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Acta Crystallogr Sect E Struct Rep Online. 2009 November 1; 65(Pt 11): m1352.
Published online 2009 October 13. doi:  10.1107/S1600536809040872
PMCID: PMC2971438

Hexaaqua­magnesium(II) bis­{[N-(4-meth­oxy-2-oxidobenzyl­idene)glycyl­glycinato(3−)]cuprate(II)} hexa­hydrate

Abstract

In the title complex, [Mg(H2O)6][Cu(C12H11N2O5)]2·6H2O, the CuII atoms lie at the center of the square plane of triple negatively charged O,N,N′,O′-tetra­dentate Schiff base ligands, which are coordinated by one phenolate O atom, one imine N atom, one deprotonated amide N atom and one carboxyl­ate O atom. The MgII center, which sits on an inversion center, is coordinated by six aqua ligands and exhibits a slightly distorted octa­hedral conformation. The asymmetric unit consists of an [N-(4-meth­oxy-2-oxidobenzyl­idene)glycyl­glycinato]cuprate(II) anion, one half of an [Mg(H2O)6]2+ cation and three free water mol­ecules. The cations and anions form columns by O—H(...)O hydrogen bonds.

Related literature

For structures of Schiff base analogues, see: Gupta et al. (2009 [triangle]); Vigato et al. (2007 [triangle]). For structures of Schiff base heteronuclear complexes, see: Jiang et al. (2009 [triangle]); Sakamoto et al. (2001 [triangle]); Vigato & Tamburini (2008 [triangle]); Zhang et al. (2008 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-65-m1352-scheme1.jpg

Experimental

Crystal data

  • [Mg(H2O)6][Cu(C12H11N2O5)]2·6H2O
  • M r = 894.04
  • Triclinic, An external file that holds a picture, illustration, etc.
Object name is e-65-m1352-efi1.jpg
  • a = 7.8606 (14) Å
  • b = 10.933 (2) Å
  • c = 11.539 (2) Å
  • α = 76.650 (2)°
  • β = 76.685 (2)°
  • γ = 80.737 (2)°
  • V = 932.8 (3) Å3
  • Z = 1
  • Mo Kα radiation
  • μ = 1.25 mm−1
  • T = 296 K
  • 0.30 × 0.28 × 0.25 mm

Data collection

  • Bruker SMART APEX CCD diffractometer
  • Absorption correction: multi-scan (SADABS; Sheldrick, 2004 [triangle]) T min = 0.696, T max = 0.736
  • 6808 measured reflections
  • 3262 independent reflections
  • 2836 reflections with I > 2σ(I)
  • R int = 0.084

Refinement

  • R[F 2 > 2σ(F 2)] = 0.036
  • wR(F 2) = 0.097
  • S = 1.04
  • 3262 reflections
  • 278 parameters
  • 18 restraints
  • H atoms treated by a mixture of independent and constrained refinement
  • Δρmax = 0.76 e Å−3
  • Δρmin = −0.57 e Å−3

Data collection: SMART (Bruker, 2002 [triangle]); cell refinement: SAINT-Plus (Bruker, 2003 [triangle]); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL and DIAMOND (Brandenburg, 2006 [triangle]); software used to prepare material for publication: SHELXTL.

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809040872/zq2010sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809040872/zq2010Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

This work was supported by SRF for ROCS, SEM and Yangzhou University.

supplementary crystallographic information

Comment

The Schiff bases are widely employed as ligands in coordination chemistry. These ligands are readily available, versatile, they exhibit various denticities and functionalities (Vigato et al., 2007; Gupta et al., 2009). Moreover, the number, the nature, and the relative position of the donor atoms of a Schiff base ligand allow a good control over the stereochemistry of the metallic centers, as well as over the number of the metal ions within homo- and heteronuclear complexes (Vigato et al., 2008; Sakamoto et al., 2001). Now we report the synthesis and structure of CuII—MgII Schiff base complex derived from glycylglycine and 4-methoxy-salicylaldehyde.

