Poly[[di-μ-aqua-tetraaquadi-μ-hydroxido-bis­(μ₃-3-nitro­phthalato)tricopper(II)] dihydrate]

The novel title complex, {[Cu₃(C₈H₃NO₆)₂(OH)₂(H₂O)₆]·2H₂O}_n, has a one-dimensional polymeric double chain structure where the three Cu atoms are linked by μ₂-OH and μ₂-H₂O groups, and these trinuclear centres are bridged by two 3-nitro­phthalate ligands. The asymmetric unit contains one and a half crystallographically independent Cu atoms (one lying on a centre of inversion), both coordinated by six O atoms and exhibiting distorted octa­hedral coordination geometries, but with different coordination environments. Each 3-nitro­phthalate ligand connects to three Cu atoms through two O atoms of one carboxyl­ate group and one O atom of the nitro group. The remaining carboxyl­ate group is free and is involved in intrachain hydrogen bonds, reinforcing the chain linkage.

S1. Comment

In constructing coordination polymers, aromatic dicarboxylic acids, such as o-phthalic, m-phthalic and p-phthalic acids, have been shown to produce a great variety of interesting structures (Zheng et al., 2002; Wang et al., 2001; Wan et al., 2003, 2002; Hong & Do, 1997; Eddaoudi et al., 2001). Among these isomeric forms of phthalate, the o-phthalate ligand, with two carboxylate groups in ortho-positions, can bind metal ions in a diversity of bonding modes and thus lead to the formation of interesting network architectures (Baca et al., 2004).

On the other hand, if an electron-withdrawing nitro group is also present in the ligand, it can not only coordinate metal ions in a variety of ways but also act as a hydrogen-bond acceptor, taking part in the formation of polymeric networks (Liu et al., 2006). Recently, a series of lanthanide and transition metal complexes with 3-nitrophthalic acid were successfully obtained; however, in most of these complexes the 3-nitrophthalic ligands are coordinated to the metal ions with two carboxylate groups (Deng, Liu et al., 2007; Deng, Wang et al., 2007; Huang et al., 2007; Song et al., 2007). In this paper, we used 3-nitrophthalic acid as a rigid ligand and synthesized the one-dimensional coordination polymer [Cu₃(C₈H₃NO₆)₂(OH)₂(H₂O)₆]_n.2nH₂O, in which the nitro group of the 3-nitrophthalic anion is also coordinated to the metal ion.

The title complex presents a double chain structure. There are one and a half crystallographically independent Cu atoms in the asymmetric unit, (one of them lies at an inversion centre) one complete 3-nitrophthalic anion, one hydroxyl group and three coordinated water molecules together with a free water molecule, and Fig. 1 shows the full coordination environments of the Cu atoms in a symmetry-expanded view.

In the complex, the Cu atoms are both six-coordinated, but they have two different coordination environments. Atom Cu1 lies on the inversion centre and is coordinated to an O₆ donor set. Four equatorial sites are occupied by four O atoms from two monodentate carboxylate groups [O1 and O1ⁱ; symmetry code: (i) -x + 1, -y + 1, -z + 1] of two equivalent 3-nitrophthalic anions and two coordinated water molecules (O7 and O7ⁱ). The Cu1—O_carboxylate distances are both 1.948 (3) Å and the Cu1—O_water distances are both 1.944 (2) Å. The axial sites are completed by two O atoms from two hydroxyl groups, and the Cu1—O_hydroxyl distances are both 2.408 (3) Å. For atom Cu2, the six O atoms belong to three water molecules, one carboxylate group of one 3-nitrophthalate anion, one nitro group of another 3-nitrophthalate anion and one hydroxyl group. The Cu2—O_water distances are in the range 1.916 (2)–1.996 (3) Å, the Cu2—O_carboxylate distance is 1.958 (3) Å, the Cu2—O_hydroxyl distance is 2.603 (3) Å and the Cu2—O_nitro distance is 2.603 (3) Å, which is longer than normal Cu—O bond lengths. For both cations the coordination environment is a significantly distorted octahedron.

