{5,5′-Bis(methoxy­carbonyl­meth­oxy)-2,2′-[ethane-1,2-diylbis(nitrilo­methyl­idyne)]­diphenolato}copper(II)

Wang, Z.-H.; Ma, J.-F.; Wu, H.; Liu, H.-Y.

doi:10.1107/S1600536808033084

metal-organic compounds

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ISSN: 2056-9890

Volume 64| Part 11| November 2008| Page m1432

doi:10.1107/S1600536808033084

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{5,5′-Bis(methoxycarbonylmethoxy)-2,2′-[ethane-1,2-diylbis(nitrilomethylidyne)]diphenolato}copper(II)

Zhi-Hui Wang,^a Jian-Fang Ma,^a ^* Hua Wu ^a and Hai-Yan Liu ^a

^aDepartment of Chemistry, Northeast Normal University, Changchun 130024, People's Republic of China
^*Correspondence e-mail: majf247nenu@yahoo.com.cn

(Received 12 September 2008; accepted 13 October 2008; online 18 October 2008)

The title compound, [Cu(C₂₂H₂₂N₂O₈)], is a tetradentate Schiff base complex. The Cu^II ion has a nearly square-planar geometry, being coordinated by two N atoms and two O atoms. The two chemically equivalent halves of the molecule are crystallographically independent. One of the carboxylic acid methyl ester units is located in the main plane of the molecule and the other is rotated by 65.3 (5)° with respect to this unit. In the crystal structure, there are π–π stacking interactions between adjacent six-membered chelate rings, with centroid-to-centroid distances of 3.602 (2) Å.

Related literature

For general background, see: Paschke et al. (2002 ); Blake et al. (1995 ). For related structures, see: Bbadbhade & Srinivas (1993 ). Shamim et al. (1988 ) report the synthesis of the precursor of the organic ligand.

Experimental

Crystal data

[Cu(C₂₂H₂₂N₂O₈)]
M_r = 505.96
Triclinic, $[P \overline 1]$
a = 9.668 (1) Å
b = 10.012 (1) Å
c = 11.763 (2) Å
α = 85.251 (2)°
β = 80.381 (2)°
γ = 75.383 (2)°
V = 1085.3 (2) Å³
Z = 2
Mo Kα radiation
μ = 1.06 mm⁻¹
T = 293 (2) K
0.40 × 0.30 × 0.25 mm

Data collection

Bruker APEX CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ) T_min = 0.677, T_max = 0.778
6326 measured reflections
4482 independent reflections
3096 reflections with I > 2σ(I)
R_int = 0.018

Refinement

R[F² > 2σ(F²)] = 0.053
wR(F²) = 0.124
S = 1.03
4482 reflections
298 parameters
H-atom parameters constrained
Δρ_max = 0.47 e Å⁻³
Δρ_min = −0.32 e Å⁻³

Data collection: SMART (Bruker, 1997 ); cell refinement: SAINT (Bruker, 1999 ); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL-Plus (Sheldrick, 2008); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808033084/zl2141sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808033084/zl2141Isup2.hkl

checkCIF report

Comment top

There is a great interest in the use of Schiff base metal complexes as symmetrical and unsymmetrical liquid crystal compounds, because of their ready chemical modifiability (Paschke et al., 2002). Substitution around the aromatic rings can drastically influence the structures and the properties of liquid crystal compounds. Many symmetrically substituted Salen-copper complexes reported are characterized by high melting and clearing temperatures, whereby detailed investigation is difficult because of decomposition after entering the S_A phase (Blake et al., 1995). This work was incomplete in lacking direct structural evidence and the absence of ways to lower the melt temperatures. Afterwards, a series of asymmetrically substituted Salen-copper(II) complexes and ways of decreasing the melting temperatures by lateral and unsymmetrical substitution were reported (Paschke et al., 2002). To further widen the scope of application of such compounds, we synthesized a new salen copper(II) compound and its structure is described in this paper.

