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Acta Cryst. (2009). E65, m289    [ doi:10.1107/S1600536809005078 ]

[N,N'-Bis(4-bromobenzylidene)-2,2-dimethylpropane-[kappa]2N,N']iodidocopper(I)

R. Kia, H.-K. Fun and H. Kargar

Abstract top

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 CuI 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...[pi] interactions, which link the molecules into chains along the b axis.

Comment top

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).

Related literature top

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

Experimental top

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.

Refinement top

All H atoms were positioned geometrically with C—H = 0.95–0.99 Å and refined in a riding model approximation with Uiso(H) = 1.2Ueq(C). The highest peak (2.64 e. Å-3) is located 1.02 Å from I1 and the deepest hole (-0.99 e. Å-3) is located 0.58 Å from H10A.

Computing details top

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

Figures top
[Figure 1] Fig. 1. The molecular structure of (I), showing 40% probability displacement ellipsoids and the atomic numbering. Symmetry code for A atoms; x, -y + 1, z.
[Figure 2] Fig. 2. The crystal packing of (I), viewed down the c-axis, showing C—H···π interactions linking the molecules into chains along the b-axis.
[N,N'-Bis(4-bromobenzylidene)-2,2-dimethylpropane- κ2N,N']iodidocopper(I) top
Crystal data top
[CuI(C19H20Br2N2)]F(000) = 1200
Mr = 626.63Dx = 1.966 Mg m−3
Monoclinic, C2/mMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yCell parameters from 4080 reflections
a = 16.2224 (15) Åθ = 2.5–29.5°
b = 12.2807 (12) ŵ = 6.27 mm−1
c = 10.6292 (12) ÅT = 100 K
β = 91.599 (6)°Needle, yellow
V = 2116.8 (4) Å30.58 × 0.09 × 0.05 mm
Z = 4
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer		1936 independent reflections
Radiation source: fine-focus sealed tube1474 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.099
φ and ω scansθmax = 25.0°, θmin = 2.1°
Absorption correction: multi-scan
(SADABS; Bruker, 2005)		h = −19→19
Tmin = 0.119, Tmax = 0.714k = −14→14
10374 measured reflectionsl = −12→12
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.050Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.112H-atom parameters constrained
S = 1.16 w = 1/[σ2(Fo2) + (0.0405P)2 + 16.0151P]
where P = (Fo2 + 2Fc2)/3
1936 reflections(Δ/σ)max < 0.001
121 parametersΔρmax = 2.64 e Å−3
0 restraintsΔρmin = −0.99 e Å−3
Crystal data top
[CuI(C19H20Br2N2)]V = 2116.8 (4) Å3
Mr = 626.63Z = 4
Monoclinic, C2/mMo Kα radiation
a = 16.2224 (15) ŵ = 6.27 mm−1
b = 12.2807 (12) ÅT = 100 K
c = 10.6292 (12) Å0.58 × 0.09 × 0.05 mm
β = 91.599 (6)°
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer		1936 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2005)		1474 reflections with I > 2σ(I)
Tmin = 0.119, Tmax = 0.714Rint = 0.099
10374 measured reflectionsθmax = 25.0°
Refinement top
R[F2 > 2σ(F2)] = 0.050 w = 1/[σ2(Fo2) + (0.0405P)2 + 16.0151P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.112Δρmax = 2.64 e Å−3
S = 1.16Δρmin = −0.99 e Å−3
1936 reflectionsAbsolute structure: ?
121 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
H-atom parameters constrained
Special details top

Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > 2sigma(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
I10.38486 (4)0.50000.14862 (6)0.0166 (2)
Br10.11472 (5)0.16378 (8)0.54336 (7)0.0309 (3)
Cu10.25251 (8)0.50000.02730 (11)0.0168 (3)
N10.1853 (3)0.3798 (6)−0.0519 (5)0.0167 (14)
C10.1751 (5)0.3315 (7)0.2223 (7)0.0213 (18)
H1A0.20850.39230.20220.026*
C20.1683 (4)0.3023 (7)0.3463 (7)0.0210 (18)
H2A0.19570.34260.41130.025*
C30.1204 (5)0.2130 (7)0.3742 (6)0.0193 (18)
C40.0779 (5)0.1560 (7)0.2811 (8)0.026 (2)
H4A0.04420.09580.30210.031*
C50.0852 (4)0.1878 (7)0.1556 (7)0.0188 (18)
H5A0.05590.14960.09070.023*
C60.1354 (4)0.2756 (7)0.1260 (7)0.0172 (18)
C70.1428 (4)0.3030 (7)−0.0085 (7)0.0184 (17)
H7A0.11300.2590−0.06750.022*
C80.1816 (5)0.3967 (7)−0.1892 (7)0.0213 (18)
H8A0.15420.3330−0.22920.026*
H8B0.23870.3997−0.21980.026*
C90.1360 (7)0.5000−0.2327 (9)0.020 (3)
C100.0477 (6)0.5000−0.1869 (11)0.028 (3)
H10A0.04920.5000−0.09470.041*
H10B0.01870.4348−0.21770.041*
C110.1346 (7)0.5000−0.3771 (10)0.024 (3)
H11A0.19160.5000−0.40550.036*
H11B0.10610.5652−0.40910.036*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
I10.0191 (4)0.0171 (4)0.0134 (4)0.000−0.0029 (3)0.000
Br10.0371 (5)0.0400 (6)0.0154 (4)−0.0155 (4)−0.0026 (3)0.0048 (4)
Cu10.0195 (7)0.0188 (8)0.0121 (7)0.000−0.0020 (5)0.000
N10.020 (3)0.018 (4)0.012 (3)0.001 (3)0.001 (2)−0.002 (3)
C10.024 (4)0.021 (5)0.019 (4)−0.007 (3)0.002 (3)−0.003 (4)
C20.025 (4)0.023 (5)0.015 (4)−0.009 (4)−0.004 (3)−0.007 (4)
C30.031 (4)0.022 (5)0.005 (4)−0.003 (4)0.001 (3)0.002 (3)
C40.031 (5)0.022 (5)0.025 (5)−0.010 (4)0.002 (4)0.003 (4)
C50.018 (4)0.025 (5)0.013 (4)−0.001 (3)−0.002 (3)−0.002 (4)
C60.019 (4)0.014 (5)0.020 (4)0.005 (3)0.004 (3)−0.002 (4)
C70.022 (4)0.016 (5)0.017 (4)0.000 (3)−0.005 (3)−0.010 (4)
C80.031 (4)0.019 (5)0.014 (4)−0.003 (4)0.001 (3)−0.002 (4)
C90.029 (6)0.024 (7)0.007 (5)0.0000.003 (4)0.000
C100.022 (6)0.034 (8)0.027 (7)0.000−0.009 (5)0.000
C110.038 (7)0.020 (7)0.015 (6)0.000−0.006 (5)0.000
Geometric parameters (Å, º) top
I1—Cu12.4735 (14)C5—C61.392 (11)
Br1—C31.902 (7)C5—H5A0.9500
Cu1—N12.006 (6)C6—C71.477 (11)
Cu1—N1i2.006 (6)C7—H7A0.9500
N1—C71.263 (10)C8—C91.533 (10)
N1—C81.474 (9)C8—H8A0.9900
C1—C21.374 (11)C8—H8B0.9900
C1—C61.378 (10)C9—C101.527 (15)
C1—H1A0.9500C9—C8i1.533 (10)
C2—C31.381 (11)C9—C111.535 (14)
C2—H2A0.9500C10—H10A0.9800
C3—C41.381 (11)C10—H10B0.9800
C4—C51.398 (11)C11—H11A0.9800
C4—H4A0.9500C11—H11B0.9801
N1—Cu1—N1i94.8 (4)C5—C6—C7117.3 (7)
N1—Cu1—I1132.24 (18)N1—C7—C6125.7 (7)
N1i—Cu1—I1132.24 (18)N1—C7—H7A117.1
C7—N1—C8117.4 (6)C6—C7—H7A117.1
C7—N1—Cu1133.8 (5)N1—C8—C9114.9 (7)
C8—N1—Cu1108.5 (5)N1—C8—H8A108.5
C2—C1—C6122.3 (8)C9—C8—H8A108.5
C2—C1—H1A118.9N1—C8—H8B108.5
C6—C1—H1A118.9C9—C8—H8B108.5
C1—C2—C3118.3 (7)H8A—C8—H8B107.5
C1—C2—H2A120.9C10—C9—C8i110.7 (6)
C3—C2—H2A120.9C10—C9—C8110.7 (6)
C4—C3—C2121.4 (7)C8i—C9—C8111.7 (9)
C4—C3—Br1118.7 (6)C10—C9—C11109.3 (9)
C2—C3—Br1119.8 (6)C8i—C9—C11107.1 (6)
C3—C4—C5119.2 (8)C8—C9—C11107.1 (6)
C3—C4—H4A120.4C9—C10—H10A108.7
C5—C4—H4A120.4C9—C10—H10B109.8
C6—C5—C4119.8 (7)H10A—C10—H10B109.5
C6—C5—H5A120.1C9—C11—H11A108.6
C4—C5—H5A120.1C9—C11—H11B109.9
C1—C6—C5118.9 (7)H11A—C11—H11B109.5
C1—C6—C7123.8 (7)
N1i—Cu1—N1—C7−119.0 (7)C4—C5—C6—C1−1.9 (11)
I1—Cu1—N1—C770.2 (8)C4—C5—C6—C7178.0 (7)
N1i—Cu1—N1—C854.2 (5)C8—N1—C7—C6−177.4 (7)
I1—Cu1—N1—C8−116.5 (4)Cu1—N1—C7—C6−4.5 (12)
C6—C1—C2—C30.8 (12)C1—C6—C7—N1−0.3 (12)
C1—C2—C3—C4−2.2 (12)C5—C6—C7—N1179.8 (7)
C1—C2—C3—Br1175.9 (6)C7—N1—C8—C9109.6 (8)
C2—C3—C4—C51.6 (13)Cu1—N1—C8—C9−64.9 (7)
Br1—C3—C4—C5−176.6 (6)N1—C8—C9—C10−57.8 (9)
C3—C4—C5—C60.5 (12)N1—C8—C9—C8i66.0 (10)
C2—C1—C6—C51.3 (12)N1—C8—C9—C11−176.9 (7)
C2—C1—C6—C7−178.6 (7)
Symmetry code: (i) x, −y+1, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C8—H8A···Cg1ii0.992.833.631 (9)138
Symmetry code: (ii) −x+1/2, −y+1/2, −z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C8—H8A···Cg1i0.992.833.631 (9)138
Symmetry code: (i) −x+1/2, −y+1/2, −z.
Acknowledgements top

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.

references
References top

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