In the present structure, there is only one type of 3-nitrophthalate anion, which adopts 1,3-bridging and monodentate modes to coordinate with Cu atoms (see scheme). Atom O5 of the nitro group adopts a monodentate mode to connect with one Cu atom, and atoms O1 and O2 of one carboxylate group adopt a 1,3-bridging mode to link two Cu atoms; the other carboxylate group of 3-nitrophthalic anion is free.

This is the first example of this type of coordination mode for the 3-nitrophthalate anion. There is a previously reported structure with a binding nitro group [K₂Cu(NPA)₂(H₂O)₄]_n (H₂NPA is 3-nitrophthalic acid; Shen et al., 2006), but in the latter, the 3-nitrophthalate ligand coordinates to K and Cu ions with the nitro and both carboxylate groups, while in the title complex, the 3-nitrophthalate ligand coordinates to Cu ions with only one carboxylate group and the nitro group, the other carboxylate group being free. To the best of our knowledge, this type of coordination mode for the 3-nitrophthalate ligand has not been reported in the literature

In this way, a one-dimensional polymeric double chain structure with a trinuclear centre builds up, where the cations are linked by µ₂-OH and µ₂-H₂O groups and further bridged by two 3-nitrophthalate ligands (Fig. 2). The Cu1···Cu2 separation in the trinuclear unit is 3.041 (1) Å, which could be considered a weak interaction since it is in the range of the sum of the van der Waals radii of two Cu ions.

In the double chain, 3-nitrophthalic anions interconnect with Cu atoms, forming two different types of ring – a six-membered one containing two Cu atoms and a 19-membered one containing four Cu atoms – which are alternate along the infinite one-dimensional array. The chains are further stabilized by intra-chain hydrogen bonds involving the free carboxylate groups as acceptors and coordinated water molecules or hydroxyl groups as donors (Table 2).

Fig. 3 shows a view of the packing of the title compound. There are a number of distinct hydrogen-bond interactions involving the ligands, both intra-chain (reinforcing the chain linkage) and inter-chain (assembling these one-dimensional chains into a three-dimensional network structure). Free water molecules (O11) reside between layers and also enter into hydrogen bonding with the free carboxylate group (O3), coordinated water molecules (O7) and the hydroxyl group (O8), further stabilizing the three-dimensional supramolecular network.

Related literature

For related literature, see: Baca et al. (2004); Deng et al. (2007a, 2007b); Eddaoudi et al. (2001); Hong & Do (1997); Huang et al. (2007); Liu et al. (2006); Shen et al. (2006); Song et al. (2007); Wan et al. (2002, 2003); Wang et al. (2001); Zheng et al. (2002).

S2. Experimental

The addition of anhydrous sodium carbonate (0.53 g, 5 mmol) to a stirred solution of copper nitrate hexahydrate (1.20 g, 4 mol) in water (20 ml) produced a blue precipitate, which was filtered off and washed with distilled water. The precipitate was subsequently added to a stirred solution of 3-nitrophthalic acid (0.53 g, 2.5 mol) in boiling water (15 ml) over a period of 20 min. After filtration, slow evaporation over a period of two weeks at room temperature yielded blue block-like crystals of (I).

S3. Refinement

All water H atoms were found in difference Fourier maps and were kept fixed during refinement with O—H distances of 0.84–0.85 Å and U_iso(H) equal to 1.2U_eq(O). H atoms of CH groups were idealized and treated as riding, with C—H distances of 0.93 Å and U_iso(H) values of 1.2U_eq(C).

Computing details

Data collection: CrystalClear (Rigaku/MSC, 2005); cell refinement: CrystalClear (Rigaku/MSC, 2005); data reduction: CrystalClear (Rigaku/MSC, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. A view of the structure of (I), showing the atom-numbering scheme and coordination environments of the Cu atom. Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as small spheres of arbitrary radii. [Symmetry codes: (i) -x + 1, -y + 1, -z + 1; (ii) x + 1, y - 1, z; (iii) -x, 2 - y, 1 - z.] [iii does not match table]
	Fig. 2. The one-dimensional double chain structure of complex (I), containing the intra-chain hydrogen bonds, viewed along the ab diagonal direction. [Symmetry codes: (i) -x + 1, -y + 1, -z + 1; (ii) x + 1, y - 1, z.]
	Fig. 3. A packing diagram for (I), showing the hydrogen-bond interactions (dashed lines) linking the chains.

