An azide-bridged copper(II) complex: poly[piperazine-1,4-dium [tetra-μ₃-azido-κ¹²N¹:N¹:N¹-hexa-μ₂-azido-κ¹²N¹:N¹-di-μ₂-azido-κ⁴N¹:N³-penta­copper(II)] tetra­hydrate]

A new Cu^II–azide complex, {(C₄H₁₂N₂)[Cu₅(N₃)₁₂]·4H₂O}_n, has been synthesized by the reaction of piperazine, Cu(OAc)₂·2H₂O (OAc is acetate) and NaN₃. In the structure, μ₂-1,1- and μ₃-1,1,1-azide anions bridge five Cu^II cations to form a linear penta­nuclear cluster unit, which is further linked by μ₂-1,1- and μ₂-1,3-azide anions to form a two-dimensional condensed [Cu₅(N₃)₁₂]_n layer. The diprotonated piperazine and the solvent water mol­ecules are hydrogen bonded to the coordination layers to form a three-dimensional supra­molecular network.

S1. Introduction

In recent decades, metal complexes with an azide (N₃^-) anion acting as a bridging ligand have been studied extensively (Ribas et al., 1999), since N₃^- is a versatile ligand and can efficiently mediate magnetic coupling between paramagnetic metal ions. Due to this and its various possible binding modes, the azide anion has been extensively employed in the construction of coordination complexes with structures ranging from discrete complexes (Murugesu et al., 2004; Scott et al., 2005; Ako et al., 2006) to one-dimensional (Mukherjee et al., 2001; Liu et al., 2003; Gao et al., 2005), two-dimensional (Escuer et al., 2005; Zhai et al., 2006; Cheng et al., 2007) or three-dimensional networks (Zeng et al., 2006). Among the reported azide-based complexes, EO (µ₂-1,1-) and EE (µ₂-1,3-) coordination modes are two typical bridging modes, but the azide ligand can bridge more than two metals in a combination of EO and EE modes (see Scheme 1) (Zhang et al., 2006; Escuer et al., 2010; Yu et al., 2010; Mukherjee et al., 2011). To our knowledge, the azide anion usually co-operates with the organic co-ligand to construct coordination complexes. The topology structures of these complexes are strongly affected by the nature of the organic co-ligands, for example, shape, size, coordination ability etc. Thus, detailed research into the effect of organic co-ligands on the structural features of azide compounds is very important. Indeed, until now the major emphasis in the field has been the search for suitable organic co-ligands. Some bridging or chelating organics ligands, such as ethyl­enedi­amine (Mondal & Mukherjee, 2008), 2,2'-bi­pyridyl (Yang et al., 2008) and some pyridine derivatives (Ray et al., 2008), have been used as co-ligands to construct polynuclear or high-dimensional metal–azide compounds. While some weakly coordinating organic ligands can also affect the structural features of metal–azide compounds, these have been only rarely studied (Liu et al., 2008; Wu et al., 2011; Mautner et al., 1999). Here, a novel Cu^II–azide compound modified by a simple weak coordinating N-donor organic ligand, namely poly[piperazine-1,4-dium [tetra-µ₃-azido-κ¹²N¹:N¹:N¹-hexa-µ₂-azido-κ¹²N¹:N¹-di-µ₂-azido-κ⁴N¹:N³-penta­copper(II)] tetra­hydrate], (I), is reported. In (I), azide ligands link Cu^II cations to form two-dimensional condensed layers. The piperazine molecules are diprotonated and act as counter-cations.

S2. Experimental

S2.1. Synthesis and crystallization

Crystals of (I) were obtained by slow diffusion in an H-shaped tube. In one side of the H-tube was placed an aqueous solution containing Cu(OAc)₂.H₂O (0.25 g, 1.25 mmol). NaN₃ (0.18 g, 2.5 mmol) and piperazine (0.24 g, 2.5 mmol) were dissolved in ethanol (5 ml; pH = 4, adjusted by HCl), which was placed in the other side of the H-tube. Ethanol was then carefully added until the solutions on both sides reached the bridge. Slow diffusion between the two solutions afforded black block-shaped crystals of (I) after one week (yield 65%, based on Cu). Analysis, calculated for C₄H₂₀Cu₅N₃₈O₄: C 4.89, N 54.16, H 2.04%; found: C 4.93, N 54.82, H 1.99%. IR (KBr, ν, cm^-1): 3436 (br, s), 2063 (s), 2037 (s), 1631 (m), 1384 (m), 1128 (w), 884 (w), 619 (w).

