Tris(4,4′-bi-1,3-thia­zole-κ2 N,N′)iron(II) tetra­bromidoferrate(III) bromide

Anita Abedi; Vahid Amani; Nasser Safari

doi:10.1107/S1600536811004181

. 2011 Feb 9;67(Pt 3):m311–m312. doi: 10.1107/S1600536811004181

Tris(4,4′-bi-1,3-thiazole-κ² N,N′)iron(II) tetrabromidoferrate(III) bromide

Anita Abedi ^a, Vahid Amani ^b, Nasser Safari ^b,^*

PMCID: PMC3052137 PMID: 21522247

Abstract

In the [Fe(4,4′-bit)₃]²⁺ (4,4′-bit is 4,4′-bi-1,3-thiazole) cation of the title compound, [Fe(C₆H₄N₂S₂)₃][FeBr₄]Br, the Fe^II atom (3 symmetry) is six-coordinated in a distorted octahedral geometry by six N atoms from three 4,4′-bit ligands. In the [FeBr₄]⁻ anion, the Fe^III atom (3 symmetry) is four-coordinated in a distorted tetrahedral geometry. In the crystal, intermolecular C—H⋯Br hydrogen bonds and Br⋯π interactions [Br⋯centroid distances = 3.562 (3) and 3.765 (2) Å] link the cations and anions, stabilizing the structure.

Related literature

For general background to metal complexes with 4,4′-bi-1,3-thiazole ligands, see: Baker & Goodwin (1985 ▶); Mahjoub & Morsali (2001 ▶, 2002a ▶,b ▶). For related structures, see: Al-Hashemi et al. (2009 ▶); Ali & Al-Far (2007 ▶); Amani et al. (2007a ▶,b ▶, 2009 ▶); Craig et al. (1988 ▶); Figgis et al. (1983 ▶); Jia et al. (2006 ▶); Khavasi et al. (2008 ▶); Kulkarni et al. (1998 ▶); Notash et al. (2008 ▶, 2009 ▶); Rahimi et al. (2009 ▶); Safari et al. (2009 ▶). For the synthesis of the ligand, see: Erlenmeyer & Ueberwasser (1939 ▶).

Experimental

Crystal data

[Fe(C₆H₄N₂S₂)₃][FeBr₄]Br
M _r = 1015.95
Trigonal,
a = 12.0638 (7) Å
c = 17.6907 (13) Å
V = 2229.7 (2) Å³
Z = 3
Mo Kα radiation
μ = 8.14 mm⁻¹
T = 100 K
0.45 × 0.35 × 0.30 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T _min = 0.031, T _max = 0.086
8430 measured reflections
2508 independent reflections
2427 reflections with I > 2σ(I)
R _int = 0.099

Refinement

R[F ² > 2σ(F ²)] = 0.036
wR(F ²) = 0.085
S = 1.01
2508 reflections
112 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.93 e Å⁻³
Δρ_min = −0.78 e Å⁻³
Absolute structure: Flack (1983 ▶), 1195 Friedel pairs
Flack parameter: 0.021 (9)

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); 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 ▶) and Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811004181/hy2404sup1.cif

e-67-0m311-sup1.cif^{(15.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811004181/hy2404Isup2.hkl

e-67-0m311-Isup2.hkl^{(123.3KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Fe1—N1	1.962 (3)
Fe1—N2	1.974 (3)
Fe2—Br1	2.3348 (5)
Fe2—Br2	2.3370 (12)

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C2—H2A⋯Br3	0.93	2.81	3.665 (5)	153
C5—H5A⋯Br3	0.93	2.97	3.798 (5)	149

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Acknowledgments

We thank the Graduate Study Councils of the Islamic Azad University, North Tehran Branch, and Shahid Beheshti University for financial support.

supplementary crystallographic information

Comment

Erlenmeyer & Ueberwasser (1939) first reported the synthesis of 4,4'-bi-1,3-thiazole (4,4'-bit) and Craig et al. (1988) determined the structure of this compound. Although 4,4'-bit is a good bidentate ligand, a few of its metal complexes have been prepared, such as those of nickel and iron (Baker & Goodwin, 1985), lead (Mahjoub & Morsali, 2001, 2002a) and bismuth (Mahjoub & Morsali, 2002b). We recently introduced the coordination chemistry of 2,2'-dimethyl-4,4'-bi-1,3-thiazole with copper (Al-Hashemi et al., 2009), zinc and mercury (Khavasi et al., 2008; Safari et al., 2009), cadmium (Notash et al., 2009) and thallium (Notash et al., 2008). We report here the synthesis and crystal structure of the title compound.

