Bis{(E)-2-eth­oxy-6-[2-(ethyl­ammonio)ethyl­iminometh­yl]phenolato}nickel(II) bis(perchlorate)

Xue-Wen Zhu; Xu-Zhao Yang

doi:10.1107/S1600536808023684

. 2008 Jul 31;64(Pt 8):m1096–m1097. doi: 10.1107/S1600536808023684

Bis{(E)-2-ethoxy-6-[2-(ethylammonio)ethyliminomethyl]phenolato}nickel(II) bis(perchlorate)

Xue-Wen Zhu ^a,^*, Xu-Zhao Yang ^a

PMCID: PMC2962001 PMID: 21203071

Abstract

In the title centrosymmetric mononuclear nickel(II) complex, [Ni(C₁₃H₂₀N₂O₂)₂](ClO₄)₂, the Ni^II atom is four-coordinated by the imine N and phenolate O atoms of the zwitterionic forms of two Schiff base ligands in a square-planar coordination geometry. In the crystal structure, molecules are linked through intermolecular N—H⋯O hydrogen bonds, forming chains running along the a axis.

Related literature

For background to the chemistry of the Schiff base complexes, see: Ali et al. (2008 ▶); Biswas et al. (2008 ▶); Carlsson et al. (2002 ▶, 2004 ▶); Chen et al. (2008 ▶); Darensbourg & Frantz (2007 ▶); Habibi et al. (2007 ▶); Kawamoto et al. (2008 ▶); Tomat et al. (2007 ▶); Wu et al. (2008 ▶); Yuan et al. (2007 ▶). For related structures, see: Ma et al. (2008 ▶); Skovsgaard et al. (2005 ▶); Zhao (2007 ▶).

Experimental

Crystal data

[Ni(C₁₃H₂₀N₂O₂)₂](ClO₄)₂
M _r = 730.23
Monoclinic,
a = 8.386 (3) Å
b = 8.566 (3) Å
c = 21.862 (6) Å
β = 99.068 (4)°
V = 1550.8 (9) Å³
Z = 2
Mo Kα radiation
μ = 0.87 mm⁻¹
T = 298 (2) K
0.23 × 0.20 × 0.20 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2004 ▶) T _min = 0.826, T _max = 0.846
12509 measured reflections
3363 independent reflections
2770 reflections with I > 2σ(I)
R _int = 0.041

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.102
S = 1.04
3363 reflections
207 parameters
H-atom parameters constrained
Δρ_max = 0.28 e Å⁻³
Δρ_min = −0.34 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); 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 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808023684/sj2526sup1.cif

e-64-m1096-sup1.cif^{(18.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808023684/sj2526Isup2.hkl

e-64-m1096-Isup2.hkl^{(165KB, hkl)}

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

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

Ni1—O1	1.836 (2)
Ni1—N1	1.910 (2)

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O1ⁱ—Ni1—O1	180
O1ⁱ—Ni1—N1	87.67 (7)
O1—Ni1—N1	92.33 (7)
N1ⁱ—Ni1—N1	180

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Symmetry code: (i) Inline graphic .

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2B⋯O2ⁱ	0.90	2.34	3.013 (3)	131
N2—H2B⋯O1ⁱ	0.90	1.97	2.764 (2)	146
N2—H2A⋯O3	0.90	2.56	3.242 (3)	132
N2—H2A⋯O3ⁱⁱ	0.90	2.13	2.916 (3)	145

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

supplementary crystallographic information

Comment

Schiff bases have widely been used as versatile ligands in coordination chemistry (Biswas et al., 2008; Wu et al., 2008; Kawamoto et al., 2008; Ali et al., 2008; Habibi et al., 2007), and their metal complexes are of great interest in many fields (Chen et al., 2008; Yuan et al., 2007; Tomat et al., 2007; Darensbourg & Frantz, 2007). Nickel(II) is present in the active sites of urease (Carlsson et al., 2002, 2004). In this paper, a new nickel(II) complex, (I), Fig. 1, with the Schiff base ligand (E)-2-ethoxy-6-((3-(methylamino)propylimino)methyl)phenol has been synthesized and structurally characterized.

Complex (I) consists of a centrosymmetric mononuclear nickel(II) complex cation and two perchlorate anions. The Ni^II atom in the cation, lies on an inversion centre, with the asymmetric unit made up from one half of the Ni(II) complex and one perchlorate anion. The Ni(II) atom is four-coordinated by two imine N and two phenolate O atoms from two zwitterionic Schiff base ligands in a square-planar coordination geometry. The coordinate bond lengths (Table 1) are typical and comparable to the corresponding values observed in similar nickel(II) Schiff base complexes (Zhao, 2007; Skovsgaard et al., 2005; Ma et al., 2008).

In the crystal structure, molecules are linked through intermolecular N–H···O hydrogen bonds (Table 2), forming chains running along the a axis (Fig. 2).

Experimental

The Schiff base compound was prepared by the condensation of equimolar amounts of 3-ethoxysalicylaldehyde with N-ethylethane-1,2-diamine in a methanol solution. The complex was prepared by the following method. To a methanol solution (5 ml) of Ni(ClO₄)₂.6H₂O (36.6 mg, 0.1 mmol) was added a methanol solution (10 ml) of the Schiff base compound (23.6 mg, 0.1 mmol) with stirring. The mixture was stirred for 30 min at room temperature and filtered. Upon keeping the filtrate in air for a few days, red block-shaped crystals formed at the bottom of the vessel on slow evaporation of the solvent.