catena-Poly[[[diaqua-iron(II)]-μ-pyrazine-2,3-dicarboxyl-ato] dihydrate].

The crystal structure of the title compound, {[Fe(C(6)H(2)N(2)O(4))(H(2)O)(2)]·2H(2)O}(n), was synthesized by a diffusion method. It has a one-dimensional polymeric chain structure and the chains are further connected into a three-dimensional structure by hydrogen bonds. The Fe(II) ion has a distorted octa-hedral coordination environment, with two N and two O atoms from the pyrazine-2,3-dicarboxyl-ate ligands in the equatorial plane and with two water mol-ecules in axial positions. The Fe atom lies on a crystallographic centre of symmetry and a twofold rotation axis passes through the pyrazine ring.

Related literature

For related literature, see: Kondo et al. (1999 ▶); Kitaura et al. (2002 ▶); Zheng et al. (2002 ▶); Mao et al. (1996 ▶); Castillo et al. (2003 ▶); Konar et al. (2004 ▶); Muranishi & Okabe (2003 ▶); Richard et al. (1973 ▶); Xiang et al. (2004 ▶); Zou et al. (1999 ▶).

Experimental

Crystal data

[Fe(C6n class="Species">H2N2O4)(H2O)2]·2H2O

M = 294.01

Monoclinic,

a = 12.5650 (2) Å

b = 7.5158 (1) Å

c = 11.8314 (2) Å

β = 110.759 (1)°

V = 1044.77 (3) Å3

Z = 4

Mo Kα radiation

μ = 1.48 mm−1

T = 298 (2) K

0.23 × 0.20 × 0.18 mm

Data collection

Siemens SMART CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T min = 0.727, T max = 0.777

5477 measured reflections

1291 independent reflections

1219 reflections with I > 2σ’(I)

R int = 0.019

Refinement

R[F 2 > 2σ(F 2)] = 0.029

wR(F 2) = 0.088

S = 1.03

1291 reflections

80 parameters

H-atom parameters constrained

Δρmax = 0.59 e Å−3

Δρmin = −0.70 e Å−3

Data collection: SMART (Siemens, 1996 ▶); cell refinement: SAINT (Siemens, 1996 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a ▶); molecular graphics: SHELXTL (Sheldrick, 1997b ▶); software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536807064501/br2063sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536807064501/br2063Isup2.hkl

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

[Fe(C6H2N2O4)(H2O)2]·2H2O	F000 = 600
Mr = 294.01	Dx = 1.869 Mg m−3
Monoclinic, C2/c	Mo Kα radiation λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 3554 reflections
a = 12.5650 (2) Å	θ = 3.3–28.2º
b = 7.5158 (1) Å	µ = 1.48 mm−1
c = 11.8314 (2) Å	T = 298 (2) K
β = 110.759 (1)º	Block, red
V = 1044.77 (3) Å3	0.23 × 0.20 × 0.18 mm
Z = 4

CCD area-detector diffractometer	1291 independent reflections
Radiation source: fine-focus sealed tube	1219 reflections with I > 2σ(I)
Monochromator: graphite	Rint = 0.019
T = 298(2) K	θmax = 28.3º
φ and ω scans	θmin = 3.2º
Absorption correction: multi-scan(SADABS; Sheldrick, 1996)	h = −12→16
Tmin = 0.727, Tmax = 0.777	k = −10→10
5477 measured reflections	l = −15→15

Refinement on F2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F2 > 2σ(F2)] = 0.029	w = 1/[σ2(Fo2) + (0.0523P)2 + 1.9364P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.088	(Δ/σ)max < 0.001
S = 1.04	Δρmax = 0.59 e Å−3
1291 reflections	Δρmin = −0.70 e Å−3
80 parameters	Extinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.028 (2)
Secondary atom site location: difference Fourier map

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
Fe1	0.2500	0.2500	0.5000	0.01865 (18)
C1	0.08321 (16)	−0.0176 (3)	0.38935 (17)	0.0225 (4)
C2	0.04250 (15)	0.1436 (3)	0.30732 (16)	0.0202 (4)
C3	0.04814 (18)	0.4486 (3)	0.30161 (19)	0.0289 (5)
H3	0.0840	0.5557	0.3320	0.035*
N1	0.09020 (14)	0.2975 (2)	0.35810 (15)	0.0228 (3)
O1	0.18127 (13)	−0.0012 (2)	0.47077 (14)	0.0283 (3)
O2	0.01979 (14)	−0.1458 (2)	0.37732 (17)	0.0378 (4)
O3	0.32048 (15)	0.2010 (3)	0.36718 (16)	0.0387 (4)
H3A	0.3336	0.0941	0.3525	0.046*
H3B	0.3619	0.2805	0.3524	0.046*
O4	0.1817 (2)	0.2742 (3)	0.14299 (19)	0.0509 (6)
H4A	0.1531	0.1832	0.1004	0.061*
H4B	0.2226	0.3406	0.1168	0.061*

