Poly[[diaqua­tetra­kis­(μ2-benzene-1,4-di­carbonitrile-κ2N:N′)iron(II)] bis­[tetra­chlorido­ferrate(III)] nitro­methane tetra­solvate]

Prommon, P.; Promseenong, P.; Chainok, K.

doi:10.1107/S1600536812002486

metal-organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 68| Part 2| February 2012| Pages m211-m212

doi:10.1107/S1600536812002486

Open

access

Poly[[diaquatetrakis(μ₂-benzene-1,4-dicarbonitrile-κ²N:N′)iron(II)] bis[tetrachloridoferrate(III)] nitromethane tetrasolvate]

Pimonrat Prommon,^a Pinyada Promseenong ^a and Kittipong Chainok ^a ^*

^aDepartment of Chemistry, Faculty of Science, Naresuan University, Muang Phitsanulok 65000, Thailand
^*Correspondence e-mail: kittipongc@nu.ac.th

(Received 18 January 2012; accepted 19 January 2012; online 31 January 2012)

In the title compound, {[Fe^II(C₈H₄N₂)₂(H₂O)₂][Fe^IIICl₄]₂·4CH₃NO₂}_n, the Fe^II and Fe^III ions are hexa- and tetracoordinated, respectively. Each unique benzene-1,4-dicarbonitrile molecule lies across a crystallographic inversion centre and bridges two Fe^II ions (each situated on an inversion centre), generating two-dimensional (4,4) square grid layers. The tetrachloridoferrate(III) anions and nitromethane solvent molecules lie between the square grid layers and are further link to the adjacent layers into a three-dimensional supramolecular structure through O—H⋯Cl and O—H⋯O hydrogen bonds.

Related literature

For background to Fe^II spin-crossover complexes, see: Kahn & Martinez (1998 ); Neville et al. (2007 , 2008 ); Murray (2008 ). For the use of two connecting organodinitrile ligands for the development of magnetism, see: Chainok et al. (2010 , 2012 ). For the synthesis, see: Chainok et al. (2012).

Experimental

Crystal data

[Fe(C₈H₄N₂)₂(H₂O)₂][FeCl₄]₂·4CH₃NO₂
M_r = 987.62
Monoclinic, P 2₁ /n
a = 12.1307 (9) Å
b = 12.1554 (9) Å
c = 13.8209 (10) Å
β = 102.466 (1)°
V = 1989.9 (3) Å³
Z = 2
Mo Kα radiation
μ = 1.67 mm⁻¹
T = 100 K
0.27 × 0.27 × 0.24 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ) T_min = 0.661, T_max = 0.690
11573 measured reflections
4397 independent reflections
3541 reflections with I > 2σ(I)
R_int = 0.030

Refinement

R[F² > 2σ(F²)] = 0.032
wR(F²) = 0.073
S = 1.03
4397 reflections
233 parameters
3 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.76 e Å⁻³
Δρ_min = −0.50 e Å⁻³

Table 1
Selected bond lengths (Å)

Fe1—O1	2.0884 (15)
Fe1—N21	2.1309 (17)
Fe1—N11	2.1649 (17)
Cl1—Fe2	2.2070 (6)
Fe2—Cl2	2.1811 (6)
Fe2—Cl3	2.1968 (6)
Fe2—Cl4	2.1996 (6)

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯O2	0.87 (2)	1.99 (2)	2.804 (2)	155 (3)
O1—H1⋯O4	0.87 (2)	2.57 (3)	3.074 (3)	118 (2)
O1—H2⋯Cl1	0.84 (2)	2.43 (2)	3.2731 (16)	177 (3)

Data collection: SMART (Bruker, 2001 ); cell refinement: SAINT (Bruker, 2002 ); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ) and DIAMOND (Brandenburg, 2006 ); software used to prepare material for publication: publCIF (Westrip, 2010 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536812002486/tk5052sup1.cif

