[N,N′-Bis(4-bromo­benzyl­idene)-2,2-di­methyl­propane-κ2 N,N′]iodidocopper(I)

Reza Kia; Hoong-Kun Fun; Hadi Kargar

doi:10.1107/S1600536809005078

. 2009 Feb 18;65(Pt 3):m289. doi: 10.1107/S1600536809005078

[N,N′-Bis(4-bromobenzylidene)-2,2-dimethylpropane-κ² N,N′]iodidocopper(I)

Reza Kia ^a, Hoong-Kun Fun ^a,^*, Hadi Kargar ^b

PMCID: PMC2968488 PMID: 21582073

Abstract

The title compound, [CuI(C₁₉H₂₀Br₂N₂)], lies across a crystallographic mirror plane. The coordination around the copper centre is distorted trigonal planar, with a bite angle of 94.7 (3)°. A six-membered chelate ring in a chair conformation is formed by the coordination of the imine N atoms of the bidentate ligand to the Cu^I atom. This conformation is required by the crystallographic mirror symmetry. The interplanar angle between the benzene rings is 74.85 (19)°. The crystal structure exhibits weak intermolecular C—H⋯π interactions, which link the molecules into chains along the b axis.

Related literature

For the puckering parameters, see: Cremer & Pople (1975 ▶). For related literature and the catalytic applications see, for example: Killian et al. (1996 ▶); Jung et al. (1996 ▶); Small et al. (1998 ▶). For a related structure, see: Kia et al. (2009 ▶). For the stability of the temperature controller, see Cosier & Glazer (1986 ▶).

Experimental

Crystal data

[CuI(C₁₉H₂₀Br₂N₂)]
M _r = 626.63
Monoclinic,
a = 16.2224 (15) Å
b = 12.2807 (12) Å
c = 10.6292 (12) Å
β = 91.599 (6)°
V = 2116.8 (4) Å³
Z = 4
Mo Kα radiation
μ = 6.27 mm⁻¹
T = 100 K
0.58 × 0.09 × 0.05 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.119, T _max = 0.714
10374 measured reflections
1936 independent reflections
1474 reflections with I > 2σ(I)
R _int = 0.099

Refinement

R[F ² > 2σ(F ²)] = 0.050
wR(F ²) = 0.112
S = 1.16
1936 reflections
121 parameters
H-atom parameters constrained
Δρ_max = 2.64 e Å⁻³
Δρ_min = −0.99 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: APEX2; data reduction: SAINT (Bruker, 2005 ▶); 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 and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809005078/ez2161sup1.cif

e-65-0m289-sup1.cif^{(16.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809005078/ez2161Isup2.hkl

e-65-0m289-Isup2.hkl^{(95.4KB, hkl)}

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

Table 1. Hydrogen-bond geometry (Å, °).

Cg1 is the centroid of the C1–C6 benzene ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C8—H8A⋯Cg1ⁱ	0.99	2.83	3.631 (9)	138

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Symmetry code: (i) Inline graphic .

Acknowledgments

HKF and RK thank the Malaysian Government and Universiti Sains Malaysia for Science Fund grant No. 305/PFIZIK/613312. RK thanks Universiti Sains Malaysia for a post-doctoral research fellowship. HK thanks PNU for financial support.

supplementary crystallographic information

Comment

In recent years, an increasing amount of research has been focused on the design and preparation of mono- or dinuclear mixed ligand transition metal complexes with neutral, chelating nitrogen-containing ligands. Early and late transition metal complexes of this type have been extensively used as catalysts for a wide categories of reactions, including olefin polymerization (Killian et al., 1996) and oxygen activation (Jung et al., 1996). In this context, diverse chelating Schiff base type ligands, amines and pyridine derivatives (Small et al., 1998) have successfully been applied in the preparation of these homogeneous catalysts. Here we report the crystal structure of an aldimine Schiff base ligand with copper(I) iodide. To the best of our knowledge, only one such related compound has been published (Kia et al., 2009). The title compound is the second tricoordinate complex of an aldimine bis-Schiff base ligand with copper(I) iodide adopting trigonal planar geometry.

The title compound, I, Fig. 1, lies across a crystallographic mirror plane. Atoms I1, Cu1, C9, C10 and C11 lies on this mirror plane. The asymmetric unit of (I) is composed of one-half of the molecule. The coordination around the copper centre is distorted trigonal planar, with a bite angle of 94.7 (3)°. The deviation of the Cu atom from the N1/N1A/I1 plane is -0.105 (4) Å. A six-membered chelate ring with a chair conformation is formed by the coordination of iminic N atoms of the bidentate ligand to the Cu(I) atom, with ring puckering parameters (Cremer & Pople, 1975) of Q = 0.696 (7) Å, Θ = 172.2 (6)°, Φ = 180 (5)°. This conformation is required if the local symmetry of the metal coordination site is in accordance with the mirror plane that passes through the metal atom normal to the line connecting the nitrogen atoms. The dihedral angle between the phenyl rings is 74.85 (19)°. The crystal structure is stabilized by weak intermolecular C—H···π interactions (Cg1 is the centroid of the C1–C6 benzene ring) which link the molecules into chains along the b-axis (Fig. 2 and Table 1).

Experimental

N,N'-Bis(4-bromobenzylidene)-2,2-dimethylpropane (783 mg, 2 mmol) was added dropwise to a suspension of CuI (380 mg, 2.0 mmol) in 50 ml of THF. After 15 min a clear yellowish solution was obtained. The volume of the reaction mixture was reduced until the formation of a yellow precipitate occurred. Single crystals suitable for X-ray diffraction were grown from the acetonitrile solution.