The heteronuclear complex (I) crystallizes in the triclinic space group P1. The asymmetric unit consists of one [CuL]- anion (L is a Schiff base derived from glycylglycine and 4-methoxy-salicylaldehyde), one half of the Mg(H2O)62+ cation [Mg1, O6, O7, O8] and three uncoordinated water molecules [O9, O10, O11] in the complex (I) (Fig. 1). The deprotonated Schiff base is a triple negatively charged tetradentate ONNO ligand, coordinating to the CuII atom by one phenolate O atom [O1] (Cu1—O1 = 1.880 (2) Å), one imine N atom [N1] (Cu1—N1 = 1.920 (2) Å), one deprotonated amide N atom [N2] (Cu1—N2 = 1.892 (2) Å) and one carboxylato O atom [O3] (Cu1—O3 = 1.980 (2) Å). [CuL]- exhibits approximately a square-planar structure. The CuII atom is in a slightly distorted square-planar environment with four donor atoms deviating from their mean plane by -0.0506 (9) Å (N1), +0.0626 (9) Å (N2), +0.0513 (8) Å (O1) and -0.0496 (9) Å (O3) (observed bond angles vary from 83.5 (1)° to 96.9 (1)°). The benzene ring [C1–C6] and the chelate ring [O1, C1, C6, C7, N1, Cu1] are almost coplanar with a dihedral angle of 0.11 (9)°, suggesting a large π-electron delocalization. The MgII atom lies on an inversion center and the coordination by six aqua ligands exhibits a slightly distorted octahedral environment. The six Mg—O bonds in the structure are in the range of 2.059 (2) - 2.063 (2) Å. In the crystal structure, the [CuL]- anions and [Mg(H2O)6]2+ cations each form columns by hydrogen bonds along the a-axis (Fig. 2, Table 1).

Experimental

Glycylglycine (5 mmol), 4-methoxy-salicylaldehyde (5 mmol) and NaOH (10 mmol) were dissolved in MeOH/H2O (30 ml, v: v = 1: 1) and refluxed for 30 min. Then Cu(ClO4)2.6H2O (5 mmol) was added to the solution and the resulting solution was adjusted to 9–11 by 5 mol/L NaOH solution. After stirring at room temperature for another 1 hr, MgCl2.6H2O (2.5 mmol) was added. A violet precipitate was obtained immediately. After stirring for 30 min and then filtered, the precipitate was recrystallized in water. The violet crystals of complex (I) suitable for an X-ray diffraction analyses were obtained after 1 week.

Refinement

The water H atoms were located in a difference Fourier map and refined with restraints: O—H = 0.85 Å and Uiso(H) =1.5Ueq(O). All other H atoms were positioned geometrically and constrained as riding atoms, with C—H distances of 0.93–0.97 Å and Uiso(H) set to 1.2 or 1.5Ueq(C) of the parent atom.

Figures

Fig. 1.
The molecular structure of (I), with atom labels and 50% probability displacement ellipsoids. Unlabeled atoms are related to labeled atoms by the symmetry code (-x + 1, -y + 2, -z + 1).
Fig. 2.
A packing diagram of (I), viewed down the a-axis, showing a separated column stacking structure connected by O—H···O hydrogen bonds (dashed lines).

Crystal data

[Mg(H2O)6][Cu(C12H11N2O5)]2·6H2OZ = 1
Mr = 894.04F(000) = 464
Triclinic, P1Dx = 1.592 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 7.8606 (14) ÅCell parameters from 7186 reflections
b = 10.933 (2) Åθ = 1.0–28.3°
c = 11.539 (2) ŵ = 1.25 mm1
α = 76.650 (2)°T = 296 K
β = 76.685 (2)°Block, violet
γ = 80.737 (2)°0.30 × 0.28 × 0.25 mm
V = 932.8 (3) Å3

Data collection

Bruker SMART APEX CCD diffractometer2836 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.084
[var phi] and ω scansθmax = 25.0°, θmin = 1.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)h = −9→9
Tmin = 0.696, Tmax = 0.736k = −12→12
6808 measured reflectionsl = −13→13
3262 independent reflections

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.036Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.097H atoms treated by a mixture of independent and constrained refinement
S = 1.03w = 1/[σ2(Fo2) + (0.0593P)2] where P = (Fo2 + 2Fc2)/3
3262 reflections(Δ/σ)max = 0.001
278 parametersΔρmax = 0.76 e Å3
18 restraintsΔρmin = −0.57 e Å3

