Bis{([mu]-acetato)[[mu]-bis(salicylidene)-1,3-propanediaminato]zinc(II)}zinc(II)

In the title linear trinuclear compound, [Zn{Zn(CH₃COO)(C₁₇H₁₆N₂O₂)}₂], the central Zn²⁺ ion, which is located on an inversion centre, has a distorted octahedral coordination involving four bridging O atoms from two N,N'-bis­(salicyl­idene)-1,3-propane­diaminate ligands in the equatorial plane and one O atom from each bridging acetate group in the axial positions. The coordination around the terminal Zn²⁺ ion is irregular square pyramidal, with two O and two N atoms of the ligand in the basal plane and one O atom from an acetate group in the apical position. The acetate bridges linking the central and terminal Zn²⁺ ions are mutually trans. The Zn...Zn distance is 3.0520 (8) Å. The relationship of this structure to that of [Zn{Cu(CH₃COO)(C₁₇H₁₆N₂O₂)}₂] is discussed.

S1. Comment

Structural studies and the magnetic properties of trinuclear complexes prepared with the deprotonated N,N'-bis(salicylidene)-1,3-propanediamine (SALPD^2-, C₁₇H₁₆N₂O₂) ligand have been the subject of considerable interest in our laboratory. In these complexes, acetate or nitrite anions constitute the µ-bridging between the three metal ions, which are also doubly oxygen bridged, so that the metal ions used in the synthesis (M is Zn²⁺, Ni²⁺, Cd²⁺, Cu²⁺ or Co²⁺) are all triply bridged (Ülkü et al., 1999; Atakol, Arici, Ercan & Ülkü, 1999; Atakol, Arici, Tahir et al., 1999; Atakol, Tatar et al., 1999; Tahir et al., 1998; Ülkü, Ercan et al., 1997; Ülkü, Tahir et al., 1997, and references therein). Since there are three metal ions in these linear complexes, various combinations of metallic ions are possible in the central and terminal locations, so that homonuclear as well as heteronuclear compounds can be synthesized. When the synthesis involves a paramagnetic ion, then the magnetic properties of the compound become interesting, due to the superexchange interaction between the diamagnetic ions of the bridges. The ligand stereochemistry around the metal ions and the structure of the O-atom bridges influence these magnetic exchange interactions, and therefore the structural parameters are important.

The synthesis of similar trinuclear complexes of the general formulae [MCu₂(SALPD)₂(CH₃COO)₂] (M is Mn²⁺, Co²⁺, Ni²⁺, Cu²⁺ or Zn²⁺) and [MNi₂(SALPD)₂(CH₃COO)₂] (M is Mg²⁺, Mn²⁺, Co²⁺ or Ni²⁺) were reported by Fukuhara et al. (1990). Only the structure of [ZnCu₂(SALPD)₂(CH₃COO)₂] in this group of compounds has been determined by X-ray diffraction to date (Fukuhara et al., 1990). Gerli et al. (1991) reported trinuclear structures formulated as [M₃{(SALPN)(CH₃COO)[(CH₃)₂NCHO]}₂] [M is Co²⁺ or Fe²⁺; SALPN is N,N'-bis(salicylidene)-2,2-dimethylpropylenediamine]. We report here a new member of the linear homometallic trinuclear compound family, the title compound, (I), in which the central as well as the terminal metal ion locations are occupied by zinc atoms. \sch

Among the trinuclear complexes cited above, this complex resembles the complex of [Zn{Cu(CH₃COO)(C₁₇H₁₆N₂O₂)}₂], (II) (Fukuhara et al., 1990), more than any other trinuclear complex, so that the two are almost identical molecules. In both molecules, the central Zn²⁺ ion, located on an inversion centre, has as its nearest neighbours four bridging O atoms from two SALPD^2- ligands (O1, O2, O1ⁱ and O2ⁱ) and two O atoms from two bridging acetate groups (O3 and O3ⁱ) [symmetry code: (i) -x, -y, -z]. This environment constitutes an irregular octahedral geometry around the Zn ion. The Zn—O bond lengths around the central Zn ion in both complexes have equal values within experimental error.