As shown in Fig. 1, the title compound CuC₂₂H₂₂N₂O₈ is a tetradentate salen Schiff base complex. The Cu^II ion has a nearly square-planar geometry, being coordinated by two N atoms and two O atoms from the Schiff base ligand consisting of two Cu—O bonds [Cu(1)—O(1) = 1.897 (3) Å and Cu(1)—O(2) = 1.894 (2) Å], and two Cu—N bonds [Cu(1)—N(1) = 1.941 (3) Å and Cu(1)—N(2) = 1.922 (3) Å]. These bond distances are within the normal range observed in similar complexes (Bbadbhade & Srinivas, 1993). The two chemically equivalent halves of the molecule are crystallographically independent. One of the carboxylic acid methyl ester units is located in the main plane of the molecule, the other is rotated by 65.3 (5)° with respect to this unit.

As shown in Fig. 2, there are π–π stacking interactions between adjacent six-membered chelate rings, with a centroid–centroid distance of 3.602 (2) Å [symmetry code: -x, -y, 1 - z], which leads to the formation of π-stacked dimers of the title complex.

Related literature top

For general background, see: Paschke et al. (2002); Blake et al. (1995). For related structures, see: Bbadbhade & Srinivas (1993). Shamim et al. (1988) report the synthesis of the precursor of the organic ligand.

Experimental top

The first step is the preparation of 2-hydroxy-4-[(carboxymethyl)oxy]benzaldehyde methyl ester according to the reported procedure (Shamim et al., 1988). The second step is the preparation of the ligand C₂₂H₂₄N₂O₈ (H₂L). The white powder obtained in the first step (2.10 g, 10 mmol) was dissolved in methanol (40 ml), and ethylenediamine (0.30 g, 5 mmol) was added dropwise. The solution was stirred for 1 h, the yellow precipitation was collected, washed with ethanol, and then dried in a vacuum desiccator. The resulting yellow precipitate was H₂L (1.55 g, 3.5 mmol, yield 70%).

H₂L (0.022 g, 0.05 mmol) then dissolved in CHCl₃ (20 ml), was stirred at room temperature and was added to the solution of CuNO₃ (0.012 g, 0.05 mmol) in ethanol (20 ml). The mixture was stirred for 1 h and then the resulting solution was filtered and left in a dark place to slowly evaporate. Brown single crystals were obtained after several days (0.027 g, 0.04 mmol, yeild 80%). IR (cm^-1, KBr): ν(C═N), 1606vs; ν(C═O), 1758vs; ν(C—OMe), 1213vs; ν(Ar—O), 1278vs.

Computing details top

Data collection: SMART (Bruker, 1997); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL-Plus (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. A view of the molecule of (I). Displacement ellipsoids are drawn at the 30% probability level. H atoms have been omitted for clarity.
	Fig. 2. (a) Top and (b) side view of the title compound , showing π–π stacking and the formation of π-stacked dimers. For clarity, H atoms are omitted.

{5,5'-Bis(methoxycarbonylmethoxy)-2,2'-[ethane-1,2- diylbis(nitrilomethylidyne)]diphenolato}copper(II) top

Crystal data top

[Cu(C₂₂H₂₂N₂O₈)]	Z = 2
M_r = 505.96	F(000) = 522
Triclinic, P1	D_x = 1.548 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71069 Å
a = 9.668 (1) Å	Cell parameters from 4482 reflections
b = 10.012 (1) Å	θ = 1.8–26.7°
c = 11.763 (2) Å	µ = 1.06 mm⁻¹
α = 85.251 (2)°	T = 293 K
β = 80.381 (2)°	Block, brown
γ = 75.383 (2)°	0.40 × 0.30 × 0.25 mm
V = 1085.3 (2) Å³

Data collection top

Bruker APEX CCD area-detector diffractometer	4482 independent reflections
Radiation source: fine-focus sealed tube	3096 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.018
ω scans	θ_max = 26.7°, θ_min = 1.8°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −9→12
T_min = 0.677, T_max = 0.778	k = −9→12
6326 measured reflections	l = −13→14

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)] = 0.053	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.124	H-atom parameters constrained
S = 1.03	w = 1/[σ²(F_o²) + (0.0435P)² + 0.7616P] where P = (F_o² + 2F_c²)/3
4482 reflections	(Δ/σ)_max < 0.001
298 parameters	Δρ_max = 0.47 e Å⁻³
0 restraints	Δρ_min = −0.32 e Å⁻³

Crystal data top

[Cu(C₂₂H₂₂N₂O₈)]	γ = 75.383 (2)°
M_r = 505.96	V = 1085.3 (2) Å³
Triclinic, P1	Z = 2
a = 9.668 (1) Å	Mo Kα radiation
b = 10.012 (1) Å	µ = 1.06 mm⁻¹
c = 11.763 (2) Å	T = 293 K
α = 85.251 (2)°	0.40 × 0.30 × 0.25 mm
β = 80.381 (2)°