Poly[[hexaaquadi-µ-hydroxido-bis(µ-3-nitrophthalato)tricopper(II)] dihydrate]

Crystal data

[Cu3(C8H3NO6)2(OH)2(H2O)6]·2H2O	Z = 1
Mr = 786.99	F(000) = 397
Triclinic, P1	Dx = 2.072 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.2192 (14) Å	Cell parameters from 1826 reflections
b = 8.3899 (17) Å	θ = 2.6–27.5°
c = 11.191 (2) Å	µ = 2.61 mm^−1
α = 74.81 (3)°	T = 133 K
β = 84.38 (3)°	Block, blue
γ = 74.77 (3)°	0.16 × 0.12 × 0.08 mm
V = 630.9 (2) Å^3

Data collection

Rigaku Saturn diffractometer	2192 independent reflections
Radiation source: rotating anode	1757 reflections with I > 2σ(I)
Confocal monochromator	Rint = 0.051
Detector resolution: 27.482 pixels mm^-1	θmax = 25.0°, θmin = 2.6°
ω scans	h = −7→8
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2005)	k = −8→9
Tmin = 0.702, Tmax = 0.815	l = −13→12
3616 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.108	H-atom parameters constrained
S = 1.03	w = 1/[σ^2(Fo^2) + (0.067P)^2] where P = (Fo^2 + 2Fc^2)/3
2192 reflections	(Δ/σ)max < 0.001
196 parameters	Δρmax = 0.83 e Å^−3
6 restraints	Δρmin = −0.69 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Cu1	0.5000	0.5000	0.5000	0.0093 (2)
Cu2	0.60502 (6)	0.14889 (5)	0.67727 (4)	0.01014 (18)
O1	0.4137 (4)	0.5396 (3)	0.6626 (2)	0.0140 (6)
O2	0.4923 (4)	0.2840 (3)	0.7968 (2)	0.0133 (6)
O3	0.2545 (4)	0.8884 (3)	0.6656 (2)	0.0141 (6)
O4	0.0364 (3)	0.7545 (3)	0.6431 (2)	0.0136 (6)
N1	−0.0760 (4)	0.8992 (4)	0.9138 (3)	0.0134 (7)
O5	−0.0914 (4)	0.9901 (3)	0.8074 (2)	0.0186 (6)
O6	−0.1828 (4)	0.9354 (4)	1.0003 (3)	0.0224 (7)
C1	0.4125 (5)	0.4405 (5)	0.7685 (3)	0.0122 (8)
C2	0.3040 (5)	0.5173 (4)	0.8683 (3)	0.0108 (8)
C3	0.3238 (5)	0.4248 (5)	0.9919 (3)	0.0124 (8)
H3	0.4059	0.3163	1.0102	0.015*
C4	0.2259 (5)	0.4892 (5)	1.0865 (3)	0.0145 (8)
H4	0.2456	0.4267	1.1682	0.017*
C5	0.0972 (5)	0.6478 (5)	1.0605 (3)	0.0138 (8)
H5A	0.0278	0.6925	1.1239	0.017*
C6	0.0742 (5)	0.7389 (4)	0.9371 (3)	0.0121 (8)
C7	0.1780 (5)	0.6809 (4)	0.8390 (3)	0.0109 (8)
C8	0.1552 (5)	0.7822 (4)	0.7051 (3)	0.0109 (8)
O7	0.2814 (3)	0.6783 (3)	0.4260 (2)	0.0111 (5)
H7A	0.2155	0.7125	0.4851	0.013*
H7B	0.2210	0.6430	0.3807	0.013*
O8	0.3426 (3)	0.2698 (3)	0.5484 (2)	0.0129 (6)
