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Acta Cryst. (2008). E64, m1541-m1542    [ doi:10.1107/S1600536808036635 ]

{4,4'-Dibromo-2,2'-[2,2-dimethylpropane-1,3-diylbis(nitrilomethylidyne)]diphenolato-[kappa]4O,N,N',O'}copper(II)

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

Abstract top

In the title compound, [Cu(C19H18Br2N2O2)], the CuII ion is in a tetrahedrally distorted planar geometry, involving two N and two O atoms from the tetradentate Schiff base ligand. Intermolecular C-H...O hydrogen bonds form an eight-membered R22(8) motif. The dihedral angle betwen two benzene rings is 36.34 (9)°. There are intermolecular Cu...Br [3.4566 (5) Å] and Cu...·N [3.569 (3) Å] contacts, which are significantly shorter than the sum of van der Waals radii of the relevant atoms. These interactions, along with the intermolecular C-H...[pi] and [pi]-[pi] [centroid-centroid distances of 3.709 (1) and 3.968 (2) Å] interactions, link neighbouring molecules into a one-dimensional infinite chain along the c axis.

Comment top

Schiff base complexes are some of the most important stereochemical models in transition metal coordination chemistry, with their ease of preparation and structural variations (Elmali et al., 2000; Granovski et al.,1993). Transition metal complexes of Schiff base ligands are always of interest since they exhibit a marked tendency to oligomerize, thus leading to novel structural types, and also display a wide variety of magnetic properties (Blower, 1998; Shahrokhian et al., 2000). Many of the reported structural investigations of these complexes are discussed in some details in a review (Hodgson, 1975). Tetradentate Schiff base metal complexes may form trans or cis planar or tetrahedral structures (Elmali et al., 2000).

In the title compound (Fig. 1), the CuII ion shows a planar geometry distorted towards tetrahedral, which is defined by two imine N atoms and two phenolate O atoms of the tetradentate Schiff base ligand (Table 1). Intermolecular C—H···O hydrogen bonds form an eight-membered ring R22(8) motif (Fig. 2) (Bernstein et al., 1995). The bond lengths are within the normal ranges (Allen et al., 1987) and are comparable with the related structure (Arici et al., 2001). The dihedral angle between two benzene rings is 36.34 (9)°. The chelate ring composed of Cu1, N1, C8, C9, C10 and N2 atoms has a distorted boat conformation with puckering paremeters of Q = 0.807 (3) Å, Θ = 91.1 (2)° and Φ = 264.58 (17)°. The interesting feature of the crystal structure is short intermolecular Cu1···Br1iii [3.4566 (5) Å] and Cu1···N2ii [3.569 (3) Å] interactions [symmetry codes: (ii) 1 - x, -y, 1 - z; (iii) 1 - x, -y, 2 - z], which are significantly shorter than the sum of van der Waals radii of the relevant atoms [Cu: 2.32; Br: 1.85; N: 1.55 Å (Bondi, 1964; Spek, 2003)]. These interactions along with the intermolecular C—H···π (Table 2) and π–π interactions [centroid–centroid distances: Cg2···Cg3iii = 3.709 (1) and Cg2···Cg2iii = 3.968 (2) Å; Cg2 = centroid of the C1–C6 ring and Cg3 = centroid of the Cu1, N1, O1, C1, C6, C7 ring] link the neighbouring molecules into one-dimensional infinite chains along the c axis (Fig. 3).

Related literature top

For bond-length data, see: Allen et al. (1987). For hydrogen-bond motifs, see: Bernstein et al. (1995). For values of van der Waals radii, see: Bondi (1964). For related structures, see: Arici et al. (2001); Elmali et al. (2000); Hodgson (1975); Granovski et al. (1993). For the application of transition-metal complexes with Schiff base ligands, see: Blower (1998); Shahrokhian et al. (2000). Cg1 is the centroid of the Cu1, N2, O2, C11, C12, C17 ring.

Experimental top

The title compound was prepared based on the reported method (Arici et al., 2001). Single crystals suitable for X-ray analysis were obtained from an ethanol solution at room temperature.

Refinement top

H atoms were positioned geometrically and refined using a riding model, with C—H = 0.93 (aromatic), 0.97 (CH2) and 0.96 (CH3) Å and Uiso(H) = 1.2 (1.5 for methyl groups) Ueq(C). The highest difference peak is located 0.81 Å from Br2 and the deepest hole is located 0.76 Å from Cu1.

