Tetra-μ-acetato-κ8 O:O′-bis­{[N-(4-methyl­phen­yl)pyridin-2-amine-κN 1]copper(II)}(Cu—Cu)

Zainal Abidin Fairuz; Zaharah Aiyub; Zanariah Abdullah; Seik Weng Ng; Edward R T Tiekink

doi:10.1107/S1600536811044333

. 2011 Oct 29;67(Pt 11):m1636. doi: 10.1107/S1600536811044333

Tetra-μ-acetato-κ⁸ O:O′-bis{[N-(4-methylphenyl)pyridin-2-amine-κN ¹]copper(II)}(Cu—Cu)

Zainal Abidin Fairuz ^a, Zaharah Aiyub ^a, Zanariah Abdullah ^a,^‡, Seik Weng Ng ^a,^b, Edward R T Tiekink ^a,^*

PMCID: PMC3247553 PMID: 22219858

Abstract

The complete dinuclear molecule of the title complex, [Cu₂(CH₃COO)₄(C₁₂H₁₂N₂)₂], is generated by a centre of inversion. The Cu^II atoms are connected [Cu—Cu = 2.6329 (16) Å] and bridged by four acetate ligands. The distorted octahedral coordination geometry is completed by a terminal pyridine N atom. The amine H atom forms an intramolecular N—H⋯O hydrogen bond.

Related literature

For related examples of tetrakisacetatobis[(substituted 2-aminopyridyl)copper] complexes, see: Fairuz et al. (2010a ▶,b ▶).

Experimental

Crystal data

[Cu₂(C₂H₃O₂)₄(C₁₂H₁₂N₂)₂]
M _r = 731.75
Monoclinic,
a = 7.6285 (9) Å
b = 11.3242 (13) Å
c = 18.566 (2) Å
β = 95.717 (2)°
V = 1595.9 (3) Å³
Z = 2
Mo Kα radiation
μ = 1.39 mm⁻¹
T = 100 K
0.22 × 0.13 × 0.05 mm

Data collection

Bruker SMART APEX diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.495, T _max = 0.862
11607 measured reflections
2806 independent reflections
2203 reflections with I > 2σ(I)
R _int = 0.103

Refinement

R[F ² > 2σ(F ²)] = 0.077
wR(F ²) = 0.209
S = 1.08
2806 reflections
211 parameters
H-atom parameters constrained
Δρ_max = 1.31 e Å⁻³
Δρ_min = −1.29 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811044333/hg5122sup1.cif

e-67-m1636-sup1.cif^{(18.8KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811044333/hg5122Isup2.hkl

e-67-m1636-Isup2.hkl^{(137.8KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Cu—O2ⁱ	1.947 (5)
Cu—O1	1.950 (5)
Cu—O3	1.976 (5)
Cu—O4ⁱ	1.976 (5)
Cu—N1	2.205 (6)

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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—H2n⋯O3	0.86	2.21	2.911 (8)	139

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Acknowledgments

We thank the University of Malaya (grant No. RG027/09AFR) for supporting this study.

supplementary crystallographic information

Comment

The crystal structure of the title complex, (I), was investigated in connection with structural studies of tetrakisacetatobis[(substituted 2-aminopyridyl)copper(II)] complexes (Fairuz et al., 2010a; Fairuz et al., 2010b). The complex, Fig. 1, is centrosymmetric and feature four symmetrically bridging acetate ligands and two terminally connected pyridyl-N atoms. These define an NO₄ donor set and the distorted octahedral geometry is completed by a Cu atom, Table 1. The orientation of the N-p-tolylpyridin-2-amine ligand is such to enable the formation of an intramolecular N—H···O hydrogen bond, Table 2. The pyridyl-2-amine ligand is twisted with the dihedral angle between the pyridyl and benzene rings being 59.3 (4)°.

Experimental

N-p-Tolylpyridin-2-amine (0.2 g, 1.1 mmol) was dissolved in acetonitrile (15 ml), added to trimethyl orthoformate (10 ml) and the mixture then heated to 50 °C. Copper acetate (0.1 g, 0.5 mmol) dissolved in acetonitrile (15 ml) was added to the solution. The green precipitate that formed, was collected and recrystallized from acetonitrile to give green crystals.