Special details

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)

xyzUiso*/Ueq
Mg10.50001.00000.50000.0274 (3)
Cu10.53658 (3)0.70272 (3)0.98705 (2)0.02798 (13)
C10.7984 (3)0.5135 (2)0.8983 (2)0.0278 (5)
C20.9093 (3)0.4662 (2)0.8009 (2)0.0318 (5)
H20.91060.51160.72190.038*
C31.0174 (3)0.3528 (2)0.8201 (3)0.0338 (6)
C41.0200 (3)0.2837 (2)0.9381 (3)0.0378 (6)
H41.09470.20890.95100.045*
C50.9110 (3)0.3276 (2)1.0342 (3)0.0357 (6)
H50.91200.28081.11240.043*
C60.7962 (3)0.4422 (2)1.0192 (2)0.0297 (5)
C70.6919 (3)0.4804 (2)1.1269 (2)0.0311 (5)
H70.70450.42831.20120.037*
C80.4821 (3)0.6142 (3)1.2436 (2)0.0354 (6)
H8A0.56250.62011.29400.043*
H8B0.40770.54881.28750.043*
C90.3683 (3)0.7412 (2)1.2172 (2)0.0289 (5)
C100.2895 (3)0.9088 (2)1.0529 (2)0.0319 (5)
H10A0.32560.97901.07620.038*
H10B0.16420.90651.08440.038*
C110.3290 (3)0.9256 (2)0.9147 (2)0.0308 (5)
C121.1256 (4)0.3610 (3)0.6070 (3)0.0504 (7)
H12A1.00810.36950.59300.076*
H12B1.20290.31080.55400.076*
H12C1.16430.44320.59110.076*
N10.5819 (3)0.58115 (19)1.12892 (18)0.0301 (4)
N20.3860 (3)0.79083 (19)1.10172 (18)0.0315 (5)
O10.6989 (2)0.62339 (15)0.87217 (15)0.0315 (4)
O30.4460 (2)0.84413 (16)0.86727 (15)0.0352 (4)
O40.2500 (2)1.01549 (17)0.85495 (16)0.0434 (5)
O20.2727 (2)0.78645 (17)1.30527 (15)0.0370 (4)
O51.1276 (2)0.30083 (17)0.73004 (18)0.0458 (5)
O60.4664 (2)1.10040 (18)0.63586 (15)0.0376 (4)
H6A0.553 (3)1.120 (3)0.656 (3)0.056*
H6B0.394 (3)1.077 (3)0.702 (2)0.056*
O70.2365 (2)1.0350 (2)0.49409 (17)0.0423 (5)
H7A0.159 (4)1.017 (3)0.557 (2)0.063*
H7B0.194 (4)1.096 (2)0.448 (2)0.063*
O80.4514 (3)0.83655 (18)0.62765 (16)0.0423 (5)
H8C0.393 (4)0.785 (3)0.616 (3)0.063*
H8D0.442 (5)0.836 (3)0.7002 (18)0.063*
O90.8995 (3)0.7896 (2)0.68699 (18)0.0479 (5)
H9A0.908 (5)0.855 (2)0.712 (3)0.072*
H9B0.837 (4)0.742 (3)0.737 (3)0.072*
O101.0000 (3)0.9857 (2)0.28950 (19)0.0462 (5)
H10C1.072 (4)0.922 (2)0.298 (3)0.069*
H10D0.934 (4)0.984 (3)0.246 (3)0.069*
O110.2361 (3)0.6905 (2)0.56744 (19)0.0483 (5)
H11A0.145 (3)0.724 (3)0.602 (3)0.072*