S2.2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. All H atoms were positioned geometrically and treated as riding on their parent atoms, with N—H = 0.90 Å, alkyl C—H = 0.97 Å and water O—H = 0.85 Å, and with U_iso(H) = 1.2U_eq(N,C,O). Atoms N6 and O1 were resolved into two positions using SHELXL97 (Sheldrick, 2008) PART instructions.

S3. Results and discussion

X-ray single-crystal diffraction studies of (I) (Fig. 1) reveal that the crystallographically unique unit is composed of two and a half Cu^II cations, six azide anions, half of a diprotonated piperazine molecule and two solvent water molecules. Among the six crystallographically unique azide anions, two [N1–N3 bridging atoms Cu1, Cu2ⁱ and Cu3^iv, and N7—N9 bridging Cu1^v, Cu2 and Cu3; symmetry code: (i) -x, -y+2, -z+1, (iv) -x, -y+1, z+1; (v) x, y-1, z] adopt the µ₃-1,1,1-N₃^- coordination mode, three (N4–N6, N10–N12 and N13–N15) adopt the EO coordination mode, while N16/N18 adopts an EE coordination mode. Among the three crystallographically unique Cu^II cations, Cu1 sits on a centre of inversion and adopts an o­cta­hedral geometry, the equatorial (eq) plane is surrounded by two µ₃-1,1,1-N₃^- (N1–N3 and N1ⁱ–N3ⁱ) and two EO azide anions [N1/N3 and N4/N6, and their symmetry-related counterparts N1ⁱ/N3ⁱ and N4ⁱ/N6ⁱ, bridging Cu1 and Cu2, and Cu1 and Cu2ⁱ, respectively; symmetry code: (i) ???? [Please complete]]. The Cu1—N distances are 1.984 (3) and 1.998 (3) Å, respectively. The axial (ax) positions are occupied by another two µ₃-1,1,1-N₃^- anions [N7ⁱⁱ–N9ⁱⁱ and N7^iv–N9^iv; symmetry code: (ii) x, y+1, z]. The Cu—N_ax distance 2.747 (3) Å is apparently longer than that of Cu—N_eq, which may be explained by the Jahn–Teller effect. Atom Cu2 is located in a square-pyramidal environment coordinated by two µ₃-1,1,1-N₃^- (N1ⁱ–N3ⁱ and N7–N9) and three EO azide anions (N4/N6, N10/N12 and N13ⁱⁱ/N15ⁱⁱ), of which four N atoms (N1A, N4, N7 and N10 bridging Cu1 and Cu2, Cu2 and Cu3, respectively) occupy the equatorial plane with an average Cu2—N_eq distance of 2.001 (3) Å. The axial position of the square pyramid is occupied by a fifth N atom (N13ⁱⁱ), which bridges to atom Cu3ⁱⁱ. The Cu2—N_ax distance is 2.309 (3) Å. Atom Cu3 also adopts a square-pyramidal geometry coordinated by three EO azide (N7/N9, N10/N12 and N13/N15) and two EE azide anions [N16/N18 and N16^iv/N18^iv; symmetry code: (iv) ???? [Please complete]]. The three EO azide N atoms (N7, N10 and N13) and one EE azide N atom (N18^iv, bridging to Cu3^iv) occupy the equatorial plane, with an average Cu3—N_eq distance of 2.002 (3) Å. The axial position of the square pyramid of Cu3 is occupied by the other EE azide N atom [N16, bridging to Cu3ⁱⁱⁱ; symmetry code: (iii) ???? [Please complete]], with a Cu3—N_ax distance of 2.358 (3) Å. The square pyramids of Cu2 and Cu3 are both slightly distorted, with τ values of 0.050 and 0.075, respectively (Addison et al., 1984). Thus, two unique Cu^II cations (Cu2 and Cu3), their centrosymmetrically equivalent Cu^II cations (Cu2ⁱ and Cu3ⁱ) and the central Cu1 atom are linearly arranged and all doubly bridged by EO azide anions in an equatorial–equatorial disposition to generate a linear penta­nuclear unit. The Cu—N(EO—N₃)—Cu angles are similar, with an average value of 100.99 (15)°.

