metal-organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

Bis(μ-pyridine-2,4-di­carboxyl­ato)-κ3N,O2:O2;κ3O2:N,O2-bis­­[tri­aqua­magnesium(II)]

aCollege of Chemistry and Chemical Engineering, Liaocheng University, Shandong 252059, People's Republic of China
*Correspondence e-mail: zhangqingfu@foxmail.com

(Received 29 July 2010; accepted 2 August 2010; online 11 August 2010)

In the title centrosymmetric MgII complex, [Mg2(C7H3NO4)2(H2O)6], each Mg cation is N,O-chelated by a pyridine-2,4-dicarboxyl­ate dianion and is coordinated by three water mol­ecules. A carboxyl­ate O atom from the neighboring pyridine-2,4-dicarboxyl­ate dianion bridges the Mg cation to complete the MgNO5 distorted octa­hedral coordination geometry. The dinuclear complex mol­ecules are linked by inter­molecular O—H⋯O hydrogen bonding, forming a three-dimensional supra­molecular structure.

Related literature

For the applications of Mg complexes, see: Davies et al. (2007[Davies, R. P., Less, R. J., Lickiss, P. D. & White, A. J. P. (2007). Dalton Trans. pp. 2528-2535.]); Dinca & Long (2005[Dinca, M. & Long, J. R. (2005). J. Am. Chem. Soc. 127, 9376-9377.]).

[Scheme 1]

Experimental

Crystal data
  • [Mg2(C7H3NO4)2(H2O)6]

  • Mr = 486.92

  • Orthorhombic, P b c a

  • a = 7.9221 (8) Å

  • b = 12.0951 (12) Å

  • c = 20.2989 (18) Å

  • V = 1945.0 (3) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.21 mm−1

  • T = 293 K

  • 0.25 × 0.18 × 0.15 mm

Data collection
  • Bruker SMART CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.951, Tmax = 0.970

  • 8884 measured reflections

  • 1719 independent reflections

  • 1289 reflections with I > 2σ(I)

  • Rint = 0.042

Refinement
  • R[F2 > 2σ(F2)] = 0.040

  • wR(F2) = 0.100

  • S = 1.06

  • 1719 reflections

  • 145 parameters

  • H-atom parameters constrained

  • Δρmax = 0.36 e Å−3

  • Δρmin = −0.30 e Å−3

Table 1
Selected bond lengths (Å)

Mg1—N1 2.2202 (19)
Mg1—O1 2.1011 (19)
Mg1—O1i 2.0613 (16)
Mg1—O5 2.0953 (19)
Mg1—O6 2.017 (2)
Mg1—O7 2.033 (2)
Symmetry code: (i) -x, -y+1, -z.

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O5—H5A⋯O4ii 0.87 1.80 2.668 (3) 172
O5—H5B⋯O2iii 0.86 2.12 2.834 (3) 140
O6—H6A⋯O3iv 0.87 1.73 2.576 (3) 163
O6—H6B⋯O5v 0.87 2.07 2.880 (2) 154
O7—H7A⋯O4vi 0.86 1.89 2.745 (2) 174
O7—H7B⋯O4vii 0.86 2.02 2.857 (3) 166
Symmetry codes: (ii) [x-{\script{1\over 2}}, y, -z+{\script{1\over 2}}]; (iii) [-x-{\script{1\over 2}}, y+{\script{1\over 2}}, z]; (iv) [-x, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]; (v) [x+{\script{1\over 2}}, -y+{\script{3\over 2}}, -z]; (vi) [-x+{\script{1\over 2}}, -y+1, z-{\script{1\over 2}}]; (vii) [x+{\script{1\over 2}}, y, -z+{\script{1\over 2}}].

Data collection: SMART (Siemens, 1996[Siemens. (1996). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Siemens, 1996[Siemens. (1996). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

Magnesium(II) complexes have been extensively studied in recent year due to their wide application in synthesis of inorganic materials, catalysis of organic reactions and storage of hydrogen (Dinca & Long, 2005). In order to explore the relationship between these applications and their structures, a series of magnesium(II) complexes have been prepared and structural characterized (Davies et al., 2007). To expand research in this area, here we report a dinuclear magnesium(II) complex.

As shown in Fig.1, each magnesium(II) ion in the title complex is coordinated by two carboxyl O atoms, one pyridyl N atom and three water molecules, forming a distorted octahedral geometry (axial angle, O7—Mg1—O5 = 173.33 (9)°). Interestingly, the two adjacent magnesium(II) ions are linked by two µ2-carboxylate O atoms to form a dinuclear strucutre.

In the crystal strucutre, these dimeric molecules are linked by intermolecular O—H···O H-bonding interactions into a three-dimensional framework (Fig.2).