Data collection top

Bruker APEX CCD area-detector diffractometer	4482 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	3096 reflections with I > 2σ(I)
T_min = 0.677, T_max = 0.778	R_int = 0.018
6326 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.053	0 restraints
wR(F²) = 0.124	H-atom parameters constrained
S = 1.03	Δρ_max = 0.47 e Å⁻³
4482 reflections	Δρ_min = −0.32 e Å⁻³
298 parameters

Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 > σ(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	−0.02639 (5)	0.15738 (5)	0.40718 (4)	0.04568 (17)
C1	0.8714 (5)	0.5674 (5)	0.3845 (4)	0.0811 (15)
H1A	0.8657	0.6225	0.4488	0.122*
H1B	0.8845	0.6213	0.3139	0.122*
H1C	0.9518	0.4882	0.3850	0.122*
C2	0.7312 (5)	0.4448 (4)	0.3101 (4)	0.0581 (11)
C3	0.5930 (4)	0.3988 (4)	0.3310 (3)	0.0519 (10)
H3A	0.5849	0.3465	0.4039	0.062*
H3B	0.5108	0.4782	0.3334	0.062*
C4	0.4834 (4)	0.2571 (4)	0.2380 (3)	0.0528 (10)
C5	0.4966 (4)	0.1810 (5)	0.1410 (3)	0.0578 (11)
H5	0.5777	0.1718	0.0845	0.069*
C6	0.3889 (4)	0.1208 (4)	0.1310 (3)	0.0558 (10)
H6	0.3973	0.0705	0.0661	0.067*
C7	0.2642 (4)	0.1313 (4)	0.2149 (3)	0.0466 (9)
C8	0.2522 (4)	0.2083 (4)	0.3138 (3)	0.0447 (9)
C9	0.3649 (4)	0.2707 (4)	0.3234 (3)	0.0499 (9)
H9	0.3593	0.3212	0.3877	0.060*
C10	0.1556 (4)	0.0667 (4)	0.1949 (3)	0.0546 (10)
H10	0.1739	0.0167	0.1286	0.066*
C11	−0.0766 (5)	0.0142 (6)	0.2262 (4)	0.0791 (15)
H11A	−0.1344	0.0822	0.1785	0.095*
H11B	−0.0307	−0.0662	0.1809	0.095*
C12	−0.1694 (5)	−0.0249 (5)	0.3272 (4)	0.0785 (15)
H12A	−0.1265	−0.1178	0.3546	0.094*
H12B	−0.2629	−0.0241	0.3069	0.094*
C13	−0.2968 (4)	0.0871 (4)	0.4993 (4)	0.0567 (11)
H13	−0.3664	0.0395	0.4938	0.068*
C14	−0.3203 (4)	0.1694 (4)	0.5965 (3)	0.0484 (9)
C15	−0.2202 (4)	0.2436 (4)	0.6176 (3)	0.0461 (9)
C16	−0.2502 (4)	0.3153 (4)	0.7201 (3)	0.0501 (10)
H16	−0.1866	0.3655	0.7347	0.060*
C17	−0.4452 (4)	0.1743 (5)	0.6791 (4)	0.0609 (11)
H17	−0.5127	0.1285	0.6649	0.073*
C18	−0.4712 (4)	0.2421 (5)	0.7772 (4)	0.0628 (12)
H18	−0.5545	0.2420	0.8297	0.075*
C19	−0.3721 (4)	0.3127 (4)	0.7997 (3)	0.0548 (10)
C20	−0.3016 (4)	0.4378 (5)	0.9347 (4)	0.0638 (12)
H20A	−0.3435	0.4885	1.0040	0.077*
H20B	−0.2760	0.5030	0.8741	0.077*
C21	−0.1672 (5)	0.3315 (5)	0.9570 (3)	0.0571 (11)
C22	0.0779 (5)	0.3088 (6)	0.9761 (5)	0.1005 (19)
H22A	0.1489	0.3625	0.9632	0.151*
H22B	0.1110	0.2290	0.9299	0.151*
H22C	0.0634	0.2799	1.0562	0.151*
N1	−0.1881 (3)	0.0725 (3)	0.4185 (3)	0.0542 (8)
N2	0.0342 (3)	0.0715 (3)	0.2610 (3)	0.0540 (8)
O1	−0.1002 (3)	0.2473 (3)	0.5482 (2)	0.0537 (7)
O2	0.1423 (3)	0.2237 (3)	0.3977 (2)	0.0534 (7)
O3	−0.4053 (3)	0.3772 (3)	0.9017 (2)	0.0682 (8)