As shown in Fig. 2, each penta­nuclear unit is connected to two adjacent units via four single EO azide bridges at the Cu2 and Cu3 sites in an equatorial–axial disposition to form a one-dimensional tape extending along the b axis, with a Cu—N(EO—N₃)—Cu angle of 109.72 (13)°. The tapes are further linked through EE azide anions at the Cu3 sites in an equatorial–axial disposition to form a two-dimensional condensed layer parallel to the [101] plane, with a Cu—N(EE—N₃)—Cu dihedral angle of 25.5 (3)°. As far as we know, many Cu–azide compounds have been studied, in which the N-donor organic co-ligands cooperate with the azide anions to link the Cu centres to form one-, two- or three-dimensional structures. Only a few Cu–azide condensed layers have been reported, for example [Cu₆(N₃)₁₄]_n (Liu et al., 2008) and [Cu₇(N₃)₁₆]_n (Wu et al., 2011) layers, which are constructed by Cu₆ rings and Cu₇ linear chains, respectively. Thus, (I) is a novel example containing penta­nuclear linear units. The [Cu₅(N₃)₁₂]_n layer is anionic, which is charge-balanced by a layer of diprotonated piperazine molecules hydrogen-bonded to water molecules, similar to the reported Cu–azide condensed compounds, in which N,N'-di­methyl­ethylenedi­ammonium, N,N,N'-tri­methyl­ethylenedi­ammonium and 1-(pyridin-2-yl)-2-(2-hy­droxy­ethyl)­imidazo[1,5-a]pyridinium were selected as counter-cations.

As shown in Fig. 3(a), the O2 water molecule acts as a hydrogen-bond donor to the adjacent disordered O1/O1' water molecule, forming an O—H···O hydrogen bond. Simutaneously, O2 acts as a hydrogen-bond acceptor from the protonated piperazine atom H1B to form an N—H···O hydrogen bond. Thus, the symmetric piperazine-1,4-dium (H₂pip) cation hydrogen-bonds with two O2 water molecules through its two equivalent >NH₂⁺ groups. Thus, one H₂pip cation and four solvent water molecules hydrogen-bond with each other to form a water–piperazinediium supra­molecular subunit. In this supra­molecular subunit, atoms O1/O1' are both involved in one O—H···O hydrogen bond as hydrogen-bond acceptors, while O2 acts as a hydrogen-bond donor and acceptor, bonding with O1/O1' and N19, respectively, and is involved in one O—H···O and one N—H···O hydrogen bond.

In the supra­molecular subunit, there are six types of H atom which are not involved in O—H···O or N—H···O hydrogen bonds, namely four attached to the disordered water molecule O1/O1', one attached to O2 and one from the –NH₂ group. These H atoms all form hydrogen bonds with azide N atoms from adjacent [Cu₅(N₃)₁₂]_n coordination layers. As shown in Fig. 3(b), the two >NH₂⁺ groups of the H₂pip cation hydrogen-bond with two N18 atoms from two adjacent coordination layers through atoms H1A. The solvent water molecules O1/O1' and O2 provide their remaining H atoms to form hydrogen bonds with N6/N6', and N9 and N15, respectively, from the coordination layers. Thus, the water–piperazinediium supra­molecular subunits act as a `glue' and link the [Cu₅(N₃)₁₂]_n coordination layers through hydrogen bonds to form a three-dimensional supra­molecular network. The parameters of selected coordination bonds and all hydrogen bonds are listed in Tables 2 and 3, respectively.

In summary, the simple N-donor organic molecule piperazine has been used to tune the structure of the Cu–azide system, resulting in a novel compound, {(H₂pip)[Cu₅(N₃)₁₂].4H₂O}_n. In this compound, five Cu^II centres are arranged in a linear manner through eight EO azide anions, which are further connected with each other to form two-dimensional condensed Cu–azide anion layers by another eight azide anions adopting EO or EE coordination modes. The protonated piperazine cations and solvent water molecules are located between the Cu–azide layers and hydrogen-bond with the azide N atoms. Thus, the Cu–azide coordination layers are linked to form a three-dimensional supra­molecular network.