	U11	U22	U33	U12	U13	U23
Fe1	0.0141 (2)	0.0209 (3)	0.0166 (2)	−0.00144 (12)	0.00016 (15)	−0.00229 (12)
C1	0.0209 (8)	0.0219 (9)	0.0224 (8)	0.0007 (7)	0.0047 (7)	0.0014 (7)
C2	0.0158 (8)	0.0194 (9)	0.0222 (9)	−0.0005 (6)	0.0030 (7)	0.0004 (7)
C3	0.0279 (10)	0.0193 (9)	0.0318 (11)	−0.0031 (8)	0.0010 (9)	−0.0023 (8)
N1	0.0181 (7)	0.0223 (8)	0.0226 (8)	−0.0007 (6)	0.0005 (5)	−0.0013 (6)
O1	0.0244 (7)	0.0240 (6)	0.0276 (7)	−0.0012 (5)	−0.0018 (6)	0.0040 (5)
O2	0.0301 (8)	0.0273 (8)	0.0484 (10)	−0.0073 (6)	0.0047 (7)	0.0081 (7)
O3	0.0317 (9)	0.0544 (11)	0.0337 (9)	−0.0109 (8)	0.0160 (7)	−0.0108 (8)
O4	0.0651 (14)	0.0589 (13)	0.0310 (9)	−0.0257 (10)	0.0200 (10)	−0.0104 (8)

Fe1—O1i	2.0539 (15)	C2—N1	1.343 (3)
Fe1—O1	2.0539 (15)	C2—C2ii	1.398 (3)
Fe1—O3	2.0919 (17)	C3—N1	1.329 (3)
Fe1—O3i	2.0919 (17)	C3—C3ii	1.381 (4)
Fe1—N1i	2.1420 (17)	C3—H3	0.9300
Fe1—N1	2.1420 (17)	O3—H3A	0.8500
C1—O2	1.226 (3)	O3—H3B	0.8500
C1—O1	1.273 (2)	O4—H4A	0.8500
C1—C2	1.523 (3)	O4—H4B	0.8501
O1i—Fe1—O1	180.0	O2—C1—C2	119.56 (17)
O1i—Fe1—O3	91.35 (7)	O1—C1—C2	114.93 (16)
O1—Fe1—O3	88.65 (7)	N1—C2—C2ii	120.03 (11)
O1i—Fe1—O3i	88.65 (7)	N1—C2—C1	113.86 (16)
O1—Fe1—O3i	91.35 (7)	C2ii—C2—C1	125.94 (10)
O3—Fe1—O3i	180.000 (1)	N1—C3—C3ii	120.82 (11)
O1i—Fe1—N1i	78.46 (6)	N1—C3—H3	119.6
O1—Fe1—N1i	101.54 (6)	C3ii—C3—H3	119.6
O3—Fe1—N1i	91.76 (7)	C3—N1—C2	118.46 (17)
O3i—Fe1—N1i	88.24 (7)	C3—N1—Fe1	129.20 (14)
O1i—Fe1—N1	101.54 (6)	C2—N1—Fe1	110.65 (13)
O1—Fe1—N1	78.46 (6)	C1—O1—Fe1	116.94 (13)
O3—Fe1—N1	88.24 (7)	Fe1—O3—H3A	118.9
O3i—Fe1—N1	91.76 (7)	Fe1—O3—H3B	118.9
N1i—Fe1—N1	180.0	H3A—O3—H3B	116.4
O2—C1—O1	125.39 (19)	H4A—O4—H4B	116.0

D—H···A	D—H	H···A	D···A	D—H···A
O4—H4A···O1iii	0.85	2.17	2.890 (3)	142
O4—H4A···O2iii	0.85	2.59	3.227 (3)	133
O4—H4B···O1iv	0.85	2.20	3.045 (3)	174
O3—H3A···O4v	0.85	2.41	3.210 (3)	156
O3—H3B···O2vi	0.85	1.98	2.720 (2)	145
C3—H3···O2vii	0.93	2.51	3.232 (3)	135

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O4—H4A⋯O1i	0.85	2.17	2.890 (3)	142
O4—H4A⋯O2i	0.85	2.59	3.227 (3)	133
O4—H4B⋯O1ii	0.85	2.20	3.045 (3)	174
O3—H3A⋯O4iii	0.85	2.41	3.210 (3)	156
O3—H3B⋯O2iv	0.85	1.98	2.720 (2)	145
C3—H3⋯O2v	0.93	2.51	3.232 (3)	135

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) .