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Acta Crystallogr Sect E Struct Rep Online. 2008 July 1; 64(Pt 7): m888–m889.
Published online 2008 June 7. doi:  10.1107/S1600536808015316
PMCID: PMC2961772

Poly[[diaqua-μ4-pyrazine-2,3-dicarboxyl­ato-κ6 N,O 2:O 2′:O 3,O 3′:O 3-strontium(II)] monohydrate]

Abstract

In the title compound, {[Sr(C6H2N2O4)(H2O)2]·H2O}n, the SrII ions are bridged by the pyrazine-2,3-dicarboxyl­ate ligands with the formation of two-dimensional polymeric layers parallel to the ac plane. Each SrII ion is eight-coordinated by one N and five O atoms from the four ligands and two water mol­ecules. The coordination polyhedron is derived from a penta­gonal bipyramid with an O atom at the apex on one side of the equatorial plane and two O atoms sharing the apical site on the other side. The coordinated and uncoordinated water mol­ecules are involved in O—H(...)O and O—H(...)N hydrogen bonds, which consolidate the crystal structure.

Related literature

For related literature, see: Takusagawa & Shimada (1973 [triangle]); Richard et al. (1973 [triangle]); Zou et al. (1999 [triangle]); Konar et al. (2004 [triangle]); Li et al. (2003 [triangle]); Xu et al. (2008 [triangle]); Ma et al. (2006 [triangle]); Ptasiewicz-Bak & Leciejewicz (1997a [triangle],b [triangle]); Starosta & Leciejewicz (2005 [triangle]); Tombul et al. (2006 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-64-0m888-scheme1.jpg

Experimental

Crystal data

  • [Sr(C6H2N2O4)(H2O)2]·H2O
  • M r = 307.76
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-64-0m888-efi8.jpg
  • a = 10.4931 (7) Å
  • b = 6.9839 (4) Å
  • c = 13.5208 (8) Å
  • β = 94.2670 (10)°
  • V = 988.10 (10) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 5.48 mm−1
  • T = 120 (2) K
  • 0.28 × 0.25 × 0.10 mm

Data collection

  • Bruker SMART 1000 CCD area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 1998 [triangle]) T min = 0.240, T max = 0.568
  • 8338 measured reflections
  • 1934 independent reflections
  • 1595 reflections with I > 2σ(I)
  • R int = 0.040

Refinement

  • R[F 2 > 2σ(F 2)] = 0.024
  • wR(F 2) = 0.054
  • S = 1.00
  • 1934 reflections
  • 145 parameters
  • H-atom parameters constrained
  • Δρmax = 0.92 e Å−3
  • Δρmin = −0.45 e Å−3

Data collection: SMART (Bruker, 1998 [triangle]); cell refinement: SAINT-Plus (Bruker, 1998 [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; software used to prepare material for publication: SHELXTL.

Table 1
Selected bond lengths (Å)
Table 2
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808015316/cv2408sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808015316/cv2408Isup2.hkl

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

Acknowledgments

We are grateful to the Islamic Azad University, North Tehran Branch, for financial support.

supplementary crystallographic information

Comment

Takusagawa & Shimada (1973) first determined the structure of pyrazine-2,3-dicarboxlic acid by single-crystal X-ray analysis. Almost at the same time, the first metal-organic compound of pyrazine-2,3-dicarboxylic acid was reported (Richard et al., 1973). Among many reported compounds containing pyrazine-2,3-dicarboxylic acid, most are complexes of transition metal ions, including manganese (Zou et al., 1999), copper (Konar et al., 2004), zinc (Li et al., 2003), iron (Xu et al., 2008) and cadmium (Ma et al., 2006). Also, there are many reported compounds of pyrazine-2,3-dicarboxylic acid with main group metals such as calcium (Ptasiewicz-Bak & Leciejewicz, 1997a; Starosta & Leciejewicz, 2005), magnesium (Ptasiewicz-Bak & Leciejewicz, 1997b) and sodium (Tombul et al., 2006) complexes. For further investigation of pyrazine-2,3-dicarboxylic acid, we synthesized the title compound, (I).