The coordination polyhedra around the inversion-related terminal ions, Zn in (I) and Cu in (II), are slightly distorted square-pyramids, whose basal plane is made up of the two bridging O atoms and two N atoms of the SALPD^2- ligand, while the apical positions are occupied by an O atom of the acetate group. The corresponding M—O and M—N distances within the coordination polyhedra around the terminal ions are different in these two complexes, so that the square pyramid around the Cu ion in (II) is slightly elongated when compared with the square pyramid around the Zn ion in (I).

These two almost identical molecules of (I) and (II) crystallize in the space groups P2₁/c and P2₁/a, respectively, and have almost the same unit-cell volume [1771.8 (4) and 1766.7 (9) ų, respectively]. However, the unit-cell parameters of the Cu—Zn—Cu trimer, (II) [a = 16.228 (5), b = 11.971 (2) and c = 9.239 (3) Å, and β = 100.15 (3)°], are considerably different from the corresponding values of the Zn—Zn—Zn trimer, (I), especially with respect to a and b. This results in different molecular packing, as can be seen in Fig. 2. For clarity reasons H atoms have been omitted and the least overlapping projections are shown in the drawing.

An intermolecular interaction analysis shows that in the Zn—Zn—Zn trimer there is one intermolecular hydrogen bond between atoms C11 and O4ⁱⁱ [symmetry code: (ii) x, -1/2 - y, z - 1/2], with a donor-acceptor distance of 3.475 (7) Å. Several weaker interactions with intermolecular distances of less than 3.5 Å are observed in both structures. In the Zn—Zn—Zn trimer four such interactions exist, between O3 and C16ⁱⁱ [3.238 (7) Å], and O3 and C2ⁱⁱ [3.251 (8) Å]. Two additional interactions are found between C3 and C15ⁱⁱⁱ [3.437 (9) Å; symmetry code: (iii) -x, -y, -1 - z] and between C7 and C7^iv [3.431 (8) Å; symmetry code: (iv) 1 - x, -y, -z].

In the Cu—Zn—Cu trimer, the number of intermolecular contacts of less than 3.5 Å is almost twice as many as the number of interactions observed in (I). They are as follows: O2···C2ⁱ [3.398 (18) Å], O3···C2ⁱ [2.83 (3) Å], C2···C17ⁱ [3.49 (2) Å], Cu···C4^v [3.287 (17) Å], N1···C4ⁱ [3.43 (2) Å], C1···C5^v [3.47 (2) Å] and C6···C6^v [3.39 (2) Å]. [Symmetry code: (v) -x, -y, 1 - z].

These two almost identical molecules of (I) and (II) crystallize so that they seem to be polymorphs.

NB Each symop definition must be used only once so as not to cause confusion. There were two different definitions of (i) in the original CIF and two of (ii). They have been renumbered, but please check them all carefully.

Related literature

For related literature, see: Atakol, Arici, Ercan & Ülkü (1999); Atakol, Arici, Tahir, Kurtaran & Ülkü (1999); Atakol, Tatar, Akay & Ülkü (1999); Fukuhara et al. (1990); Gerli et al. (1991); Tahir et al. (1998); Ülkü et al. (1999); Ülkü, Ercan, Atakol & Dinçer (1997); Ülkü, Tahir, Atakol & Nazir (1997).

S2. Experimental

N,N'-Bis(salicylidene)-1,3-propanediamine (0.564 g, 2 mmol) was dissolved in methanol (250 ml) by heating to boiling point. A solution of Zn(CH₃COO)₂·2H₂O (0.660 g, 3 mmol) in hot methanol (100 ml) was added to the solution. The resulting mixture was set aside for 1 d and the colourless prismatic crystals of (I) which formed were filtered off and dried in air.

