A novel threefold-inter­penetrating primitive cubic network based on a dinuclear Zn₂ node

In the mixed-ligand metal–organic polymeric compound poly[[μ₂-1,4-bis­(imidazol-1-yl)benzene](μ₂-terephthalato)dizinc(II)], [Zn₂(C₈H₄O₄)₂(C₁₂H₁₀N₄)]_n or [Zn₂(bdc)₂(bib)]_n [H₂bdc is terephthalic acid and bib is 1,4-bis­(imidazol-1-yl)benzene], the asymmetric unit contains one Zn^II ion, with two half bdc anions and one half bib mol­ecule lying around inversion centers. The Zn^II ion is in a slightly distorted tetra­hedral environment, coordinated by three carboxyl­ate O atoms from three different bdc anions and by one bib N atom. The crystal structure is constructed from the secondary building unit (SBU) [Zn₂(CO₂)₂N₂O₂], in which the two metal centers are held together by two bdc linkers with bis­(syn,syn-bridging bidentate) bonding modes. The SBU is connected by bdc bridges to form a two-dimensional grid-like (4,4)-layer, which is further pillared by the bib ligand. Topologically, the dinuclear SBU can be considered to be a six-connected node, and the extended structure exhibits an elongated primitive approximately cubic framework. The three-dimensional framework possesses a large cavity with dimensions of approximately 10 × 13 × 17 Å in cross-section. The potential porosity is filled with mutual inter­penetration of two identical equivalent frameworks, generating a novel threefold inter­penetrating network with an α-polonium topology [Abrahams, Hoskins, Robson & Slizys (2002). CrystEngComm, 4, 478–482].

S1. Comment

Metal–organic frameworks (MOFs) are hybrid materials where metal ions or small clusters are bridged by multifunctional organic linkers into one-dimensional chains, two-dimensional layers or three-dimensional nets. During the past decade, the construction of MOFs through crystal engineering has attracted considerable attention owing to their various intriguing architectures and potential applications as functional materials (Kitaura et al., 2003; Eddaoudi et al., 2000; Kepert et al., 2001). As nature abhors a vacuum, mutual interpenetration is a common phenomenon in supramolecular chemistry and provides a unique class of robust framework (Carlucci et al., 2000). Comprehensive reviews of interpenetration, which has been the most investigated type of entanglement, are given by Batten (2001) and Blatov et al. (2004). Much effort has been devoted to the synthesis of novel interpenetrating networks with interesting topologies. The most commonly used synthetic strategy is to select appropriate long-chain ligands, which bridge metal ions to afford infinite networks. Recently, the synthetic strategy utilizing secondary building units (SBUs) has achieved stable, highly porous open frameworks; two efficient SBUs are the tetrameric M₄O(COO)₆ clusters and the paddle-wheel dimeric M₂(COO)₄ clusters formed by carboxylate ligands (Chae et al., 2004; Sun et al., 2006; Han et al., 2008; Chen, Che et al., 2007). There are many inorganic–organic hybrid complexes composed of polyoxometalates (POMs) associated with various metal–ligand systems (Tian et al., 2008). A large number of attractive MOFs of ingenious design based on flexible bis(imidazole) ligands have been crystallographically characterized (Jin et al., 2006; Li et al., 2006; Fan et al., 2006). In order to enrich the coordination chemistry of interpenetrating MOFs based on POMs as nodes, we describe the synthesis and crystal structure of a novel threefold-interpenetrating primitive cubic network constructed from terephthalic acid (H₂bdc), 1,4-bis(imidazol-1-yl)benzene (bib) and Zn^II, namely [Zn₂(bdc)₂(bib)]_∞, (I).