Related literature top

For the applications of Mg complexes, see: Davies et al. (2007); Dinca & Long (2005).

Experimental top

A mixture of pyridine-2,4-dicarboxylic acid (16.7 mg, 0.10 mmol) and magnesium chloride hexahydrate (20.3 mg, 0.10 mmol) in 5 ml dimethyl acetamide (DMA) was heated to 373 K in a sealed 10 ml Teflon-lined reactor for 72 h. The mixture was allowed to cool to room temperature and the resulting block-shaped colorless crystals filtered from the reaction mixture. Yield, 72%.

Refinement top

The H atoms on water were located in a difference Fourier map and refined in riding mode with the fixed Uiso(H) = 0.105 Å2. The aromatic H atoms were placed at calculated positions and were treated as riding on the parent C atoms with C—H = 0.93 Å and Uiso(H) = 1.2Ueq(C).

Structure description top

Magnesium(II) complexes have been extensively studied in recent year due to their wide application in synthesis of inorganic materials, catalysis of organic reactions and storage of hydrogen (Dinca & Long, 2005). In order to explore the relationship between these applications and their structures, a series of magnesium(II) complexes have been prepared and structural characterized (Davies et al., 2007). To expand research in this area, here we report a dinuclear magnesium(II) complex.

As shown in Fig.1, each magnesium(II) ion in the title complex is coordinated by two carboxyl O atoms, one pyridyl N atom and three water molecules, forming a distorted octahedral geometry (axial angle, O7—Mg1—O5 = 173.33 (9)°). Interestingly, the two adjacent magnesium(II) ions are linked by two µ2-carboxylate O atoms to form a dinuclear strucutre.

In the crystal strucutre, these dimeric molecules are linked by intermolecular O—H···O H-bonding interactions into a three-dimensional framework (Fig.2).

For the applications of Mg complexes, see: Davies et al. (2007); Dinca & Long (2005).

Computing details top

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT (Siemens, 1996); 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: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, showing 30% probability displacement ellipsoids.
[Figure 2] Fig. 2. The packing diagram of the title complex.
Bis(µ-pyridine-2,4-dicarboxylato)- κ3N,O2:O2;κ3O2:N,O2- bis[triaquamagnesium(II)] top
Crystal data top
[Mg2(C7H3NO4)2(H2O)6]F(000) = 1008
Mr = 486.92Dx = 1.663 Mg m3
Orthorhombic, PbcaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2abCell parameters from 2705 reflections
a = 7.9221 (8) Åθ = 3.2–26.8°
b = 12.0951 (12) ŵ = 0.21 mm1
c = 20.2989 (18) ÅT = 293 K
V = 1945.0 (3) Å3Block, colorless
Z = 40.25 × 0.18 × 0.15 mm
Data collection top
Bruker SMART CCD area-detector
diffractometer
1719 independent reflections
Radiation source: fine-focus sealed tube1289 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.042
φ and ω scansθmax = 25.0°, θmin = 2.0°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 59
Tmin = 0.951, Tmax = 0.970k = 1414
8884 measured reflectionsl = 2423
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)] = 0.040Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.100H-atom parameters constrained
S = 1.06 w = 1/[σ2(Fo2) + (0.0376P)2 + 1.7679P]
where P = (Fo2 + 2Fc2)/3
1719 reflections(Δ/σ)max < 0.001
145 parametersΔρmax = 0.36 e Å3
0 restraintsΔρmin = 0.30 e Å3
Crystal data top
[Mg2(C7H3NO4)2(H2O)6]V = 1945.0 (3) Å3
Mr = 486.92Z = 4
Orthorhombic, PbcaMo Kα radiation
a = 7.9221 (8) ŵ = 0.21 mm1
b = 12.0951 (12) ÅT = 293 K
c = 20.2989 (18) Å0.25 × 0.18 × 0.15 mm
Data collection top
Bruker SMART CCD area-detector
diffractometer
1719 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
1289 reflections with I > 2σ(I)
Tmin = 0.951, Tmax = 0.970Rint = 0.042
8884 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0400 restraints
wR(F2) = 0.100H-atom parameters constrained
S = 1.06Δρmax = 0.36 e Å3
1719 reflectionsΔρmin = 0.30 e Å3
145 parameters
Special details top