The asymmetric unit of the title compound, (Fig. 1), contains molecular sheets in which SrII ions are bridged by the carboxylate groups of the ligand molecules. Two bridging paths are evident. In the first, an N,O-bonding moiety formed by a hetero-ring nitrogen atom and the carboxylate oxygen atom nearest to it and both oxygen atoms of the second carboxylic group are active. The second path is formed by the other oxygen atom from the carboxylic group involved in the N,O-bonding moiety and an oxygen atom from the second carboxylic group. The latter atom is bidentate. A two-dimensional molecular pattern is formed. Each SrII ion is also coordinated by two water oxygen atoms, making the number of coordinated atoms eight. The coordination polyhedron is a distorted pentagonal bipyramid with an oxygen atom at the apex on one side of the equatorial plane and two oxygen atoms forming the apices on the other side. There is also one non-coordinated water molecule in the asymmetric unit. The Sr—O and Sr—N bond lengths are collected in Table 1.

Intermolecular O—H···O and O—H···N hydrogen bonds (Table 2) help to consolidate the crystal packing (Fig. 2).

Experimental

A solution of pyrazine-2,3-dicarboxlic acid (0.5 g, 2.91 mmol) in methanol (40 ml) was added to a solution of Sr(NO3)2 (0.31 g, 1.46 mmol) in water (10 ml) and the resulting colourless solution was stirred for 10 min at room temperature. This solution was left to evaporate slowly at room temperature. After one week, colourless plate crystals of the title compound were isolated (yield 0.35 g, 78.03%).

Refinement

C-bound H atoms were geometrically positioned (C-H 0.95 Å), while O-bound H atoms were found in difference Fourier maps, but placed in idealized positions with O-H of 0.85 Å. All hydrogen atoms were refined in riding model approximation with Uiso(H) = 1.2Ueq of the paren atom.

Figures

Fig. 1.
A portion of the polymeric structure of (I) with the atom-numbering scheme and displacement ellipsoids drawn at the 40% probability level [symmetry codes: (i) -x - 1/2,y - 1/2,-z + 1/2, (ii) -x - 1/2, y + 1/2,-z + 1/2, (iii) x - 1/2,-y + 1/2,z + 1/2]. ...
Fig. 2.
A packing diagram for (I). Hydrogen bonds are shown as dashed lines.

Crystal data

[Sr(C6H2N2O4)(H2O)2]·H2OF000 = 608
Mr = 307.76Dx = 2.069 Mg m3
Monoclinic, P21/nMo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 156 reflections
a = 10.4931 (7) Åθ = 3–26º
b = 6.9839 (4) ŵ = 5.48 mm1
c = 13.5208 (8) ÅT = 120 (2) K
β = 94.2670 (10)ºPlate, colorless
V = 988.10 (10) Å30.28 × 0.25 × 0.10 mm
Z = 4

Data collection

Bruker SMART 1000 CCD area-detector diffractometer1934 independent reflections
Radiation source: fine-focus sealed tube1595 reflections with I > 2σ(I)
Monochromator: graphiteRint = 0.040
T = 120(2) Kθmax = 26.0º
[var phi] and ω scansθmin = 2.4º
Absorption correction: multi-scan(SADABS; Bruker, 1998)h = −12→12
Tmin = 0.240, Tmax = 0.568k = −8→8
8338 measured reflectionsl = −16→16

Refinement

Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: mixed
R[F2 > 2σ(F2)] = 0.024H-atom parameters constrained
wR(F2) = 0.054  w = 1/[σ2(Fo2) + (0.026P)2] where P = (Fo2 + 2Fc2)/3
S = 1.01(Δ/σ)max = 0.002
1934 reflectionsΔρmax = 0.92 e Å3
145 parametersΔρmin = −0.45 e Å3
Primary atom site location: structure-invariant direct methodsExtinction correction: none