S3. Refinement

The H atoms of C19 were taken from a difference map, while the other H atoms were placed geometrically 0.95 Å from their parent atoms. For all H atoms a riding model was used, with U_eq(H) = 1.3U_eq(C).

Computing details

Data collection: MolEN (Fair, 1990); cell refinement: MolEN; data reduction: MolEN; program(s) used to solve structure: MolEN; program(s) used to refine structure: MolEN; molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: MolEN and PLATON99 (Spek, 1990).

Figures

Fig. 1. The molecular structure (ORTEP-3 for Windows; Farrugia, 1997) of (I) with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as small circles of arbitrary radii [symmetry code: (i) -x, -y, -z]. Fig. 2. The molecular packing of the two trinuclear complexes, (a) (I) and (b) (II) (PLATON for Windows; Spek, 2000).

(I)

Crystal data

[Zn{Zn(CH3COO)(C17H16N2O2)}2]	F(000) = 896
Mr = 874.91	Dx = 1.640 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 10.4243 (14) Å	Cell parameters from 25 reflections
b = 20.3334 (18) Å	θ = 8.6–11.4°
c = 8.3832 (11) Å	µ = 2.07 mm^−1
β = 85.639 (13)°	T = 295 K
V = 1771.8 (4) Å^3	Prismatic, colourless
Z = 2	0.20 × 0.10 × 0.05 mm

Data collection

Enraf-Nonius CAD-4 diffractometer	Rint = 0.033
ω/2θ scans	θmax = 26.7°
Absorption correction: ψ-scan (MolEN; Fair, 1990)	h = 0→13
Tmin = 0.798, Tmax = 0.902	k = 0→25
4101 measured reflections	l = −10→10
3724 independent reflections	3 standard reflections every 120 min
2514 reflections with I > 2σ(I)	intensity decay: 0.036%

Refinement

Refinement on F	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.045	Weighting scheme based on measured s.u.'s w = 1/[σ^2(F) + (0.02F)^2 + 0.25]
wR(F^2) = 0.056	(Δ/σ)max < 0.001
S = 1.01	Δρmax = 0.84 e Å^−3
2514 reflections	Δρmin = −0.23 e Å^−3
241 parameters

