{6,6′-Dieth­oxy-2,2′-[4,5-dimethyl-o-phenyl­enebis(nitrilo­methyl­idyne)]diphenolato}copper(II)

Jamshidvand, A.; Kargar, H.; Kia, R.; Tahir, M.N.

doi:10.1107/S1600536810042789

metal-organic compounds

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ISSN: 2056-9890

Volume 66| Part 11| November 2010| Page m1473

https://doi.org/10.1107/S1600536810042789

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{6,6′-Diethoxy-2,2′-[4,5-dimethyl-o-phenylenebis(nitrilomethylidyne)]diphenolato}copper(II)

Arezoo Jamshidvand,^a Hadi Kargar,^a Reza Kia ^b,^c ^* and Muhammad Nawaz Tahir ^d ^*

^aDepartment of Chemistry, School of Science, Payame Noor University (PNU), Ardakan, Yazd, Iran, ^bDepartment of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran, ^cX-ray Crystallography Lab., Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran, Iran, and ^dDepartment of Physics, University of Sargodha, Punjab, Pakistan
^*Correspondence e-mail: zsrkk@yahoo.com, rkia@srbiau.ac.ir, dmntahir_uos@yahoo.com

(Received 9 October 2010; accepted 21 October 2010; online 30 October 2010)

In the title complex, [Cu(C₂₆H₂₆N₂O₄)], the Cu^II ion lies on a crystallographic twofold rotation axis and is coordinated in a slightly distorted square-planar environment. The dihedral angle between the central benzene ring and each of the two symmetry-related outer benzene rings is 5.1 (2)°. The crystal structure is stabilized by intermolecular π–π interactions with centroid–centroid distances in the range 3.466 (2)–3.6431 (16) Å.

Related literature

For background to Schiff base–metal complexes, see: Granovski et al. (1993 ); Blower et al. (1998 ); Elmali et al. (2000 ). For standard bond lengths, see: Allen et al. (1987 ).

Experimental

Crystal data

[Cu(C₂₆H₂₆N₂O₄)]
M_r = 494.03
Monoclinic, C 2/c
a = 14.9755 (7) Å
b = 15.8803 (7) Å
c = 12.2264 (6) Å
β = 119.285 (2)°
V = 2536.0 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.89 mm⁻¹
T = 296 K
0.27 × 0.21 × 0.11 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ) T_min = 0.982, T_max = 0.992
31403 measured reflections
3157 independent reflections
1910 reflections with I > 2σ(I)
R_int = 0.049

Refinement

R[F² > 2σ(F²)] = 0.066
wR(F²) = 0.147
S = 1.05
3157 reflections
152 parameters
H-atom parameters constrained
Δρ_max = 0.43 e Å⁻³
Δρ_min = −0.46 e Å⁻³

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT; 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 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S1600536810042789/lh5150sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810042789/lh5150Isup2.hkl

checkCIF report

Comment top

Schiff base complexes are one of the most important stereochemical models in transition metal coordination chemistry, with the ease of preparation and structural variations (Granovski et al., 1993). Metal derivatives of the Schiff bases have been studied extensively, and Ni(II) and Cu(II) complexes play a major role in both synthetic and structural research (Elmali et al., 2000; Blower et al., 1998).

The molecular structure of the title compound is shown in Fig. 1. The asymmetric unit comprises half of a Schiff base complex. The bond lengths (Allen et al., 1987) and angles are within the normal ranges. The geometry around the Cu^II ion is slightly distorted square-planar for which the coordination is a N₂O₂ donor set of the Schiff base ligand. The dihedral angle between the mean planes of the centeral aromatic ring with the two symmetry-related outer rings is 5.1 (2)°. The crystal structure is stabilized by intermolecular π–π interactions [Cg1···Cg3ⁱ = 3.594 (2)Å, (i) -x, 1 - y, -z; Cg2···Cg2ⁱ = 3.6431 (16)Å, Cg2···Cg3ⁱ = 3.466 (2)Å, Cg1, Cg2, and Cg3 are the centroids of Cu1/N1/C8/C8A/N1A, C1–C6, and Cu1/O1/C1/C6/C7/N1, respectively.