As shown in Fig. 1, the Zn^II centre is four-coordinated by one N atom from the bib ligand and three O atoms from individual bdc anions to form a slightly distorted tetrahedral configuration, in which the Zn—O/N bond lengths are in the range 1.927 (3)–1.990 (3) Å (Table 1), comparable to those observed in related Zn^II polymeric structures (Li et al., 2008; Chen, Che et al., 2007; Wang et al., 2006). The bdc and bib ligands lie about centers of symmetry. In the bdc anion, the two carboxylate groups show different bridging modes, viz. monodentate and syn–syn bidentate (Fig. 2). The bib ligand is trans-coordinated to the Zn^II centre and keeps its rigid conformation in the self-assembly of the coordination polymer. As depicted in Fig. 2, two crystallographically equivalent Zn^II atoms, i.e. Zn1 and Zn1(-x + 2, -y, -z + 1), are bridged by two syn–syn connecting carboxylates with a Zn···Zn distance of 3.706 (1) Å. This arrangement constitutes a relatively rare dinuclear SBU [Zn₂(CO₂)₂N₂O₂], in which two Zn^II centres are encompassed by two syn–syn bridging and two monodentate carboxylates, respectively. Thus, it is quite different from the common paddle-wheel dimeric unit, which is bridged by four syn–syn connecting carboxylates. Some similar zinc-based SBUs linked by this carboxylate bridging mode are found in coordination polymers, but there are minor differences from the present compound in the coordination environments of the Zn^II ions (Dietzel et al., 2006; Wang et al., 2006). One closely related structure is reported by Chen, Zhang & Lu (2007), with the dinuclear Zn^II unit also connected by two bdc ligands; however, the Zn···Zn distances within this unit are 3.522 (1) and 3.564 (1) Å, respectively, somewhat shorter than here. Furthermore, the Zn···Zn separations in paddle-wheel SBUs are generally around 2.9 Å, and two intra-unit Zn^II centres are typically much closer (Ma et al., 2005; Zhou et al., 2000; Li et al., 2004; Chun et al., 2005).

A better insight into this fascinating structure can be achieved by the application of topology analysis. Although each Zn^II centre sits in a tetrahedral coordination environment, the dinuclear SBU is octahedrally connected by four bdc anions and two bib molecules (Fig. 2). Each six-connected SBU is linked to four equivalent units through four bdc anions to generate a neutral two-dimensional square-grid (4,4)-layer, [Zn₂(bdc)₂]_∞. As shown in Fig. 3, the two-dimensional layer is further pillared by the long bib ligand to afford an extended three-dimensional framework, [Zn₂(bdc)₂(bib)]_∞, with a cube-like structure, which is also found in the two-dimensional parallel catenation of bilayer [Zn₂(bdc)₂(bpp)]_∞ [bpp is 1,3-bis(4-pyridyl)-propane; Chen, Zhang & Lu, 2007]. If the dinuclear SBU is simplified to a six-connected node and, accordingly, the bdc and bib ligands act as two-connected linkers, the overall topology can be described as an α-polonium framework (Abrahams et al., 2002), which possesses large cubic cavities of approximately 10 × 13 × 17 Å. (Fig. 4). The large voids formed by a single three-dimensional framework allow the incorporation of two identical frameworks, thus giving a threefold-interpenetraing α-polonium-related network, as shown in Fig. 5. The nodes of the second and third nets are located, equally spaced, along the cubic diagonal of the first net, and each square window has a rod from each of the adjacent two nets passing through it, giving a complicated interpenetration. We recognize as did previous workers that, among the currently known examples of α-polonium topology, the majority are twofold (Niel et al., 2002; Jensen et al., 2002; Yang et al., 2002), and only a few threefold-interpenetrated frameworks have been identified (Abrahams et al., 2002; Wang et al., 2006).

In summary, a novel threefold-interpenetrating network with an α-polonium topology has been synthesized and is another interpenetrating MOF based on a POM as the node.

Related literature

For related literature, see: Abrahams et al. (2002); Batten (2001); Blatov et al. (2004); Carlucci et al. (2000); Chae et al. (2004); Chen, Che, Batten & Zheng (2007); Chen, Zhang & Lu (2007); Dietzel et al. (2006); Eddaoudi et al. (2000); Fan et al. (2006); Han et al. (2008); Jensen et al. (2002); Jin et al. (2006); Kepert et al. (2001); Kitaura et al. (2003); Li et al. (2006, 2008); Niel et al. (2002); Sun et al. (2006); Tian et al. (2008); Wang et al. (2006); Yang et al. (2002).