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Zn1	0	0	0	0.0331 (3)
Zn2	0.20732 (6)	−0.10627 (3)	−0.01408 (8)	0.0318 (2)
O1	0.1971 (3)	−0.0079 (2)	−0.0694 (5)	0.0371 (12)
O2	0.0194 (3)	−0.1004 (2)	−0.0623 (5)	0.0375 (12)
O3	0.0485 (4)	−0.0264 (2)	0.2330 (5)	0.0414 (12)
O4	0.1920 (4)	−0.1076 (2)	0.2222 (5)	0.0403 (12)
N1	0.4031 (4)	−0.0999 (2)	−0.0678 (5)	0.0357 (14)
N2	0.2087 (4)	−0.2043 (2)	−0.0812 (6)	0.0344 (12)
C1	0.2764 (5)	0.0260 (3)	−0.1667 (6)	0.0337 (16)
C2	0.2396 (6)	0.0872 (3)	−0.2279 (7)	0.0417 (17)
C3	0.3210 (7)	0.1228 (3)	−0.3307 (8)	0.0488 (19)
C4	0.4429 (6)	0.1007 (3)	−0.3766 (8)	0.0529 (19)
C5	0.4846 (6)	0.0440 (3)	−0.3142 (8)	0.0487 (19)
C6	0.4047 (5)	0.0053 (3)	−0.2089 (7)	0.0368 (17)
C7	0.4598 (5)	−0.0535 (3)	−0.1464 (7)	0.0409 (18)
C8	0.4799 (5)	−0.1548 (3)	−0.0147 (8)	0.0453 (17)
C9	0.4490 (5)	−0.2178 (3)	−0.0981 (8)	0.0469 (19)
C10	0.3184 (6)	−0.2473 (3)	−0.0455 (8)	0.0459 (19)
C11	0.1204 (5)	−0.2324 (3)	−0.1555 (7)	0.0368 (17)
C12	0.0010 (5)	−0.2032 (3)	−0.2001 (6)	0.0335 (17)
C13	−0.0726 (6)	−0.2437 (3)	−0.2937 (7)	0.0431 (17)
C14	−0.1892 (6)	−0.2228 (3)	−0.3416 (7)	0.051 (2)
C15	−0.2337 (6)	−0.1621 (3)	−0.2938 (7)	0.0476 (19)
C16	−0.1652 (5)	−0.1210 (3)	−0.2007 (7)	0.0420 (17)
C17	−0.0447 (5)	−0.1405 (3)	−0.1523 (6)	0.0305 (12)
C18	0.1187 (6)	−0.0673 (3)	0.2970 (7)	0.0410 (17)
C19	0.1194 (9)	−0.0697 (5)	0.4764 (8)	0.088 (3)
H2	0.156	0.104	−0.197	0.0532
H3	0.292	0.163	−0.372	0.0646
H4	0.497	0.125	−0.451	0.0671
H5	0.570	0.029	−0.343	0.0633
H7	0.550	−0.058	−0.166	0.0519
H11	0.135	−0.277	−0.185	0.0494
H13	−0.041	−0.286	−0.324	0.0557
H14	−0.238	−0.250	−0.407	0.0659
H15	−0.315	−0.148	−0.326	0.0633
H16	−0.199	−0.079	−0.169	0.0545
H81	0.462	−0.160	0.097	0.0595
H82	0.569	−0.145	−0.037	0.0595
H91	0.513	−0.249	−0.078	0.0621
H92	0.451	−0.209	−0.210	0.0621
H101	0.310	−0.288	−0.099	0.0595
H102	0.315	−0.255	0.067	0.0595
H191	0.176	−0.104	0.505	0.1039