H11B0.249 (4)0.708 (3)0.4918 (16)0.072*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Mg10.0289 (6)0.0339 (6)0.0190 (5)−0.0054 (4)−0.0024 (4)−0.0058 (4)
Cu10.03038 (19)0.03127 (19)0.01925 (18)0.00204 (12)−0.00343 (12)−0.00437 (12)
C10.0263 (11)0.0252 (11)0.0331 (13)−0.0035 (9)−0.0082 (10)−0.0054 (10)
C20.0310 (12)0.0309 (12)0.0332 (14)−0.0027 (10)−0.0070 (10)−0.0061 (10)
C30.0276 (12)0.0311 (12)0.0450 (15)−0.0024 (10)−0.0071 (11)−0.0135 (11)
C40.0351 (13)0.0284 (12)0.0506 (17)0.0032 (10)−0.0149 (12)−0.0075 (11)
C50.0374 (13)0.0292 (12)0.0409 (15)−0.0032 (10)−0.0161 (12)−0.0003 (11)
C60.0287 (12)0.0280 (12)0.0338 (13)−0.0039 (9)−0.0105 (10)−0.0042 (10)
C70.0321 (12)0.0335 (13)0.0275 (13)−0.0082 (10)−0.0113 (10)0.0023 (10)
C80.0336 (13)0.0496 (15)0.0211 (12)−0.0027 (11)−0.0070 (10)−0.0031 (11)
C90.0267 (11)0.0408 (13)0.0230 (12)−0.0097 (10)−0.0048 (9)−0.0104 (10)
C100.0386 (13)0.0327 (13)0.0226 (12)−0.0009 (10)−0.0006 (10)−0.0096 (10)
C110.0338 (13)0.0300 (12)0.0263 (13)−0.0012 (10)−0.0015 (10)−0.0070 (10)
C120.0512 (17)0.0503 (17)0.0473 (18)0.0053 (13)−0.0041 (14)−0.0182 (14)
N10.0284 (10)0.0366 (11)0.0248 (10)−0.0029 (8)−0.0071 (8)−0.0038 (8)
N20.0365 (11)0.0345 (11)0.0217 (10)−0.0004 (9)−0.0042 (9)−0.0062 (8)
O10.0340 (9)0.0305 (8)0.0250 (9)0.0041 (7)−0.0038 (7)−0.0033 (7)
O30.0448 (10)0.0347 (9)0.0193 (9)0.0084 (7)−0.0018 (7)−0.0053 (7)
O40.0514 (11)0.0391 (10)0.0290 (10)0.0146 (8)−0.0035 (8)−0.0040 (8)
O20.0370 (9)0.0524 (11)0.0215 (9)−0.0036 (8)−0.0024 (7)−0.0116 (8)
O50.0446 (11)0.0409 (10)0.0486 (12)0.0102 (8)−0.0060 (9)−0.0161 (9)
O60.0400 (10)0.0481 (11)0.0269 (9)−0.0122 (8)0.0019 (8)−0.0154 (8)
O70.0303 (9)0.0610 (12)0.0288 (10)−0.0006 (8)−0.0027 (8)−0.0019 (9)
O80.0591 (12)0.0455 (11)0.0240 (9)−0.0185 (9)−0.0083 (9)−0.0016 (8)
O90.0487 (12)0.0496 (12)0.0385 (12)−0.0082 (9)−0.0032 (9)0.0015 (9)
O100.0365 (11)0.0617 (13)0.0366 (11)0.0040 (9)−0.0026 (8)−0.0140 (10)
O110.0530 (12)0.0529 (12)0.0393 (12)−0.0108 (10)−0.0093 (10)−0.0067 (10)