Supporting information file. DOI: 10.1107/S1600536812002486/tk5052Isup2.cdx

Structure factors: contains datablock I. DOI: 10.1107/S1600536812002486/tk5052Isup3.hkl

checkCIF report

Comment top

The d⁶ Fe(II) complexes exhibiting spin-crossover (SCO) transitions between a ¹A₁ low spin (S = 0) and a ⁵T₂ high spin (S = 2) states are of interest due to their possible applications as molecular switches or materials for information storage (Kahn & Martinez 1998). Although the fundamental origin of the SCO phenomenon is molecular, SCO transitions in the crystal structure can be reversibly switched by external stimuli such as light, temperature and pressure as well as the existence of long or short range supramolecular interactions (Neville et al. 2007, 2008; Murray 2008). The title compound was obtained as a minor product in another an earlier from part of further study of how the nature of the two-connecting organodinitrile bridging ligands affect the SCO phenomenon in the Fe(II) complexes (Chainok et al. 2010).

A fragment containing the asymmetric unit with atom numbering and coordination environments of the metal centre of the title compound is shown in Fig. 1. The asymmetric unit contains one iron(II) cation (half-occupancy), one coordinated water molecule, half of two independent benzene-1,4-dicarbonitrile ligand, one tetrachloridoferrate(III) anion, and two nitromethane solvent molecules. The Fe^II ion resides in an inversion center and is octahedrally coordinated by four nitrogen atoms from benzene-1,4-dicarbonitrile ligands in the equatorial plane and two equivalent terminal water molecules occupying the axial positions. The Fe—N and Fe—O bond lengths in the title compound, Table 1, are comparable to that observed for a high spin species in the corresponding Fe(II) complex containing the two-connecting organodinitrile ligands such as [Fe^II(AIBN)(H₂O)][Fe^IIICl₄]₂ (Fe—N = 2.144 (1)–2.171 (1) Å and Fe–O = 2.084 (1) Å), AIBN = 2,2'-azobisisobutyronitrile (Chainok et al. 2010). Each benzene-1,4-dicarbonitrile ligand has crystallographically imposed inversion symmetry and is bound to two neighboring Fe^II ions generating two-dimensional approximate square grid layers with (4,4) topology perpendicular to the c axis, with the dimension of 12.1307 (9) × 12.1554 (9) Å (Fe^II···Fe^II distances across the benzene-1,4-dicarbonitrile ligand), Fig. 2. The layers are packed to each other with an interlayer separation of 6.0777 (5) Å.

The Fe^III atom is a tetrahedrally coordinated to four chloride anions. The bond lengths and angles around the Fe(III) ions are within the common ranges for this type of coordination environment (Chainok et al. 2010). The tetrachloridoferrate(III) anions and the nitromethane solvent molecules all lie in general position in the structure, and are included in the layers by eschewing the interpenetration of the networks. These guest molecules are then further linked to the adjacent two-dimensional layers into a three-dimensional supramolecular structure through O—H···Cl and O—H···O hydrogen bonds formed between the apically water molecules coordinated to the metal ions and Cl and O atoms of the guest molecules, Table 2.

Related literature top

For background to Fe^II spin-crossover complexes, see: Kahn & Martinez (1998); Neville et al. (2007, 2008); Murray (2008). For the use of two connecting organodinitrile ligands for the development of magnetism, see: Chainok et al. (2010, 2012). For the synthesis, see: Chainok et al. (2012).

Experimental top

Single crystals of the title compound were obtained as the minor product during the synthesis of [Fe^II(C₈H₄N₂)₂][Fe^IIICl₄]₂ (Chainok et al. 2012) when traces of air and moisture are presented. Typically, FeCl₂ (62 mg, 0.5 mmol) and FeCl₃ (163 mg, 1 mmol) were dissolved in 3 ml of CH₃NO₂ to formed a yellow brown solution and this was pipetted into one side of the H-tube. Benzene-1,4-dicarbonitrile (192 mg, 1.5 mmol) was dissolved in 3 ml of CH₃NO₂ to give a colorless solution and this was pipetted into the other side arm of the H-tube. The H-tube was then carefully filled with CH₃NO₂. Upon slow diffusion for two weeks, yellow block-shaped of the major product (ca. 60% yield based on FeCl₂) and pale yellow plate of the minor product (ca. 5% yield based on FeCl₂) single crystals were formed in the iron-containing side of the H-tube.

