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Acta Cryst. (2009). E65, m107    [ doi:10.1107/S1600536808042529 ]

Diaqua(5-methylpyrazine-2-carboxylato-[kappa]2N1,O)iron(II)

G. Fan, J.-J. Sun, J.-C. Zhang, Z.-Y. Ma and S.-L. Gao

Abstract top

In the neutral title complex, [Fe(C6H5N2O2)2(H2O)2], the coordination geometry aound the FeII atom, which lies on an inversion centre, is distorted octahedral comprising two N atoms and two O atoms from two 5-methylpyrazine-2-carboxylate ligands, and two water molecules. The crystal structure is stabilized by a network of O-H...O hydrogen bonds, resulting in a two-dimensional supramolecular structure.

Comment top

The background to this study is set out in the preceding paper (Fan et al., 2007). Here we report the crystal structure of a mononuclear FeII (Fig. 1).

The asymmetric unit consists of a FeII atom, which lies on an inversion centre, one 2mpac ligand and two water molecules. A ring nitrogen atom and an oxygen atom of the carboxylate group from 2mpac ligand with Fe1—O1 = 2.103 (2) Å and Fe1—N1 = 2.167 (3) Å are involved in coordination to the FeII atom; these form a square. The coordination of the two water molecules with Fe1—O3 = 2.114 (2) Å occupied the axial sites results in the formation of a distorted octahedral geometry.

In the crystal structure, hydrogen bonding interactions are observed between the hydrogen atoms of the coordinated water molecules and the oxygen atoms of the carboxyl groups of a neighbouring unit, affording a two-dimensional supramolecular structure (Figure 2).

Related literature top

For background to this study, see: Fan et al. (2007).

Experimental top

The title compound was obtained from the mixture of ferrous ammonium sulfate hexahydrate(0.10 g, 0.25 mmol), 5-methylpyrazine-2-carboxylic acid (0.70 g, 0.5 mmol) and distilled water (20 ml), which was placed at room temperature for two weeks and red single crystals were obtained finally.

Refinement top

All H atoms attached to C atoms from the organic ligands were generated in idealized positions and constrained to ride on their parent atoms, with d(C—H) = 0.93 Å, Uiso=1.2Ueq (C) for aromatic and 0.96 Å, Uiso = 1.5Ueq (C) for CH3 atoms.

