Four rare structurally characterized hetero-pentanuclear [Zn4Ln] bis(salamo)-type complexes: syntheses, crystal structures and spectroscopic properties.

Four new hetero-pentanuclear 3d-4f complexes [Zn4(L)2La(NO3)2(OEt)(H2O)] (1), [Zn4(L)2Ce(NO3)2(OMe)(MeOH)] (2), [Zn4(L)2Pr(NO3)2(OEt)(EtOH)] (3) and [Zn4(L)2Nd(NO3)2(OMe)(MeOH)] (4) were synthesized by the reactions of a newly synthesized octadentate bis(salamo)-based tetraoxime ligand (H4L) with Zn(OAc)2·2H2O and Ln(NO3)3·6H2O (Ln = La, Ce, Pr and Nd), respectively, and characterized via elemental analyses, FT-IR, UV-Vis spectroscopy and single crystal X-ray crystallography. The X-ray crystallographic investigation revealed that all ZnII ions were located in N2O3 coordination spheres, and possessed a trigonal bipyramid coordination environment. The LnIII ion lay in an O8 coordination sphere, and adopted a distorted square antiprismatic coordination environment. Furthermore, supramolecular interactions and fluorescence properties were investigated. This journal is © The Royal Society of Chemistry.

Introduction

Salen-type ligands and their analogues are very versatile chelating ligands in inorganic and organometallic chemistry.[1] Their complexes have considerable intrinsic value due to their wide applications in electrochemistry,[2] building supramolecular structures,[3] catalysis fields,[4] magnetism,[5] biological fields[6] and so forth.

In recent years, a preferable class of salen-type compounds (salamo: (R–CHN–O–(CH2)–O–NCH–R)) has been reported,[7] and the large electronegativity of O atoms is expected to lead to different and novel structures and properties of the resulting complexes. The 3d–4f complexes have attracted much attention due to the visible and near-infrared luminescence produced by lanthanide f–f transitions.[8] Luminescence applications of lanthanides are a consequence of their narrow emission bands, large Stokes shifts, negligible environmental influences and relatively long luminescence lifetimes. However, 3d–4f complexes with salamo-like ligands have been rarely reported.[9]

Herein, a series of rare heteropentanuclear [Zn4Ln] (Ln = La, Ce, Pr and Nd) complexes containing octadentate bis(salamo)-based tetraoxime ligand H4L were synthesized and structurally characterized. Meanwhile, the luminescence properties of complexes 1–4 were studied.

Experimental

Materials and methods

1,2-Dimethoxybenzene, 1,2-dibromoethane, TMEDA, n-butyllithium, boron tribromide and 2-hydroxy-1-naphthaldehyde (99%) were purchased from Alfa Aesar and used without further purification. Other reagents and solvents were analytical grade reagents from Tianjin Chemical Reagent Factory.

Elemental analyses for carbon, hydrogen and nitrogen were obtained using a GmbH VariuoEL V3.00 automatic elemental analysis instrument (Berlin, Germany). LaIII, CeIII, PrIII and NdIII were gained using an IRIS ER/S-WP-1 ICP atomic emission spectrometer (Berlin, Germany). Melting points were obtained via a microscopic melting point apparatus made by Beijing Taike Instrument Company Limited. IR spectra (4000–400 cm−1) were determined via a Vertex 70 FT-IR spectrophotometer (Bruker, Billerica, MA, USA), with samples prepared as KBr pellets. UV-Vis absorption spectra were determined using a Shimadzu UV-3900 spectrometer (Shimadzu, Japan). 1H NMR spectra were determined via German Bruker AVANCE DRX-400/600 spectroscopy. X-ray single crystal structure determinations for complexes 1, 2, 3 and 4 were carried out on a Bruker APEX-II CCD diffractometer. Fluorescence spectra were recorded on an F-7000 FL spectrophotometer. Near infrared (NIR) spectra were determined through PTI QM4 spectrofluorometer with a PTI QM4 Near infrared InGaAs detector.

Synthesis of the H4L

The reaction steps of the ligand (H4L) can be seen from Scheme 1. 1,2-Bis(aminooxy)ethane, 2,3-dihydroxybenzene-1,4-dicarbaldehyde and 2-[O-(1-ethyloxyamide)]oxime-2-naphthol were prepared according to analogous methods reported earlier.[10]

Scheme 1

Synthetic route to H4L.