Computing details top

Data collection: SMART (Bruker, 2001); 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: ORTEP-3 for Windows (Farrugia,1997) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top

	Fig. 1. Displacement ellipsoid plot of a fragment at the 50% probability level containing the asymmetric unit with atom numbering and coordination environments of the metal centers of the title compound.
	Fig. 2. Inclusion of tetrachloridoferrate(III) anions and nitromethane molecules in the square grid networks of the title compound.

Poly[[diaquatetrakis(µ₂-benzene-1,4-dicarbonitrile- κ²N:N')iron(II)] bis[tetrachloroferrate(III)] nitromethane tetrasolvate] top

Crystal data top

[Fe(C₈H₄N₂)₂(H₂O)₂][FeCl₄]₂·4CH₃NO₂	F(000) = 988
M_r = 987.62	D_x = 1.648 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 3583 reflections
a = 12.1307 (9) Å	θ = 2.4–27.4°
b = 12.1554 (9) Å	µ = 1.67 mm⁻¹
c = 13.8209 (10) Å	T = 100 K
β = 102.466 (1)°	Block, yellow
V = 1989.9 (3) Å³	0.27 × 0.27 × 0.24 mm
Z = 2

Data collection top

Bruker SMART APEX CCD area-detector diffractometer	4397 independent reflections
Radiation source: fine-focus sealed tube	3541 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.030
Detector resolution: 8 pixels mm^-1	θ_max = 28.1°, θ_min = 2.0°
ω and ϕ scans	h = −15→16
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	k = −12→15
T_min = 0.661, T_max = 0.690	l = −17→17
11573 measured reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.032	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.073	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ²(F_o²) + (0.042P)²] where P = (F_o² + 2F_c²)/3
4397 reflections	(Δ/σ)_max = 0.001
233 parameters	Δρ_max = 0.76 e Å⁻³
3 restraints	Δρ_min = −0.50 e Å⁻³

Crystal data top

[Fe(C₈H₄N₂)₂(H₂O)₂][FeCl₄]₂·4CH₃NO₂	V = 1989.9 (3) Å³
M_r = 987.62	Z = 2
Monoclinic, P2₁/n	Mo Kα radiation
a = 12.1307 (9) Å	µ = 1.67 mm⁻¹
b = 12.1554 (9) Å	T = 100 K
c = 13.8209 (10) Å	0.27 × 0.27 × 0.24 mm
β = 102.466 (1)°

Data collection top

Bruker SMART APEX CCD area-detector diffractometer	4397 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	3541 reflections with I > 2σ(I)
T_min = 0.661, T_max = 0.690	R_int = 0.030
11573 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.032	3 restraints
wR(F²) = 0.073	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	Δρ_max = 0.76 e Å⁻³
4397 reflections	Δρ_min = −0.50 e Å⁻³
233 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

