Triethyl­ammonium bis­{2-[(2-oxido-5-nitro­benzylidene)amino]­benzoato}ferrate(III) monohydrate

Eduard N Chygorin; Svetlana R Petrusenko; Volodymyr N Kokozay; Yuri O Smal; Volodymyr V Bon

doi:10.1107/S1600536811011196

. 2011 Apr 13;67(Pt 5):m593–m594. doi: 10.1107/S1600536811011196

Triethylammonium bis{2-[(2-oxido-5-nitrobenzylidene)amino]benzoato}ferrate(III) monohydrate

Eduard N Chygorin ^a,^*, Svetlana R Petrusenko ^a, Volodymyr N Kokozay ^a, Yuri O Smal ^a, Volodymyr V Bon ^b

PMCID: PMC3089355 PMID: 21754314

Abstract

In the title compound, [NH(C₂H₅)₃][Fe(C₁₄H₈N₂O₅)₂]·H₂O, the iron(III) ion is hexacoordinated by four O atoms in the basal plane [Fe—O distances in the range 1.904 (4)–1.909 (4) Å] and two N atoms in the axial plane [Fe—N = 1.981 (4) and 1.985 (4) Å] of two tridentate fully deprotonated 2-{[(2-oxido-5-nitrophenyl)methylene]amino}benzoato (H₂ L) ligands, forming a tetragonally elongated octahedral geometry. The triethylammonium cations and complex anions are linked by N—H⋯O hydrogen bonds into chains parallel to [100]. Disordered water molecules (occupancy ratio 0.6:0.4) occupy the voids in the crystal structure.

Related literature

For the stuctures of related compexes, including those with phenyl-salicyliden-imine (PSI) ligands similar to H₂ L, see: Rotondo et al. (2009 ▶); Patel (2009 ▶); Patel et al. (2008 ▶); Laye & Sanudo (2009 ▶); Lu et al. (2006 ▶); Rosair et al. (2002 ▶). For bond-valence sums, see: Brown & Altermatt (1985 ▶).

Experimental

Crystal data

(C₆H₁₆N)[Fe(C₁₄H₈N₂O₅)₂]·H₂O
M _r = 742.50
Monoclinic,
a = 10.2688 (3) Å
b = 14.7128 (4) Å
c = 25.0800 (7) Å
β = 97.230 (2)°
V = 3759.03 (18) Å³
Z = 4
Mo Kα radiation
μ = 0.46 mm⁻¹
T = 296 K
0.35 × 0.05 × 0.04 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.855, T _max = 0.982
20469 measured reflections
6432 independent reflections
5305 reflections with I > 2σ(I)
R _int = 0.035

Refinement

R[F ² > 2σ(F ²)] = 0.081
wR(F ²) = 0.242
S = 1.13
6432 reflections
466 parameters
H-atom parameters constrained
Δρ_max = 0.89 e Å⁻³
Δρ_min = −0.61 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811011196/zk2002sup1.cif

e-67-0m593-sup1.cif^{(30.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811011196/zk2002Isup2.hkl

e-67-0m593-Isup2.hkl^{(314.8KB, 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
N5—H5A⋯O7	0.91	2.00	2.865 (13)	159

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supplementary crystallographic information

Comment

There is growing interest in transition metal complexes with phenyl-salicyliden-imines (PSI) ligands due to their important applications and pharmacological activities (Rotondo et al., 2009, Patel, 2009, Patel et al., 2008, Laye & Sanudo, 2009). Here we represent a new complex with nitro-substituted PSI ligand, 2-(((2-hydroxy-5-nitrophenyl)methylene)amino)benzoic acid (H₂L), wich was obtained as by-product during the invistigation of the system Co – FeCl₂^.4H₂O – MnCl₂^.4H₂O – H₂L – Et₃N – DMF.

The synthesis of {NH(C₂H₅)₃}[Fe(C₁₄H₈NO₅)₂]^.H₂O, I, is carried out in air that leads to stabilization of iron(III) ion. The formation of the complex can be understood if one considers the following reaction scheme: FeCl₂^.4H₂O + 2H₂L + 3Et₃N + 0.25O₂→ (NHEt₃)[Fe^IIIL₂] + 2Et₃N^.HCl + 9H₂O

The crystal structure of I consists of triethylammonium cations and complex anions (Fig. 1) linked together by "strong" N—H···O hydrogen bonds (Fig. 2). The Fe centre is hexacoordinated in an axially elongated octahedral fashion (FeO₄N₂-chromophore) with oxidation state Fe(III), as it can be seen from close examination of the structured parameters and bond-valence sum calculations (Brown & Altermatt, 1985). Angular deviations from octahedral geometry are not significant, less than 5° for cis- and trans-angles.

In the crystal packing of I there are channels along the a axis (Fig. 3), accounting in total 610.7 Å³ per unit cell, i.e. some 16.2% of the total volume. The voids were examined using PLATON (Spek, 2009). The channels are occupied by disordered water molecules.

Experimental

2-aminobenzoic acid (0.51 g, 3.75 mmol), 5-Nitrosalicylaldehyde (0.63 g, 3.75 mmol), and triethylamine (0.53 ml, 3.75 mmol) were dissolved in DMF (25 ml) in this order, forming a yellow solution and magnetically stirred at 50 – 60°C (10 min). Then, cobalt powder (0.08 g, 1.25 mmol), FeCl₂^.4H₂O (0.25 g, 1.25 mmol) and MnCl₂^.4H₂O (0.26 g, 1.25 mmol) were successfully added to the hot yellow solution with stirring about 2 h. Red crystals suitable for X-ray analysis were isolated by adding of iPrOH from the dark red solution after 1 day. Yield: 0.34 g, 0.32% (per Fe). Elemental analysis for C₃₄H₃₄Fe₁N₅O₁₁ (Mr=744.52). Calcd: C, 54.85; N, 9.41; H, 4.6; Fe, 7.5. Found: C, 54.5; N, 9.6; H, 4.6; Fe, 7.2. The compound is sparingly soluble in DMSO and DMF, and it is stable in air. The infrared spectrum of solid recorded using KBr disk shows an adsorption at 3440 cm^-1, which attributed to ν(OH) of H₂O solvation molecules. The presence in IR spectrum of a band at 1680 cm^-1 attributable to the ν(C=N)_imine stretching frequency together with the absence of the band due to the ν(C=O) of the carbonyl indicates the formation of the Schiff base (Fig. 4).