Related literature

For related literature, see: Addison et al. (1984); Ako et al. (2006); Cheng et al. (2007); Escuer et al. (2005, 2010); Gao et al. (2005); Liu et al. (2003, 2008); Mautner et al. (1999); Mondal & Mukherjee (2008); Mukherjee et al. (2001, 2011); Murugesu et al. (2004); Ray et al. (2008); Ribas et al. (1999); Scott et al. (2005); Sheldrick (2008); Wu et al. (2011); Yang et al. (2008); Yu et al. (2010); Zeng et al. (2006); Zhai et al. (2006); Zhang et al. (2006).

Computing details

Data collection: SMART (Bruker, 2002); cell refinement: SMART (Bruker, 2002); data reduction: SAINT (Bruker, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures

	Fig. 1. The coordination environments of the linear pentanuclear unit of (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. [Symmetry codes: (i) -x, -y + 2, -z + 1; (ii) x, y + 1, z; (iii) -x + 1/2, y - 1/2, -z + 3/2.] [No symop iii visible, only iv. Should the atoms labelled with symop iv in fact be iii?]
	Fig. 2. The pentanuclear units of (I), linked by single EO- and double EE-bridges to form a two-dimensional condensed layer. [Symmetry codes: (ii) x, y + 1, z; (iii) -x + 1/2, y - 1/2, -z + 3/2.]
	Fig. 3. (a) The solvent water–piperazine supramolecular subunit and (b) the hydrogen bonding (dashed lines) between the water–piperazine supramolecular subunits and adjacent Cu–azide layers, forming the three-dimensional supramolecular network.

Poly[piperazine-1,4-dium [tetra-µ₃-azido-κ¹²N¹:N¹:N¹-hexa-µ₂-azido-κ¹²N¹:N¹-di-µ₂-azido-κ⁴N¹:N³-pentacopper(II)] tetrahydrate]

Crystal data

(C4H12N2)[Cu5(N3)12]·4H2O	F(000) = 974
Mr = 982.28	Dx = 2.066 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 16.343 (3) Å	Cell parameters from 2772 reflections
b = 5.7477 (11) Å	θ = 1.7–25.0°
c = 16.812 (3) Å	µ = 3.40 mm^−1
β = 91.10 (3)°	T = 293 K
V = 1579.0 (5) Å^3	Block, black
Z = 2	0.22 × 0.21 × 0.19 mm

Data collection

Bruker SMART CCD area-detector diffractometer	2772 independent reflections
Radiation source: fine-focus sealed tube	2080 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.053
ϕ and ω scans	θmax = 25.0°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Bruker, 2002)	h = −19→19
Tmin = 0.522, Tmax = 0.564	k = −6→6
7506 measured reflections	l = −15→19