O4	0.5962 (3)	0.3158 (3)	0.2393 (2)	0.0674 (8)
O5	−0.1593 (3)	0.2113 (3)	0.9815 (3)	0.0723 (9)
O6	−0.0568 (3)	0.3915 (3)	0.9447 (3)	0.0736 (9)
O7	0.7385 (3)	0.5219 (3)	0.3929 (2)	0.0650 (8)
O8	0.8223 (4)	0.4170 (5)	0.2289 (4)	0.1257 (18)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cu1	0.0420 (3)	0.0513 (3)	0.0476 (3)	−0.0201 (2)	−0.0019 (2)	−0.0069 (2)
C1	0.071 (3)	0.092 (4)	0.095 (4)	−0.043 (3)	−0.011 (3)	−0.020 (3)
C2	0.058 (3)	0.058 (3)	0.062 (3)	−0.023 (2)	0.001 (2)	−0.009 (2)
C3	0.051 (2)	0.059 (3)	0.049 (2)	−0.0212 (19)	−0.0031 (18)	−0.003 (2)
C4	0.052 (2)	0.061 (3)	0.048 (2)	−0.024 (2)	−0.0011 (19)	−0.001 (2)
C5	0.050 (2)	0.075 (3)	0.048 (2)	−0.023 (2)	0.0092 (19)	−0.008 (2)
C6	0.056 (2)	0.066 (3)	0.044 (2)	−0.018 (2)	0.0061 (19)	−0.016 (2)
C7	0.049 (2)	0.044 (2)	0.046 (2)	−0.0125 (17)	−0.0030 (18)	−0.0057 (18)
C8	0.042 (2)	0.048 (2)	0.045 (2)	−0.0152 (17)	0.0003 (17)	−0.0038 (17)
C9	0.051 (2)	0.057 (2)	0.047 (2)	−0.0233 (19)	0.0004 (18)	−0.0109 (19)
C10	0.059 (2)	0.060 (3)	0.049 (2)	−0.022 (2)	−0.001 (2)	−0.016 (2)
C11	0.073 (3)	0.113 (4)	0.069 (3)	−0.053 (3)	0.000 (2)	−0.033 (3)
C12	0.073 (3)	0.093 (4)	0.086 (3)	−0.050 (3)	−0.005 (3)	−0.025 (3)
C13	0.046 (2)	0.065 (3)	0.066 (3)	−0.029 (2)	−0.007 (2)	0.002 (2)
C14	0.039 (2)	0.055 (2)	0.053 (2)	−0.0189 (18)	−0.0059 (18)	0.0068 (19)
C15	0.0350 (19)	0.055 (2)	0.047 (2)	−0.0136 (17)	−0.0037 (17)	0.0067 (19)
C16	0.040 (2)	0.062 (3)	0.049 (2)	−0.0179 (18)	−0.0001 (17)	−0.0035 (19)
C17	0.044 (2)	0.073 (3)	0.071 (3)	−0.029 (2)	−0.004 (2)	0.002 (2)
C18	0.041 (2)	0.077 (3)	0.066 (3)	−0.018 (2)	0.011 (2)	0.003 (2)
C19	0.041 (2)	0.064 (3)	0.052 (2)	−0.0060 (19)	0.0019 (19)	0.000 (2)
C20	0.053 (2)	0.072 (3)	0.061 (3)	−0.011 (2)	0.009 (2)	−0.018 (2)
C21	0.065 (3)	0.065 (3)	0.038 (2)	−0.014 (2)	0.0038 (19)	−0.010 (2)
C22	0.075 (4)	0.095 (4)	0.136 (5)	−0.007 (3)	−0.044 (3)	−0.012 (4)
N1	0.0485 (19)	0.060 (2)	0.061 (2)	−0.0244 (16)	−0.0032 (17)	−0.0137 (17)
N2	0.054 (2)	0.063 (2)	0.053 (2)	−0.0263 (17)	−0.0062 (16)	−0.0137 (17)
O1	0.0457 (14)	0.0697 (19)	0.0502 (15)	−0.0286 (13)	0.0075 (12)	−0.0129 (14)
O2	0.0483 (15)	0.0673 (18)	0.0489 (15)	−0.0277 (13)	0.0086 (12)	−0.0172 (13)
O3	0.0498 (17)	0.088 (2)	0.0567 (18)	−0.0110 (16)	0.0147 (14)	−0.0127 (16)
O4	0.0584 (17)	0.093 (2)	0.0611 (18)	−0.0453 (17)	0.0108 (14)	−0.0208 (16)
O5	0.087 (2)	0.063 (2)	0.065 (2)	−0.0197 (17)	−0.0041 (16)	−0.0023 (16)
O6	0.066 (2)	0.070 (2)	0.086 (2)	−0.0150 (17)	−0.0160 (17)	−0.0054 (18)
O7	0.0600 (18)	0.078 (2)	0.0647 (19)	−0.0299 (16)	−0.0067 (15)	−0.0144 (16)
O8	0.093 (3)	0.181 (4)	0.126 (3)	−0.091 (3)	0.052 (3)	−0.097 (3)