S2. Experimental

A mixture of Zn(NO₃)₂.6H₂O (149 mg, 0.5 mmol), H₂bdc (83 mg, 0.5 mmol), bib (78 mg, 0.25 mmol), water (6 ml) and ethanol (8 ml) was placed in a Teflon reactor (23 ml). The mixture was heated at 413 K for 3 d, and then it was cooled to room temperature at 5 K h^-1. Colorless block-shaped crystals of (I) were obtained (yield 37%, based on Zn). Analysis calculated for C₁₄H₉N₂O₄Zn: C 50.25, H 2.71, N 8.37%; found: C 49.99; H 2.64; N 8.53.

S3. Refinement

All H atoms were positioned geometrically and refined using a riding model [C—H = 0.93 Å and U_iso(H) = 1.2U_eq(C)].

Computing details

Data collection: SMART (Bruker, 1997); cell refinement: SAINT (Bruker, 1997); data reduction: SAINT (Bruker, 1997); 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 coordination environment of the Zn^II cation in (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms are shown as spheres of arbitrary radii. [Symmetry codes: (i) -x + 2, -y, -z + 1; (ii) -x + 2, -y - 1, -z; (iii) x - 1, y - 1, z; (iv) -x, -y, -z; (v) -x + 3, -y +1, -z + 1.]
	Fig. 2. The dinuclear Zn2 SBU of (I), showing an Oh symmetry node. Zn1 and Zn1^iare linked by two syn–syn-connecting carboxylates. The insert shows an ideal octahedral node. [Symmetry code: (i) -x + 2, -y, -z + 1.]
	Fig. 3. A schematic representation of the cube-like structure of (I), based on dinuclear Zn2 clusters. The insert shows the Zn^II coordination environment.
	Fig. 4. The large channel of one single α-polonium framework in (I), with dimensions of 10 × 13 × 17 Å (see text).
	Fig. 5. A view of the threefold-interpenetrating α-polonium network of (I). The dinuclear Zn2 SBU acts as a node, while bridging ligands bdc and bib act as linkers. These alternating frameworks are shown in turquoise, pink and blue, respectively, in the electronic version of the paper.

poly[[µ₂-1,4-bis(imidazol-1-yl)benzene](µ₂-terephthalato)dizinc(II)]

Crystal data

[Zn2(C8H4O4)2(C12H10N4)]	Z = 2
Mr = 334.60	F(000) = 338
Triclinic, P1	Dx = 1.744 Mg m^−3
a = 6.9711 (14) Å	Mo Kα radiation, λ = 0.71073 Å
b = 8.0784 (16) Å	Cell parameters from 6093 reflections
c = 11.903 (2) Å	θ = 3.2–27.6°
α = 102.68 (3)°	µ = 1.95 mm^−1
β = 99.68 (3)°	T = 293 K
γ = 96.32 (3)°	Prism, colorless
V = 637.1 (2) Å^3	0.20 × 0.20 × 0.20 mm

Data collection

Bruker SMART 1000 CCD diffractometer	1952 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.046
Graphite monochromator	θmax = 25.0°, θmin = 3.2°
Detector resolution: 9 pixels mm^-1	h = −8→8
ω scans	k = −9→9
5445 measured reflections	l = −14→14
2244 independent 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)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.103	H-atom parameters constrained
S = 1.11	w = 1/[σ^2(Fo^2) + (0.0461P)^2 + 0.183P] where P = (Fo^2 + 2Fc^2)/3
2244 reflections	(Δ/σ)max < 0.001
190 parameters	Δρmax = 0.45 e Å^−3
0 restraints	Δρmin = −0.37 e Å^−3

Special details

Experimental. IR (KBr): 3434(w), 3160(m), 3145(w), 1607(s), 1525(s), 1501(m), 1440(m), 1394(s), 1363(s), 1348(s), 1326(m), 1298(m), 1273(m), 1230(m), 1131(m), 1060(m), 1014(m), 963(m), 948(w), 895(w), 862(w), 835(m), 823(s), 749(s), 653(m), 582(m), 557(m), 524(m), 498(m), 453(w).