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)] = 0.031	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.072	H-atom parameters constrained
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0265P)^2] where P = (Fo^2 + 2Fc^2)/3
2772 reflections	(Δ/σ)max = 0.001
252 parameters	Δρmax = 0.45 e Å^−3
522 restraints	Δρmin = −0.50 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	Occ. (<1)
Cu1	0.0000	1.0000	0.5000	0.02402 (17)
Cu2	0.07589 (2)	0.57208 (8)	0.58419 (2)	0.02086 (13)
Cu3	0.13723 (2)	0.11424 (7)	0.66215 (2)	0.02121 (14)
N1	0.00263 (17)	1.1650 (5)	0.39549 (16)	0.0245 (7)
N2	0.04243 (19)	1.1250 (6)	0.33707 (19)	0.0325 (8)
N3	0.0785 (2)	1.0904 (8)	0.2810 (2)	0.0705 (14)
N4	0.06828 (18)	0.7236 (5)	0.47703 (16)	0.0265 (7)
N7	0.12900 (17)	0.2692 (5)	0.55257 (16)	0.0226 (7)
N8	0.1836 (2)	0.2482 (6)	0.50541 (19)	0.0333 (8)
N9	0.2340 (3)	0.2218 (8)	0.4603 (2)	0.0767 (14)
N10	0.06509 (18)	0.3886 (5)	0.68196 (17)	0.0273 (7)
N11	0.04725 (18)	0.4540 (5)	0.74812 (19)	0.0272 (7)
N12	0.0300 (2)	0.5116 (7)	0.8105 (2)	0.0518 (11)
N13	0.18198 (18)	−0.1853 (5)	0.62292 (17)	0.0276 (7)
N14	0.2487 (2)	−0.1951 (5)	0.59446 (17)	0.0280 (7)
N15	0.3128 (2)	−0.2094 (7)	0.5675 (2)	0.0534 (11)
N16	0.2715 (2)	0.2613 (6)	0.6757 (2)	0.0471 (10)
N17	0.32242 (18)	0.3779 (5)	0.70271 (17)	0.0273 (7)
N18	0.37683 (18)	0.4982 (5)	0.72859 (17)	0.0303 (8)
N19	0.00763 (19)	−0.0287 (6)	0.91541 (17)	0.0382 (9)
H1A	0.0341	0.0032	0.8702	0.046*
H1B	−0.0347	−0.1230	0.9032	0.046*
C1	−0.0234 (2)	0.1897 (7)	0.9499 (2)	0.0402 (11)
H19A	−0.0624	0.2602	0.9130	0.048*
H19B	0.0217	0.2975	0.9577	0.048*
C2	0.0641 (2)	−0.1485 (7)	0.9720 (2)	0.0347 (10)
H2A	0.1127	−0.0543	0.9805	0.042*
H2B	0.0808	−0.2962	0.9496	0.042*
O2	0.87024 (18)	0.7007 (6)	0.90155 (18)	0.0768 (11)
H2E	0.8479	0.6958	0.9468	0.092*
H2F	0.8362	0.6508	0.8667	0.092*
O1	0.7768 (5)	0.545 (2)	0.7752 (5)	0.108 (4)	0.589 (11)
H1E	0.7343	0.6188	0.7886	0.130*	0.589 (11)
H1F	0.7714	0.5025	0.7269	0.130*	0.589 (11)
O1'	0.8184 (9)	0.363 (3)	0.8038 (7)	0.126 (5)	0.411 (11)
H1'A	0.7716	0.3014	0.8092	0.152*	0.411 (11)
H1'B	0.8272	0.3799	0.7544	0.152*	0.411 (11)
N5	0.1105 (2)	0.6869 (6)	0.4225 (2)	0.0365 (8)