An ethanol solution (10 mL) of 2,3-dihydroxybenzene-1,4-dicarbaldehyde (166.2 mg, 1.0 mmol) was added to an ethanol solution (20 mL) of 2-[O-(1-ethyloxyamide)]oxime-2-naphthol (492.6 mg, 2 mmol). The mixed solution was stirred at 55 °C for 8 h, cooling to room temperature, the precipitate was filtered and washed with n-hexane to obtain a yellow powder. Yield: 87%. mp.: 198–200 °C. Anal. calc. for C34H30N4O8: C, 65.59; H, 4.86; N, 9.00%. Found: C, 65.65; H, 4.94; N, 8.92%. 1H NMR (400 MHz, CDCl3) δ 10.82 (s, 2H), 9.70 (s, 2H), 9.17 (s, 2H), 8.25 (d, J = 2.5 Hz, 2H), 7.96 (d, J = 8.7 Hz, 2H), 7.80–7.72 (m, 4H), 7.50 (t, J = 7.7 Hz, 2H), 7.35 (t, J = 7.5 Hz, 2H), 7.20 (d, J = 9.0 Hz, 2H), 6.75 (s, 2H), 4.56 (s, 8H).

General procedure for the preparation of complexes 1–4

The synthesis methods of complexes 2–4 are similar to that of complex 1 (Scheme 2). An ethanol solution (3 mL) of Zn(OAc)2·2H2O (13.155 mg, 0.065 mmol) was added to a chloroform solution (5 mL) of H4L (18.675 mg, 0.03 mmol) under constant magnetic stirring, and an ethanol solution (3 mL) of La(NO3)3·6H2O (4.33 mg, 0.015 mmol) was then added. The mixed solution was stirred for 15 minutes at room temperature and then filtered off, and the filtrate was transferred to a cillin bottle. Sealed the opening of the bottle with tinfoil and let it stand for two weeks, some block-like crystals suitable for X-ray diffraction were formed.

Scheme 2

Synthetic routes to H4L and its complexes 1–4.

Complex 1, yellow block-like crystals. Yield: 52%. Elemental analysis: anal. calc. for [Zn4(L)2La(NO3)2(OEt)(H2O)] (C70H59LaZn4N10O24) (%): C, 46.08; H, 3.26; N, 7.68; Zn, 14.33; La, 7.61. Found (%): C, 46.19; H, 3.38; N, 7.53; Zn, 14.41; La, 7.48.

Complex 2, yellow block-like crystals. Yield: 62%. Elemental analysis: anal. calc. for [Zn4(L)2Ce(NO3)2(OMe)(MeOH)] (C70H59CeZn4N10O24) (%): C, 46.05; H, 3.26; N, 7.67; Zn, 14.32; Ce, 7.67. Found (%): C, 46.12; H, 3.37; N, 7.56; Zn, 14.39; Ce, 7.81.

Complex 3, yellow block-like crystals. Yield: 69%. Elemental analysis: anal. calc. for [Zn4(L)2Pr(NO3)2(OEt)(EtOH)] (C72H63PrZn4N10O24) (%): C, 46.62; H, 3.42; N, 7.55; Zn, 14.10; Pr, 7.60. Found (%): C, 46.79; H, 3.48; N, 7.50; Zn, 14.15; Pr, 7.68.

Complex 4, yellow block-like crystals. Yield: 64%. Elemental analysis: anal. calc. for [Zn4(L)2Nd(NO3)2(OMe)(MeOH)] (C70H59NdZn4N10O24) (%): C, 45.94; H, 3.25; N, 7.65; Zn, 14.29; Nd, 7.88. Found (%): C, 46.09; H, 3.38; N, 7.53; Zn, 14.38; Nd, 7.96.

X-ray crystallographic analysis

Crystal data for complexes 1–4 were collected on a Bruker APEX-II CCD area detector with Mo Kα radiation (λ = 0.71073 Å) at 296(2), 173(2), 173(2) and 173(2) K. respectively. Reflection data were corrected for LP factors semi-empirical absorption were using SADABS. The single crystal structures were solved by the direct methods (SHELXS-2016).[11] All hydrogen atoms were included at the calculated positions, and their positions were refined by a riding model. All non-hydrogen atoms were refined anisotropically using a full-matrix least-squares procedure on F2 with SHELXL-2016.[11] Crystallographic data and the structure refinements for complexes 1–4 are presented in Table 3.