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
Zn1	0.84927 (6)	−0.01369 (5)	0.35343 (4)	0.03680 (18)
O1	1.0430 (4)	0.1996 (3)	0.4058 (2)	0.0494 (7)
N1	0.6388 (4)	0.0861 (4)	0.2678 (3)	0.0372 (7)
O2	1.2514 (4)	0.0873 (3)	0.5188 (2)	0.0427 (6)
N2	0.3656 (4)	0.1063 (4)	0.1542 (2)	0.0370 (7)
O3	0.9684 (4)	−0.1888 (4)	0.2643 (2)	0.0545 (7)
C12	1.3577 (5)	0.3584 (4)	0.4867 (3)	0.0345 (8)
O4	0.6639 (4)	−0.3220 (4)	0.1847 (3)	0.0600 (8)
C4	0.1782 (5)	0.0520 (5)	0.0748 (3)	0.0356 (8)
C14	1.3100 (5)	0.4962 (5)	0.4413 (3)	0.0395 (9)
H14A	1.1825	0.4936	0.4015	0.047*
C7	0.8411 (6)	−0.3024 (5)	0.1871 (3)	0.0438 (9)
C11	1.2067 (5)	0.2044 (5)	0.4700 (3)	0.0367 (8)
C8	0.9230 (5)	−0.4100 (5)	0.0924 (3)	0.0404 (9)
C6	0.1595 (5)	−0.0783 (5)	−0.0231 (3)	0.0405 (9)
H6A	0.2676	−0.1310	−0.0384	0.049*
C10	1.1244 (6)	−0.4108 (5)	0.1024 (3)	0.0432 (9)
H10A	1.2095	−0.3506	0.1717	0.052*
C13	1.5482 (5)	0.3623 (5)	0.5450 (3)	0.0390 (9)
H13A	1.5812	0.2700	0.5751	0.047*
C2	0.6358 (5)	0.2556 (5)	0.2666 (3)	0.0375 (8)
H2A	0.7342	0.3463	0.3075	0.045*
C3	0.4682 (5)	0.2697 (5)	0.1972 (3)	0.0412 (9)
H3A	0.4294	0.3702	0.1814	0.049*
C5	0.0201 (5)	0.1316 (5)	0.0992 (3)	0.0403 (9)
H5A	0.0343	0.2203	0.1661	0.048*
C9	0.8000 (6)	−0.5012 (5)	−0.0120 (3)	0.0438 (9)
H9A	0.6647	−0.5026	−0.0207	0.053*
C1	0.4740 (5)	0.0006 (5)	0.1994 (3)	0.0433 (9)
H1A	0.4373	−0.1176	0.1843	0.052*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Zn1	0.0276 (3)	0.0359 (3)	0.0423 (3)	−0.00506 (17)	−0.00592 (18)	0.0146 (2)
O1	0.0329 (15)	0.0431 (16)	0.0635 (18)	−0.0123 (11)	−0.0105 (13)	0.0190 (14)
N1	0.0299 (17)	0.0373 (17)	0.0406 (17)	0.0003 (13)	−0.0041 (13)	0.0121 (14)
O2	0.0381 (15)	0.0409 (15)	0.0504 (15)	−0.0020 (11)	0.0057 (12)	0.0200 (13)
N2	0.0263 (16)	0.0450 (18)	0.0384 (17)	0.0036 (13)	−0.0029 (13)	0.0151 (15)
O3	0.0473 (17)	0.0528 (18)	0.0573 (18)	0.0070 (14)	0.0024 (14)	0.0071 (15)
C12	0.032 (2)	0.036 (2)	0.0316 (19)	−0.0084 (15)	0.0023 (15)	0.0089 (16)
O4	0.0440 (18)	0.0553 (19)	0.078 (2)	0.0051 (14)	0.0142 (15)	0.0095 (16)
C4	0.030 (2)	0.044 (2)	0.036 (2)	0.0056 (16)	−0.0001 (15)	0.0195 (18)
C14	0.0294 (19)	0.042 (2)	0.041 (2)	−0.0056 (16)	−0.0069 (16)	0.0121 (18)
C7	0.045 (3)	0.035 (2)	0.052 (2)	0.0036 (18)	0.004 (2)	0.0166 (19)
C11	0.034 (2)	0.038 (2)	0.0345 (19)	−0.0027 (16)	0.0016 (16)	0.0086 (17)
C8	0.036 (2)	0.038 (2)	0.049 (2)	0.0041 (16)	0.0037 (17)	0.0201 (19)
C6	0.030 (2)	0.048 (2)	0.045 (2)	0.0107 (16)	0.0024 (17)	0.0141 (19)
C10	0.037 (2)	0.040 (2)	0.049 (2)	−0.0021 (17)	−0.0017 (18)	0.0145 (19)
C13	0.034 (2)	0.035 (2)	0.042 (2)	−0.0063 (15)	−0.0053 (16)	0.0141 (17)
C2	0.037 (2)	0.033 (2)	0.037 (2)	0.0027 (15)	0.0009 (16)	0.0043 (16)
C3	0.040 (2)	0.038 (2)	0.044 (2)	0.0095 (17)	0.0011 (17)	0.0093 (18)
C5	0.036 (2)	0.046 (2)	0.036 (2)	0.0078 (17)	0.0019 (16)	0.0072 (18)
C9	0.032 (2)	0.045 (2)	0.052 (2)	−0.0008 (17)	0.0019 (18)	0.016 (2)
C1	0.029 (2)	0.043 (2)	0.055 (2)	−0.0019 (16)	−0.0089 (17)	0.0230 (19)