Related literature top

For background to Schiff base–metal complexes, see: Granovski et al. (1993); Blower et al. (1998); Elmali et al. (2000). For standard bond lengths, see: Allen et al. (1987).

Experimental top

The title compound was synthesized by adding bis(3-ethoxysalicylidene)-4,5- dimethyl phenylenediamine (2 mmol) to a solution of CuCl₂.4H₂O (2 mmol) in ethanol (30 ml). The mixture was refluxed with stirring for half an hour. The resultant solution was filtered. Dark-green single crystals of the title compound suitable for X-ray structure determination were recrystallized from ethanol by slow evaporation of the solvents at room temperature over several days.

Structure description top

For background to Schiff base–metal complexes, see: Granovski et al. (1993); Blower et al. (1998); Elmali et al. (2000). For standard bond lengths, see: Allen et al. (1987).

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (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

	Fig. 1. The molecular structure of the title compound, showing 40% probability displacement ellipsoids and the atomic numbering. Symmetry code for the unlabled atoms: -x, y, -z + 1/2
	Fig. 2. Part of the crystal structure viewed approximately along the b-axis showing π–π stacking interactions as dashed lines.

{6,6'-Diethoxy-2,2'-[4,5-dimethyl-o- phenylenebis(nitrilomethylidyne)]diphenolato}copper(II) top

Crystal data top

[Cu(C₂₆H₂₆N₂O₄)]	F(000) = 1028
M_r = 494.03	D_x = 1.294 Mg m⁻³
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 2273 reflections
a = 14.9755 (7) Å	θ = 2.5–27.5°
b = 15.8803 (7) Å	µ = 0.89 mm⁻¹
c = 12.2264 (6) Å	T = 296 K
β = 119.285 (2)°	Block, green
V = 2536.0 (2) Å³	0.27 × 0.21 × 0.11 mm
Z = 4

Data collection top

Bruker SMART APEXII CCD area-detector diffractometer	3157 independent reflections
Radiation source: fine-focus sealed tube	1910 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.049
φ and ω scans	θ_max = 28.3°, θ_min = 2.0°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −16→20
T_min = 0.982, T_max = 0.992	k = 0→21
3157 measured reflections	l = −16→0

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.066	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.147	H-atom parameters constrained
S = 1.05	w = 1/[σ²(F_o²) + (0.0549P)² + 4.1197P] where P = (F_o² + 2F_c²)/3
3157 reflections	(Δ/σ)_max = 0.001
152 parameters	Δρ_max = 0.43 e Å⁻³
0 restraints	Δρ_min = −0.46 e Å⁻³

Crystal data top

[Cu(C₂₆H₂₆N₂O₄)]	V = 2536.0 (2) Å³
M_r = 494.03	Z = 4
Monoclinic, C2/c	Mo Kα radiation
a = 14.9755 (7) Å	µ = 0.89 mm⁻¹
b = 15.8803 (7) Å	T = 296 K
c = 12.2264 (6) Å	0.27 × 0.21 × 0.11 mm
β = 119.285 (2)°

Data collection top

Bruker SMART APEXII CCD area-detector diffractometer	3157 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2005)	1910 reflections with I > 2σ(I)
T_min = 0.982, T_max = 0.992	R_int = 0.049
3157 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.066	0 restraints
wR(F²) = 0.147	H-atom parameters constrained
S = 1.05	Δρ_max = 0.43 e Å⁻³
3157 reflections	Δρ_min = −0.46 e Å⁻³
152 parameters

