Bis[N-(pyridin-2-ylcarbon­yl)pyridine-2-carboxamidato]iron(III) perchlorate monohydrate

Xi-Feng Li; Tian-Bao Qiu; Li-Xin Hu; Chun-Yue Hu

doi:10.1107/S1600536811047684

. 2011 Nov 16;67(Pt 12):m1765–m1766. doi: 10.1107/S1600536811047684

Bis[N-(pyridin-2-ylcarbonyl)pyridine-2-carboxamidato]iron(III) perchlorate monohydrate

Xi-Feng Li ^a,^*, Tian-Bao Qiu ^a, Li-Xin Hu ^a, Chun-Yue Hu ^a

PMCID: PMC3238670 PMID: 22199561

Abstract

The structure of the title salt complex, [Fe(C₁₂H₈N₃O₂)₂]ClO₄·H₂O, contains one Fe^III cation, two N-(pyridin-2-ylcarbonyl)pyridine-2-carboxamidate (bpca⁻) anions, one perchlorate anion and one water molecule. The Fe^III cation has an approximate octahedral geometry, defined by six N atoms from two bpca⁻ anions. The nearly parallel [dihedral angle = 1.50 (1)°] bpca⁻ anions form two-dimensional supermolecules along the a axis by the way of weak π–π stacking inteactirons [centroid–centroid distances = 3.948 (2), 4.000 (2), 3.948 (2), 3.911 (2), 3.897 (2), 3.984 (2) and 3.929 (2) Å]. Intra- and intermolecular C—H⋯O hydrogen bonding occurs. The water molecule [occupancies 0.520 (5) and 0.480 (5)], two carbonyl O atoms [occupancies 0.622 (7) and 0.378 (7)] and the four perchlorate O atoms [occupancies 0.887 (4) and 0.113 (4)] are each disordered over two positions.

Related literature

For the use of organic ligands containing nitrogen heteroatoms in the synthesis of transition-metal complexes, see: Feng et al. (2006 ▶); Wu et al. (2009 ▶); Xie & Huang (2011 ▶); Yu et al. (2010 ▶). For the N-donor tridentate rigid ligand Hbpca, see: Casellas et al. (2005 ▶); Kajiwara et al. (2002 ▶). For mononuclear complexes of the tridentate ligand bpca⁻, see: Madariaga et al. (1991 ▶); Marcos et al. (1989 ▶, 1990 ▶); Wocadlo & Massa (1993 ▶).

Experimental

Crystal data

[Fe(C₁₂H₈N₃O₂)₂]ClO₄·H₂O
M _r = 625.74
Triclinic,
a = 8.8828 (8) Å
b = 11.7228 (3) Å
c = 14.4551 (9) Å
α = 109.931 (3)°
β = 103.585 (4)°
γ = 99.456 (3)°
V = 1325.39 (15) Å³
Z = 2
Mo Kα radiation
μ = 0.73 mm⁻¹
T = 298 K
0.20 × 0.14 × 0.10 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T _min = 0.867, T _max = 0.930
8065 measured reflections
5880 independent reflections
4516 reflections with I > 2σ(I)
R _int = 0.021

Refinement

R[F ² > 2σ(F ²)] = 0.053
wR(F ²) = 0.165
S = 1.06
5880 reflections
407 parameters
50 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.70 e Å⁻³
Δρ_min = −0.40 e Å⁻³

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: SHELXS97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811047684/jj2105sup1.cif

e-67-m1765-sup1.cif^{(29.3KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811047684/jj2105Isup2.hkl

e-67-m1765-Isup2.hkl^{(287.8KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Fe1—N5	1.902 (2)
Fe1—N2	1.914 (2)
Fe1—N4	1.964 (2)
Fe1—N3	1.974 (2)
Fe1—N6	1.976 (2)
Fe1—N1	1.979 (2)

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C12—H12⋯O3ⁱ	0.93	2.30	3.084 (3)	142
C12—H12⋯O4ⁱ	0.93	2.55	3.288 (4)	136
C2—H2⋯O5	0.93	2.52	3.292 (5)	140
C2—H2⋯O5A	0.93	2.41	3.116 (8)	133
C11—H11⋯O6ⁱ	0.93	2.62	3.385 (6)	140
C11—H11⋯O8Aⁱ	0.93	2.32	3.191 (11)	156
C16—H16⋯O6Aⁱⁱ	0.93	2.58	3.431 (10)	153

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

This study was supported by the Science and Technology Department of Henan Province (102102310321) and the Doctoral Research Fund of Henan Chinese Medicine (BSJJ2009–38)

supplementary crystallographic information

Comment

Organic ligands containing nitrogen heteroatoms play an important role in the assembling process of transition-metal complexes (Wu et al., 2009; Xie et al., 2011; Feng et al., 2006; Yu et al., 2010). The N-donor tridentate rigid ligand Hbpca (Hbpca = bis(2-pyridylcarbonyl)amine) has been attracting widespread attention (Kajiwara et al., 2002; Casellas et al., 2005). Mononuclear complexes of the tridentate ligand bpca^-, [M(bpca)]⁺ (M = divalent metal ions] exemplify these types of complexed ligands (Marcos et al., 1989, 1990); Madariaga et al., 1991; Wocadlo et al., 1993).

As a continuation of our studies related to the behaviour of the bpca ligand with Fe^III ions, we have synthesized the title salt complex [Fe(bpca)₂(ClO₄) . H₂O]. As shown in Fig. 1, each asymmetric unit contains one Fe^III cation, two bpca^- anions, one perchlorate anion and one lattice water molecule. The bpca ligands are nearly parallel in the structure and form two-dimensional supermolecules by the way of weak π–π stacking inteactions [centroid to centroid distances = 3.9475Å, 3.9997Å, 3.9488Å, 3.9107Å, 3.8973Å, 3.9838Å and 3.9287Å, respectively]. The bond lengths for Fe—N vary from 1.902 (2)Å to 1.979 (2)Å, and the angles for N—Fe—N are between 81.65 (9)° and 178.54 (10)°. These bond lengths and angles are in agreement with those found in similar related Fe^III compounds (Wocadlo et al., 1993).

Experimental

A mixture of methanol and water (1:1, 2 ml) was gently layered on the top of a solution of Fe(ClO₄)₃.6H₂O (46.2 mg, 0.1 mmol) in water (3 ml). A solution of Hbpca = bis(2-pyridylcarbonyl)amine (22.7 mg, 0.1 mmol), in methanol (10 ml) was added carefully as the third layer. Red crystals suitable for X-ray diffraction were obtained after 3 weeks, washed with ethanol and ether, and dried in air.