H8A	0.3077	0.2192	0.5020	0.015*
O9	0.4909 (4)	−0.0296 (3)	0.7909 (2)	0.0156 (6)
H9A	0.4176	−0.0575	0.7500	0.019*
H9B	0.4347	0.0290	0.8407	0.019*
O10	0.7143 (3)	−0.0160 (3)	0.5746 (2)	0.0129 (6)
H10A	0.7214	0.0292	0.4970	0.015*
H10B	0.8244	−0.0745	0.6022	0.015*
O11	0.0155 (4)	0.4078 (3)	0.6559 (2)	0.0160 (6)
H11A	0.1077	0.3645	0.6117	0.019*
H11B	0.0135	0.5114	0.6470	0.019*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0098 (3)	0.0093 (3)	0.0082 (3)	0.0007 (2)	0.0008 (2)	−0.0048 (2)
Cu2	0.0110 (3)	0.0092 (3)	0.0106 (3)	−0.00073 (18)	0.00081 (18)	−0.00528 (18)
O1	0.0163 (14)	0.0147 (12)	0.0091 (12)	−0.0003 (11)	0.0006 (10)	−0.0036 (11)
O2	0.0167 (13)	0.0110 (12)	0.0120 (12)	−0.0006 (10)	−0.0009 (10)	−0.0050 (10)
O3	0.0164 (14)	0.0142 (12)	0.0139 (12)	−0.0047 (11)	0.0006 (10)	−0.0066 (10)
O4	0.0132 (13)	0.0136 (12)	0.0144 (12)	0.0002 (10)	−0.0010 (10)	−0.0078 (10)
N1	0.0116 (16)	0.0165 (15)	0.0167 (16)	−0.0031 (13)	0.0038 (13)	−0.0138 (14)
O5	0.0202 (15)	0.0180 (13)	0.0155 (14)	0.0022 (11)	−0.0017 (11)	−0.0072 (11)
O6	0.0207 (15)	0.0249 (14)	0.0209 (14)	−0.0003 (12)	0.0063 (12)	−0.0124 (12)
C1	0.0050 (17)	0.0178 (17)	0.0149 (18)	−0.0017 (14)	−0.0025 (14)	−0.0065 (15)
C2	0.0099 (18)	0.0142 (17)	0.0109 (17)	−0.0039 (14)	−0.0012 (14)	−0.0064 (14)
C3	0.0111 (18)	0.0154 (17)	0.0138 (18)	−0.0073 (15)	−0.0027 (14)	−0.0040 (15)
C4	0.0159 (19)	0.0206 (18)	0.0096 (17)	−0.0070 (15)	0.0006 (14)	−0.0057 (15)
C5	0.015 (2)	0.0185 (18)	0.0129 (17)	−0.0076 (15)	0.0041 (15)	−0.0114 (15)
C6	0.0100 (19)	0.0138 (17)	0.0141 (17)	0.0001 (14)	0.0003 (14)	−0.0098 (15)
C7	0.0098 (18)	0.0146 (17)	0.0116 (17)	−0.0054 (14)	0.0007 (14)	−0.0069 (14)
C8	0.0109 (11)	0.0106 (10)	0.0111 (10)	−0.0001 (8)	0.0004 (8)	−0.0054 (8)
O7	0.0106 (12)	0.0130 (12)	0.0117 (12)	−0.0021 (10)	0.0008 (10)	−0.0080 (10)
O8	0.0115 (13)	0.0149 (12)	0.0175 (13)	−0.0062 (10)	−0.0031 (11)	−0.0088 (11)
O9	0.0194 (14)	0.0159 (12)	0.0138 (13)	−0.0049 (11)	0.0009 (11)	−0.0080 (11)
O10	0.0120 (13)	0.0134 (12)	0.0131 (12)	−0.0016 (10)	−0.0026 (10)	−0.0038 (10)
O11	0.0172 (13)	0.0157 (12)	0.0160 (13)	−0.0006 (11)	0.0052 (10)	−0.0111 (11)

Geometric parameters (Å, º)

