Di-μ-aqua-bis­[diaqua­bis(thio­cyanato-κN)iron(II)] 4-(4-chloro­phen­yl)-1,2,4-triazole hexa­solvate

Xiuhua Li; Ya Zuo

doi:10.1107/S1600536808019326

. 2008 Jul 5;64(Pt 8):m996–m997. doi: 10.1107/S1600536808019326

Di-μ-aqua-bis[diaquabis(thiocyanato-κN)iron(II)] 4-(4-chlorophenyl)-1,2,4-triazole hexasolvate

Xiuhua Li ^a,^*, Ya Zuo ^b

PMCID: PMC2961922 PMID: 21203091

Abstract

The title complex, [Fe₂(NCS)₄(H₂O)₆]·6C₈H₆ClN₃, comprises two distorted octahedral iron(II) centers straddling a crystallographic inversion center and bridged by two aqua O atoms to form a quadrilateral core. The aqua O atom of the core is involved in hydrogen bonds with the triazole N atoms of the solvent molecules, generating one-dimensional ladder motifs, and three intermolecular C—H⋯S hydrogen bonds, forming a three-dimensional hydrogen-bonding network.

Related literature

For related literature, see: Hsu et al. (1999 ▶); MacMurdo et al. (2000 ▶); Nordlund & Eklund (1993 ▶); Sazinsky et al. (2004 ▶); Stubbe & Van der Donk (1998 ▶); Yoon et al. (2004 ▶); Zheng et al. (1999 ▶).

Experimental

Crystal data

[Fe₂(NCS)₄(H₂O)₆]·6C₈H₆ClN₃
M _r = 1529.76
Triclinic,
a = 7.944 (3) Å
b = 11.085 (5) Å
c = 19.912 (10) Å
α = 105.613 (10)°
β = 97.750 (10)°
γ = 97.932 (7)°
V = 1645.1 (12) Å³
Z = 1
Mo Kα radiation
μ = 0.88 mm⁻¹
T = 298 (2) K
0.25 × 0.21 × 0.17 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.810, T _max = 0.865
8642 measured reflections
5705 independent reflections
2903 reflections with I > 2σ(I)
R _int = 0.032

Refinement

R[F ² > 2σ(F ²)] = 0.044
wR(F ²) = 0.076
S = 0.77
5705 reflections
439 parameters
9 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT (Bruker, 1998 ▶); data reduction: SAINT; 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 and PLATON (Spek, 2003 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808019326/si2093sup1.cif

e-64-0m996-sup1.cif^{(23.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808019326/si2093Isup2.hkl

e-64-0m996-Isup2.hkl^{(279.3KB, hkl)}

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

Table 1. Selected geometric parameters (Å, °).

Fe1—N1	2.086 (3)
Fe1—O2	2.100 (2)
Fe1—O3	2.102 (3)
Fe1—N2	2.107 (3)
Fe1—O1ⁱ	2.264 (3)
Fe1—O1	2.281 (2)

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N1—Fe1—O2	90.22 (11)
N1—Fe1—O3	89.68 (12)
O2—Fe1—O3	101.01 (10)
N1—Fe1—N2	178.33 (12)
O2—Fe1—O1ⁱ	89.04 (10)
O3—Fe1—O1ⁱ	169.95 (9)
N2—Fe1—O1ⁱ	91.32 (11)
O1ⁱ—Fe1—O1	78.36 (9)
Fe1ⁱ—O1—Fe1	101.64 (9)

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Symmetry code: (i) Inline graphic .

Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯N10ⁱⁱ	0.87 (3)	1.97 (3)	2.827 (4)	170 (3)
O1—H2⋯N9	0.88 (3)	1.94 (3)	2.819 (4)	173 (3)
O2—H3⋯N7ⁱⁱⁱ	0.88 (3)	1.98 (3)	2.866 (5)	178 (3)
O2—H4⋯N4^iv	0.88 (2)	1.97 (3)	2.853 (4)	175 (3)
O3—H5⋯N6	0.88 (3)	1.92 (3)	2.802 (4)	174 (3)
O3—H6⋯N3^v	0.88 (2)	1.93 (2)	2.803 (4)	172 (3)
C3—H7⋯S2^vi	0.93	2.72	3.624 (5)	165
C22—H21⋯S2ⁱⁱ	0.93	2.87	3.736 (5)	156
C11—H13⋯S1^vii	0.93	2.87	3.783 (5)	167

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Symmetry codes: (ii) Inline graphic ; (iii) ; (iv) ; (v) ; (vi) ; (vii) .

supplementary crystallographic information

Comment

The diiron unit, with a carboxylate-rich coordination environment, continue to attract considerable attention due to the enzyme catalysis activity, which occur in related multicompent dioxygen dependent enzymes, including toluene monooxygenase (Sazinsky et al., 2004), the R2 subunit of ribonucleotide reductase (Stubbe & Van der Donk, 1998; Nordlund & Eklund, 1993). With the development of compounds that contained the diiron center, the structure of a series of Fe2(II,II) (MacMurdo et al., 2000), Fe2(III,III) (Zheng et al., 1999) and Fe2(III,IV) (Hsu et al., 1999) complexes with a central 2Fe2O quadrilateral have been currently obtained. Compared with the chelating to the iron atoms with the carboxylic oxygen atoms, it is rarely reported that the quadrilateral center includes both aqueous oxygen atoms. In order to explore the furthur details of the coordinated environment of the diiron system, the title complex was synthesized. As shown in Fig. 1, the complex structure comprises two distorted octahedron iron(II) centers straddling a crystallographic inversion center bridged by two aqueous oxygen atoms to form a quadrilateral core. The separation between the iron atoms is 3.523 (2) Å, which is remarkably different from that 3.0430 (7)Å reported previously, owing to the absence of two carboxylate ligands (Yoon et al., 2004). Moreover, the distance of Fe—Fe is comparatively distinguished from that diiron containing the other higher valence of iron (MacMurdo et al., 2000; Zheng et al., 1999; Hsu et al., 1999). The bond lengths of Fe—O1 and Fe—O1a are 2.264 (3) and 2.281 (2) Å, and the angles of O1—Fe—O1a and Fe1a—O1—Fe are 78.36 (9)° and 101.64 (9)°. Each Fe(II) center resides in a six-coordinated octahedron of N₂O₄. On the equator plane, the center is bridged by two symmetrical O1 (water) to form the quadrilateral core with the mean distance of 2.272 (2) Å, and is connected with O2 and O3 offered by different waters as the terminal ligands with the bond lengths 2.102 (3)Å and 2.100 (2) Å. The axial positions are occupied by two N atoms from the NCS^- anions with the distances 2.086 (3)Å and 2.107 (3)Å to the iron core. Selected bonds and angles are listed in Table 1. As indicated in Fig.2, the classic intermolecular O—H···N H-bonds are formed between the triazol nitrogen atom supplied by the uncoordinated organic ligand 1,2,4-triazol-chloro-benzene and aquous oxygen atoms supplied by the bridging and terminal water ligands to generate a one-dimension ladder structure with the N···O separation ranged from 2.803 (2)Å to 2.866 (4) Å. Moreover, there are three weak intermolecular hydrogen bonding contacts C—H···S that form a three-dimensional network with the C···S distances between 3.624 (5) Å and 3.783 (5) Å. The details of the hydrogen bonds are shown in Table 2.

Experimental

The compound was synthesized under hydrothermal conditions. A mixture of L (L=1,2,4-triazol-chloro-benzene) (0.3 mmol, 0.0538 g), FeSO₄˙7H₂O (0.1 mmol, 0.028 g), KSCN (0.2 mmol, 0.019 g) and water (10 mL) was placed in a 25 mL acid digestion bomb and heated at 433 K for two days, then equably cooled to room temperature for three days. After washed by 5 ml water for twice, green block crystals of the compound were obtained.