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); 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, 2003).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, showing 50% probability displacement ellipsoids.
[Figure 2] Fig. 2. The crystal packing of the title compound, viewed down the a axis, showing the hydrogen-bond motif R22(8).
[Figure 3] Fig. 3. The crystal packing of the title compound, viewed down the b axis, showing one-dimensional infinite chains along the c axis. Intermolecular Cu···Br and Cu···N interactions are shown as dashed lines.
{4,4'-Dibromo-2,2'-[2,2-dimethylpropane-1,3- diylbis(nitrilomethylidyne)]diphenolato- κ4O,N,N',O'}copper(II) top
Crystal data top
[Cu(C19H18Br2N2O2)]Z = 2
Mr = 529.71F(000) = 522
Triclinic, P1Dx = 1.883 Mg m−3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 9.1416 (3) ÅCell parameters from 9921 reflections
b = 9.6398 (3) Åθ = 2.2–33.8°
c = 11.5382 (3) ŵ = 5.46 mm−1
α = 75.210 (2)°T = 100 K
β = 78.913 (2)°Block, red
γ = 73.435 (2)°0.41 × 0.21 × 0.15 mm
V = 934.42 (5) Å3
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer		5410 independent reflections
Radiation source: fine-focus sealed tube4345 reflections with I > 2σ(I)
graphiteRint = 0.037
φ and ω scansθmax = 30.0°, θmin = 1.8°
Absorption correction: multi-scan
(SADABS; Bruker, 2001)		h = −12→12
Tmin = 0.195, Tmax = 0.443k = −13→13
29164 measured reflectionsl = −16→16
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)] = 0.033Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.093H-atom parameters constrained
S = 1.07 w = 1/[σ2(Fo2) + (0.0524P)2 + 0.5947P]
where P = (Fo2 + 2Fc2)/3
5410 reflections(Δ/σ)max = 0.002
235 parametersΔρmax = 1.27 e Å−3
0 restraintsΔρmin = −0.61 e Å−3
Crystal data top
[Cu(C19H18Br2N2O2)]γ = 73.435 (2)°
Mr = 529.71V = 934.42 (5) Å3
Triclinic, P1Z = 2
a = 9.1416 (3) ÅMo Kα radiation
b = 9.6398 (3) ŵ = 5.46 mm−1
c = 11.5382 (3) ÅT = 100 K
α = 75.210 (2)°0.41 × 0.21 × 0.15 mm
β = 78.913 (2)°
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer		5410 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2001)		4345 reflections with I > 2σ(I)
Tmin = 0.195, Tmax = 0.443Rint = 0.037
29164 measured reflectionsθmax = 30.0°
Refinement top
R[F2 > 2σ(F2)] = 0.033H-atom parameters constrained
wR(F2) = 0.093Δρmax = 1.27 e Å−3
S = 1.07Δρmin = −0.61 e Å−3
5410 reflectionsAbsolute structure: ?
235 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
Special details top