	x	y	z	U_iso*/U_eq
Fe1	0.5000	0.5000	0.5000	0.01056 (10)
Cl1	0.31456 (5)	0.45491 (4)	0.76369 (4)	0.02217 (13)
O1	0.52584 (13)	0.46637 (12)	0.65141 (11)	0.0173 (3)
N1	0.74782 (15)	0.26095 (15)	0.71549 (13)	0.0200 (4)
C1	0.7964 (2)	0.15057 (19)	0.74355 (17)	0.0270 (5)
H1A	0.7828	0.1301	0.8086	0.040*
H1B	0.8778	0.1522	0.7465	0.040*
H1C	0.7606	0.0965	0.6941	0.040*
H1	0.576 (2)	0.417 (2)	0.676 (2)	0.052 (9)*
Fe2	0.29049 (3)	0.29511 (2)	0.83208 (2)	0.01702 (9)
Cl2	0.42489 (5)	0.18565 (5)	0.80885 (4)	0.02811 (14)
O2	0.64553 (13)	0.26786 (12)	0.68614 (12)	0.0259 (4)
N2	0.67018 (18)	0.34984 (17)	0.93557 (15)	0.0297 (5)
C2	0.6206 (3)	0.3774 (2)	1.0194 (2)	0.0437 (7)
H2A	0.6721	0.3550	1.0810	0.066*
H2B	0.5485	0.3388	1.0131	0.066*
H2C	0.6080	0.4570	1.0205	0.066*
H2	0.4716 (18)	0.466 (2)	0.6803 (19)	0.043 (9)*
Cl3	0.12062 (5)	0.23479 (4)	0.76444 (4)	0.02225 (13)
O3	0.81115 (14)	0.33973 (14)	0.72375 (13)	0.0318 (4)
Cl4	0.30172 (5)	0.31921 (5)	0.99164 (4)	0.02609 (14)
O4	0.6489 (2)	0.41206 (17)	0.86466 (15)	0.0661 (7)
O5	0.72545 (17)	0.26586 (17)	0.93885 (17)	0.0515 (6)
N11	0.49078 (14)	0.32436 (14)	0.47352 (13)	0.0159 (4)
C11	0.49325 (17)	0.23044 (17)	0.47862 (15)	0.0151 (4)
C12	0.49595 (17)	0.11201 (16)	0.48873 (15)	0.0164 (4)
C13	0.48332 (19)	0.06644 (17)	0.57797 (16)	0.0203 (5)
H13	0.4724	0.1125	0.6306	0.024*
C14	0.51318 (19)	0.04656 (17)	0.41060 (16)	0.0200 (5)
H14	0.5224	0.0791	0.3503	0.024*
N21	0.32197 (14)	0.50641 (13)	0.48775 (13)	0.0166 (4)
C21	0.22841 (17)	0.50554 (16)	0.48975 (15)	0.0148 (4)
C22	0.11031 (17)	0.50257 (16)	0.49328 (15)	0.0146 (4)
C23	0.07732 (17)	0.42932 (16)	0.55939 (15)	0.0160 (4)
H23	0.1310	0.3821	0.5994	0.019*
C24	0.03464 (17)	0.57343 (17)	0.43427 (15)	0.0164 (4)
H24	0.0595	0.6230	0.3903	0.020*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Fe1	0.0092 (2)	0.00766 (19)	0.0156 (2)	0.00009 (14)	0.00442 (15)	0.00041 (15)
Cl1	0.0274 (3)	0.0176 (3)	0.0228 (3)	−0.0022 (2)	0.0083 (2)	0.0030 (2)
O1	0.0169 (8)	0.0178 (8)	0.0186 (8)	0.0021 (6)	0.0067 (6)	0.0021 (6)
N1	0.0243 (11)	0.0234 (10)	0.0130 (9)	0.0027 (8)	0.0053 (8)	0.0015 (7)
C1	0.0316 (14)	0.0252 (13)	0.0236 (12)	0.0121 (10)	0.0046 (10)	0.0056 (10)
Fe2	0.02082 (17)	0.01520 (16)	0.01655 (17)	0.00175 (12)	0.00737 (13)	0.00109 (12)
Cl2	0.0319 (3)	0.0281 (3)	0.0275 (3)	0.0120 (2)	0.0134 (3)	0.0028 (2)
O2	0.0192 (8)	0.0229 (8)	0.0328 (9)	0.0043 (6)	−0.0009 (7)	−0.0019 (7)
N2	0.0383 (13)	0.0251 (11)	0.0270 (11)	−0.0068 (9)	0.0104 (9)	−0.0065 (9)
C2	0.072 (2)	0.0264 (14)	0.0435 (17)	0.0025 (13)	0.0369 (16)	−0.0013 (12)
Cl3	0.0246 (3)	0.0183 (3)	0.0254 (3)	−0.0026 (2)	0.0088 (2)	−0.0022 (2)
O3	0.0274 (10)	0.0317 (10)	0.0394 (10)	−0.0080 (7)	0.0139 (8)	−0.0008 (8)
Cl4	0.0343 (3)	0.0283 (3)	0.0175 (3)	0.0041 (2)	0.0098 (2)	0.0008 (2)
O4	0.132 (2)	0.0412 (13)	0.0303 (11)	−0.0064 (13)	0.0280 (13)	0.0054 (10)
O5	0.0399 (12)	0.0445 (12)	0.0723 (15)	0.0128 (9)	0.0172 (11)	−0.0088 (11)
N11	0.0160 (9)	0.0117 (9)	0.0203 (9)	−0.0003 (6)	0.0046 (7)	−0.0003 (7)
C11	0.0140 (10)	0.0146 (11)	0.0176 (10)	−0.0011 (8)	0.0055 (8)	−0.0002 (8)
C12	0.0167 (10)	0.0095 (9)	0.0228 (11)	−0.0021 (8)	0.0041 (9)	−0.0010 (8)
C13	0.0283 (12)	0.0125 (10)	0.0219 (11)	−0.0007 (8)	0.0097 (9)	−0.0039 (9)
C14	0.0285 (12)	0.0131 (10)	0.0197 (11)	−0.0022 (9)	0.0081 (9)	0.0017 (9)
N21	0.0145 (9)	0.0137 (9)	0.0223 (9)	−0.0001 (7)	0.0058 (7)	−0.0005 (7)
C21	0.0165 (11)	0.0118 (10)	0.0169 (10)	0.0000 (8)	0.0053 (8)	−0.0001 (8)
C22	0.0109 (9)	0.0154 (10)	0.0186 (10)	−0.0018 (7)	0.0054 (8)	−0.0041 (8)
C23	0.0147 (10)	0.0149 (10)	0.0178 (10)	0.0018 (8)	0.0018 (8)	−0.0010 (8)
C24	0.0157 (10)	0.0151 (10)	0.0198 (11)	−0.0022 (8)	0.0071 (9)	−0.0003 (8)