N6	0.1731 (14)	0.702 (4)	0.3866 (15)	0.044 (4)	0.29 (3)
N6'	0.1405 (10)	0.626 (2)	0.3625 (6)	0.061 (3)	0.71 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0314 (4)	0.0213 (4)	0.0195 (3)	0.0118 (3)	0.0045 (3)	0.0049 (3)
Cu2	0.0275 (3)	0.0176 (3)	0.0176 (2)	0.00720 (19)	0.00326 (18)	0.00312 (18)
Cu3	0.0262 (3)	0.0163 (3)	0.0212 (2)	0.0047 (2)	0.00177 (18)	0.00195 (19)
N1	0.0338 (18)	0.0217 (18)	0.0184 (16)	0.0126 (14)	0.0052 (14)	0.0049 (14)
N2	0.0362 (19)	0.031 (2)	0.0306 (19)	0.0112 (16)	0.0042 (16)	0.0096 (16)
N3	0.078 (3)	0.088 (4)	0.047 (2)	0.044 (3)	0.037 (2)	0.022 (2)
N4	0.0393 (19)	0.0245 (19)	0.0159 (16)	0.0150 (15)	0.0075 (14)	0.0050 (13)
N7	0.0289 (17)	0.0178 (17)	0.0213 (16)	0.0085 (13)	0.0047 (13)	0.0018 (13)
N8	0.039 (2)	0.031 (2)	0.0305 (19)	0.0128 (16)	0.0020 (16)	0.0055 (15)
N9	0.082 (3)	0.086 (4)	0.064 (3)	0.040 (3)	0.046 (2)	0.022 (3)
N10	0.0396 (19)	0.0204 (19)	0.0223 (17)	0.0126 (15)	0.0071 (14)	0.0042 (14)
N11	0.0335 (18)	0.0186 (19)	0.0295 (19)	0.0083 (14)	0.0033 (15)	0.0079 (15)
N12	0.079 (3)	0.048 (3)	0.028 (2)	0.014 (2)	0.0190 (19)	0.0017 (18)
N13	0.0292 (18)	0.0176 (17)	0.0360 (19)	0.0018 (14)	0.0025 (15)	−0.0029 (14)
N14	0.036 (2)	0.0185 (19)	0.0297 (18)	0.0056 (15)	−0.0015 (16)	−0.0013 (14)
N15	0.043 (2)	0.051 (3)	0.068 (3)	0.012 (2)	0.027 (2)	0.000 (2)
N16	0.037 (2)	0.048 (2)	0.055 (2)	−0.0148 (18)	−0.0058 (17)	−0.0198 (18)
N17	0.0284 (18)	0.029 (2)	0.0248 (17)	0.0013 (16)	0.0049 (14)	−0.0046 (15)
N18	0.0322 (19)	0.030 (2)	0.0285 (18)	−0.0122 (15)	0.0009 (14)	−0.0126 (15)
N19	0.042 (2)	0.042 (2)	0.0314 (19)	−0.0028 (17)	0.0172 (15)	0.0021 (17)
C1	0.045 (3)	0.033 (3)	0.043 (3)	0.005 (2)	0.012 (2)	0.009 (2)
C2	0.035 (2)	0.027 (3)	0.042 (2)	0.0035 (19)	0.0145 (19)	0.001 (2)
O2	0.057 (2)	0.112 (3)	0.063 (2)	−0.028 (2)	0.0219 (17)	−0.029 (2)
O1	0.084 (6)	0.145 (8)	0.097 (6)	−0.016 (5)	0.037 (4)	−0.067 (6)
O1'	0.128 (9)	0.161 (11)	0.092 (7)	−0.024 (8)	0.036 (6)	−0.058 (8)
N5	0.046 (2)	0.028 (2)	0.036 (2)	0.0148 (17)	0.0069 (17)	0.0152 (17)
N6	0.042 (7)	0.051 (7)	0.038 (7)	0.007 (6)	0.018 (6)	0.002 (6)
N6'	0.077 (7)	0.066 (6)	0.040 (4)	0.021 (5)	0.029 (4)	0.002 (4)