Experimental. The low-temperature data was collected with the Oxford Cyrosystem Cobra low-temperature attachment.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Cu10.60215 (4)0.07295 (3)0.63222 (3)0.01866 (8)
Br10.15151 (3)−0.15996 (3)1.22034 (2)0.02498 (8)
Br20.80441 (4)0.43866 (3)−0.00230 (2)0.02942 (9)
O10.4262 (2)0.1481 (2)0.73927 (16)0.0210 (4)
O20.5974 (2)0.2636 (2)0.53114 (17)0.0226 (4)
N10.6688 (3)−0.1090 (2)0.7503 (2)0.0195 (4)
N20.6996 (3)−0.0301 (2)0.5008 (2)0.0193 (4)
C10.3696 (3)0.0739 (3)0.8409 (2)0.0187 (5)
C20.2233 (3)0.1404 (3)0.8980 (2)0.0216 (5)
H2A0.17010.23360.86040.026*
C30.1577 (3)0.0712 (3)1.0073 (2)0.0222 (5)
H3A0.06170.11761.04230.027*
C40.2363 (3)−0.0692 (3)1.0654 (2)0.0209 (5)
C50.3765 (3)−0.1391 (3)1.0130 (2)0.0202 (5)
H5A0.4274−0.23251.05200.024*
C60.4441 (3)−0.0708 (3)0.9004 (2)0.0182 (5)
C70.5935 (3)−0.1509 (3)0.8535 (2)0.0195 (5)
H7A0.6390−0.24020.90190.023*
C80.8231 (3)−0.1986 (3)0.7167 (3)0.0220 (5)
H8A0.8583−0.27070.78770.026*
H8B0.8935−0.13470.68890.026*
C90.8276 (3)−0.2804 (3)0.6167 (2)0.0215 (5)
C100.7088 (3)−0.1897 (3)0.5308 (2)0.0208 (5)
H10A0.7350−0.22620.45660.025*
H10B0.6084−0.20490.56770.025*
C110.7379 (3)0.0315 (3)0.3905 (2)0.0191 (5)
H11A0.7818−0.03040.33640.023*
C120.7183 (3)0.1880 (3)0.3441 (2)0.0184 (5)
C130.7662 (3)0.2337 (3)0.2195 (2)0.0200 (5)
H13A0.81380.16300.17340.024*
C140.7432 (3)0.3807 (3)0.1663 (2)0.0206 (5)
C150.6701 (3)0.4888 (3)0.2346 (2)0.0221 (5)
H15A0.65340.58870.19750.026*
C160.6231 (3)0.4473 (3)0.3559 (2)0.0221 (5)
H16A0.57550.52020.39990.027*
C170.6454 (3)0.2960 (3)0.4160 (2)0.0193 (5)
C180.7856 (3)−0.4283 (3)0.6727 (3)0.0255 (6)
H18A0.7886−0.47820.60980.038*
H18B0.6840−0.41060.71650.038*
H18C0.8580−0.48890.72680.038*
C190.9898 (3)−0.3061 (3)0.5469 (3)0.0267 (6)
H19A0.9944−0.35650.48410.040*
H19B1.0627−0.36530.60110.040*
H19C1.0142−0.21240.51180.040*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu10.02588 (17)0.01331 (15)0.01503 (15)−0.00383 (12)−0.00011 (12)−0.00300 (12)
Br10.03447 (15)0.02289 (14)0.01814 (13)−0.01260 (11)0.00257 (10)−0.00364 (10)
Br20.04858 (18)0.01898 (14)0.01683 (13)−0.00907 (12)0.00283 (11)−0.00148 (10)
O10.0275 (9)0.0161 (9)0.0166 (9)−0.0040 (7)0.0010 (7)−0.0029 (7)
O20.0316 (10)0.0154 (9)0.0182 (9)−0.0037 (8)0.0001 (7)−0.0036 (7)
N10.0240 (11)0.0159 (10)0.0180 (10)−0.0030 (8)−0.0029 (8)−0.0047 (9)
N20.0282 (11)0.0131 (10)0.0166 (10)−0.0057 (8)−0.0023 (8)−0.0032 (8)
C10.0268 (13)0.0156 (11)0.0162 (11)−0.0069 (10)−0.0036 (9)−0.0055 (9)
C20.0268 (13)0.0164 (12)0.0211 (13)−0.0055 (10)−0.0031 (10)−0.0031 (10)
C30.0245 (13)0.0219 (13)0.0217 (13)−0.0070 (10)−0.0001 (10)−0.0080 (11)
C40.0287 (13)0.0198 (12)0.0161 (12)−0.0103 (10)−0.0011 (10)−0.0037 (10)
C50.0286 (13)0.0170 (12)0.0160 (12)−0.0079 (10)−0.0029 (10)−0.0027 (10)