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
Sr1−0.44206 (2)0.17756 (3)0.375530 (17)0.01058 (9)
N1−0.4291 (2)0.1488 (3)0.17632 (16)0.0137 (5)
N2−0.3958 (2)0.2550 (3)−0.01781 (16)0.0138 (5)
O1−0.14140 (18)0.1344 (3)−0.07125 (13)0.0154 (4)
O2−0.09707 (18)0.3655 (3)0.03862 (13)0.0148 (4)
O3−0.21964 (18)0.1162 (3)0.30617 (13)0.0164 (4)
O4−0.10633 (16)0.0171 (3)0.18088 (13)0.0131 (4)
C1−0.3115 (2)0.1518 (4)0.14221 (19)0.0114 (6)
C2−0.2956 (3)0.2059 (4)0.04464 (19)0.0117 (6)
C3−0.5114 (3)0.2480 (4)0.0166 (2)0.0156 (6)
H3A−0.58410.2794−0.02640.019*
C4−0.5277 (3)0.1963 (4)0.11335 (19)0.0150 (6)
H4A−0.61150.19450.13560.018*
C5−0.2037 (3)0.0901 (4)0.21630 (19)0.0123 (6)
C6−0.1670 (3)0.2340 (4)0.00239 (19)0.0114 (6)
O1W−0.64324 (17)−0.0101 (3)0.30768 (13)0.0161 (4)
H1W1−0.6382−0.11060.27270.019*
H2W1−0.71740.03550.29320.019*
O2W−0.31193 (17)0.2633 (3)0.53262 (13)0.0150 (4)
H1W2−0.32200.38020.54780.018*
H2W2−0.32460.18530.57910.018*
O3W0.11689 (17)0.1471 (3)0.28299 (13)0.0161 (4)
H1W30.04440.12030.25400.019*
H2W30.10110.17870.34150.019*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Sr10.00953 (13)0.01224 (14)0.01019 (13)0.00004 (11)0.00220 (9)0.00048 (11)
N10.0110 (12)0.0183 (13)0.0119 (11)0.0000 (10)0.0026 (9)−0.0003 (10)
N20.0112 (12)0.0163 (12)0.0140 (11)0.0013 (9)0.0021 (9)0.0000 (10)
O10.0168 (10)0.0174 (10)0.0125 (9)−0.0015 (8)0.0050 (8)−0.0024 (8)
O20.0123 (10)0.0160 (11)0.0163 (10)−0.0026 (8)0.0029 (8)−0.0017 (8)
O30.0142 (10)0.0245 (11)0.0106 (9)0.0028 (8)0.0022 (8)−0.0006 (8)
O40.0084 (9)0.0159 (10)0.0154 (9)0.0020 (8)0.0033 (8)−0.0022 (8)
C10.0086 (13)0.0133 (14)0.0124 (13)−0.0008 (11)0.0016 (10)−0.0041 (11)
C20.0137 (14)0.0095 (13)0.0123 (13)−0.0030 (11)0.0024 (11)−0.0016 (11)
C30.0119 (15)0.0185 (14)0.0161 (14)0.0013 (11)−0.0009 (11)−0.0008 (12)
C40.0096 (14)0.0195 (15)0.0157 (14)−0.0006 (11)0.0005 (11)−0.0008 (12)
C50.0126 (14)0.0099 (13)0.0144 (14)−0.0027 (11)0.0017 (11)0.0027 (11)
C60.0115 (14)0.0108 (13)0.0118 (13)0.0017 (11)−0.0001 (11)0.0027 (11)
O1W0.0123 (10)0.0176 (10)0.0184 (10)0.0009 (8)0.0016 (8)−0.0007 (8)
O2W0.0161 (10)0.0145 (10)0.0142 (10)−0.0007 (8)0.0010 (8)0.0013 (8)
O3W0.0112 (10)0.0257 (11)0.0113 (9)−0.0009 (8)0.0012 (8)−0.0013 (8)

Geometric parameters (Å, °)