Geometric parameters (Å, º)

Cu1—N4	1.984 (3)	N2—N3	1.139 (4)
Cu1—N4^i	1.984 (3)	N4—N5	1.176 (4)
Cu1—N1	1.998 (3)	N7—N8	1.211 (4)
Cu1—N1^i	1.998 (3)	N8—N9	1.141 (5)
Cu1—N7^ii	2.747 (3)	N10—N11	1.215 (4)
Cu2—N10	1.964 (3)	N11—N12	1.141 (4)
Cu2—N4	2.003 (3)	N13—N14	1.201 (4)
Cu2—N1^i	2.016 (3)	N13—Cu2^v	2.309 (3)
Cu2—N7	2.021 (3)	N14—N15	1.152 (4)
Cu2—N13^ii	2.309 (3)	N16—N17	1.155 (4)
Cu3—N18^iii	1.972 (3)	N17—N18	1.201 (4)
Cu3—N13	1.988 (3)	N18—Cu3^vi	1.972 (3)
Cu3—N10	2.001 (3)	N19—C1	1.477 (5)
Cu3—N7	2.048 (3)	N19—C2	1.482 (4)
Cu3—N16	2.358 (3)	C1—C2^vii	1.502 (5)
Cu3—N1^iv	2.942 (3)	C2—C1^vii	1.502 (5)
N1—N2	1.210 (4)	N5—N6'	1.182 (11)
N1—Cu2^i	2.016 (3)
N4—Cu1—N4^i	180.000 (1)	N13—Cu3—N1^iv	72.94 (10)
N4—Cu1—N1	100.79 (11)	N10—Cu3—N1^iv	91.62 (10)
N4^i—Cu1—N1	79.21 (11)	N18^iii—Cu3—N1^iv	91.07 (10)
N4—Cu1—N1^i	79.21 (11)	N16—Cu3—N1^iv	160.58 (10)
N4^i—Cu1—N1^i	100.79 (11)	N2—N1—Cu1	130.1 (2)
N1—Cu1—N1^i	180.000 (1)	N2—N1—Cu2^i	129.3 (2)
N1—Cu1—N7^ii	89.22 (10)	Cu1—N1—Cu2^i	100.51 (13)
N4—Cu1—N7^ii	94.74 (10)	N3—N2—N1	178.3 (4)
N1^i—Cu1—N7^ii	90.79 (10)	N5—N4—Cu1	129.5 (3)
N4^i—Cu1—N7^ii	85.26 (10)	N5—N4—Cu2	126.6 (2)
N10—Cu2—N4	168.95 (13)	Cu1—N4—Cu2	101.45 (13)
N10—Cu2—N1^i	101.13 (12)	N8—N7—Cu2	125.7 (3)
N4—Cu2—N1^i	78.33 (11)	N8—N7—Cu3	120.6 (2)
N10—Cu2—N7	78.67 (12)	Cu2—N7—Cu3	99.15 (12)
N4—Cu2—N7	99.06 (11)	N9—N8—N7	177.8 (5)
N1^i—Cu2—N7	165.54 (12)	N11—N10—Cu2	128.9 (2)
N10—Cu2—N13^ii	99.63 (12)	N11—N10—Cu3	123.3 (2)
N4—Cu2—N13^ii	91.40 (12)	Cu2—N10—Cu3	102.78 (13)
N1^i—Cu2—N13^ii	88.66 (12)	N12—N11—N10	178.8 (4)
N7—Cu2—N13^ii	105.68 (11)	N14—N13—Cu3	121.0 (3)
N18^iii—Cu3—N13	93.81 (13)	N14—N13—Cu2^v	122.8 (2)
N18^iii—Cu3—N10	91.83 (12)	Cu3—N13—Cu2^v	109.72 (13)
N13—Cu3—N10	163.64 (12)	N15—N14—N13	178.6 (4)
N18^iii—Cu3—N7	167.98 (12)	N17—N16—Cu3	155.3 (3)
N13—Cu3—N7	95.54 (12)	N16—N17—N18	177.9 (4)
N10—Cu3—N7	77.18 (11)	N17—N18—Cu3^vi	115.7 (3)
N18^iii—Cu3—N16	98.96 (13)	C1—N19—C2	110.9 (3)
N13—Cu3—N16	89.72 (12)	N19—C1—C2^vii	111.7 (3)
N10—Cu3—N16	104.56 (13)	N19—C2—C1^vii	110.7 (3)
N7—Cu3—N16	88.64 (12)	N4—N5—N6'	167.6 (11)
N7—Cu3—N1^iv	85.48 (10)

Symmetry codes: (i) −x, −y+2, −z+1; (ii) x, y+1, z; (iii) −x+1/2, y−1/2, −z+3/2; (iv) −x, −y+1, −z+1; (v) x, y−1, z; (vi) −x+1/2, y+1/2, −z+3/2; (vii) −x, −y, −z+2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N19—H1A···N18^iii	0.90	2.23	3.103 (4)	163
N19—H1B···O2^viii	0.90	1.85	2.738 (4)	167
O2—H2E···N15^ix	0.85	2.12	2.961 (5)	170
O2—H2F···O1	0.85	1.90	2.744 (8)	169
O2—H2F···O1′	0.85	1.98	2.672 (12)	138
O1—H1E···N6^x	0.85	2.20	2.94 (2)	145
O1—H1F···N6^xi	0.85	2.43	3.19 (3)	149
O1′—H1′A···N9^ix	0.85	2.63	3.034 (12)	111
O1′—H1′B···N6′^xi	0.85	2.05	2.888 (14)	171

Symmetry codes: (iii) −x+1/2, y−1/2, −z+3/2; (viii) x−1, y−1, z; (ix) x+1/2, −y+1/2, z+1/2; (x) x+1/2, −y+3/2, z+1/2; (xi) −x+1, −y+1, −z+1.