Hydrogen bonding distances (Å) and bond angles (o) for complexes 1–4

D–H⋯A	d(D–H)	d(H–A)	d(D–A)	∠D–X–A	Sum
Complex 1
C7–H7A⋯O14	0.93	2.55	3.436(5)	159
C47–H47B⋯O21	0.97	1.89	2.653(12)	134
C56–H56A⋯O15	0.97	2.54	3.507(8)	174
C12–H12A⋯O3	0.97	2.44	3.214(5)	137	1 − x, 1 − y, 1 − z
C47–H47A⋯O15	0.97	2.56	3.244(8)	128	−1/2 + x, 1/2 + y, z
Complex 2
C2–H2⋯O9	0.95	2.51	3.451(5)	173	1 − x, y, 1/2 − z
C22–H22A⋯O7	0.99	2.51	3.490(6)	172
Complex 3
C13–H13B⋯O10	0.99	2.53	3.516(4)	173
C23–H23B⋯O10	0.99	2.54	3.148(4)	120	1/2 + x, 1/2 + y, z
C27–H27⋯O9	0.95	2.50	3.448(4)	175	−x, y, 1/2 − z
C35–H35B⋯O11	0.98	2.58	3.438(8)	146	−x, y, 1/2 − z
Complex 4
C2–H2A⋯O9	0.95	2.51	3.456(6)	172	1 − x, y, 1/2 − z
C6–H6⋯O8	0.95	2.56	3.361(11)	142	−1/2 + x, 1/2 − y, −1/2 + z
C22–H22A⋯O7	0.99	2.52	3.499(6)	172

Results and discussion

IR spectra

IR spectra of H4L and its corresponding complexes 1–4 displayed various bands in the 4000–400 cm−1 region (Fig. 1).

Fig. 1

IR spectra of H4L and its corresponding complexes 1–4.

In the infrared spectrum of H4L, a typical CN stretching band appeared at ca. 1603 cm−1, and CN stretching bands of complexes 1–4 were observed at 1609–1614 cm−1, indicating that H4L has coordinated with ZnII ions.[12] In addition, the free ligand H4L exhibited a typical Ar–O stretching frequency at ca. 1239 cm−1, while the Ar–O stretching frequencies in complexes 1–4 were observed at ca. 1232, 1235, 1231 and 1232 cm−1, which are shifted to lower frequencies, indicating that the Zn–O or Ln–O bond is formed between the oxygen atoms of phenolic group and the metal ions.[13] Meanwhile, the hydroxyl stretching band of H4L was observed at ca. 3435 cm−1 that belongs to the phenolic O–H groups. These absorption bands in complexes 1–4 were observed at ca. 3441–3443 cm−1, indicating the existence of coordinated water, methanol or ethanol molecules.[14]

UV-Vis spectra

The UV-Vis absorption spectra of H4L and its complexes 1–4 in CHCl3/CH3CH2OH solution (v/v = 1 : 1) are shown in Fig. 2. The absorption spectrum of H4L (1.0 × 10−5 M) showed four relatively strong absorption peaks at ca. 302, 313, 341 and 355 nm, the former two peaks can be assigned to the π–π* transitions of the naphthalene rings. The later two absorption peaks can be assigned to the intra-ligand π–π* transition of the oxime group.[15] Compared with the absorption peaks of the free ligand H4L, the first absorption peaks were observed at 326, 325, 321 and 325 nm in complexes 1–4, respectively. These peaks are bathochromically shifted, indicating coordination of the (L)4− moieties with metal(ii/iii) ions. Meanwhile, the new peaks emerged at ca. 382 nm in complexes 1–4, respectively, which belong to the n–π* charge transfer transitions from the lone-pair electrons of the N atoms of CN groups to benzene rings.[16]

Fig. 2

UV-Vis spectra of the free ligand H4L and its complexes 1–4.

Crystal structure descriptions

X-ray crystallographic analysis revealed the crystal structures of complexes 1–4. Selected bond lengths and angles are given in Table 1