H192	0.146	−0.029	0.512	0.1039
H193	0.034	−0.079	0.522	0.1039

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Zn1	0.0265 (4)	0.0290 (4)	0.0434 (5)	0.0062 (4)	0.0009 (4)	−0.0026 (4)
Zn2	0.0265 (2)	0.0285 (3)	0.0399 (3)	0.0057 (3)	0.0002 (2)	−0.0019 (3)
O1	0.028 (2)	0.029 (2)	0.053 (2)	0.008 (2)	0.006 (2)	0.006 (2)
O2	0.030 (2)	0.032 (2)	0.051 (2)	0.006 (2)	−0.006 (2)	−0.013 (2)
O3	0.043 (2)	0.040 (2)	0.041 (2)	0.004 (2)	−0.001 (2)	0.001 (2)
O4	0.042 (2)	0.033 (2)	0.045 (2)	0.010 (2)	0.003 (2)	0.001 (2)
N1	0.030 (2)	0.032 (2)	0.044 (2)	0.003 (2)	−0.003 (2)	−0.003 (2)
N2	0.029 (2)	0.027 (2)	0.047 (2)	0.007 (2)	−0.001 (2)	−0.002 (2)
C1	0.031 (2)	0.035 (3)	0.035 (3)	−0.004 (2)	−0.002 (2)	−0.003 (2)
C2	0.040 (3)	0.037 (3)	0.048 (3)	0.003 (3)	−0.002 (3)	0.003 (3)
C3	0.058 (4)	0.039 (3)	0.050 (3)	−0.006 (3)	−0.008 (3)	0.005 (3)
C4	0.054 (3)	0.051 (4)	0.051 (3)	−0.013 (3)	0.013 (3)	0.003 (3)
C5	0.038 (3)	0.043 (3)	0.063 (4)	−0.006 (3)	0.009 (3)	−0.006 (3)
C6	0.034 (3)	0.035 (3)	0.041 (3)	−0.003 (2)	−0.001 (2)	−0.009 (2)
C7	0.021 (2)	0.047 (3)	0.054 (3)	−0.001 (2)	0.000 (2)	−0.012 (3)
C8	0.030 (3)	0.049 (3)	0.057 (3)	0.009 (3)	−0.010 (3)	−0.000 (3)
C9	0.033 (3)	0.040 (3)	0.068 (4)	0.014 (3)	−0.005 (3)	−0.005 (3)
C10	0.040 (3)	0.037 (3)	0.061 (4)	0.008 (3)	−0.006 (3)	0.002 (3)
C11	0.037 (3)	0.026 (3)	0.046 (3)	0.004 (2)	0.006 (2)	−0.003 (2)
C12	0.038 (3)	0.028 (3)	0.035 (3)	−0.003 (2)	0.000 (2)	0.001 (2)
C13	0.045 (3)	0.038 (3)	0.046 (3)	−0.005 (3)	−0.002 (3)	−0.005 (3)
C14	0.051 (3)	0.055 (4)	0.047 (3)	−0.004 (3)	−0.012 (3)	−0.012 (3)
C15	0.035 (3)	0.061 (4)	0.047 (3)	0.001 (3)	−0.011 (2)	−0.007 (3)
C16	0.032 (3)	0.042 (3)	0.050 (3)	0.005 (2)	−0.003 (2)	−0.006 (3)
C17	0.030 (2)	0.030 (2)	0.031 (2)	−0.005 (2)	−0.000 (2)	0.003 (2)
C18	0.041 (3)	0.042 (3)	0.039 (3)	0.004 (3)	0.003 (2)	0.001 (3)
C19	0.107 (6)	0.113 (6)	0.043 (4)	0.059 (5)	0.000 (4)	−0.002 (4)