Geometric parameters (Å, º) top

Fe1—O1	2.0884 (15)	N2—C2	1.455 (3)
Fe1—O1ⁱ	2.0884 (15)	C2—H2A	0.9800
Fe1—N21ⁱ	2.1309 (17)	C2—H2B	0.9800
Fe1—N21	2.1309 (17)	C2—H2C	0.9800
Fe1—N11	2.1649 (17)	N11—C11	1.144 (3)
Fe1—N11ⁱ	2.1649 (17)	C11—C12	1.446 (3)
Cl1—Fe2	2.2070 (6)	C12—C13	1.390 (3)
O1—H1	0.872 (17)	C12—C14	1.393 (3)
O1—H2	0.840 (16)	C13—C14ⁱⁱ	1.382 (3)
N1—O3	1.218 (2)	C13—H13	0.9500
N1—O2	1.222 (2)	C14—C13ⁱⁱ	1.382 (3)
N1—C1	1.483 (3)	C14—H14	0.9500
C1—H1A	0.9800	N21—C21	1.141 (3)
C1—H1B	0.9800	C21—C22	1.444 (3)
C1—H1C	0.9800	C22—C24	1.388 (3)
Fe2—Cl2	2.1811 (6)	C22—C23	1.395 (3)
Fe2—Cl3	2.1968 (6)	C23—C24ⁱⁱⁱ	1.380 (3)
Fe2—Cl4	2.1996 (6)	C23—H23	0.9500
N2—O5	1.217 (3)	C24—C23ⁱⁱⁱ	1.380 (3)
N2—O4	1.221 (3)	C24—H24	0.9500

