2,6-Diamino­pyridinium bis­(4-hydroxy­pyridine-2,6-dicarboxyl­ato-κ3 O 2,N,O 6)ferrate(III) dihydrate

Masoud Rafizadeh; Zohreh Derikvand; Andya Nemati

doi:10.1107/S1600536808029280

. 2008 Sep 20;64(Pt 10):m1300–m1301. doi: 10.1107/S1600536808029280

2,6-Diaminopyridinium bis(4-hydroxypyridine-2,6-dicarboxylato-κ³ O ²,N,O ⁶)ferrate(III) dihydrate

Masoud Rafizadeh ^a,^*, Zohreh Derikvand ^a, Andya Nemati ^a

PMCID: PMC2959321 PMID: 21201040

Abstract

The reaction of iron(II) sulfate heptahydrate with the proton-transfer compound (pydaH)(hypydcH) (pyda = pyridine-2,6-diamine; hypydcH₂ = 4-hydroxypyridine-2,6-dicarboxylic acid) in an aqueous solution led to the formation of the title compound, (C₅H₈N₃)[Fe(C₇H₃NO₅)₂]·2H₂O. The anion is a six-coordinated complex with a distorted octahedral geometry around the Fe^III atom. Extensive intermolecular O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds, involving the complex anion, (pydaH)⁺ counter-ion and two uncoordinated water molecules, and π–π [centroid-to-centroid distance 3.323 (11) Å] and C—O⋯π [O–centroid distance 3.150 (15) Å] interactions connect the various components into a supramolecular structure.

Related literature

For other complexes with pyridinedicarboxylic acids, see: Rafizadeh et al. (2004 ▶, 2006 ▶, 2007a ▶,b ▶); Rafizadeh & Amani (2006 ▶).

Experimental

Crystal data

(C₅H₈N₃)[Fe(C₇H₃NO₅)₂]·2H₂O
M _r = 564.23
Monoclinic,
a = 6.9389 (4) Å
b = 20.8845 (12) Å
c = 14.9908 (8) Å
β = 96.371 (1)°
V = 2159.0 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.78 mm⁻¹
T = 100 (2) K
0.40 × 0.40 × 0.20 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T _min = 0.746, T _max = 0.860
33555 measured reflections
8157 independent reflections
5648 reflections with I > 2σ(I)
R _int = 0.073

Refinement

R[F ² > 2σ(F ²)] = 0.045
wR(F ²) = 0.110
S = 1.02
8157 reflections
342 parameters
H-atom parameters constrained
Δρ_max = 0.49 e Å⁻³
Δρ_min = −0.61 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I. DOI: 10.1107/S1600536808029280/hy2152sup1.cif

e-64-m1300-sup1.cif^{(24.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808029280/hy2152Isup2.hkl

e-64-m1300-Isup2.hkl^{(399.1KB, hkl)}

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

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

Fe1—O3	2.0101 (13)
Fe1—O8	2.0135 (14)
Fe1—N2	2.0392 (15)
Fe1—O6	2.0413 (13)
Fe1—N1	2.0478 (14)
Fe1—O1	2.0544 (13)

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O3—Fe1—O8	95.80 (6)
O3—Fe1—N2	107.52 (6)
O8—Fe1—N2	76.88 (6)
O3—Fe1—O6	91.49 (5)
O8—Fe1—O6	152.40 (5)
N2—Fe1—O6	75.54 (6)
O3—Fe1—N1	76.40 (5)
O8—Fe1—N1	105.50 (6)
N2—Fe1—N1	175.34 (6)
O6—Fe1—N1	102.08 (5)
O3—Fe1—O1	151.34 (5)
O8—Fe1—O1	94.61 (5)
N2—Fe1—O1	100.83 (5)
O6—Fe1—O1	91.53 (5)
N1—Fe1—O1	75.10 (5)

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N3—H3N⋯O2ⁱ	0.92	2.00	2.8431 (19)	152
N4—H4NA⋯O2Wⁱⁱ	0.92	2.04	2.957 (2)	173
N4—H4NB⋯O3	0.92	2.33	3.139 (2)	147
O5—H5⋯O1W	0.85	1.74	2.566 (2)	164
O10—H10⋯O2W	0.85	1.80	2.614 (2)	159
N5—H5NA⋯O2ⁱ	0.92	1.98	2.800 (2)	148
N5—H5NB⋯O6ⁱⁱⁱ	0.92	1.96	2.832 (2)	157
O1W—H1WA⋯O7^iv	0.85	1.98	2.826 (2)	173
O1W—H1WB⋯O4ⁱⁱ	0.85	2.05	2.877 (2)	166
O2W—H2WA⋯O1^v	0.85	1.88	2.716 (2)	168
O2W—H2WB⋯O9^vi	0.85	1.87	2.709 (2)	168
C16—H16A⋯O3	0.95	2.55	3.323 (2)	139

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

supplementary crystallographic information

Comment

Noncovalent interactions including hydrogen bonding, ion pairing, hydrophobic or hydrophilic and donor–acceptor interactions play a key role in chemical, catalytic and biochemical processes, as well as supramolecular chemistry and crystal engineering. Our research group has recently focused on synthesis of water soluble self-assembly systems that can function as suitable ligands in the synthesis of metal complexes. We have reported some complexes with pyridinedicarboxylic acids (Rafizadeh et al., 2004, 2006, 2007a,b; Rafizadeh & Amani, 2006).

In the title compound (Fig. 1), the Fe^III atom has a distorted octahedral geometry. The bond angles (Table 1) and the torsion angles O6—Fe1—O1—C1 [100.80 (13)°], O1—Fe1—O6—C8 [103.59 (13)°], O8—Fe1—O3—C7 [104.38 (13)°] and O3—Fe1—O8—C14 [106.46 (14)°] indicate that two dianionic hypydc ligands are almost perpendicular to each other. In this work we used Fe^II ions as starting material. Most probably during the synthesis process, Fe^II was oxidized into Fe^III. There are a large number of O—H···O, N—H···O and C—H···O hydrogen bonds between the cations, anions and water molecules (Table 2). Considerable π–π interaction [centroid–centroid distance = 3.323 (11) Å] between the cation and anion, and C—O···π interaction [O–centroid distance = 3.150 (15) Å] between two anions are observed (Fig. 2). Hydrogen bonds, π–π and C—O···π interactions result in the formation of a supramolecular structure (Fig. 3).

Experimental

The reaction of FeSO₄.7H₂O (0.139 g, 0.5 mmol) in water (20 ml) with (pydaH)(hypydcH) (0.264 g, 1.0 mmol) in water (20 ml) gave colorless crystal of the title compound. Crystals suitable for X-ray diffraction were obtained by slow evaporation of the solvent at room temperature.