)max (Å−1) | 0.648 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.029, 0.074, 1.14 |
No. of reflections | 1401 |
No. of parameters | 154 |
No. of restraints | 8 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.25, −0.27 |
Computer programs: RAPID-AUTO (Rigaku, 1998), CrystalStructure (Rigaku/MSC, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H3D···O5i | 0.84 | 1.83 | 2.668 (2) | 178 |
O6—H6D···O2ii | 0.82 | 1.85 | 2.666 (2) | 174 |
O7—H7A···O2iii | 0.83 | 1.94 | 2.768 (2) | 171 |
O7—H7B···O5iv | 0.83 | 1.85 | 2.678 (2) | 177 |
O8—H8A···O1iii | 0.83 | 2.12 | 2.933 (2) | 167 |
O8—H8B···O4i | 0.83 | 1.94 | 2.765 (2) | 168 |
Symmetry codes: (i) x−1/2, −y+1/2, −z+2; (ii) −x+1, y+1/2, −z+3/2; (iii) x−1, y, z; (iv) −x+1/2, −y+1, z−1/2. |
Acknowledgements
This project was supported by the Scientific Research Fund of Ningbo University (grant Nos. XKL11058 and XYL11005). Sincere thanks are also extended to the K. C. Wong Magna Fund in Ningbo University.
References
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In the past decades, more attention have been paid to design and rational synthesis of coordination polymers based on self-assemblies of metal ions with lactic acid. The crystal structures of a number of metal lactates and their complexes have been reported (Carballo et al., 2007; Chen et al., 2000; Qiu et al., 2010; Zeng et al., 2010).
In the asymmetric unit of the the title compound, Mg(H2O)2(C3H4O3)2, the Mg2+ cation is chelated by two lactate anions bound through the carboxylate and hydroxyl groups. The other two sites are occupied by water molecules forming MgO6 distorted octahedral geometry (Fig. 1). The complexes greatly favor strong hydrogen bonding in the crystalline state. The hydroxyl group O3—H3D of the lactate ligand forms a hydrogen bond with the carboxylate atom O5i of a symmetry-related lactate anion (Table 1). This hydrogen bonding interaction leads to assemble the complexes into one-dimensional helical chain parallel to the a axis (Fig. 2). Other H-bonds link chains forming the three-dimensional architecture (Fig. 3).