Geometric parameters (Å, º)

Zn1—Zn2	3.0520 (8)	C6—C7	1.442 (8)
Zn1—O1	2.098 (3)	C7—H7	0.95
Zn1—O2	2.113 (4)	C8—C9	1.507 (9)
Zn1—O3	2.124 (4)	C8—H81	0.95
Zn2—O1	2.057 (4)	C8—H82	0.95
Zn2—O2	2.034 (4)	C9—C10	1.522 (8)
Zn2—O4	1.975 (4)	C9—H91	0.95
Zn2—N1	2.060 (4)	C9—H92	0.95
Zn2—N2	2.071 (4)	C10—H101	0.95
O1—C1	1.312 (6)	C10—H102	0.95
O2—C17	1.325 (6)	C11—C12	1.453 (8)
O3—C18	1.254 (7)	C11—H11	0.95
O4—C18	1.256 (7)	C12—C13	1.405 (8)
N1—C7	1.271 (7)	C12—C17	1.409 (7)
N1—C8	1.463 (7)	C13—C14	1.376 (9)
N2—C10	1.487 (7)	C13—H13	0.95
N2—C11	1.284 (7)	C14—C15	1.369 (9)
C1—C2	1.410 (8)	C14—H14	0.95
C1—C6	1.421 (7)	C15—C16	1.379 (9)
C2—C3	1.369 (9)	C15—H15	0.95
C2—H2	0.95	C16—C17	1.407 (8)
C3—C4	1.376 (9)	C16—H16	0.95
C3—H3	0.95	C18—C19	1.505 (9)
C4—C5	1.351 (9)	C19—H191	0.947
C4—H4	0.95	C19—H192	0.934
C5—C6	1.407 (8)	C19—H193	0.959
C5—H5	0.95
O1—Zn1—O2	77.5 (1)	C1—C6—C5	119.5 (5)
O1—Zn1—O3	86.5 (1)	C1—C6—C7	123.2 (5)
O2—Zn1—O3	87.6 (2)	C5—C6—C7	117.2 (5)
O1—Zn1—O1^i	180.0	N1—C7—C6	128.4 (5)
O1—Zn1—O2^i	102.5 (1)	N1—C7—H7	115.8
O1—Zn1—O3^i	93.5 (2)	C6—C7—H7	115.8
O2—Zn1—O2^i	180.0	N1—C8—C9	111.5 (5)
O2—Zn1—O3^i	92.4 (2)	N1—C8—H81	108.9
O3—Zn1—O3^i	180.0	N1—C8—H82	109.0
O1—Zn2—O2	80.3 (1)	C9—C8—H81	108.9
O1—Zn2—O4	103.7 (2)	C9—C8—H82	109.0
O1—Zn2—N1	87.5 (2)	H81—C8—H82	109.5
O1—Zn2—N2	150.9 (2)	C8—C9—C10	114.8 (5)
O2—Zn2—O4	101.2 (2)	C8—C9—H91	108.1
O2—Zn2—N1	155.0 (2)	C8—C9—H92	108.1
O2—Zn2—N2	89.4 (2)	C10—C9—H91	108.2
O4—Zn2—N1	102.9 (2)	C10—C9—H92	108.2
O4—Zn2—N2	104.9 (2)	H91—C9—H92	109.5
N1—Zn2—N2	90.9 (2)	N2—C10—C9	113.3 (5)
Zn1—O1—Zn2	94.5 (1)	N2—C10—H101	108.5
Zn1—O1—C1	133.6 (3)	N2—C10—H102	108.6
Zn2—O1—C1	127.6 (3)	C9—C10—H101	108.4
Zn1—O2—Zn2	94.8 (2)	C9—C10—H102	108.5
Zn1—O2—C17	133.8 (3)	H101—C10—H102	109.5
Zn2—O2—C17	127.7 (3)	N2—C11—C12	127.1 (5)
Zn1—O3—C18	138.4 (4)	N2—C11—H11	116.5
Zn2—O4—C18	119.5 (4)	C12—C11—H11	116.4
O3—C18—O4	124.9 (5)	C11—C12—C13	114.7 (5)
O3—C18—C19	119.7 (6)	C11—C12—C17	125.1 (5)
O4—C18—C19	115.4 (6)	C13—C12—C17	120.2 (5)
Zn2—N1—C7	125.0 (4)	C12—C13—C14	120.9 (6)
Zn2—N1—C8	116.2 (3)	C12—C13—H13	119.4
C7—N1—C8	118.7 (4)	C14—C13—H13	119.7
Zn2—N2—C10	120.0 (4)	C13—C14—C15	118.7 (6)
Zn2—N2—C11	124.7 (4)	C13—C14—H14	120.7
C10—N2—C11	115.3 (5)	C15—C14—H14	120.6
O1—C1—C2	121.0 (5)	C14—C15—C16	122.3 (6)
O1—C1—C6	122.4 (5)	C14—C15—H15	118.8