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
Mg10.07954 (11)0.60169 (7)0.04323 (3)0.0240 (2)
O10.0075 (2)0.43818 (14)0.05141 (7)0.0272 (4)
O20.0923 (4)0.30663 (19)0.12021 (10)0.0760 (9)
O30.0102 (4)0.3649 (2)0.35781 (9)0.0875 (11)
H6A0.11780.80680.07650.105*
H5B0.18920.72460.08480.105*
H5A0.23770.61930.08260.105*
H7A0.35030.54010.01940.105*
H7B0.40540.56000.04570.105*
H6B0.21740.80160.02110.105*
O40.1026 (2)0.51899 (15)0.39638 (8)0.0364 (5)
O50.1604 (2)0.66298 (14)0.06670 (8)0.0323 (5)
O60.1539 (3)0.76106 (16)0.04659 (9)0.0491 (6)
O70.3209 (2)0.56088 (17)0.01937 (8)0.0430 (5)
N10.1126 (3)0.56101 (17)0.14911 (9)0.0257 (5)
C10.0232 (4)0.3941 (2)0.10852 (11)0.0325 (6)
C20.0461 (3)0.4620 (2)0.16485 (11)0.0261 (6)
C30.0314 (3)0.4258 (2)0.22895 (11)0.0302 (6)
H30.01350.35640.23780.036*
C40.0838 (3)0.4934 (2)0.28011 (11)0.0281 (6)
C50.0576 (4)0.4556 (2)0.35037 (12)0.0361 (7)
C60.1530 (4)0.5952 (2)0.26430 (11)0.0318 (6)
H60.19020.64260.29730.038*
C70.1660 (4)0.6255 (2)0.19836 (11)0.0325 (6)
H70.21390.69350.18810.039*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Mg10.0328 (5)0.0234 (5)0.0157 (4)0.0004 (4)0.0015 (3)0.0008 (3)
O10.0415 (11)0.0250 (10)0.0151 (8)0.0001 (8)0.0028 (8)0.0000 (7)
O20.151 (3)0.0485 (15)0.0289 (11)0.0543 (16)0.0205 (13)0.0080 (10)
O30.176 (3)0.0627 (17)0.0241 (11)0.0682 (19)0.0088 (14)0.0028 (10)
O40.0497 (12)0.0419 (12)0.0176 (8)0.0064 (9)0.0043 (8)0.0016 (8)
O50.0379 (11)0.0271 (10)0.0320 (9)0.0057 (8)0.0049 (8)0.0031 (8)
O60.0683 (15)0.0308 (11)0.0482 (12)0.0158 (10)0.0282 (11)0.0089 (9)
O70.0339 (11)0.0693 (15)0.0260 (9)0.0104 (10)0.0014 (8)0.0103 (9)
N10.0348 (13)0.0239 (12)0.0185 (10)0.0021 (9)0.0003 (9)0.0002 (8)
C10.0538 (18)0.0229 (14)0.0208 (13)0.0060 (13)0.0040 (12)0.0003 (11)
C20.0327 (15)0.0238 (14)0.0220 (12)0.0006 (11)0.0008 (11)0.0010 (10)
C30.0445 (17)0.0256 (14)0.0205 (12)0.0074 (12)0.0023 (12)0.0028 (10)
C40.0349 (15)0.0301 (15)0.0194 (12)0.0011 (12)0.0010 (11)0.0007 (10)
C50.0526 (19)0.0362 (17)0.0193 (13)0.0074 (14)0.0014 (12)0.0027 (12)
C60.0449 (16)0.0308 (15)0.0196 (12)0.0068 (13)0.0052 (12)0.0026 (10)
C70.0466 (17)0.0275 (15)0.0236 (13)0.0102 (13)0.0025 (12)0.0009 (11)
Geometric parameters (Å, º) top
Mg1—N12.2202 (19)O7—H7A0.8581
Mg1—O12.1011 (19)O7—H7B0.8563
Mg1—O1i2.0613 (16)N1—C71.336 (3)
Mg1—O52.0953 (19)N1—C21.347 (3)
Mg1—O62.017 (2)C1—C21.511 (3)
Mg1—O72.033 (2)C2—C31.378 (3)
O1—C11.282 (3)C3—C41.385 (3)
O2—C11.215 (3)C3—H30.9300
O3—C51.231 (3)C4—C61.385 (4)
O4—C51.260 (3)C4—C51.512 (3)
O5—H5B0.8616C6—C71.392 (3)
O5—H5A0.8701C6—H60.9300
O6—H6A0.8688C7—H70.9300
O6—H6B0.8725
O6—Mg1—O788.02 (9)H6A—O6—H6B104.2
O6—Mg1—O1i109.63 (8)Mg1—O7—H7A123.0
O7—Mg1—O1i88.93 (7)Mg1—O7—H7B126.1
O6—Mg1—O585.36 (8)H7A—O7—H7B110.8
O7—Mg1—O5173.33 (9)C7—N1—C2117.7 (2)
O1i—Mg1—O592.50 (7)C7—N1—Mg1129.22 (17)
O6—Mg1—O1173.16 (8)C2—N1—Mg1112.37 (15)
O7—Mg1—O195.68 (8)O2—C1—O1125.6 (2)
O1i—Mg1—O176.26 (7)O2—C1—C2119.3 (2)
O5—Mg1—O190.98 (8)O1—C1—C2115.0 (2)
O6—Mg1—N198.32 (8)N1—C2—C3122.7 (2)
O7—Mg1—N193.77 (8)N1—C2—C1116.5 (2)
O1i—Mg1—N1152.00 (8)C3—C2—C1120.7 (2)
O5—Mg1—N188.02 (8)C2—C3—C4119.7 (2)
O1—Mg1—N175.74 (7)C2—C3—H3120.2
O6—Mg1—Mg1i148.06 (7)C4—C3—H3120.2
O7—Mg1—Mg1i92.97 (6)C6—C4—C3118.0 (2)
O1i—Mg1—Mg1i38.56 (5)C6—C4—C5122.8 (2)
O5—Mg1—Mg1i92.20 (6)C3—C4—C5119.2 (2)
O1—Mg1—Mg1i37.70 (4)O3—C5—O4125.1 (2)
N1—Mg1—Mg1i113.44 (7)O3—C5—C4116.5 (2)
C1—O1—Mg1i135.94 (16)O4—C5—C4118.4 (2)
C1—O1—Mg1119.66 (15)C4—C6—C7119.1 (2)
Mg1i—O1—Mg1103.74 (7)C4—C6—H6120.5
Mg1—O5—H5B130.0C7—C6—H6120.5
Mg1—O5—H5A120.5N1—C7—C6122.9 (2)
H5B—O5—H5A100.5N1—C7—H7118.6
Mg1—O6—H6A122.4C6—C7—H7118.6
Mg1—O6—H6B133.3
Symmetry code: (i) x, y+1, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O5—H5A···O4ii0.871.802.668 (3)172
O5—H5B···O2iii0.862.122.834 (3)140
O6—H6A···O3iv0.871.732.576 (3)163
O6—H6B···O5v0.872.072.880 (2)154
O7—H7A···O4vi0.861.892.745 (2)174
O7—H7B···O4vii0.862.022.857 (3)166
Symmetry codes: (ii) x1/2, y, z+1/2; (iii) x1/2, y+1/2, z; (iv) x, y+1/2, z+1/2; (v) x+1/2, y+3/2, z; (vi) x+1/2, y+1, z1/2; (vii) x+1/2, y, z+1/2.