Geometric parameters (Å, º)

Zn1—O3	1.927 (3)	C14—C13^ii	1.387 (5)
Zn1—O2^i	1.955 (3)	C14—H14A	0.9300
Zn1—O1	1.978 (3)	C7—C8	1.499 (6)
Zn1—N1	1.990 (3)	C8—C9	1.386 (5)
O1—C11	1.253 (4)	C8—C10	1.390 (5)
N1—C1	1.313 (4)	C6—C5^iii	1.379 (5)
N1—C2	1.375 (4)	C6—H6A	0.9300
O2—C11	1.256 (4)	C10—C9^iv	1.371 (6)
O2—Zn1^i	1.955 (3)	C10—H10A	0.9300
N2—C1	1.340 (4)	C13—C14^ii	1.387 (5)
N2—C3	1.374 (5)	C13—H13A	0.9300
N2—C4	1.439 (4)	C2—C3	1.344 (5)
O3—C7	1.284 (5)	C2—H2A	0.9300
C12—C13	1.385 (5)	C3—H3A	0.9300
C12—C14	1.388 (5)	C5—C6^iii	1.379 (5)
C12—C11	1.492 (5)	C5—H5A	0.9300
O4—C7	1.223 (4)	C9—C10^iv	1.371 (6)
C4—C6	1.365 (5)	C9—H9A	0.9300
C4—C5	1.376 (5)	C1—H1A	0.9300
O3—Zn1—O2^i	112.06 (12)	O2—C11—C12	118.6 (3)
O3—Zn1—O1	107.96 (12)	C9—C8—C10	118.0 (4)
O2^i—Zn1—O1	113.91 (11)	C9—C8—C7	120.4 (3)
O3—Zn1—N1	118.46 (12)	C10—C8—C7	121.3 (3)
O2^i—Zn1—N1	107.67 (11)	C4—C6—C5^iii	119.8 (3)
O1—Zn1—N1	95.96 (11)	C4—C6—H6A	120.1
C11—O1—Zn1	120.9 (2)	C5^iii—C6—H6A	120.1
C1—N1—C2	106.1 (3)	C9^iv—C10—C8	121.2 (4)
C1—N1—Zn1	126.1 (3)	C9^iv—C10—H10A	119.4
C2—N1—Zn1	127.7 (2)	C8—C10—H10A	119.4
C11—O2—Zn1^i	129.3 (2)	C12—C13—C14^ii	120.1 (3)
C1—N2—C3	107.2 (3)	C12—C13—H13A	119.9
C1—N2—C4	124.6 (3)	C14^ii—C13—H13A	119.9
C3—N2—C4	128.3 (3)	C3—C2—N1	109.3 (3)
C7—O3—Zn1	112.6 (3)	C3—C2—H2A	125.3
C13—C12—C14	119.6 (3)	N1—C2—H2A	125.3
C13—C12—C11	120.0 (3)	C2—C3—N2	106.4 (3)
C14—C12—C11	120.4 (3)	C2—C3—H3A	126.8
C6—C4—C5	121.0 (3)	N2—C3—H3A	126.8
C6—C4—N2	119.5 (3)	C4—C5—C6^iii	119.2 (4)
C5—C4—N2	119.4 (3)	C4—C5—H5A	120.4
C13^ii—C14—C12	120.3 (3)	C6^iii—C5—H5A	120.4