C2—C1—C6	116.5 (5)	C16—C15—H15	119.0
C1—C2—C3	121.6 (5)	C15—C16—C17	120.3 (5)
C1—C2—H2	118.8	C15—C16—H16	120.1
C3—C2—H2	119.6	C17—C16—H16	119.6
C2—C3—C4	121.2 (6)	O2—C17—C12	123.0 (5)
C2—C3—H3	119.3	O2—C17—C16	119.4 (5)
C4—C3—H3	119.5	C12—C17—C16	117.6 (5)
C3—C4—C5	119.3 (6)	C18—C19—H191	108.9
C3—C4—H4	120.3	C18—C19—H192	108.5
C5—C4—H4	120.4	C18—C19—H193	109.3
C4—C5—C6	121.8 (6)	H191—C19—H192	111.1
C4—C5—H5	119.4	H191—C19—H193	109.0
C6—C5—H5	118.9	H192—C19—H193	110.1
O2—Zn1—O1—Zn2	−26.4 (1)	O1—Zn2—N2—C10	123.6 (4)
O2—Zn1—O1—C1	130.5 (5)	O1—Zn2—N2—C11	−55.6 (6)
O3—Zn1—O1—Zn2	61.9 (2)	O2—Zn2—N2—C10	−167.9 (4)
O3—Zn1—O1—C1	−141.2 (5)	O2—Zn2—N2—C11	12.9 (5)
O1—Zn1—O2—Zn2	26.7 (2)	O4—Zn2—N2—C10	−66.5 (4)
O1—Zn1—O2—C17	−131.8 (5)	O4—Zn2—N2—C11	114.4 (5)
O3—Zn1—O2—Zn2	−60.2 (2)	N1—Zn2—N2—C10	37.1 (4)
O3—Zn1—O2—C17	141.3 (5)	N1—Zn2—N2—C11	−142.1 (5)
O1—Zn1—O3—C18	−43.8 (6)	Zn1—O1—C1—C2	11.6 (8)
O2—Zn1—O3—C18	33.8 (6)	Zn1—O1—C1—C6	−171.9 (4)
O2—Zn2—O1—Zn1	27.2 (2)	Zn2—O1—C1—C2	161.9 (4)
O2—Zn2—O1—C1	−131.7 (4)	Zn2—O1—C1—C6	−21.5 (7)
O4—Zn2—O1—Zn1	−72.1 (2)	Zn1—O2—C17—C12	167.9 (4)
O4—Zn2—O1—C1	129.0 (4)	Zn1—O2—C17—C16	−13.5 (7)
N1—Zn2—O1—Zn1	−174.7 (2)	Zn2—O2—C17—C12	15.3 (7)
N1—Zn2—O1—C1	26.3 (4)	Zn2—O2—C17—C16	−166.0 (4)
N2—Zn2—O1—Zn1	97.9 (3)	Zn1—O3—C18—C19	−177.8 (5)
N2—Zn2—O1—C1	−61.0 (6)	Zn2—O4—C18—C19	−176.7 (5)
O1—Zn2—O2—Zn1	−27.0 (2)	C8—N1—C7—C6	−179.3 (6)
O1—Zn2—O2—C17	133.4 (4)	Zn2—N1—C8—C9	64.7 (6)
O4—Zn2—O2—Zn1	75.2 (2)	C7—N1—C8—C9	−113.3 (6)
O4—Zn2—O2—C17	−124.3 (4)	Zn2—N2—C10—C9	−50.1 (6)
N1—Zn2—O2—Zn1	−89.0 (4)	C11—N2—C10—C9	129.2 (6)
N1—Zn2—O2—C17	71.5 (6)	C10—N2—C11—C12	177.6 (5)
N2—Zn2—O2—Zn1	−179.7 (2)	O1—C1—C2—C3	−179.4 (5)
N2—Zn2—O2—C17	−19.2 (4)	O1—C1—C6—C5	179.9 (5)
O1—Zn2—O4—C18	36.6 (4)	C2—C1—C6—C7	175.2 (5)
O2—Zn2—O4—C18	−46.0 (4)	C4—C5—C6—C7	−178.6 (6)
N1—Zn2—O4—C18	127.2 (4)	C1—C6—C7—N1	11.4 (9)
N2—Zn2—O4—C18	−138.4 (4)	C5—C6—C7—N1	−169.9 (6)
O1—Zn2—N1—C7	−16.6 (5)	N1—C8—C9—C10	−71.8 (7)
O1—Zn2—N1—C8	165.6 (4)	C8—C9—C10—N2	63.1 (7)
O2—Zn2—N1—C7	43.9 (7)	N2—C11—C12—C13	174.5 (6)
O2—Zn2—N1—C8	−133.9 (4)	N2—C11—C12—C17	−7.7 (9)
O4—Zn2—N1—C7	−120.2 (5)	C11—C12—C13—C14	178.6 (6)
O4—Zn2—N1—C8	62.1 (4)	C11—C12—C17—C16	−177.3 (5)
N2—Zn2—N1—C7	134.3 (5)	C13—C12—C17—O2	179.1 (5)
N2—Zn2—N1—C8	−43.5 (4)	C15—C16—C17—O2	−179.7 (5)

Symmetry code: (i) −x, −y, −z.