Sr1—O2i2.4887 (18)O2—Sr1ii2.4887 (18)
Sr1—O2W2.5106 (18)O2—Sr1v2.8517 (18)
Sr1—O4ii2.5533 (18)O3—C51.252 (3)
Sr1—O1W2.5937 (19)O4—C51.267 (3)
Sr1—O32.6145 (18)O4—Sr1i2.5533 (18)
Sr1—O1iii2.6155 (18)C1—C21.394 (4)
Sr1—N12.714 (2)C1—C51.517 (4)
Sr1—O2iii2.8517 (18)C2—C61.516 (4)
Sr1—C6iii3.082 (3)C3—C41.381 (4)
Sr1—Sr1iv4.4235 (5)C3—H3A0.9500
Sr1—H1W22.9292C4—H4A0.9500
Sr1—H2W22.9320C6—Sr1v3.082 (3)
N1—C41.332 (3)O1W—H1W10.8500
N1—C11.349 (3)O1W—H2W10.8500
N2—C31.331 (3)O2W—H1W20.8500
N2—C21.343 (3)O2W—H2W20.8500
O1—C61.260 (3)O3W—H1W30.8501
O1—Sr1v2.6155 (18)O3W—H2W30.8499
O2—C61.252 (3)
O2i—Sr1—O2W75.75 (6)O2iii—Sr1—H1W270.9
O2i—Sr1—O4ii157.35 (6)C6iii—Sr1—H1W276.3
O2W—Sr1—O4ii85.61 (6)Sr1iv—Sr1—H1W278.0
O2i—Sr1—O1W79.88 (6)O2i—Sr1—H2W262.3
O2W—Sr1—O1W142.83 (6)O2W—Sr1—H2W215.6
O4ii—Sr1—O1W122.57 (6)O4ii—Sr1—H2W2100.6
O2i—Sr1—O384.44 (6)O1W—Sr1—H2W2128.0
O2W—Sr1—O384.19 (6)O3—Sr1—H2W290.9
O4ii—Sr1—O380.93 (6)O1iii—Sr1—H2W291.2
O1W—Sr1—O3121.00 (6)N1—Sr1—H2W2152.2
O2i—Sr1—O1iii114.76 (6)O2iii—Sr1—H2W260.0
O2W—Sr1—O1iii92.48 (6)C6iii—Sr1—H2W276.1
O4ii—Sr1—O1iii78.28 (6)Sr1iv—Sr1—H2W254.3
O1W—Sr1—O1iii72.81 (6)H1W2—Sr1—H2W228.2
O3—Sr1—O1iii159.14 (6)C4—N1—C1117.7 (2)
O2i—Sr1—N1112.29 (6)C4—N1—Sr1121.46 (17)
O2W—Sr1—N1142.46 (6)C1—N1—Sr1116.91 (16)
O4ii—Sr1—N175.33 (6)C3—N2—C2117.5 (2)
O1W—Sr1—N173.21 (6)C6—O1—Sr1v99.33 (16)
O3—Sr1—N161.32 (6)C6—O2—Sr1ii153.65 (17)
O1iii—Sr1—N1114.22 (6)C6—O2—Sr1v88.36 (15)
O2i—Sr1—O2iii68.33 (6)Sr1ii—O2—Sr1v111.67 (6)
O2W—Sr1—O2iii71.13 (6)C5—O3—Sr1124.02 (17)
O4ii—Sr1—O2iii117.81 (5)C5—O4—Sr1i132.10 (16)
O1W—Sr1—O2iii73.99 (5)N1—C1—C2120.3 (2)
O3—Sr1—O2iii146.69 (6)N1—C1—C5115.2 (2)
O1iii—Sr1—O2iii47.66 (5)C2—C1—C5124.4 (2)
N1—Sr1—O2iii146.41 (6)N2—C2—C1121.3 (2)
O2i—Sr1—C6iii91.29 (7)N2—C2—C6114.0 (2)
O2W—Sr1—C6iii82.66 (6)C1—C2—C6124.4 (2)
O4ii—Sr1—C6iii99.08 (6)N2—C3—C4121.4 (3)
O1W—Sr1—C6iii70.19 (6)N2—C3—H3A119.3
O3—Sr1—C6iii166.80 (6)C4—C3—H3A119.3
O1iii—Sr1—C6iii23.79 (6)N1—C4—C3121.7 (3)
N1—Sr1—C6iii131.61 (7)N1—C4—H4A119.1
O2iii—Sr1—C6iii23.97 (6)C3—C4—H4A119.1
O2i—Sr1—Sr1iv36.81 (4)O3—C5—O4126.5 (2)
O2W—Sr1—Sr1iv69.70 (4)O3—C5—C1116.9 (2)
O4ii—Sr1—Sr1iv145.08 (4)O4—C5—C1116.6 (2)
O1W—Sr1—Sr1iv73.93 (4)O2—C6—O1124.1 (2)
O3—Sr1—Sr1iv118.96 (4)O2—C6—C2117.4 (2)
O1iii—Sr1—Sr1iv78.55 (4)O1—C6—C2118.3 (2)