C60.0251 (12)0.0154 (11)0.0155 (11)−0.0062 (9)−0.0023 (9)−0.0045 (10)
C70.0258 (13)0.0154 (11)0.0171 (12)−0.0039 (10)−0.0046 (10)−0.0028 (10)
C80.0236 (12)0.0184 (12)0.0230 (13)−0.0033 (10)−0.0027 (10)−0.0048 (11)
C90.0262 (13)0.0162 (12)0.0213 (13)−0.0040 (10)−0.0029 (10)−0.0042 (10)
C100.0302 (13)0.0137 (11)0.0185 (12)−0.0066 (10)−0.0011 (10)−0.0036 (10)
C110.0256 (12)0.0147 (11)0.0170 (12)−0.0049 (9)−0.0026 (9)−0.0037 (9)
C120.0227 (12)0.0152 (11)0.0175 (12)−0.0057 (9)−0.0010 (9)−0.0040 (10)
C130.0246 (12)0.0187 (12)0.0173 (12)−0.0057 (10)−0.0012 (10)−0.0056 (10)
C140.0272 (13)0.0188 (12)0.0158 (12)−0.0082 (10)−0.0014 (10)−0.0021 (10)
C150.0303 (14)0.0137 (11)0.0212 (13)−0.0059 (10)−0.0039 (10)−0.0011 (10)
C160.0289 (13)0.0147 (12)0.0217 (13)−0.0043 (10)0.0001 (10)−0.0056 (10)
C170.0232 (12)0.0162 (11)0.0181 (12)−0.0052 (9)−0.0013 (9)−0.0038 (10)
C180.0361 (15)0.0163 (12)0.0230 (13)−0.0064 (11)−0.0042 (11)−0.0020 (11)
C190.0269 (14)0.0234 (14)0.0287 (15)−0.0048 (11)0.0008 (11)−0.0083 (12)
Geometric parameters (Å, °) top
Cu1—O21.9027 (19)C8—H8A0.9700
Cu1—O11.9146 (18)C8—H8B0.9700
Cu1—N11.948 (2)C9—C181.530 (4)
Cu1—N21.955 (2)C9—C191.531 (4)
Br1—C41.902 (3)C9—C101.535 (4)
Br2—C141.901 (3)C10—H10A0.9700
O1—C11.305 (3)C10—H10B0.9700
O2—C171.303 (3)C11—C121.437 (4)
N1—C71.286 (3)C11—H11A0.9300
N1—C81.467 (3)C12—C131.413 (4)
N2—C111.287 (3)C12—C171.432 (3)
N2—C101.470 (3)C13—C141.366 (4)
C1—C21.422 (4)C13—H13A0.9300
C1—C61.425 (4)C14—C151.405 (4)
C2—C31.379 (4)C15—C161.373 (4)
C2—H2A0.9300C15—H15A0.9300
C3—C41.402 (4)C16—C171.420 (4)
C3—H3A0.9300C16—H16A0.9300
C4—C51.371 (4)C18—H18A0.9600
C5—C61.411 (4)C18—H18B0.9600
C5—H5A0.9300C18—H18C0.9600
C6—C71.442 (4)C19—H19A0.9600
C7—H7A0.9300C19—H19B0.9600
C8—C91.544 (4)C19—H19C0.9600
O2—Cu1—O192.77 (8)C19—C9—C10110.3 (2)
O2—Cu1—N1160.11 (9)C18—C9—C8110.1 (2)
O1—Cu1—N193.32 (9)C19—C9—C8108.4 (2)
O2—Cu1—N293.40 (8)C10—C9—C8110.7 (2)
O1—Cu1—N2151.78 (9)N2—C10—C9113.6 (2)
N1—Cu1—N290.14 (9)N2—C10—H10A108.8
C1—O1—Cu1126.57 (17)C9—C10—H10A108.8
C17—O2—Cu1128.01 (16)N2—C10—H10B108.8
C7—N1—C8119.4 (2)C9—C10—H10B108.8
C7—N1—Cu1125.97 (19)H10A—C10—H10B107.7
C8—N1—Cu1114.58 (17)N2—C11—C12125.4 (2)
C11—N2—C10118.7 (2)N2—C11—H11A117.3
C11—N2—Cu1125.90 (18)C12—C11—H11A117.3
C10—N2—Cu1114.85 (16)C13—C12—C17120.1 (2)
O1—C1—C2118.6 (2)C13—C12—C11116.7 (2)
O1—C1—C6124.7 (2)C17—C12—C11123.1 (2)
C2—C1—C6116.7 (2)C14—C13—C12120.7 (2)
C3—C2—C1122.2 (3)C14—C13—H13A119.7
C3—C2—H2A118.9C12—C13—H13A119.7
C1—C2—H2A118.9C13—C14—C15120.3 (2)
C2—C3—C4119.7 (2)C13—C14—Br2119.65 (19)
C2—C3—H3A120.1C15—C14—Br2120.0 (2)
C4—C3—H3A120.1C16—C15—C14120.2 (2)
C5—C4—C3120.3 (2)C16—C15—H15A119.9
C5—C4—Br1119.8 (2)C14—C15—H15A119.9
C3—C4—Br1119.8 (2)C15—C16—C17121.8 (2)