O1—Fe1—O1ⁱ	180.0	Cl4—Fe2—Cl1	109.08 (2)
O1—Fe1—N21ⁱ	89.02 (6)	O5—N2—O4	124.7 (2)
O1ⁱ—Fe1—N21ⁱ	90.98 (6)	O5—N2—C2	118.9 (2)
O1—Fe1—N21	90.98 (6)	O4—N2—C2	116.4 (2)
O1ⁱ—Fe1—N21	89.02 (6)	N2—C2—H2A	109.5
N21ⁱ—Fe1—N21	180.00 (9)	N2—C2—H2B	109.5
O1—Fe1—N11	88.13 (6)	H2A—C2—H2B	109.5
O1ⁱ—Fe1—N11	91.87 (6)	N2—C2—H2C	109.5
N21ⁱ—Fe1—N11	89.53 (6)	H2A—C2—H2C	109.5
N21—Fe1—N11	90.47 (6)	H2B—C2—H2C	109.5
O1—Fe1—N11ⁱ	91.87 (6)	C11—N11—Fe1	166.95 (17)
O1ⁱ—Fe1—N11ⁱ	88.13 (6)	N11—C11—C12	177.9 (2)
N21ⁱ—Fe1—N11ⁱ	90.47 (6)	C13—C12—C14	121.59 (19)
N21—Fe1—N11ⁱ	89.53 (6)	C13—C12—C11	118.55 (19)
N11—Fe1—N11ⁱ	180.0	C14—C12—C11	119.85 (19)
Fe1—O1—H1	118.0 (19)	C14ⁱⁱ—C13—C12	119.4 (2)
Fe1—O1—H2	120.9 (19)	C14ⁱⁱ—C13—H13	120.3
H1—O1—H2	111 (2)	C12—C13—H13	120.3
O3—N1—O2	123.50 (19)	C13ⁱⁱ—C14—C12	119.0 (2)
O3—N1—C1	118.69 (19)	C13ⁱⁱ—C14—H14	120.5
O2—N1—C1	117.81 (18)	C12—C14—H14	120.5
N1—C1—H1A	109.5	C21—N21—Fe1	173.63 (17)
N1—C1—H1B	109.5	N21—C21—C22	179.0 (2)
H1A—C1—H1B	109.5	C24—C22—C23	122.29 (19)
N1—C1—H1C	109.5	C24—C22—C21	119.98 (19)
H1A—C1—H1C	109.5	C23—C22—C21	117.71 (18)
H1B—C1—H1C	109.5	C24ⁱⁱⁱ—C23—C22	118.85 (19)
Cl2—Fe2—Cl3	113.33 (3)	C24ⁱⁱⁱ—C23—H23	120.6
Cl2—Fe2—Cl4	110.02 (2)	C22—C23—H23	120.6
Cl3—Fe2—Cl4	108.69 (2)	C23ⁱⁱⁱ—C24—C22	118.86 (19)
Cl2—Fe2—Cl1	107.56 (2)	C23ⁱⁱⁱ—C24—H24	120.6
Cl3—Fe2—Cl1	108.07 (2)	C22—C24—H24	120.6

O1—Fe1—N11—C11	−10.8 (7)	O1—Fe1—N21—C21	−13.1 (15)
O1ⁱ—Fe1—N11—C11	169.2 (7)	O1ⁱ—Fe1—N21—C21	166.9 (15)
N21ⁱ—Fe1—N11—C11	78.2 (7)	N21ⁱ—Fe1—N21—C21	141 (2)
N21—Fe1—N11—C11	−101.8 (7)	N11—Fe1—N21—C21	75.1 (15)
N11ⁱ—Fe1—N11—C11	−43 (18)	N11ⁱ—Fe1—N21—C21	−104.9 (15)
Fe1—N11—C11—C12	25 (7)	Fe1—N21—C21—C22	−35 (15)
N11—C11—C12—C13	2 (6)	N21—C21—C22—C24	−168 (13)
N11—C11—C12—C14	−177 (100)	N21—C21—C22—C23	14 (14)
C14—C12—C13—C14ⁱⁱ	−0.6 (4)	C24—C22—C23—C24ⁱⁱⁱ	0.6 (3)
C11—C12—C13—C14ⁱⁱ	−179.35 (19)	C21—C22—C23—C24ⁱⁱⁱ	178.61 (18)
C13—C12—C14—C13ⁱⁱ	0.6 (4)	C23—C22—C24—C23ⁱⁱⁱ	−0.6 (3)
C11—C12—C14—C13ⁱⁱ	179.33 (19)	C21—C22—C24—C23ⁱⁱⁱ	−178.57 (18)