Cu1—O7	1.944 (2)	C2—C3	1.398 (5)
Cu1—O7^i	1.944 (2)	C2—C7	1.409 (5)
Cu1—O1^i	1.948 (3)	C3—C4	1.366 (6)
Cu1—O1	1.948 (3)	C3—H3	0.9300
Cu1—O8	2.408 (3)	C4—C5	1.386 (5)
Cu1—O8^i	2.408 (3)	C4—H4	0.9300
Cu1—Cu2^i	3.0409 (12)	C5—C6	1.395 (5)
Cu2—O7^i	1.916 (2)	C5—H5A	0.9300
Cu2—O2	1.958 (3)	C6—C7	1.389 (5)
Cu2—O10	1.984 (3)	C7—C8	1.518 (5)
Cu2—O9	1.996 (3)	O7—Cu2^i	1.916 (2)
Cu2—O8	2.336 (3)	O7—H7A	0.8436
Cu2—O5^ii	2.603 (3)	O7—H7B	0.8517
O1—C1	1.258 (4)	O8—H8A	0.8431
O2—C1	1.256 (4)	O9—H9A	0.8433
O3—C8	1.253 (4)	O9—H9B	0.8435
O4—C8	1.256 (5)	O10—H10A	0.8544
N1—O6	1.228 (4)	O10—H10B	0.8549
N1—O5	1.232 (4)	O11—H11A	0.8500
N1—C6	1.469 (4)	O11—H11B	0.8457
C1—C2	1.489 (5)
O7—Cu1—O7^i	180.0	O1—C1—C2	116.3 (3)
O7—Cu1—O1^i	90.03 (11)	C3—C2—C7	119.7 (3)
O7^i—Cu1—O1^i	89.97 (11)	C3—C2—C1	119.7 (3)
O7—Cu1—O1	89.97 (11)	C7—C2—C1	120.6 (3)
O7^i—Cu1—O1	90.03 (11)	C4—C3—C2	121.9 (3)
O1^i—Cu1—O1	180.0	C4—C3—H3	119.1
O7—Cu1—O8	96.75 (10)	C2—C3—H3	119.1
O7^i—Cu1—O8	83.25 (10)	C3—C4—C5	119.8 (3)
O1^i—Cu1—O8	91.97 (10)	C3—C4—H4	120.1
O1—Cu1—O8	88.03 (10)	C5—C4—H4	120.1
O7—Cu1—O8^i	83.25 (10)	C4—C5—C6	118.4 (4)
O7^i—Cu1—O8^i	96.75 (10)	C4—C5—H5A	120.8
O1^i—Cu1—O8^i	88.03 (10)	C6—C5—H5A	120.8
O1—Cu1—O8^i	91.97 (10)	C7—C6—C5	123.3 (3)
O8—Cu1—O8^i	180.0	C7—C6—N1	120.4 (3)
O7—Cu1—Cu2^i	37.71 (7)	C5—C6—N1	116.2 (3)
O7^i—Cu1—Cu2^i	142.29 (7)	C6—C7—C2	116.8 (3)
O1^i—Cu1—Cu2^i	75.43 (7)	C6—C7—C8	123.1 (3)
O1—Cu1—Cu2^i	104.57 (7)	C2—C7—C8	120.1 (3)
O8—Cu1—Cu2^i	130.90 (6)	O3—C8—O4	125.2 (3)
O8^i—Cu1—Cu2^i	49.10 (6)	O3—C8—C7	117.4 (3)
O7^i—Cu2—O2	94.14 (11)	O4—C8—C7	117.3 (3)
O7^i—Cu2—O10	93.43 (11)	Cu2^i—O7—Cu1	103.95 (12)
O2—Cu2—O10	172.00 (10)	Cu2^i—O7—H7A	111.3
O7^i—Cu2—O9	177.67 (11)	Cu1—O7—H7A	106.3
O2—Cu2—O9	84.26 (11)	Cu2^i—O7—H7B	108.7
O10—Cu2—O9	88.09 (11)	Cu1—O7—H7B	111.1
O7^i—Cu2—O8	85.83 (10)	H7A—O7—H7B	114.9
O2—Cu2—O8	92.82 (10)	Cu2—O8—Cu1	79.72 (8)
O10—Cu2—O8	90.30 (10)	Cu2—O8—H8A	123.7
O9—Cu2—O8	95.92 (10)	Cu1—O8—H8A	130.8
C1—O1—Cu1	132.5 (3)	Cu2—O9—H9A	108.6