The asymmetric unit of the title compound (Fig. 1), contains one third of an [Fe(4,4'-bit)₃]²⁺ cation, one third of an [FeBr₄]^- anion and one third of a Br^- anion. In the [Fe(4,4'-bit)₃]²⁺ cation, the Fe^II atom (3 symmetry) is six-coordinated in a distorted octahedral geometry by six N atoms from three 4,4'-bit ligands. The Fe—N bond lengths are 1.962 (3) and 1.974 (3) Å (Table 1). The average Fe—N bond distances in high-spin iron(II) and (III) complexes with phenanthroline and bipyridine are around 2.2 Å. However, for low-spin iron(II) and (III) complexes, the Fe—N distances less than 2.0 Å have been reported (Amani et al., 2007a,b, 2009; Figgis et al., 1983; Kulkarni et al., 1998; Rahimi et al., 2009). Therefore, in the [Fe(4,4'-bit)₃]²⁺ cation, the Fe—N bond distances are unambiguous in accord with low-spin iron(II). The N—Fe—N bond angles are in the range of 82.00 (14) to 171.87 (14)°. The bond angles and distances are in good agreement to those of [Fe(4,4'-bit)₃]²⁺ cations, which have been found in other structures (Baker & Goodwin, 1985). In the [FeBr₄]^- anion, the Fe^III atom (3 symmetry) is four-coordinated in a distorted tetrahedral geometry by four Br atoms. The Fe—Br bond lengths are 2.3348 (5) and 2.3370 (12) Å. The Br—Fe—Br angles, in turn, span the ranges of 108.64 (3) to 110.29 (3)°, and the bond angles and distances are in good agreement to those of [FeBr₄]^- anions, which have been found in other structures (Ali & Al-Far 2007; Jia et al., 2006).

Fig. 2 shows significant intermolecular C—H···Br hydrogen bonds in the title compound (Table 2). The hydrogen bonds cause the formation of a supramolecular architecture, best described as built up by Br(thiazol)₉ supramolecular synthons (Fig. 2) assembled via C—H···Br hydrogen bonds, where nine thiazole groups surround one (central) uncoordinated bromide ion. These synthons are further connected into an adamantoid-like network that extends into a three-dimensional structure. The discrete [FeBr₄]^- anions occupy the cavities that result from the three-dimensional assembly of the Br(thiazol)₉ entities. There also exist intermolecular Br···π interactions between the [FeBr₄]^- anions and thiazole rings in the crystal structure (Fig. 3), with Br1···Cg1 = 3.562 (3) and Br1ⁱ···Cg2 = 3.765 (2) Å [Cg1 and Cg2 are the centroids of C1, C2, C3, N2, S2 ring and C4, C5, C6, N1, S1 ring. Symmetry code: (i) 1-x+y, 2-x, z]. The hydrogen bonds and Br···π interactions link the cations and anions, which may be effective in the stabilization of the structure.

Experimental

4,4'-bi-1,3-thiazole (0.11 g, 0.63 mmol) in CH₃OH (20 ml) was added to a solution of FeBr₃ (0.06 g, 0.21 mmol) in CH₃OH (10 ml) and the resulting red solution was stirred at 313 K for 1 h. The red colored precipitated product was recrystallized from CH₃CN/CH₃OH (v/v 2:1). After two weeks, dark-red prismatic crystals of the title compound were isolated (yield: 0.08 g, 75.0%; m.p. 464 K).