{6,6′-Dimeth­oxy-2,2′-[ethane-1,2-diylbis(nitrilo­methanylyl­idene)]diphenolato}nickel(II) dimethyl­formamide monosolvate

Kouassi Ayikoé; Ray J Butcher; Yilma Gultneh

doi:10.1107/S1600536811004818

. 2011 Feb 12;67(Pt 3):m328. doi: 10.1107/S1600536811004818

{6,6′-Dimethoxy-2,2′-[ethane-1,2-diylbis(nitrilomethanylylidene)]diphenolato}nickel(II) dimethylformamide monosolvate

Kouassi Ayikoé ^a, Ray J Butcher ^a,^*, Yilma Gultneh ^a

PMCID: PMC3051997 PMID: 21522259

Abstract

In the title compound, [Ni(C₁₈H₁₈N₂O₄)]·C₃H₇NO, the central Ni^II atom is in a square-planar O₂N₂ coordination environment. The planar Ni–salen moieties (r.m.s. deviation for the plane through the conjugated part of the Ni–salen group = 0.07 Å) form parallel stacks in the a-axis direction, with alternating Ni⋯Ni separations of 3.5339 (7) and 3.6165 (7) Å. In the crystal, there are weak intermolecular C—H⋯O interactions involving the dimethylformamide O and phenolate O atoms.

Related literature

For stacking of Ni–salen units, see: Abe et al. (2006 ▶); Assey et al. (2010 ▶); Feng et al. (2007 ▶); Miyamura et al. (1995 ▶); Vasil’eva et al. (2003 ▶). For a description of the Cambridge Structural Database, see: Allen (2002 ▶).

Experimental

Crystal data

[Ni(C₁₈H₁₈N₂O₄)]·C₃H₇NO
M _r = 458.15
Monoclinic,
a = 6.8601 (1) Å
b = 15.3432 (3) Å
c = 18.9065 (4) Å
β = 91.676 (2)°
V = 1989.17 (6) Å³
Z = 4
Cu Kα radiation
μ = 1.75 mm⁻¹
T = 110 K
0.53 × 0.35 × 0.28 mm

Data collection

Oxford Diffraction Xcalibur diffractometer with a Ruby detector
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2009 ▶) T _min = 0.750, T _max = 1.000
7909 measured reflections
3911 independent reflections
3513 reflections with I > 2σ(I)
R _int = 0.020

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.114
S = 1.10
3911 reflections
275 parameters
H-atom parameters constrained
Δρ_max = 0.34 e Å⁻³
Δρ_min = −0.31 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; 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 I, global. DOI: 10.1107/S1600536811004818/tk2717sup1.cif

e-67-0m328-sup1.cif^{(23KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811004818/tk2717Isup2.hkl

e-67-0m328-Isup2.hkl^{(191.7KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Ni—N1	1.8503 (17)
Ni—N2	1.8502 (17)
Ni—O1	1.8609 (13)
Ni—O2	1.8594 (13)

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C4—H4A⋯O1S	0.95	2.62	3.310 (3)	130
C9—H9A⋯O2ⁱ	0.99	2.45	3.334 (3)	148
C10—H10A⋯O1ⁱⁱ	0.99	2.45	3.348 (3)	151

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

Acknowledgments

RJB wishes to acknowledge the NSF–MRI program (grant No. CHE-0619278) for funds to purchase the diffractometer. KA wishes to thank the National Science Foundation’s AGEP Fellowship for support.

supplementary crystallographic information

Comment

The title compound is a composed of one mononuclear nickel salen-type complex and one molecule of dimethylformamide as solvate. The central Ni is in a square planar O₂N₂ coordination environment (Fig. 1). The Ni—N and Ni—O bond distances, Table 1, are in the normal range for Ni-salen type complexes (Allen, 2002). The planar Ni salen moieties form parallel stacks in the a direction with alternating Ni—Ni separations of 3.5339 (7) and 3.6165 (7) Å as is common for this type of complex (Abe et al., 2006; Assey et al., 2010; Feng et al., 2007; Miyamura et al., 1995; Vasil'eva et al., 2003). There are weak intermolecular C—H···O interactions involving the DMF O and phenolic O atoms (Table 2 and Fig. 2).

Experimental

The ligand, N,N'-bis(3-methoxysalicylaldehyde)ethylenediimine (H₂L₁), was synthesized in a conventional way by mixing o-vanillin with ethylenediamine. To 10 g (0.066 mole) of o-vanillin weighed into a 100 ml round-bottom flask, 30 ml of methanol and 3 mL (0.035 mole) of ethylenediamine were added drop-wise while stirring. The resulting mixture was refluxed at a regulated temperature of 313 K overnight. The yellow precipitate was filtered under vacuum, dissolved in methanol and filtered a second time.

To a stirred bright yellow solution of 20 ml methanol containing 0.9 g (2.74 mmol) of H₂L₁, a 20 ml green methanol solution of 0.65 g NiCl₂.6H₂O (2.73 mmol) was added drop-wise with continuous stirring. About 2 to 3 drops of triethylamine was added to activate deprotonation of the 2-hydroxyl group on the aldehyde moiety and promote oxygen binding to the metal. The resulting dark brown complex solution was stirred and refluxed overnight at 313 K, rotary-evaporated and washed with ethanol to obtain a brown solid in over 90% yield. The complex (7 mg) was dissolved in 5 ml of N,N'-dimethyl formamide and filtered into a crystallization tube. Sufficient amount of diethyl ether was slowly layered over the dissolved complex yielding red brown crystals after several days.