Crystal data and the structure refinements for complexes 1–4

Complex	1	2	3	4
Empirical formula	C70H59LaZn4N10O24	C70H59CeZn4N10O24	C72H63PrZn4N10O24	C70H59NdZn4N10O24
Formula weight	1824.66	1824.86	1854.71	1829.99
T (K)	296(2)	173(2)	173(2)	173(2)
Wavelength (Å)	0.71073	0.71073	0.71073	0.71073
Crystal system	Monoclinic	Monoclinic	Monoclinic	Monoclinic
Space group	C2/c	C2/c	C2/c	C2/c
a (Å)	23.8927(11)	16.9226(7)	16.7809(7)	16.9226(7)
b (Å)	15.5212(7)	23.3361(10)	23.4499(7)	23.3361(10)
c (Å)	45.813(2)	24.4208(13)	24.1484(11)	24.4208(13)
α (°)	90	90	90	90
β (°)	97.7300(10)	109.4290(10)	108.736(5)	109.4290(10)
γ (°)	90	90	90	90
V (Å3)	16 835.2(13)	9094.8(7)	8999.1(7)	9094.8(7)
Z	8	4	4	4
D calc. (g cm−3)	1.440	1.333	1.369	1.336
Absorption coefficient (mm−1)	1.694	1.599	1.653	1.669
F (000)	7344	3672	3744	3684
Crystal size (mm)	0.270 × 0.250 × 0.220	0.220 × 0.190 × 0.160	0.220 × 0.200 × 0.180	0.220 × 0.190 × 0.160
θ Range (°)	2.044–25.010	2.485–25.008	1.548–26.000	2.485–25.008
Index ranges	−25 ≤ h ≤ 28	−20 ≤ h ≤ 20	−20 ≤ h ≤ 20	−20 ≤ h ≤ 17
	−18 ≤ k ≤ 18	−22 ≤ k ≤ 27	−27 ≤ k ≤ 28	−27 ≤ k ≤ 27
	−51 ≤ l ≤ 54	−29 ≤ l ≤ 29	−29 ≤ l ≤ 29	−29 ≤ l ≤ 28
Reflections collected/unique	59 539/14 818 [Rint = 0.0347]	32 276/7999 [Rint = 0.0371]	19 902/8832 [Rint = 0.0179]	32 970/8002 [Rint = 0.0391]
Completeness to θ	99.8% (θ = 25.010)	99.8% (θ = 25.008)	99.7% (θ = 25.242)	99.8% (θ = 25.008)
Data/restraints/parameters	14 818/0/1009	7999/0/493	8832/5/496	8002/6/487
GOF	0.963	1.049	1.043	1.030
Final R1, wR2 indices	0.0399, 0.1006	0.0363, 0.1003	0.0315, 0.0971	0.0377, 0.0974
R 1, wR2 indices (all data)	0.0454, 0.1044	0.0448, 0.1059	0.0412, 0.1007	0.0465, 0.1020
Largest diff. peak and hole (e Å−3)	1.492 and −1.009	1.563 and −0.981	1.048 and −0.805	1.814 and −0.783

Crystal structure of complex 1

The crystallographic data revealed that complex 1 ([Zn4(L)2La(NO3)2(OEt)(H2O)]) was a hetero-pentanuclear complex, crystallizes in the monoclinic system, space group C2/c, and consists of four ZnII ions, one LaIII ion, two (L)4− units, one coordinated ethoxy group, one coordinated water molecule and two nitrate groups (Fig. 3). N2O2 sites of the salamo moieties were occupied by four ZnII ions (Zn1, Zn2, Zn3 and Zn4), the ZnII ions were located in N2O3 coordination spheres, and assumed trigonal bipyramid coordination environment (τ1 = 0.68, τ2 = 0.71, τ3 = 0.69 and τ4 = 0.64).[17] Meanwhile, the eight phenoxo donors (O1, O4, O5, O7, O12, O13, O19 and O20) from two completely deprotonated (L)4− units as a central O8 site coordinated to LaIII ion, the LaIII ion lay in an O8 coordination sphere, and adopted a distorted square antiprismatic coordination environment. Finally, complex 1 formed a rare heteropentanuclear 3d–4f complex.[18] The distances of Zn⋯La1, Zn–N, Zn–O and La1–O bonds are in the ranges of 3.6130(5)–3.6513(5), 2.011(3)–2.149(3), 1.957(2)–2.085(3) and 2.491(2)–2.537(3) Å, respectively.

Fig. 3

(a) Molecule structure of complex 1 ([Zn4(L)2La(NO3)2(OEt)(H2O)]) (hydrogen atoms and solvent molecules are omitted for clarity). (b) Coordination polyhedrons for ZnII and LaIII ions of complex 1.

The intramolecular and intermolecular hydrogen bonds for complex 3 are presented in Table 2. Each molecule formed five intramolecular hydrogen bonds (C23–H23A⋯O12 and C8–H8A⋯O10) as shown in Fig. 4.[19] Meanwhile, a self-assembled infinite 2D supramolecular structure was formed by C12–H12A⋯O3 and C47–H47A⋯O15 hydrogen bond interactions[20] (Fig. 4).

Fig. 4

(a) View of the intramolecular hydrogen bonding interactions of complex 1. (b) View of an infinite 2D supramolecular structure of complex 1.

Crystal structure of complex 2

The crystallographic data revealed that complex 2 ([Zn4(L)2Ce(NO3)2(OMe)(MeOH)]) crystallizes in the monoclinic system, space group C2/c. Unlike complex 1, it consists of four ZnII ions, one CeIII ion, two ligand (L)4− units, one coordinated methoxo group, one coordinated methanol molecule and two monodentate nitrate groups (Fig. 5).

Fig. 5

(a) Molecule structure of complex 2 ([Zn4(L)2Ce(NO3)2(OMe)(MeOH)]) (hydrogen atoms and solvent molecules are omitted for clarity). (b) Coordination polyhedrons for ZnII and CeIII ions of complex 2.