Computing details top

Data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT (Bruker, 2002); 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. A view of the molecular structure of title complex with the atom-labling scheme. Displacement ellipsoids are drawn at the 30% probability level. Symmetry code for A: 1-X, 1-Y, 1-Z.
[Figure 2] Fig. 2. Two-dimensional supramolecular structure of the title complex.
Diaqua(5-methylpyrazine-2-carboxylato-k2N1,O)iron(II) top
Crystal data top
[Fe(C6H5N2O2)2(H2O)2]Z = 1
Mr = 366.12F(000) = 188
Triclinic, P1Dx = 1.651 Mg m−3
a = 5.068 (1) ÅMo Kα radiation, λ = 0.71073 Å
b = 6.401 (1) ÅCell parameters from 715 reflections
c = 12.3810 (12) Åθ = 3.4–26.8°
α = 103.851 (2)°µ = 1.06 mm−1
β = 91.079 (1)°T = 298 K
γ = 108.340 (2)°Block, red
V = 368.22 (10) Å30.18 × 0.09 × 0.05 mm
Data collection top
Bruker SMART CCD area-detector
diffractometer		1260 independent reflections
Radiation source: fine-focus sealed tube1061 reflections with I > 2σ(I)
graphiteRint = 0.025
φ and ω scansθmax = 25.0°, θmin = 1.7°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)		h = −5→6
Tmin = 0.832, Tmax = 0.949k = −7→7
1916 measured reflectionsl = −14→12
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)] = 0.041Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.095H-atom parameters constrained
S = 1.00 w = 1/[σ2(Fo2) + (0.0456P)2]
where P = (Fo2 + 2Fc2)/3
1260 reflections(Δ/σ)max < 0.001
107 parametersΔρmax = 0.33 e Å−3
0 restraintsΔρmin = −0.28 e Å−3
Crystal data top
[Fe(C6H5N2O2)2(H2O)2]γ = 108.340 (2)°
Mr = 366.12V = 368.22 (10) Å3
Triclinic, P1Z = 1
a = 5.068 (1) ÅMo Kα radiation
b = 6.401 (1) ŵ = 1.06 mm−1
c = 12.3810 (12) ÅT = 298 K
α = 103.851 (2)°0.18 × 0.09 × 0.05 mm
β = 91.079 (1)°
Data collection top
Bruker SMART CCD area-detector
diffractometer		1260 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)		1061 reflections with I > 2σ(I)
Tmin = 0.832, Tmax = 0.949Rint = 0.025
1916 measured reflectionsθmax = 25.0°
Refinement top
R[F2 > 2σ(F2)] = 0.041H-atom parameters constrained
wR(F2) = 0.095Δρmax = 0.33 e Å−3
S = 1.00Δρmin = −0.28 e Å−3
1260 reflectionsAbsolute structure: ?
107 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
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
Fe10.50000.50000.50000.0326 (3)
N10.5923 (6)0.4742 (4)0.3281 (2)0.0323 (7)
N20.6791 (7)0.4921 (6)0.1096 (2)0.0508 (8)
O10.3162 (5)0.7203 (4)0.45178 (18)0.0359 (6)
O20.2550 (5)0.8729 (4)0.3133 (2)0.0472 (7)
O30.8721 (5)0.7772 (4)0.56033 (19)0.0423 (6)
H3A1.01210.79750.52260.051*
H3B0.87010.90770.59610.051*
C10.3463 (7)0.7489 (5)0.3543 (3)0.0330 (8)
C20.5049 (7)0.6138 (5)0.2826 (3)0.0313 (8)
C30.5494 (8)0.6191 (7)0.1744 (3)0.0482 (10)
H30.48560.71670.14450.058*
C40.7211 (7)0.3461 (6)0.2642 (3)0.0360 (8)
H40.78550.24870.29400.043*
C50.7624 (7)0.3530 (6)0.1548 (3)0.0394 (8)
C60.9003 (9)0.2011 (7)0.0829 (3)0.0582 (11)
H6A0.76000.07220.03470.087*
H6B1.00590.14950.12970.087*
H6C1.02320.28470.03840.087*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Fe10.0405 (5)0.0352 (4)0.0282 (4)0.0197 (3)0.0122 (3)0.0092 (3)
N10.0366 (16)0.0321 (16)0.0329 (15)0.0170 (13)0.0109 (12)0.0089 (13)
N20.064 (2)0.068 (2)0.0329 (17)0.0347 (19)0.0192 (15)0.0171 (17)
O10.0419 (14)0.0395 (14)0.0356 (14)0.0238 (11)0.0170 (10)0.0118 (11)