C4—C5—C6120.7 (3)C15—C16—H16A119.1
C4—C5—H5A119.7C17—C16—H16A119.1
C6—C5—H5A119.7O2—C17—C16118.9 (2)
C5—C6—C1120.4 (2)O2—C17—C12124.1 (2)
C5—C6—C7116.8 (2)C16—C17—C12117.0 (2)
C1—C6—C7122.7 (2)C9—C18—H18A109.5
N1—C7—C6125.3 (2)C9—C18—H18B109.5
N1—C7—H7A117.3H18A—C18—H18B109.5
C6—C7—H7A117.3C9—C18—H18C109.5
N1—C8—C9112.7 (2)H18A—C18—H18C109.5
N1—C8—H8A109.0H18B—C18—H18C109.5
C9—C8—H8A109.0C9—C19—H19A109.5
N1—C8—H8B109.0C9—C19—H19B109.5
C9—C8—H8B109.0H19A—C19—H19B109.5
H8A—C8—H8B107.8C9—C19—H19C109.5
C18—C9—C19110.4 (2)H19A—C19—H19C109.5
C18—C9—C10106.9 (2)H19B—C19—H19C109.5
O2—Cu1—O1—C1−174.0 (2)C8—N1—C7—C6177.2 (2)
N1—Cu1—O1—C1−12.9 (2)Cu1—N1—C7—C60.6 (4)
N2—Cu1—O1—C183.6 (3)C5—C6—C7—N1176.6 (2)
O1—Cu1—O2—C17−151.9 (2)C1—C6—C7—N1−6.7 (4)
N1—Cu1—O2—C17100.4 (3)C7—N1—C8—C9108.8 (3)
N2—Cu1—O2—C170.6 (2)Cu1—N1—C8—C9−74.2 (2)
O2—Cu1—N1—C7114.8 (3)N1—C8—C9—C18−86.0 (3)
O1—Cu1—N1—C77.2 (2)N1—C8—C9—C19153.1 (2)
N2—Cu1—N1—C7−144.8 (2)N1—C8—C9—C1032.0 (3)
O2—Cu1—N1—C8−61.9 (3)C11—N2—C10—C9115.7 (3)
O1—Cu1—N1—C8−169.52 (17)Cu1—N2—C10—C9−72.2 (2)
N2—Cu1—N1—C838.50 (18)C18—C9—C10—N2160.8 (2)
O2—Cu1—N2—C110.1 (2)C19—C9—C10—N2−79.2 (3)
O1—Cu1—N2—C11102.4 (3)C8—C9—C10—N240.8 (3)
N1—Cu1—N2—C11−160.3 (2)C10—N2—C11—C12172.3 (2)
O2—Cu1—N2—C10−171.27 (18)Cu1—N2—C11—C121.2 (4)
O1—Cu1—N2—C10−69.0 (3)N2—C11—C12—C13−179.2 (3)
N1—Cu1—N2—C1028.31 (19)N2—C11—C12—C17−3.2 (4)
Cu1—O1—C1—C2−169.15 (18)C17—C12—C13—C14−0.2 (4)
Cu1—O1—C1—C611.1 (4)C11—C12—C13—C14175.9 (2)
O1—C1—C2—C3−178.0 (2)C12—C13—C14—C15−0.6 (4)
C6—C1—C2—C31.9 (4)C12—C13—C14—Br2−178.50 (19)
C1—C2—C3—C40.1 (4)C13—C14—C15—C160.9 (4)
C2—C3—C4—C5−1.3 (4)Br2—C14—C15—C16178.8 (2)
C2—C3—C4—Br1176.5 (2)C14—C15—C16—C17−0.4 (4)
C3—C4—C5—C60.4 (4)Cu1—O2—C17—C16176.52 (18)
Br1—C4—C5—C6−177.39 (19)Cu1—O2—C17—C12−2.5 (4)
C4—C5—C6—C11.7 (4)C15—C16—C17—O2−179.5 (2)
C4—C5—C6—C7178.5 (2)C15—C16—C17—C12−0.4 (4)
O1—C1—C6—C5177.1 (2)C13—C12—C17—O2179.8 (2)
C2—C1—C6—C5−2.7 (4)C11—C12—C17—O23.9 (4)
O1—C1—C6—C70.5 (4)C13—C12—C17—C160.7 (4)
C2—C1—C6—C7−179.3 (2)C11—C12—C17—C16−175.2 (2)
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
C16—H16A···O2i0.932.443.342 (3)163
C10—H10B···Cg1ii0.972.503.324 (3)142
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+1, −y, −z+1.
Table 1
Selected geometric parameters (Å) top
Cu1—O21.9027 (19)Cu1—N11.948 (2)
Cu1—O11.9146 (18)Cu1—N21.955 (2)
Table 2
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
C16—H16A···O2i0.932.443.342 (3)163
C10—H10B···Cg1ii0.972.503.324 (3)142
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+1, −y, −z+1.
Acknowledgements top

HKF and RK thank the Malaysian Government and Universiti Sains Malaysia for the 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
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