Zn1 and Zn2 ions were located in penta-coordinated spheres and adopted trigonal bipyramid coordination environments (τ1 = 0.704 and τ2 = 0.67).[17] The coordination number of CeIII ion is 8, consisting of eight phenolic oxygen atoms from two full deprotonated (L)4− units and adopted a distorted square antiprismatic coordination environment (Fig. 5).[18]

In the crystal structure of complex 2, there were many intramolecular hydrogen bonds (C2–H2⋯O9, C11–H11⋯O1 and C22–H22A⋯O7).[19] As shown in Fig. 6. Moreover, the 2D supramolecular structure was formed by C12–H12A⋯O7 hydrogen bonding interactions in complex 2 (ref. 21) (Fig. 6).

Fig. 6

(a) View of the intramolecular hydrogen bonding interactions of complex 2. (b) View of an infinite 2D supramolecular structure of complex 2.

Crystal structure of complex 3

Complex 3 ([Zn4(L)2Pr(NO3)2(OEt)(EtOH)]) crystallizes in the monoclinic crystal system, space group C2/c. X-ray crystallography clearly showed the formation of complex 3. Different from complexes 1 and 2, it consists of four ZnII ions, one PrIII ion, two ligand (L)4− units, one coordinated ethoxy group, one coordinated ethanol molecule and two monodentate nitrate groups (Fig. S2†).

The ZnII ions also were located in the N2O2 sites, and four ZnII ions are also penta-coordinated. The ZnII ions (Zn1 and Zn2) adopted trigonal bipyramid coordination environment (τ1 = 0.67 and τ2 = 0.72).[17] The PrIII ion was also located in the O8 site that consists of eight phenoxo oxygen atoms, forming a distorted square antiprismatic coordination environment.[18]

The main interactions in complex 3 are listed in Table 3, four pairs of intramolecular hydrogen bonds (C13–H13B⋯O10, C24–H24⋯O7, C27–H27⋯O9 and C35–H35B⋯O11) were formed.[19] Besides, The O10 atom of nitrate group as acceptor formed a hydrogen bond with the donor (C23H23B–) in complex 3, which adopted a 2D supramolecular structure[22] (Fig. S3†).

Crystal structure of complex 4

As shown in Fig. S4,† X-ray crystallographic analysis of complex 4 ([Zn4(L)2Nd(NO3)2(OMe)(MeOH)]) revealed that crystallizes in the monoclinic system, space group C2/c. Similar to the structure of complex 2, it consists of four ZnII ions, one NdIII ion, two ligand (L)4− units, one coordinated methoxo group, one coordinated methanol molecule and two monodentate nitrate groups.

All ZnII ions lay in N2O3 coordination spheres. The Zn1 and Zn2 (Zn1#4 and Zn2#4) ions were all made of the N2O2 cavities and one coordinated nitrate group, which assumed trigonal bipyramid coordination environments (τ1 = 0.69 and τ2 = 0.66).[17] The NdIII ion exhibited an O8 coordination sphere, which is made of eight phenoxo donors (O3, O4, O10, O11, O3#4, O4#4, O10#4 and O11#4) from two completely deprotonated (L)4− units, while the central NdIII ion is octa-coordinated with a distorted square antiprismatic coordination environment.[18]

In complex 4, three pairs of significant intramolecular hydrogen bonds (C2–H2A⋯O9, C11–H11⋯O1 and C22–H22A⋯O7) were formed[19] (Fig. S5(a)†). Meanwhile, complex 4 molecules formed a 2D supramolecular structure by intermolecular hydrogen bonds (C6–H6⋯O8 and C12–H12A⋯O7)[23] (Fig. S5(b)†).

Spectroscopic properties

The free ligand H4L and its corresponding complexes 1–4 were excited at 385 nm (λex) respectively (Fig. 7). The emission spectrum of H4L exhibited a broad emission band, and the emission maximum at 454 nm, which can be assigned to the π–π* electronic transitions in the ligand.[24] Compared to H4L, the absorption peaks of complexes 1–3 are bathochromically-shifted, which is may originated from the LMCT emission.

Fig. 7

(a) Visible luminescence spectra of complexes 1–3. (b) NIR luminescence spectrum of complex 4.

Due to energy mismatch, complexes 1–3 have no NIR luminescence. The NIR luminescence spectrum of complex 4 excited at 385 nm showed the characteristic emitting peaks at ca. 871, 917, 1055 and 1324 nm (Fig. 7(b)). These emission peaks are typical peaks of NdIII ions, and correspond to 4F3/2 → 4I9/2, 4F3/2 → 4I11/2 and 4F3/2 → 4I13/2 transitions.[25] The ligand (L)4− units could serve as sensitizing agent for NdIII luminescence in the NIR region.

Conclusions

In this work, four rare hetero-pentanuclear 3d–4f complexes of a bis(salamo)-type ligand (H4L) have been synthesized and structurally characterized. In complexes 1–4, all four ZnII ions presented N2O3 coordination spheres. The LnIII ion exhibited an O8 coordination sphere, and assumed a distorted square antiprismatic coordination environment. In a conclusion, the studies demonstrated that incorporation of salamo-like ligand was an optimistic approach to build ZnII–LnIII complexes which can display excellent spectroscopic resting with the lanthanide ions used.