Geometric parameters (Å, °)

Mg1—O7i2.0591 (18)C8—H8A0.9700
Mg1—O72.0591 (18)C8—H8B0.9700
Mg1—O62.0598 (17)C9—O21.266 (3)
Mg1—O6i2.0599 (17)C9—N21.302 (3)
Mg1—O82.0625 (18)C10—N21.451 (3)
Mg1—O8i2.0626 (18)C10—C111.526 (3)
Cu1—O11.8797 (17)C10—H10A0.9700
Cu1—N21.892 (2)C10—H10B0.9700
Cu1—N11.920 (2)C11—O41.231 (3)
Cu1—O31.9799 (16)C11—O31.292 (3)
C1—O11.336 (3)C12—O51.422 (4)
C1—C21.401 (3)C12—H12A0.9600
C1—C61.430 (3)C12—H12B0.9600
C2—C31.389 (3)C12—H12C0.9600
C2—H20.9300O6—H6A0.840 (17)
C3—O51.361 (3)O6—H6B0.851 (17)
C3—C41.400 (4)O7—H7A0.840 (17)
C4—C51.368 (4)O7—H7B0.833 (17)
C4—H40.9300O8—H8C0.831 (17)
C5—C61.422 (3)O8—H8D0.822 (17)
C5—H50.9300O9—H9A0.848 (18)
C6—C71.432 (4)O9—H9B0.810 (18)
C7—N11.288 (3)O10—H10C0.826 (18)
C7—H70.9300O10—H10D0.810 (17)
C8—N11.466 (3)O11—H11A0.813 (18)
C8—C91.533 (3)O11—H11B0.835 (18)
O7i—Mg1—O7179.999 (1)C9—C8—H8A109.7
O7i—Mg1—O688.05 (8)N1—C8—H8B109.7
O7—Mg1—O691.95 (8)C9—C8—H8B109.7
O7i—Mg1—O6i91.95 (8)H8A—C8—H8B108.2
O7—Mg1—O6i88.05 (8)O2—C9—N2127.6 (2)
O6—Mg1—O6i180.0O2—C9—C8119.1 (2)
O7i—Mg1—O890.55 (8)N2—C9—C8113.2 (2)
O7—Mg1—O889.45 (8)N2—C10—C11107.92 (19)
O6—Mg1—O890.60 (8)N2—C10—H10A110.1
O6i—Mg1—O889.40 (8)C11—C10—H10A110.1
O7i—Mg1—O8i89.45 (8)N2—C10—H10B110.1
O7—Mg1—O8i90.55 (8)C11—C10—H10B110.1
O6—Mg1—O8i89.40 (8)H10A—C10—H10B108.4
O6i—Mg1—O8i90.60 (8)O4—C11—O3123.8 (2)
O8—Mg1—O8i180.000 (1)O4—C11—C10118.8 (2)
O1—Cu1—N2175.66 (8)O3—C11—C10117.4 (2)
O1—Cu1—N196.90 (8)O5—C12—H12A109.5
N2—Cu1—N183.79 (9)O5—C12—H12B109.5
O1—Cu1—O395.95 (7)H12A—C12—H12B109.5
N2—Cu1—O383.51 (8)O5—C12—H12C109.5
N1—Cu1—O3167.03 (8)H12A—C12—H12C109.5
O1—C1—C2117.5 (2)H12B—C12—H12C109.5
O1—C1—C6123.6 (2)C7—N1—C8121.6 (2)
C2—C1—C6118.9 (2)C7—N1—Cu1124.53 (18)
C3—C2—C1121.2 (2)C8—N1—Cu1113.87 (16)
C3—C2—H2119.4C9—N2—C10124.0 (2)
C1—C2—H2119.4C9—N2—Cu1119.48 (17)
O5—C3—C2124.4 (2)C10—N2—Cu1116.46 (15)
O5—C3—C4115.0 (2)C1—O1—Cu1125.02 (15)
C2—C3—C4120.6 (2)C11—O3—Cu1114.46 (15)
C5—C4—C3119.0 (2)C3—O5—C12118.7 (2)
C5—C4—H4120.5Mg1—O6—H6A121 (2)
C3—C4—H4120.5Mg1—O6—H6B118 (2)
C4—C5—C6122.6 (2)H6A—O6—H6B106 (2)
C4—C5—H5118.7Mg1—O7—H7A121 (2)
C6—C5—H5118.7Mg1—O7—H7B124 (2)
C5—C6—C1117.7 (2)H7A—O7—H7B108 (2)
C5—C6—C7117.5 (2)Mg1—O8—H8C121 (2)
C1—C6—C7124.7 (2)Mg1—O8—H8D120 (2)
N1—C7—C6125.1 (2)H8C—O8—H8D112 (3)
N1—C7—H7117.4H9A—O9—H9B113 (3)
C6—C7—H7117.4H10C—O10—H10D114 (3)
N1—C8—C9109.61 (19)H11A—O11—H11B114 (3)
N1—C8—H8A109.7

Symmetry codes: (i) −x+1, −y+2, −z+1.

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
O6—H6B···O40.85 (2)1.91 (2)2.755 (3)175 (3)
O6—H6A···O2ii0.84 (2)2.02 (2)2.836 (2)165 (3)
O7—H7A···O10i0.84 (2)1.91 (2)2.734 (3)165 (3)
O7—H7B···O9i0.83 (2)1.96 (2)2.776 (3)166 (3)
O8—H8C···O110.83 (2)1.98 (2)2.797 (3)169 (3)
O8—H8D···O30.82 (2)1.96 (2)2.775 (2)173 (3)
O9—H9A···O10iii0.85 (2)1.99 (2)2.787 (3)157 (3)
O9—H9B···O10.81 (2)2.01 (2)2.816 (3)174 (4)
O10—H10C···O2iv0.83 (2)1.99 (2)2.805 (3)171 (4)
O10—H10D···O4i0.81 (2)2.05 (2)2.857 (3)176 (4)
O11—H11A···O9v0.81 (2)2.05 (2)2.857 (3)172 (4)
O11—H11B···O2vi0.84 (2)2.10 (2)2.927 (3)170 (4)

Symmetry codes: (ii) −x+1, −y+2, −z+2; (i) −x+1, −y+2, −z+1; (iii) −x+2, −y+2, −z+1; (iv) x+1, y, z−1; (v) x−1, y, z; (vi) x, y, z−1.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: ZQ2010).

References

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