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O2	0.87 (2)	1.99 (2)	2.804 (2)	155 (3)
O1—H1···O4	0.87 (2)	2.57 (3)	3.074 (3)	118 (2)
O1—H2···Cl1	0.84 (2)	2.43 (2)	3.2731 (16)	177 (3)

Experimental details

Crystal data
Chemical formula	[Fe(C₈H₄N₂)₂(H₂O)₂][FeCl₄]₂·4CH₃NO₂
M_r	987.62
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	100
a, b, c (Å)	12.1307 (9), 12.1554 (9), 13.8209 (10)
β (°)	102.466 (1)
V (Å³)	1989.9 (3)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	1.67
Crystal size (mm)	0.27 × 0.27 × 0.24

Data collection
Diffractometer	Bruker SMART APEX CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.661, 0.690
No. of measured, independent and observed [I > 2σ(I)] reflections	11573, 4397, 3541
R_int	0.030
(sin θ/λ)_max (Å⁻¹)	0.662

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.032, 0.073, 1.03
No. of reflections	4397
No. of parameters	233
No. of restraints	3
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.76, −0.50

Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2002), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia,1997) and DIAMOND (Brandenburg, 2006), publCIF (Westrip, 2010).

Selected bond lengths (Å) top

Fe1—O1	2.0884 (15)	Fe2—Cl2	2.1811 (6)
Fe1—N21	2.1309 (17)	Fe2—Cl3	2.1968 (6)
Fe1—N11	2.1649 (17)	Fe2—Cl4	2.1996 (6)
Cl1—Fe2	2.2070 (6)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O2	0.872 (17)	1.99 (2)	2.804 (2)	155 (3)
O1—H1···O4	0.872 (17)	2.57 (3)	3.074 (3)	118 (2)
O1—H2···Cl1	0.840 (16)	2.434 (17)	3.2731 (16)	177 (3)

Acknowledgements

The authors thank Professor Ian D. Williams and Dr Herman H.-Y. Sung of Department of Chemistry, The Hong Kong University of Technology, for their kind help during the X-ray study and for valuable discussions. This work was supported financially by the Faculty of Science, Naresuan University.

References

Brandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Bruker (2001). SMART. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2002). SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Chainok, K., Harding, D. J., Moubaraki, B., Batten, S. R. & Murray, S. R. (2012). Unpublished results. Google Scholar
Chainok, K., Neville, S. M., Moubaraki, B., Batten, S. R., Murray, K. S., Forsyth, C. M., Cashion, J. D. & Haller, K. J. (2010). Dalton Trans. 39, 10900–10909. CrossRef CAS PubMed Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Kahn, O. & Martinez, C. J. (1998). Science, 279, 44–48. Web of Science CrossRef CAS Google Scholar
Murray, K. S. (2008). Eur. J. Inorg. Chem. pp. 3101–3121. Web of Science CrossRef Google Scholar
Neville, S. M., Leita, B. A., Halder, G. J., Kepert, C. J., Moubaraki, B., Létard, J.-F. & Murray, K. S. (2008). Chem. Eur. J. 14, 10123–10133. CrossRef PubMed CAS Google Scholar
Neville, S. M., Leita, B. A., Offermann, D. A., Duriska, M. B., Moubaraki, B., Chapman, K. W., Halder, J. D. & Murray, K. S. (2007). Eur. J. Inorg. Chem. pp. 1073–1085. CrossRef Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.