N1—Sr1—Sr1iv138.62 (5)O2—C6—Sr1v67.67 (14)
O2iii—Sr1—Sr1iv31.52 (4)O1—C6—Sr1v56.88 (13)
C6iii—Sr1—Sr1iv54.80 (5)C2—C6—Sr1v167.25 (17)
O2i—Sr1—H1W290.3Sr1—O1W—H1W1122.1
O2W—Sr1—H1W215.7Sr1—O1W—H2W1126.8
O4ii—Sr1—H1W272.9H1W1—O1W—H2W1105.9
O1W—Sr1—H1W2144.7Sr1—O2W—H1W2111.4
O3—Sr1—H1W291.3Sr1—O2W—H2W2111.6
O1iii—Sr1—H1W281.0H1W2—O2W—H2W2114.0
N1—Sr1—H1W2140.8H1W3—O3W—H2W3104.9
O2i—Sr1—N1—C4121.4 (2)C3—N2—C2—C1−0.7 (4)
O2W—Sr1—N1—C4−143.01 (19)C3—N2—C2—C6−175.0 (2)
O4ii—Sr1—N1—C4−81.1 (2)N1—C1—C2—N2−0.4 (4)
O1W—Sr1—N1—C450.2 (2)C5—C1—C2—N2178.5 (2)
O3—Sr1—N1—C4−168.7 (2)N1—C1—C2—C6173.3 (2)
O1iii—Sr1—N1—C4−11.5 (2)C5—C1—C2—C6−7.8 (4)
O2iii—Sr1—N1—C437.4 (3)C2—N2—C3—C41.3 (4)
C6iii—Sr1—N1—C48.1 (2)C1—N1—C4—C3−0.3 (4)
Sr1iv—Sr1—N1—C489.0 (2)Sr1—N1—C4—C3156.5 (2)
O2i—Sr1—N1—C1−81.51 (18)N2—C3—C4—N1−0.8 (4)
O2W—Sr1—N1—C114.0 (2)Sr1—O3—C5—O4−162.37 (19)
O4ii—Sr1—N1—C175.96 (18)Sr1—O3—C5—C117.6 (3)
O1W—Sr1—N1—C1−152.72 (19)Sr1i—O4—C5—O396.7 (3)
O3—Sr1—N1—C1−11.61 (17)Sr1i—O4—C5—C1−83.2 (3)
O1iii—Sr1—N1—C1145.59 (17)N1—C1—C5—O3−27.8 (3)
O2iii—Sr1—N1—C1−165.53 (15)C2—C1—C5—O3153.3 (3)
C6iii—Sr1—N1—C1165.13 (16)N1—C1—C5—O4152.2 (2)
Sr1iv—Sr1—N1—C1−113.97 (17)C2—C1—C5—O4−26.8 (4)
O2i—Sr1—O3—C5115.1 (2)Sr1ii—O2—C6—O1148.1 (3)
O2W—Sr1—O3—C5−168.7 (2)Sr1v—O2—C6—O17.3 (3)
O4ii—Sr1—O3—C5−82.2 (2)Sr1ii—O2—C6—C2−26.3 (5)
O1W—Sr1—O3—C540.4 (2)Sr1v—O2—C6—C2−167.1 (2)
O1iii—Sr1—O3—C5−87.1 (3)Sr1ii—O2—C6—Sr1v140.8 (4)
N1—Sr1—O3—C5−4.08 (19)Sr1v—O1—C6—O2−8.1 (3)
O2iii—Sr1—O3—C5149.62 (18)Sr1v—O1—C6—C2166.25 (19)
C6iii—Sr1—O3—C5−173.4 (3)N2—C2—C6—O2110.2 (3)
Sr1iv—Sr1—O3—C5128.36 (19)C1—C2—C6—O2−63.9 (4)
C4—N1—C1—C20.9 (4)N2—C2—C6—O1−64.5 (3)
Sr1—N1—C1—C2−157.03 (19)C1—C2—C6—O1121.4 (3)
C4—N1—C1—C5−178.1 (2)N2—C2—C6—Sr1v−0.2 (9)
Sr1—N1—C1—C524.0 (3)C1—C2—C6—Sr1v−174.3 (7)

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

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
O1W—H1W1···O3Wi0.851.872.713 (3)170
O1W—H2W1···O3Wvi0.851.902.744 (3)171
O2W—H1W2···O1ii0.851.852.696 (3)174
O2W—H2W2···O1Wiv0.852.012.857 (3)178
O3W—H1W3···O40.851.942.781 (3)170
O3W—H2W3···N2vii0.851.962.792 (3)168

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

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: CV2408).

References

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