Experimental details

Crystal data
Chemical formula[Mg2(C7H3NO4)2(H2O)6]
Mr486.92
Crystal system, space groupOrthorhombic, Pbca
Temperature (K)293
a, b, c (Å)7.9221 (8), 12.0951 (12), 20.2989 (18)
V3)1945.0 (3)
Z4
Radiation typeMo Kα
µ (mm1)0.21
Crystal size (mm)0.25 × 0.18 × 0.15
Data collection
DiffractometerBruker SMART CCD area-detector
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.951, 0.970
No. of measured, independent and
observed [I > 2σ(I)] reflections
8884, 1719, 1289
Rint0.042
(sin θ/λ)max1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.040, 0.100, 1.06
No. of reflections1719
No. of parameters145
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.36, 0.30

Computer programs: SMART (Siemens, 1996), SAINT (Siemens, 1996), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Selected bond lengths (Å) top
Mg1—N12.2202 (19)Mg1—O52.0953 (19)
Mg1—O12.1011 (19)Mg1—O62.017 (2)
Mg1—O1i2.0613 (16)Mg1—O72.033 (2)
Symmetry code: (i) x, y+1, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O5—H5A···O4ii0.871.802.668 (3)171.5
O5—H5B···O2iii0.862.122.834 (3)139.9
O6—H6A···O3iv0.871.732.576 (3)163.2
O6—H6B···O5v0.872.072.880 (2)153.5
O7—H7A···O4vi0.861.892.745 (2)173.5
O7—H7B···O4vii0.862.022.857 (3)166.4
Symmetry codes: (ii) x1/2, y, z+1/2; (iii) x1/2, y+1/2, z; (iv) x, y+1/2, z+1/2; (v) x+1/2, y+3/2, z; (vi) x+1/2, y+1, z1/2; (vii) x+1/2, y, z+1/2.
 

Acknowledgements

We acknowledge the Scientific Research Startup Fund of Liaocheng University (31805) and the Students Science and Technology Innovation Fund of Liaocheng University, China (SRT10060HX2).

References

First citationDavies, R. P., Less, R. J., Lickiss, P. D. & White, A. J. P. (2007). Dalton Trans. pp. 2528–2535.  Web of Science CSD CrossRef Google Scholar
First citationDinca, M. & Long, J. R. (2005). J. Am. Chem. Soc. 127, 9376–9377.  Web of Science CSD CrossRef PubMed CAS Google Scholar
First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSiemens. (1996). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.  Google Scholar

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