O20.0649 (18)0.0445 (16)0.0469 (15)0.0355 (14)0.0114 (12)0.0151 (13)
O30.0427 (15)0.0346 (14)0.0527 (16)0.0186 (12)0.0178 (11)0.0082 (12)
C10.0330 (19)0.0275 (18)0.037 (2)0.0099 (15)0.0054 (14)0.0044 (15)
C20.0337 (19)0.0296 (18)0.0322 (19)0.0137 (15)0.0061 (14)0.0066 (15)
C30.063 (3)0.059 (3)0.038 (2)0.035 (2)0.0160 (18)0.020 (2)
C40.039 (2)0.037 (2)0.039 (2)0.0206 (16)0.0122 (16)0.0104 (16)
C50.038 (2)0.047 (2)0.0333 (19)0.0198 (17)0.0102 (15)0.0036 (17)
C60.065 (3)0.063 (3)0.047 (2)0.030 (2)0.019 (2)−0.001 (2)
Geometric parameters (Å, °) top
Fe1—O1i2.103 (2)O3—H3A0.8500
Fe1—O12.103 (2)O3—H3B0.8499
Fe1—O3i2.114 (2)C1—C21.510 (5)
Fe1—O32.114 (2)C2—C31.369 (5)
Fe1—N1i2.167 (3)C3—H30.9300
Fe1—N12.167 (3)C4—C51.384 (5)
N1—C41.331 (4)C4—H40.9300
N1—C21.339 (4)C5—C61.505 (5)
N2—C51.323 (4)C6—H6A0.9600
N2—C31.335 (5)C6—H6B0.9600
O1—C11.268 (4)C6—H6C0.9600
O2—C11.232 (4)
O1i—Fe1—O1180.00 (11)H3A—O3—H3B107.6
O1i—Fe1—O3i89.75 (9)O2—C1—O1126.0 (3)
O1—Fe1—O3i90.25 (9)O2—C1—C2117.9 (3)
O1i—Fe1—O390.25 (9)O1—C1—C2116.0 (3)
O1—Fe1—O389.75 (9)N1—C2—C3119.7 (3)
O3i—Fe1—O3180.00 (10)N1—C2—C1116.5 (3)
O1i—Fe1—N1i77.21 (9)C3—C2—C1123.7 (3)
O1—Fe1—N1i102.79 (9)N2—C3—C2123.6 (3)
O3i—Fe1—N1i92.02 (9)N2—C3—H3118.2
O3—Fe1—N1i87.98 (9)C2—C3—H3118.2
O1i—Fe1—N1102.79 (9)N1—C4—C5122.1 (3)
O1—Fe1—N177.21 (9)N1—C4—H4118.9
O3i—Fe1—N187.98 (9)C5—C4—H4118.9
O3—Fe1—N192.02 (9)N2—C5—C4121.0 (3)
N1i—Fe1—N1180.000 (1)N2—C5—C6117.8 (3)
C4—N1—C2117.2 (3)C4—C5—C6121.2 (3)
C4—N1—Fe1130.3 (2)C5—C6—H6A109.5
C2—N1—Fe1112.5 (2)C5—C6—H6B109.5
C5—N2—C3116.3 (3)H6A—C6—H6B109.5
C1—O1—Fe1117.6 (2)C5—C6—H6C109.5
Fe1—O3—H3A121.1H6A—C6—H6C109.5
Fe1—O3—H3B121.9H6B—C6—H6C109.5
O1i—Fe1—N1—C42.7 (3)C4—N1—C2—C30.2 (5)
O1—Fe1—N1—C4−177.3 (3)Fe1—N1—C2—C3179.5 (3)
O3i—Fe1—N1—C4−86.6 (3)C4—N1—C2—C1177.0 (3)
O3—Fe1—N1—C493.4 (3)Fe1—N1—C2—C1−3.7 (3)
N1i—Fe1—N1—C4131 (100)O2—C1—C2—N1−177.5 (3)
O1i—Fe1—N1—C2−176.5 (2)O1—C1—C2—N11.4 (4)
O1—Fe1—N1—C23.5 (2)O2—C1—C2—C3−0.9 (5)
O3i—Fe1—N1—C294.2 (2)O1—C1—C2—C3178.0 (3)
O3—Fe1—N1—C2−85.8 (2)C5—N2—C3—C21.1 (6)
N1i—Fe1—N1—C2−48 (100)N1—C2—C3—N2−0.5 (6)
O1i—Fe1—O1—C129 (100)C1—C2—C3—N2−177.0 (3)
O3i—Fe1—O1—C1−90.8 (2)C2—N1—C4—C5−0.6 (5)
O3—Fe1—O1—C189.2 (2)Fe1—N1—C4—C5−179.8 (2)
N1i—Fe1—O1—C1177.1 (2)C3—N2—C5—C4−1.5 (5)
N1—Fe1—O1—C1−2.9 (2)C3—N2—C5—C6177.9 (3)
Fe1—O1—C1—O2−179.3 (3)N1—C4—C5—N21.3 (5)
Fe1—O1—C1—C21.9 (4)N1—C4—C5—C6−178.0 (3)
Symmetry codes: (i) −x+1, −y+1, −z+1.
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
O3—H3A···O1ii0.851.932.720 (3)155
O3—H3B···O2iii0.851.862.673 (3)159
Symmetry codes: (ii) x+1, y, z; (iii) −x+1, −y+2, −z+1.
Table 1
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
O3—H3A···O1i0.851.932.720 (3)155
O3—H3B···O2ii0.851.862.673 (3)159
Symmetry codes: (i) x+1, y, z; (ii) −x+1, −y+2, −z+1.
Acknowledgements top

We gratefully acknowledge the Special Research Fund of Xianyang Normal University for Talent Introduction (08XSYK305) and the Financial Support Fund from the Education Department of Shaanxi Province (No. 07 J K424).

references
References top

Bruker (2002). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.

Fan, G., Chen, S.-P. & Gao, S.-L. (2007). Acta Cryst. E63, m772–m773.

Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.