Special details top

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

	x	y	z	U_iso*/U_eq
Cu1	0.0000	0.51186 (3)	0.2500	0.0401 (2)
O1	0.06365 (19)	0.42620 (14)	0.2039 (2)	0.0464 (6)
N1	0.0519 (2)	0.60241 (16)	0.1905 (3)	0.0401 (7)
O2	0.1286 (2)	0.28916 (14)	0.1524 (3)	0.0591 (8)
C1	0.1134 (3)	0.4353 (2)	0.1421 (3)	0.0395 (8)
C2	0.1501 (3)	0.3619 (2)	0.1111 (3)	0.0444 (9)
C3	0.2022 (3)	0.3667 (3)	0.0445 (4)	0.0548 (10)
H3A	0.2271	0.3177	0.0272	0.066*
C4	0.2178 (3)	0.4435 (3)	0.0029 (4)	0.0590 (11)
H4A	0.2514	0.4457	−0.0440	0.071*
C5	0.1843 (3)	0.5156 (3)	0.0305 (4)	0.0531 (10)
H5A	0.1958	0.5670	0.0028	0.064*
C6	0.1315 (3)	0.5138 (2)	0.1013 (3)	0.0411 (8)
C7	0.0998 (3)	0.5921 (2)	0.1269 (3)	0.0449 (9)
H7A	0.1145	0.6403	0.0954	0.054*
C8	0.0270 (3)	0.6835 (2)	0.2165 (3)	0.0436 (9)
C9	0.0525 (3)	0.7599 (2)	0.1837 (4)	0.0544 (10)
H9A	0.0881	0.7601	0.1392	0.065*
C10	0.0264 (3)	0.8356 (2)	0.2158 (4)	0.0621 (13)
C11	0.0545 (4)	0.9164 (3)	0.1760 (5)	0.0899 (18)
H11A	0.0925	0.9516	0.2481	0.135*
H11B	−0.0067	0.9451	0.1169	0.135*
H11C	0.0957	0.9041	0.1376	0.135*
C12	0.1611 (3)	0.2112 (2)	0.1270 (4)	0.0537 (10)
H12A	0.2352	0.2095	0.1671	0.064*
H12B	0.1336	0.2044	0.0373	0.064*
C13	0.1234 (4)	0.1426 (3)	0.1764 (5)	0.0774 (14)
H13A	0.1490	0.0896	0.1659	0.116*
H13B	0.0499	0.1419	0.1313	0.116*
H13C	0.1469	0.1521	0.2638	0.116*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cu1	0.0526 (4)	0.0263 (3)	0.0492 (4)	0.000	0.0309 (3)	0.000
O1	0.0652 (17)	0.0318 (12)	0.0572 (16)	0.0001 (11)	0.0415 (15)	0.0021 (11)
N1	0.0440 (18)	0.0284 (15)	0.0416 (17)	0.0005 (12)	0.0161 (15)	0.0026 (12)
O2	0.084 (2)	0.0334 (14)	0.084 (2)	0.0090 (13)	0.0601 (18)	0.0010 (13)
C1	0.041 (2)	0.0384 (19)	0.042 (2)	−0.0003 (15)	0.0224 (18)	0.0007 (15)
C2	0.050 (2)	0.045 (2)	0.044 (2)	0.0025 (17)	0.0278 (19)	−0.0011 (16)
C3	0.056 (3)	0.057 (2)	0.061 (3)	0.002 (2)	0.037 (2)	−0.006 (2)
C4	0.058 (3)	0.071 (3)	0.066 (3)	−0.005 (2)	0.045 (2)	−0.002 (2)
C5	0.057 (2)	0.053 (2)	0.052 (2)	−0.0105 (19)	0.029 (2)	0.0052 (19)
C6	0.0423 (19)	0.0403 (18)	0.0402 (19)	−0.0024 (16)	0.0199 (16)	0.0006 (16)
C7	0.049 (2)	0.040 (2)	0.042 (2)	−0.0098 (16)	0.0197 (19)	0.0053 (16)
C8	0.048 (2)	0.0262 (17)	0.042 (2)	−0.0007 (15)	0.0111 (17)	0.0014 (15)
C9	0.060 (3)	0.0328 (19)	0.054 (2)	−0.0060 (18)	0.015 (2)	0.0081 (17)
C10	0.069 (3)	0.0271 (19)	0.053 (3)	−0.0036 (18)	0.001 (2)	0.0032 (16)
C11	0.116 (4)	0.032 (2)	0.083 (4)	−0.015 (2)	0.019 (3)	0.010 (2)
C12	0.055 (2)	0.044 (2)	0.064 (3)	0.0131 (18)	0.031 (2)	−0.0042 (18)
C13	0.101 (4)	0.039 (2)	0.103 (4)	0.011 (2)	0.058 (3)	0.000 (2)