C13^ii—C14—H14A	119.9	C10^iv—C9—C8	120.7 (4)
C12—C14—H14A	119.9	C10^iv—C9—H9A	119.6
O4—C7—O3	124.8 (4)	C8—C9—H9A	119.6
O4—C7—C8	120.1 (4)	N1—C1—N2	111.0 (3)
O3—C7—C8	115.1 (3)	N1—C1—H1A	124.5
O1—C11—O2	124.1 (3)	N2—C1—H1A	124.5
O1—C11—C12	117.3 (3)
O3—Zn1—O1—C11	−60.1 (3)	C13—C12—C11—O2	6.3 (5)
O2^i—Zn1—O1—C11	65.0 (3)	C14—C12—C11—O2	−175.4 (3)
N1—Zn1—O1—C11	177.4 (3)	O4—C7—C8—C9	15.7 (5)
O3—Zn1—N1—C1	57.0 (4)	O3—C7—C8—C9	−161.7 (3)
O2^i—Zn1—N1—C1	−71.4 (3)	O4—C7—C8—C10	−169.4 (4)
O1—Zn1—N1—C1	171.2 (3)	O3—C7—C8—C10	13.1 (5)
O3—Zn1—N1—C2	−122.3 (3)	C5—C4—C6—C5^iii	0.0 (6)
O2^i—Zn1—N1—C2	109.4 (3)	N2—C4—C6—C5^iii	179.6 (3)
O1—Zn1—N1—C2	−8.1 (3)	C9—C8—C10—C9^iv	0.1 (6)
O2^i—Zn1—O3—C7	81.7 (3)	C7—C8—C10—C9^iv	−174.9 (3)
O1—Zn1—O3—C7	−152.1 (2)	C14—C12—C13—C14^ii	0.5 (6)
N1—Zn1—O3—C7	−44.6 (3)	C11—C12—C13—C14^ii	178.8 (3)
C1—N2—C4—C6	−50.9 (5)	C1—N1—C2—C3	0.0 (4)
C3—N2—C4—C6	128.5 (4)	Zn1—N1—C2—C3	179.4 (2)
C1—N2—C4—C5	128.8 (4)	N1—C2—C3—N2	−0.2 (4)
C3—N2—C4—C5	−51.8 (5)	C1—N2—C3—C2	0.3 (4)
C13—C12—C14—C13^ii	−0.5 (6)	C4—N2—C3—C2	−179.2 (3)
C11—C12—C14—C13^ii	−178.8 (3)	C6—C4—C5—C6^iii	0.0 (6)
Zn1—O3—C7—O4	−14.7 (5)	N2—C4—C5—C6^iii	−179.6 (3)
Zn1—O3—C7—C8	162.6 (2)	C10—C8—C9—C10^iv	−0.1 (6)
Zn1—O1—C11—O2	−10.0 (5)	C7—C8—C9—C10^iv	174.9 (3)
Zn1—O1—C11—C12	168.7 (2)	C2—N1—C1—N2	0.1 (4)
Zn1^i—O2—C11—O1	−68.7 (5)	Zn1—N1—C1—N2	−179.3 (2)
Zn1^i—O2—C11—C12	112.6 (3)	C3—N2—C1—N1	−0.3 (4)
C13—C12—C11—O1	−172.4 (3)	C4—N2—C1—N1	179.2 (3)
C14—C12—C11—O1	5.8 (5)

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