Conflicts of interest

There are no conflicts to declare.

Complex 1
Bond	Lengths	Bond	Lengths	Bond	Lengths
Zn1–O19	2.001(3)	Zn1–O20	2.085(3)	Zn1–O22	2.054(6)
Zn2–O1	2.051(2)	Zn2–O4	1.957(2)	Zn1–O22#1	2.019(14)
Zn2–O24	2.014(3)	Zn3–O5	1.975(2)	Zn3–O6	1.983(3)
Zn3–O7	2.081(2)	Zn4–O12	1.999(3)	Zn4–O13	2.057(3)
Zn4–O14	2.059(3)	Zn1–N3	2.149(3)	Zn1–N4	2.048(3)
Zn2–N2	2.011(3)	Zn2–N6	2.108(3)	Zn3–N1	2.127(3)
Zn3–N5	2.019(3)	Zn4–N7	2.038(4)	Zn4–N8	2.120(3)
La1–O5	2.491(2)	La1–O12	2.497(2)	La1–O19	2.500(2)
La1–O20	2.496(3)	La1–O4	2.505(2)	La1–O7	2.514(2)
La1–O1	2.534(3)	La1–O13	2.537(3)

Symmetry transformations used to generate equivalent atoms: #13/2 − x, −1/2 + y, 3/2 − z;#2−x + 1, y, −z + 1/2; #3−x, y, −z + 1/2; #4−x + 1, y, −z + 1/2.

Complex 1
Bond	Angles	Bond	Angles	Bond	Angles
O19–Zn1–O22	109.0(2)	N4–Zn1–O22	123.2(2)	O19–Zn1–O20	81.62(10)
O19–Zn1–O22#1	134.0(5)	O19–Zn1–N4	124.08(12)	O22#1–Zn1–N4	101.9(4)
O22#1–Zn1–O20	105.3(4)	N4–Zn1–O20	83.62(11)	O22–Zn1–O20	85.79(17)
O19–Zn1–N3	86.56(12)	O22#1–Zn1–N3	89.3(4)	N4–Zn1–N3	95.80(14)
O22–Zn1–N3	106.58(18)	O20–Zn1–N3	165.20(13)	O4–Zn2–N2	129.50(12)
O4–Zn2–O24	109.62(13)	N2–Zn2–O24	120.27(14)	O4–Zn2–O1	83.74(10)
N2–Zn2–O1	85.55(11)	O24–Zn2–O1	93.95(12)	O4–Zn2–N6	89.59(11)
N2–Zn2–N6	95.24(12)	O24–Zn2–N6	92.61(13)	O1–Zn2–N6	171.90(12)
O5–Zn3–O6	113.02(12)	O5–Zn3–N5	128.10(12)	O6–Zn3–N5	117.44(14)
O5–Zn3–O7	83.24(10)	O6–Zn3–O7	90.74(12)	N5–Zn3–O7	84.77(11)
O5–Zn3–N1	87.25(11)	O6–Zn3–N1	97.52(14)	N5–Zn3–N1	97.33(13)
O7–Zn3–N1	169.29(12)	O12–Zn4–N7	124.57(13)	O12–Zn4–O13	82.80(10)
N7–Zn4–O13	84.94(12)	O12–Zn4–O14	103.94(11)	N7–Zn4–O14	130.82(13)
O13–Zn4–O14	94.37(12)	O12–Zn4–N8	87.66(12)	N7–Zn4–N8	96.06(14)
O13–Zn4–N8	169.00(13)	O14–Zn4–N8	93.24(14)
O5–La1–O20	91.87(9)	O5–La1–O12	129.19(8)	O20–La1–O12	126.29(8)
O5–La1–O19	148.96(9)	O20–La1–O19	64.64(8)	O12–La1–O19	63.26(8)
O5–La1–O4	62.34(8)	O20–La1–O4	78.16(8)	O12–La1–O4	146.66(8)
O19–La1–O4	126.01(8)	O5–La1–O7	65.16(8)	O20–La1–O7	89.17(9)
O12–La1–O7	81.51(8)	O19–La1–O7	93.10(8)	O4–La1–O7	125.23(8)
O5–La1–O1	124.73(8)	O20–La1–O1	90.06(9)	O12–La1–O1	91.02(8)
O19–La1–O1	77.66(8)	O4–La1–O1	64.15(8)	O7–La1–O1	170.10(8)
O5–La1–O13	77.97(8)	O20–La1–O13	169.01(8)	O12–La1–O13	64.41(8)
O19–La1–O13	126.35(8)	O4–La1–O13	93.23(9)	O7–La1–O13	90.31(9)
O1–La1–O13	92.31(9)

