Tris(1,10-phenanthroline)iron(II) μ-oxido-bis­[trichloridoferrate(III)]

Chun Ling; Li Song; Xinping Wang

doi:10.1107/S1600536811031783

. 2011 Aug 11;67(Pt 9):m1232–m1233. doi: 10.1107/S1600536811031783

Tris(1,10-phenanthroline)iron(II) μ-oxido-bis[trichloridoferrate(III)]

Chun Ling ^a, Li Song ^a,^*, Xinping Wang ^a

PMCID: PMC3200904 PMID: 22065697

Abstract

In the title salt, [Fe(C₁₂H₈N₂)₃][Fe₂Cl₆O], the ionic components are linked into a two-dimensional supramolecular layer by two pairs of C—H⋯Cl hydrogen bonds and π–π stacking interactions [centroid–centroid distances = 3.655 (4) and 3.498 (3) Å]. The salt is characterized as a mixed-valent Fe^II–Fe^III compound, in which an Fe^II atom is coordinated by three phen ligands, forming a six-coordinated cationic entity and the anionic part is formed by two Fe^III atoms in tetrahedral coordination environments constructed by three chloride ions and one bridging oxide ligand. Intramolecular C—H⋯N hydrogen bonds are observed.

Related literature

For related compounds containing the [Cl₃FeOFeCl₃]²⁻ anion, see: Yan et al. (2000 ▶); Li et al. (2008 ▶); Haselhorst et al. (1993 ▶); Drew et al. (1978 ▶); Ondrejkovicová et al. (1998 ▶); James et al. (1997 ▶); Köhn et al. (1997 ▶); Bullen et al. (1986 ▶). For polynuclear iron(II/III) clusters, see: Pierre et al. (1996 ▶); Proul-Curry & Chasteen (1995 ▶). For the use of iron(III) complexes containing an Fe—O—Fe linkage as models for non-heme metalloproteins, see: Kurtz (1990 ▶); Gorun & Lippard (1991 ▶); Davydov et al. (1997 ▶); Ito et al. (1996 ▶); Mauerer et al. (1993 ▶); Menage et al. (1993 ▶); Okuno et al. (1997 ▶). For their use as models in studies of intramolecular antiferromagnetic spin exchange coupling between high-spin ferric ions in material science, see: Kurtz (1990 ▶); Gatteschi et al. (2000 ▶); Haselhorst et al. (1993 ▶). For π–π stacking interactions between two phen ligands, see: Chandrasekhar et al. (2006 ▶).

Experimental

Crystal data

[Fe(C₁₂H₈N₂)₃][Fe₂Cl₆O]
M _r = 936.86
Triclinic,
a = 11.422 (2) Å
b = 13.357 (3) Å
c = 14.045 (3) Å
α = 77.61 (3)°
β = 89.16 (3)°
γ = 65.99 (3)°
V = 1905.3 (7) Å³
Z = 2
Mo Kα radiation
μ = 1.59 mm⁻¹
T = 293 K
0.38 × 0.20 × 0.12 mm

Data collection

Rigaku R-AXIS RAPID diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ▶) T _min = 0.584, T _max = 0.832
18867 measured reflections
8629 independent reflections
5284 reflections with I > 2σ(I)
R _int = 0.038

Refinement

R[F ² > 2σ(F ²)] = 0.050
wR(F ²) = 0.172
S = 1.14
8629 reflections
469 parameters
H-atom parameters constrained
Δρ_max = 1.02 e Å⁻³
Δρ_min = −1.14 e Å⁻³

Data collection: PROCESS-AUTO (Rigaku, 1998 ▶); cell refinement: PROCESS-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2004 ▶); 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.

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811031783/bg2417sup1.cif

e-67-m1232-sup1.cif^{(25.2KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811031783/bg2417Isup2.hkl

e-67-m1232-Isup2.hkl^{(422KB, hkl)}

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C1—H1⋯Cl6ⁱ	0.93	2.80	3.416 (7)	125
C11—H11⋯Cl2	0.93	2.82	3.740 (7)	172
C12—H12⋯N4	0.93	2.55	3.038 (7)	113
C25—H25⋯N3	0.93	2.62	3.098 (7)	113
C36—H36⋯N2	0.93	2.60	3.084 (8)	113

Open in a new tab

Symmetry code: (i) Inline graphic .