Geometric parameters (Å, º) top

Cu1—O1ⁱ	1.898 (2)	C6—C7	1.419 (5)
Cu1—O1	1.898 (2)	C7—H7A	0.9300
Cu1—N1ⁱ	1.938 (3)	C8—C9	1.389 (5)
Cu1—N1	1.938 (3)	C8—C8ⁱ	1.406 (7)
O1—C1	1.303 (4)	C9—C10	1.379 (5)
N1—C7	1.301 (5)	C9—H9A	0.9300
N1—C8	1.419 (4)	C10—C10ⁱ	1.404 (9)
O2—C2	1.361 (4)	C10—C11	1.504 (5)
O2—C12	1.419 (4)	C11—H11A	0.9600
C1—C2	1.417 (5)	C11—H11B	0.9600
C1—C6	1.417 (5)	C11—H11C	0.9600
C2—C3	1.378 (5)	C12—C13	1.484 (6)
C3—C4	1.385 (5)	C12—H12A	0.9700
C3—H3A	0.9300	C12—H12B	0.9700
C4—C5	1.358 (5)	C13—H13A	0.9600
C4—H4A	0.9300	C13—H13B	0.9600
C5—C6	1.430 (5)	C13—H13C	0.9600
C5—H5A	0.9300

O1ⁱ—Cu1—O1	88.42 (14)	N1—C7—H7A	117.2
O1ⁱ—Cu1—N1ⁱ	93.93 (11)	C6—C7—H7A	117.2
O1—Cu1—N1ⁱ	174.47 (11)	C9—C8—C8ⁱ	119.1 (2)
O1ⁱ—Cu1—N1	174.47 (11)	C9—C8—N1	126.1 (4)
O1—Cu1—N1	93.93 (11)	C8ⁱ—C8—N1	114.82 (19)
N1ⁱ—Cu1—N1	84.17 (17)	C10—C9—C8	121.6 (4)
C1—O1—Cu1	127.2 (2)	C10—C9—H9A	119.2
C7—N1—C8	122.0 (3)	C8—C9—H9A	119.2
C7—N1—Cu1	124.8 (2)	C9—C10—C10ⁱ	119.4 (3)
C8—N1—Cu1	113.1 (2)	C9—C10—C11	119.2 (4)
C2—O2—C12	119.4 (3)	C10ⁱ—C10—C11	121.4 (3)
O1—C1—C2	118.0 (3)	C10—C11—H11A	109.5
O1—C1—C6	124.3 (3)	C10—C11—H11B	109.5
C2—C1—C6	117.6 (3)	H11A—C11—H11B	109.5
O2—C2—C3	124.8 (3)	C10—C11—H11C	109.5
O2—C2—C1	114.0 (3)	H11A—C11—H11C	109.5
C3—C2—C1	121.2 (3)	H11B—C11—H11C	109.5
C2—C3—C4	120.7 (4)	O2—C12—C13	108.2 (3)
C2—C3—H3A	119.6	O2—C12—H12A	110.1
C4—C3—H3A	119.6	C13—C12—H12A	110.1
C5—C4—C3	120.2 (4)	O2—C12—H12B	110.1
C5—C4—H4A	119.9	C13—C12—H12B	110.1
C3—C4—H4A	119.9	H12A—C12—H12B	108.4
C4—C5—C6	121.0 (4)	C12—C13—H13A	109.5
C4—C5—H5A	119.5	C12—C13—H13B	109.5
C6—C5—H5A	119.5	H13A—C13—H13B	109.5
C1—C6—C7	123.4 (3)	C12—C13—H13C	109.5
C1—C6—C5	119.2 (3)	H13A—C13—H13C	109.5
C7—C6—C5	117.3 (3)	H13B—C13—H13C	109.5
N1—C7—C6	125.7 (3)