Geometric parameters (Å, º) top

Cu1—O2	1.894 (2)	C11—H11A	0.9700
Cu1—O1	1.897 (3)	C11—H11B	0.9700
Cu1—N2	1.922 (3)	C12—N1	1.469 (5)
Cu1—N1	1.941 (3)	C12—H12A	0.9700
C1—O7	1.454 (5)	C12—H12B	0.9700
C1—H1A	0.9600	C13—N1	1.281 (5)
C1—H1B	0.9600	C13—C14	1.419 (6)
C1—H1C	0.9600	C13—H13	0.9300
C2—O8	1.186 (5)	C14—C17	1.411 (5)
C2—O7	1.313 (5)	C14—C15	1.422 (5)
C2—C3	1.497 (5)	C15—O1	1.309 (4)
C3—O4	1.407 (4)	C15—C16	1.405 (5)
C3—H3A	0.9700	C16—C19	1.381 (5)
C3—H3B	0.9700	C16—H16	0.9300
C4—O4	1.366 (4)	C17—C18	1.342 (6)
C4—C9	1.379 (5)	C17—H17	0.9300
C4—C5	1.394 (5)	C18—C19	1.395 (6)
C5—C6	1.353 (5)	C18—H18	0.9300
C5—H5	0.9300	C19—O3	1.362 (5)
C6—C7	1.412 (5)	C20—O3	1.415 (5)
C6—H6	0.9300	C20—C21	1.504 (6)
C7—C8	1.421 (5)	C20—H20A	0.9700
C7—C10	1.423 (5)	C20—H20B	0.9700
C8—O2	1.310 (4)	C21—O5	1.200 (5)
C8—C9	1.410 (5)	C21—O6	1.333 (5)
C9—H9	0.9300	C22—O6	1.444 (5)
C10—N2	1.287 (5)	C22—H22A	0.9600
C10—H10	0.9300	C22—H22B	0.9600
C11—C12	1.453 (6)	C22—H22C	0.9600
C11—N2	1.463 (5)