Acknowledgments

We are grateful for financial support from the Natural Science Foundation of Zhejiang Province (project Y4100610).

supplementary crystallographic information

Comment

Recently polynuclear iron(II/III) clusters have received considerable attention in inorganic chemistry and material science (Proul-Curry et al., 1995; Pierre et al., 1996). In particular, iron(III) complexes containing Fe—O—Fe linkage have been one of the more celebrated objects for research and exploiture. In bioioganic chemistry, they are simple and useful models for non-heme metalloproteins containing dinuclear iron units in their active site, such as the methane monooxygenase, hemerythrin, etc (Kurtz et al., 1990; Gorun et al., 1991; Davydov et al., 1997). In material science, they have also been considered as useful models in studies of intramolecular antiferromagnetic spin exchange coupling between high-spin ferric ions (Kurtz et al., 1990; Haselhorst et al., 1993; Gatteschi et al., 2000). Previously, many efforts have been contributed to these researches, especially to the models for non-heme metalloproteins (Davydov et al., 1997; Mauerer et al., 1993; Ito et al., 1996; Okuno et al., 1997; Menage et al., 1993). Here, we report a ionic compound, [Fe(phen)₃][Cl₃FeOFeCl₃] (I), composed of a dinuclear Fe^III cluster anion, [Cl₃FeOFeCl₃]^2-, and a coordinated cation containing Fe^II, [Fe(phen)₃]²⁺.

The Fe^II centre is coordinated in octahedral geometry by three phen ligands to form a coordination cation. In this FeN₆ octahedron, Fe—N bond lengths range from 1.972 (4) Å to 1.985 (4) Å and are similar to those reported in the literature (Yan et al., 2000; Li et al., 2008). In the anionic group two Fe^III cations locate in similar tetrahedral environments constructed by three Cl_- and one µ₂-bridged O^2- ligand. Fe—Cl bond lengths range from 2.206 (2) Å to 2.247 (2) Å and are similar to those in the literature (Haselhorst et al., 1993; Drew et al., 1978; Ondrejkovicová et al., 1998; James et al., 1997; Köhn et al., 1997; Bullen et al., 1986). These two FeOCl₃ tetrahedra are fused through the µ₂-bridged O^2- ligand (Fe1—O1 = 1.747 (4) Å, Fe2—O1 = 1.753 (4) Å ) to give out a dinuclear cluster.

In the crystal structure offset face-to face aromatic π-π stacking interactions and hydrogen bonds lead to the formation of a two-dimensional supramolecular layer. Firstly, along the [1 - 1 1] direction, all adjacent cation of [Fe(phen)₃]²⁺ are joined to each other by virtue of π–π stacking interactions between two phen ligands to form a one-dimensional supramolecular chain (Chandrasekhar et al., 2006). Two pairs of phen skeletons are arranged in a parallel fashion, ring 1 (C4—C9) of one cation stacks with ring 2 (C4—C9)ⁱ[(i): 2 - x, -y, 1 - z] of a neighbouring cation with an interplanar distance of 3.487 (9) Å, and ring 3 (N4/C20—C24) of one cation stacks with ring 4 (N4/C20—C24)ⁱⁱ [(ii) 1 - x, 1 - y, -z] of a neighbouring cation with an interplanar distance of 3.250 (6) Å. Adjacent chains, in turn, are fused together by the [Cl₃FeOFeCl₃]^2-inorganic anion through two pairs of (C—H···Cl) hydrogen bonding interactions between cations and anions (Table 1). As a result, the supramolecular chains interconnect to form a two-dimensional supramolecular layer.

Experimental

The title compound (I) was synthesized by solvothermal reaction of FeCl₂ tetrahydrate (20 mg, 0.1 mmol), Et₄NBr (21 mg, 0.1 mmol), α-Ketoglutaric acid (15 mg, 0.1 mmol) and 1,10-phenanthroline monohydrate (20 mg, 0.1 mmol) in 6 mL e thanol and 0.5 ml water containing NaOH (4 mg, 0.1 mmol). The mixture was heated to 373 K at a rate of 20 K/h, and kept at this temperature for 1 day and then cooled to room temperature at a rate of 2 K/h. Dark red crystals of (I) were obtained. Anal. Calc. for C36H24Cl6Fe3N6O (%): C, 46.15; H, 2.58; N, 8.97; O, 1.71. Found: C, 42.58; H, 2.73; N, 8.36;O, 1.97. Crystals of (I) suitable for single-crystal X-ray diffraction were selected directly from the sample as prepared.