C1—O2—Cu2	124.7 (2)	Cu2—O9—H9B	97.1
O6—N1—O5	122.9 (3)	H9A—O9—H9B	115.1
O6—N1—C6	118.8 (3)	Cu2—O10—H10A	114.4
O5—N1—C6	118.3 (3)	Cu2—O10—H10B	108.3
O2—C1—O1	126.0 (4)	H10A—O10—H10B	111.2
O2—C1—C2	117.7 (3)	H11A—O11—H11B	108.8
O7—Cu1—O1—C1	141.4 (3)	C5—C6—C7—C2	3.5 (5)
O7^i—Cu1—O1—C1	−38.6 (3)	N1—C6—C7—C2	−173.1 (3)
O8—Cu1—O1—C1	44.6 (3)	C5—C6—C7—C8	−178.7 (3)
O8^i—Cu1—O1—C1	−135.4 (3)	N1—C6—C7—C8	4.7 (5)
Cu2^i—Cu1—O1—C1	176.5 (3)	C3—C2—C7—C6	−2.1 (5)
O7^i—Cu2—O2—C1	41.4 (3)	C1—C2—C7—C6	176.4 (3)
O9—Cu2—O2—C1	−140.3 (3)	C3—C2—C7—C8	−179.9 (3)
O8—Cu2—O2—C1	−44.6 (3)	C1—C2—C7—C8	−1.4 (5)
Cu2—O2—C1—O1	−9.9 (5)	C6—C7—C8—O3	86.6 (4)
Cu2—O2—C1—C2	169.3 (2)	C2—C7—C8—O3	−95.7 (4)
Cu1—O1—C1—O2	9.1 (6)	C6—C7—C8—O4	−92.4 (4)
Cu1—O1—C1—C2	−170.1 (2)	C2—C7—C8—O4	85.2 (4)
O2—C1—C2—C3	12.2 (5)	O1^i—Cu1—O7—Cu2^i	−65.68 (13)
O1—C1—C2—C3	−168.5 (3)	O1—Cu1—O7—Cu2^i	114.32 (13)
O2—C1—C2—C7	−166.3 (3)	O8—Cu1—O7—Cu2^i	−157.67 (11)
O1—C1—C2—C7	13.0 (5)	O8^i—Cu1—O7—Cu2^i	22.33 (11)
C7—C2—C3—C4	−0.9 (6)	O7^i—Cu2—O8—Cu1	−18.10 (9)
C1—C2—C3—C4	−179.4 (3)	O2—Cu2—O8—Cu1	75.85 (9)
C2—C3—C4—C5	2.6 (6)	O10—Cu2—O8—Cu1	−111.52 (9)
C3—C4—C5—C6	−1.2 (5)	O9—Cu2—O8—Cu1	160.37 (9)
C4—C5—C6—C7	−2.0 (6)	O7—Cu1—O8—Cu2	−162.09 (9)
C4—C5—C6—N1	174.8 (3)	O7^i—Cu1—O8—Cu2	17.91 (9)
O6—N1—C6—C7	170.1 (4)	O1^i—Cu1—O8—Cu2	107.65 (9)
O5—N1—C6—C7	−8.6 (5)	O1—Cu1—O8—Cu2	−72.35 (9)
O6—N1—C6—C5	−6.8 (5)	Cu2^i—Cu1—O8—Cu2	180.0
O5—N1—C6—C5	174.5 (3)

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x+1, y−1, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O11—H11B···O4	0.85	2.08	2.918 (4)	172
O11—H11A···O8	0.85	1.83	2.665 (4)	166
O10—H10B···O4^ii	0.85	1.80	2.631 (3)	163
O10—H10A···O3^i	0.85	1.78	2.632 (3)	177
O9—H9A···O3^iii	0.84	1.79	2.634 (4)	178
O9—H9B···O2	0.84	2.21	2.652 (3)	113
O8—H8A···O10^iv	0.84	2.15	2.951 (4)	160
O7—H7B···O11^v	0.85	1.97	2.739 (4)	150
O7—H7A···O4	0.84	2.14	2.969 (4)	170

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x+1, y−1, z; (iii) x, y−1, z; (iv) −x+1, −y, −z+1; (v) −x, −y+1, −z+1.