O2—Cu1—O1	89.23 (10)	C11—C12—H12B	109.7
O2—Cu1—N2	93.86 (12)	N1—C12—H12B	109.7
O1—Cu1—N2	175.69 (13)	H12A—C12—H12B	108.2
O2—Cu1—N1	174.74 (13)	N1—C13—C14	125.7 (4)
O1—Cu1—N1	92.91 (12)	N1—C13—H13	117.2
N2—Cu1—N1	84.26 (13)	C14—C13—H13	117.2
O7—C1—H1A	109.5	C17—C14—C13	119.1 (4)
O7—C1—H1B	109.5	C17—C14—C15	117.9 (4)
H1A—C1—H1B	109.5	C13—C14—C15	123.0 (3)
O7—C1—H1C	109.5	O1—C15—C16	117.8 (3)
H1A—C1—H1C	109.5	O1—C15—C14	124.0 (4)
H1B—C1—H1C	109.5	C16—C15—C14	118.2 (3)
O8—C2—O7	123.9 (4)	C19—C16—C15	121.4 (4)
O8—C2—C3	124.7 (4)	C19—C16—H16	119.3
O7—C2—C3	111.4 (4)	C15—C16—H16	119.3
O4—C3—C2	107.1 (3)	C18—C17—C14	123.0 (4)
O4—C3—H3A	110.3	C18—C17—H17	118.5
C2—C3—H3A	110.3	C14—C17—H17	118.5
O4—C3—H3B	110.3	C17—C18—C19	119.4 (4)
C2—C3—H3B	110.3	C17—C18—H18	120.3
H3A—C3—H3B	108.5	C19—C18—H18	120.3
O4—C4—C9	124.2 (4)	O3—C19—C16	124.2 (4)
O4—C4—C5	114.2 (3)	O3—C19—C18	115.8 (3)
C9—C4—C5	121.7 (4)	C16—C19—C18	120.0 (4)
C6—C5—C4	118.6 (4)	O3—C20—C21	112.0 (4)
C6—C5—H5	120.7	O3—C20—H20A	109.2
C4—C5—H5	120.7	C21—C20—H20A	109.2
C5—C6—C7	122.7 (4)	O3—C20—H20B	109.2
C5—C6—H6	118.6	C21—C20—H20B	109.2
C7—C6—H6	118.6	H20A—C20—H20B	107.9
C6—C7—C8	118.3 (3)	O5—C21—O6	125.0 (4)
C6—C7—C10	118.4 (4)	O5—C21—C20	125.8 (4)
C8—C7—C10	123.3 (3)	O6—C21—C20	109.2 (4)
O2—C8—C9	117.8 (3)	O6—C22—H22A	109.5
O2—C8—C7	123.6 (3)	O6—C22—H22B	109.5
C9—C8—C7	118.5 (3)	H22A—C22—H22B	109.5
C4—C9—C8	120.2 (4)	O6—C22—H22C	109.5
C4—C9—H9	119.9	H22A—C22—H22C	109.5
C8—C9—H9	119.9	H22B—C22—H22C	109.5
N2—C10—C7	125.5 (4)	C13—N1—C12	120.7 (3)
N2—C10—H10	117.2	C13—N1—Cu1	126.4 (3)
C7—C10—H10	117.2	C12—N1—Cu1	112.7 (2)
C12—C11—N2	110.4 (4)	C10—N2—C11	121.1 (3)
C12—C11—H11A	109.6	C10—N2—Cu1	125.9 (3)
N2—C11—H11A	109.6	C11—N2—Cu1	112.9 (3)
C12—C11—H11B	109.6	C15—O1—Cu1	128.0 (2)
N2—C11—H11B	109.6	C8—O2—Cu1	127.6 (2)
H11A—C11—H11B	108.1	C19—O3—C20	118.2 (3)
C11—C12—N1	109.6 (4)	C4—O4—C3	119.5 (3)
C11—C12—H12A	109.7	C21—O6—C22	117.1 (4)
N1—C12—H12A	109.7	C2—O7—C1	116.2 (3)