Complex 2
Bond	Lengths	Bond	Lengths	Bond	Lengths
O12–Zn1	2.020(3)	O11–Zn1	2.043(2)	O10–Zn2	2.068(2)
O9–Zn2	2.026(3)	O4–Zn2	1.985(2)	O3–Zn1	1.972(2)
N4–Zn2	2.015(3)	N3–Zn2	2.137(3)	N2–Zn1	2.110(3)
N1–Zn1	2.019(3)
Ce1–O3	2.475(2)	Ce1–O10#2	2.475(2)	Ce1–O11#2	2.511(2)
Ce1–O3#2	2.475(2)	Ce1–O4#2	2.479(2)	Ce1–O11	2.511(2)
Ce1–O10	2.475(2)	Ce1–O4	2.479(2)

Complex 2
Bond	Angles	Bond	Angles	Bond	Angles
O3–Zn1–O12	113.98(12)	O3–Zn1–N1	127.13(12)	O12–Zn1–N1	117.85(14)
O3–Zn1–O11	81.90(10)	O12–Zn1–O11	93.03(11)	N1–Zn1–O11	85.67(12)
O3–Zn1–N2	88.94(11)	O12–Zn1–N2	95.64(12)	N1–Zn1–N2	95.67(13)
O11–Zn1–N2	169.37(12)	O4–Zn2–N4	122.97(12)	O4–Zn2–O9	109.03(11)
N4–Zn2–O9	127.60(13)	O4–Zn2–O10	82.84(9)	N4–Zn2–O10	84.60(11)
O9–Zn2–O10	96.52(12)	O4–Zn2–N3	87.24(11)	N4–Zn2–N3	95.14(13)
O9–Zn2–N3	93.18(14)	O10–Zn2–N3	167.93(12)
O3–Ce1–O3#2	126.22(11)	O3#2–Ce1–O10	92.34(8)	O3#2–Ce1–O10#2	127.67(8)
O3–Ce1–O10	127.67(8)	O3–Ce1–O10#2	92.34(8)	O10–Ce1–O10#2	87.78(12)
O3–Ce1–O4#2	146.35(8)	O4#2–Ce1–O4	130.09(11)	O3–Ce1–O11	63.72(8)
O3#2–Ce1–O4#2	63.21(8)	O3–Ce1–O11#2	80.04(8)	O3#2–Ce1–O11	80.03(8)
O10–Ce1–O4#2	78.78(8)	O3#2–Ce1–O11#2	63.72(8)	O10–Ce1–O11	168.47(8)
O10#2–Ce1–O4#2	65.57(8)	O10–Ce1–O11#2	90.07(8)	O10#2–Ce1–O11	90.07(8)
O3–Ce1–O4	63.21(8)	O10#2–Ce1–O11#2	168.48(8)	O4#2–Ce1–O11	90.02(8)
O3#2–Ce1–O4	146.35(8)	O4#2–Ce1–O11#2	125.03(8)	O4–Ce1–O11	125.03(8)
O10–Ce1–O4	65.57(8)	O4–Ce1–O11#2	90.03(8)	O11#2–Ce1–O11	94.20(11)
O10#2–Ce1–O4	78.78(8)

Complex 3
Bond	Lengths	Bond	Lengths	Bond	Lengths
N1–Zn1	2.015(2)	N2–Zn1	2.143(3)	N3–Zn2	2.110(3)
N4–Zn2	2.018(3)	O1–Zn1	2.0699(19)	O5–Zn2	1.9785(19)
O8–Zn2	2.0372(19)	O12–Zn2	2.015(2)
O1–Pr1	2.4646(19)	O8–Pr1	2.5097(19)	O5#3–Pr1	2.4471(19)
O4–Pr1	2.4605(19)	O1#3–Pr1	2.4646(19)	O8#3–Pr1	2.5097(19)
O5–Pr1	2.4471(19)	O4#3–Pr1	2.4605(19)