O1ⁱ—Cu1—O1—C1	169.0 (3)	C2—C1—C6—C7	−179.4 (3)
N1—Cu1—O1—C1	−6.0 (3)	O1—C1—C6—C5	−177.9 (3)
O1—Cu1—N1—C7	8.1 (3)	C2—C1—C6—C5	0.7 (5)
N1ⁱ—Cu1—N1—C7	−177.1 (4)	C4—C5—C6—C1	−0.6 (6)
O1—Cu1—N1—C8	−175.5 (2)	C4—C5—C6—C7	179.5 (3)
N1ⁱ—Cu1—N1—C8	−0.69 (17)	C8—N1—C7—C6	177.1 (3)
Cu1—O1—C1—C2	−176.4 (2)	Cu1—N1—C7—C6	−6.9 (5)
Cu1—O1—C1—C6	2.2 (5)	C1—C6—C7—N1	0.7 (6)
C12—O2—C2—C3	0.1 (6)	C5—C6—C7—N1	−179.4 (3)
C12—O2—C2—C1	179.8 (3)	C7—N1—C8—C9	−2.6 (6)
O1—C1—C2—O2	−0.6 (5)	Cu1—N1—C8—C9	−179.1 (3)
C6—C1—C2—O2	−179.3 (3)	C7—N1—C8—C8ⁱ	178.5 (4)
O1—C1—C2—C3	179.1 (3)	Cu1—N1—C8—C8ⁱ	2.0 (5)
C6—C1—C2—C3	0.5 (5)	C8ⁱ—C8—C9—C10	0.2 (6)
O2—C2—C3—C4	178.0 (4)	N1—C8—C9—C10	−178.7 (3)
C1—C2—C3—C4	−1.7 (6)	C8—C9—C10—C10ⁱ	0.7 (7)
C2—C3—C4—C5	1.8 (7)	C8—C9—C10—C11	−179.0 (4)
C3—C4—C5—C6	−0.6 (6)	C2—O2—C12—C13	−177.2 (4)
O1—C1—C6—C7	2.0 (6)

Symmetry code: (i) −x, y, −z+1/2.

Experimental details

Crystal data
Chemical formula	[Cu(C₂₆H₂₆N₂O₄)]
M_r	494.03
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	296
a, b, c (Å)	14.9755 (7), 15.8803 (7), 12.2264 (6)
β (°)	119.285 (2)
V (Å³)	2536.0 (2)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.89
Crystal size (mm)	0.27 × 0.21 × 0.11

Data collection
Diffractometer	Bruker SMART APEXII CCD area-detector
Absorption correction	Multi-scan (SADABS; Bruker, 2005)
T_min, T_max	0.982, 0.992
No. of measured, independent and observed [I > 2σ(I)] reflections	3157, 3157, 1910
R_int	0.049
(sin θ/λ)_max (Å⁻¹)	0.668

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.066, 0.147, 1.05
No. of reflections	3157
No. of parameters	152
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.43, −0.46

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Acknowledgements

HK and AJ thank PNU for financial support. RK thanks the Islamic Azad University and Professor H. M. Stoeckli-Evans for valuable help.

References

Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19. CSD CrossRef Web of Science Google Scholar
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Elmali, A., Elerman, Y. & Svoboda, I. (2000). Acta Cryst. C56, 423–424. CSD CrossRef CAS IUCr Journals Google Scholar
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