O8—C2—C3—O4	1.7 (7)	C14—C13—N1—C12	174.8 (4)
O7—C2—C3—O4	−179.1 (3)	C14—C13—N1—Cu1	0.4 (6)
O4—C4—C5—C6	−178.9 (4)	C11—C12—N1—C13	158.0 (4)
C9—C4—C5—C6	0.7 (7)	C11—C12—N1—Cu1	−26.8 (5)
C4—C5—C6—C7	−0.4 (7)	O1—Cu1—N1—C13	0.8 (4)
C5—C6—C7—C8	−0.1 (6)	N2—Cu1—N1—C13	−175.9 (4)
C5—C6—C7—C10	178.6 (4)	O1—Cu1—N1—C12	−174.0 (3)
C6—C7—C8—O2	−179.2 (4)	N2—Cu1—N1—C12	9.3 (3)
C10—C7—C8—O2	2.2 (6)	C7—C10—N2—C11	173.2 (4)
C6—C7—C8—C9	0.1 (6)	C7—C10—N2—Cu1	−4.0 (6)
C10—C7—C8—C9	−178.5 (4)	C12—C11—N2—C10	154.5 (4)
O4—C4—C9—C8	178.9 (4)	C12—C11—N2—Cu1	−28.0 (5)
C5—C4—C9—C8	−0.7 (6)	O2—Cu1—N2—C10	2.8 (4)
O2—C8—C9—C4	179.6 (4)	N1—Cu1—N2—C10	−172.3 (4)
C7—C8—C9—C4	0.3 (6)	O2—Cu1—N2—C11	−174.6 (3)
C6—C7—C10—N2	−177.2 (4)	N1—Cu1—N2—C11	10.3 (3)
C8—C7—C10—N2	1.4 (7)	C16—C15—O1—Cu1	177.8 (3)
N2—C11—C12—N1	34.7 (6)	C14—C15—O1—Cu1	−0.9 (5)
N1—C13—C14—C17	−179.5 (4)	O2—Cu1—O1—C15	−175.7 (3)
N1—C13—C14—C15	−2.2 (7)	N1—Cu1—O1—C15	−0.6 (3)
C17—C14—C15—O1	179.8 (3)	C9—C8—O2—Cu1	178.0 (3)
C13—C14—C15—O1	2.5 (6)	C7—C8—O2—Cu1	−2.7 (5)
C17—C14—C15—C16	1.1 (5)	O1—Cu1—O2—C8	−176.5 (3)
C13—C14—C15—C16	−176.2 (4)	N2—Cu1—O2—C8	0.4 (3)
O1—C15—C16—C19	−177.8 (3)	C16—C19—O3—C20	−7.3 (6)
C14—C15—C16—C19	1.0 (6)	C18—C19—O3—C20	173.4 (4)
C13—C14—C17—C18	175.5 (4)	C21—C20—O3—C19	−65.3 (5)
C15—C14—C17—C18	−1.9 (6)	C9—C4—O4—C3	−1.7 (6)
C14—C17—C18—C19	0.6 (7)	C5—C4—O4—C3	177.9 (4)
C15—C16—C19—O3	178.4 (4)	C2—C3—O4—C4	178.6 (3)
C15—C16—C19—C18	−2.4 (6)	O5—C21—O6—C22	−7.4 (6)
C17—C18—C19—O3	−179.1 (4)	C20—C21—O6—C22	172.9 (4)
C17—C18—C19—C16	1.5 (6)	O8—C2—O7—C1	−3.5 (7)
O3—C20—C21—O5	−22.9 (6)	C3—C2—O7—C1	177.3 (4)
O3—C20—C21—O6	156.8 (3)

Experimental details

Crystal data
Chemical formula	[Cu(C₂₂H₂₂N₂O₈)]
M_r	505.96
Crystal system, space group	Triclinic, P1
Temperature (K)	293
a, b, c (Å)	9.668 (1), 10.012 (1), 11.763 (2)
α, β, γ (°)	85.251 (2), 80.381 (2), 75.383 (2)
V (Å³)	1085.3 (2)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	1.06
Crystal size (mm)	0.40 × 0.30 × 0.25

Data collection
Diffractometer	Bruker APEX CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.677, 0.778
No. of measured, independent and observed [I > 2σ(I)] reflections	6326, 4482, 3096
R_int	0.018
(sin θ/λ)_max (Å⁻¹)	0.632

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.053, 0.124, 1.03
No. of reflections	4482
No. of parameters	298
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.47, −0.32

Computer programs: SMART (Bruker, 1997), SAINT (Bruker, 1999), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL-Plus (Sheldrick, 2008).

Acknowledgements

We thank the Program for New Century Excellent Talents in Chinese Universities (grant No. NCET-05-0320) and the Analysis and Testing Foundation of Northeast Normal University for support.

References

Bbadbhade, M. M. & Srinivas, D. (1993). Inorg. Chem. 32, 6122–6130. Google Scholar
Blake, A. B., Chipperfield, J. R., Hussain, W., Paschke, R. & Sinn, E. (1995). Inorg. Chem. 34, 1125–1129. CSD CrossRef CAS Web of Science Google Scholar
Bruker (1997). SMART. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (1999). SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Paschke, P., Balkow, D. & Sinn, E. (2002). Inorg. Chem. 41, 1949–1953. Web of Science CSD CrossRef PubMed CAS Google Scholar
Shamim, M. T., Ukena, D., Padgett, W. L., Hong, O. & Daly, J. W. (1988). J. Med. Chem. 31, 613–617. CrossRef CAS PubMed Web of Science Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar

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