Complex 3
Bond	Angles	Bond	Angles	Bond	Angles
O4–Zn1–N1	122.13(9)	O4–Zn1–O9	110.45(9)	N1–Zn1–O9	127.21(10)
O4–Zn1–O1	82.56(8)	N1–Zn1–O1	85.70(9)	O9–Zn1–O1	97.27(9)
O4–Zn1–N2	86.69(9)	N1–Zn1–N2	94.43(10)	O9–Zn1–N2	92.74(10)
O1–Zn1–N2	167.33(9)	O5–Zn2–O12	113.73(10)	O5–Zn2–N4	126.50(9)
O12–Zn2–N4	118.79(11)	O5–Zn2–O8	81.60(8)	O12–Zn2–O8	93.65(9)
N4–Zn2–O8	85.60(9)	O5–Zn2–N3	89.31(9)	O12–Zn2–N3	94.94(10)
N4–Zn2–N3	95.59(10)	O8–Zn2–N3	169.44(9)
O5#3–Pr1–O5	125.71(9)	O5#3–Pr1–O1#3	128.04(6)	O1–Pr1–O8#3	88.83(7)
O5#3–Pr1–O4	146.19(6)	O5–Pr1–O1#3	91.97(6)	O1#3–Pr1–O8#3	167.92(6)
O5–Pr1–O4	63.29(6)	O4–Pr1–O1#3	79.09(6)	O5#3–Pr1–O8	80.03(6)
O5#3–Pr1–O4#3	63.29(6)	O4#3–Pr1–O1#3	65.99(6)	O5–Pr1–O8	63.92(6)
O5–Pr1–O4#3	146.19(6)	O1–Pr1–O1#3	89.04(9)	O4–Pr1–O8	125.13(6)
O4–Pr1–O4#3	130.59(9)	O5#3–Pr1–O8#3	63.92(6)	O4#3–Pr1–O8	89.19(6)
O5#3–Pr1–O1	91.97(6)	O5–Pr1–O8#3	80.03(6)	O1–Pr1–O8	167.93(6)
O5–Pr1–O1	128.04(6)	O4–Pr1–O8#3	89.19(6)	O1#3–Pr1–O8	88.83(7)
O4–Pr1–O1	65.99(6)	O4#3–Pr1–O8#3	125.13(6)	O8#3–Pr1–O8	95.65(9)
O4#3–Pr1–O1	79.10(6)

Complex 4
Bond	Lengths	Bond	Lengths	Bond	Lengths
N1–Zn1	2.020(3)	N2–Zn1	2.110(3)	N3–Zn2	2.133(3)
N4–Zn2	2.017(3)	O3–Zn1	1.968(3)	O4–Zn2	1.985(2)
O9–Zn2	2.023(3)	O10–Zn2	2.061(3)	O11–Zn1	2.046(3)
O12–Zn1	2.017(3)
Nd1–O4	2.444(2)	Nd1–O3	2.450(2)	Nd1–O11#4	2.481(3)
Nd1–O4#4	2.444(2)	Nd1–O10	2.452(2)	Nd1–O11	2.481(3)
Nd1–O3#4	2.450(2)	Nd1–O10#4	2.452(2)

Complex 4
Bond	Angles	Bond	Angles	Bond	Angles
O3–Zn1–O12	113.61(13)	O3–Zn1–N1	127.19(13)	O12–Zn1–N1	118.26(15)
O3–Zn1–O11	81.28(10)	O12–Zn1–O11	93.77(12)	N1–Zn1–O11	86.07(12)
O3–Zn1–N2	89.29(12)	O12–Zn1–N2	95.15(13)	N1–Zn1–N2	95.29(14)
O11–Zn1–N2	169.03(13)	O4–Zn2–N4	122.85(13)	O4–Zn2–O9	109.21(11)
N4–Zn2–O9	127.58(13)	O4–Zn2–O10	82.07(10)	N4–Zn2–O10	85.26(12)
O9–Zn2–O10	96.81(13)	O4–Zn2–N3	87.26(12)	N4–Zn2–N3	94.59(14)
O9–Zn2–N3	93.47(14)	O10–Zn2–N3	167.13(12)
O4–Nd1–O4#4	129.52(12)	O4–Nd1–O10#4	78.43(9)	O10–Nd1–O11#4	90.19(9)
O4–Nd1–O3#4	145.82(8)	O4#4–Nd1–O10#4	65.72(8)	O10#4–Nd1–O11#4	167.33(8)
O4#4–Nd1–O3#4	63.98(8)	O3#4–Nd1–O10#4	128.56(8)	O4–Nd1–O11	126.22(8)
O4–Nd1–O3	63.98(8)	O3–Nd1–O10#4	91.74(8)	O4#4–Nd1–O11	89.50(8)
O4#4–Nd1–O3	145.82(8)	O10–Nd1–O10#4	88.34(12)	O3#4–Nd1–O11	79.37(8)
O3#4–Nd1–O3	125.79(12)	O4–Nd1–O11#4	89.50(8)	O3–Nd1–O11	64.06(9)
O4–Nd1–O10	65.72(8)	O4#4–Nd1–O11#4	126.21(8)	O10–Nd1–O11	167.33(8)
O4#4–Nd1–O10	78.43(9)	O3#4–Nd1–O11#4	64.06(8)	O10#4–Nd1–O11	90.20(9)
O3#4–Nd1–O10	91.73(8)	O3–Nd1–O11#4	79.37(8)	O11#4–Nd1–O11	93.93(12)
O3–Nd1–O10	128.56(8)