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Article

Self-Assembly of 3d-4f ZnII-LnIII (Ln = Ho and Er) Bis(salamo)-Based Complexes: Controlled Syntheses, Structures and Fluorescence Properties

by
Xiu-Yan Dong
,
Qing Zhao
,
Quan-Peng Kang
,
Xiao-Yan Li
and
Wen-Kui Dong
*
School of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China
*
Author to whom correspondence should be addressed.
Crystals 2018, 8(5), 230; https://doi.org/10.3390/cryst8050230
Submission received: 26 April 2018 / Revised: 13 May 2018 / Accepted: 19 May 2018 / Published: 20 May 2018
(This article belongs to the Section Crystal Engineering)
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Abstract

:
Two new hetero-trinuclear 3d-4f complexes [Zn2(L)Ho(μ2-OAc)2(OAc)(MeOH)]·CH2Cl2 (1) and [Zn2(L)Er(μ2-OAc)2]OAc (2), derived from a bis(salamo)-based ligand H4L, were synthesized and characterized via elemental analyses, IR, UV–Vis, fluorescence spectra and X-ray crystallography. The X-ray crystal structure analyses demonstrated that two μ2-acetateanions bridge the ZnII and LnIII (Ln = Ho (1) and Er (2)) atoms in a μ2-fashion forming similar hetero-trinuclear structures, respectively. In complex 1, one methanol molecule as coordinating solvent participates in the coordination, the two ZnII atoms are six- and five-coordinated and have geometries of slightly distorted tetragonal pyramid and octahedron, and the HoIII atom is nine-coordinated and has the geometry of a mono-capped square antiprism. In complex 2, the two ZnII atoms both possess five-coordinated tetragonal pyramid geometries, and the ErIII atom is eight-coordinated with a square antiprism geometry. Furthermore, the fluorescence properties of complexes 1 and 2 were determined.

Graphical Abstract

1. Introduction

As we know, due to easy preparation and strong coordination abilities, modified Salen-type ligands [1,2,3,4,5,6,7,8] containing tetradentate N2O2 site have been used for the synthesis of metal complexes [9,10,11,12,13] in the past few decades. The potential applications of Salen-type compounds and their corresponding metallic complexes in modern coordination chemistry and organometallic chemistry have attracted considerable attentions, such as optical sensors [14,15], catalyses [16,17], luminescence properties [18,19,20,21,22,23,24], supra-molecular buildings [25,26,27,28,29,30,31,32,33], electrochemistries [34,35], magnetic materials [36,37,38,39,40,41], biological systems [42,43,44,45,46,47,48,49,50,51] and nonlinear optical materials [52], and so forth. In recent years, Salen-type complexes have attracted considerable attention from the viewpoint of the integration effect of multiple functional units. In the meantime, a class of salen-based supramolecules is the self-assembled salen metal complexes which may be obtained by the metal-assisted self-assembly of multiple salen units [5].
More recently, Salamo, a better class of N2O2-donor ligands, has been exploited, using [–CH=N–O–(CH2)n–O–N=CH–] instead of [–CH=N–(CH2)n–N=CH–] group. The studies showed that Salamo-type ligands are relatively stable than Salen-type ligands [53]. So far, lots of reports have been documented concerning the preparation of homo-, or hetero-multinuclear metallic complexes possessing Salamo-type ligands [54,55,56,57,58,59,60,61,62,63]. Currently, hetero-multimetallic 3d-4f complexes pose an extreme yet attractive challenge in the field of coordination chemistry. This is due to the fact that stable high-nuclear and structurally novel 3d-4f metallic complexes exhibit good luminescence properties. With the expectation of obtaining novel structures and interesting properties, a bis(salamo)-type ligand H4L containing O6 coordination sphere was already prepared earlier to obtain a series of homo-, hetero-nuclear ZnII-MII, CoII-MII (M = Ca, Sr and Ba) and ZnII-LnIII (Ln = La, Ce and Dy) complexes. In addition, the crystal structures and properties of complexes have been discussed in detail [57,64,65]. Therefore, these compounds are considered to be heterotrinuclear bis(salamo)-type complexes. Owing to the bis(salamo)-type ligand H4L bearing an O6 coordination sphere, it can form homotrinuclear bis(salamo)-type complexes. The transition metal atom located in the O6 coordination sphere can be replaced by rare earth atoms with a larger atomic radius. Herein, as an extension of our previous studies, two new hetero-trinuclear 3d-4f complexes [Zn2(L)Ho(μ2-OAc)2(OAc)(MeOH)]·CH2Cl2 (1) and [Zn2(L)Er(μ2-OAc)2]OAc (2), constructed from the bis(salamo)-type ligand H4L, were prepared and characterized structurally. In addition, the fluorescence properties of complexes 1 and 2 were studied in detail.

2. Experimental

2.1. Materials and Methods

2-Hydroxy-3-methoxybenzaldehyde (99%), methyl trioctyl ammonium chloride (90%), borontribromide (99.9%) and pyridinium chlorochromate (98%) were bought from Alfa Aesar (New York, NY, USA). Hydrobromic acid 33wt % solution in acetic acid was purchased from J & K Scientific Ltd. (Beijing, China). Other chemicals were obtained from Tianjin Chemical Reagent Factory (Tianjin, China). Elemental C, H and N analyses were obtained using a GmbH VarioEL V3.00 automatic elemental analysis instrument (Elementar, Berlin, Germany). Elemental analyses for metal atoms were performed on an IRIS ER/S-WP-ICP atomic emission spectrometer (Elementar, Berlin, Germany). Melting points were determined on a microscopic melting point apparatus made in Beijing Taike Instrument Limited Company (Beijing, China) and were uncorrected. IR spectra were measured on a VERTEX70 FT-IR spectrophotometer (Bruker, Billerica, MA, USA), with samples prepared as KBr (500–4000 cm−1) pellets. UV-Vis spectra in the 250–550 nm range were measured by a Hitachi UV-3900 spectrometer (Shimadzu, Tokyo, Japan). Fluorescent spectra were determined on a Hitachi F-7000 spectrophotometer (Hitachi, Tokyo, Japan). Single crystal X-ray structure determinations were performed on a SuperNova Dual, Cu at zero, Eos four-circle diffractometer.

2.2. Synthesis of H4L

2,3-Dihydroxynaphthalene-1,4-dicarbaldehydeand 2-[O-(1-ethyloxyamide)] oxime-6-methoxyphenol were prepared according to the early reported methods [64,66]. The synthesis of H4L and its complexes is depicted in Scheme 1.
The ligand H4L was synthesized according to the previously reported method [57,64,65]. Yield, 54.1%. m.p. 171–172 °C. Anal. Calcd. for C32H32N4O10 (%): C, 60.75; H, 5.10; N, 8.86; Found: C, 60.93; H, 5.22; N 8.70. 1H NMR (400 MHz, CDCl3) δ 11.03 (s, 2H), 9.82 (s, 2H), 9.14 (s, 2H), 8.29 (s, 2H), 7.97 (q, J = 3.2 Hz, 2H), 7.41 (q, J = 6.0, 2.9 Hz, 2H), 7.06–6.68 (m, 6H), 4.58 (t, 8H), 3.89 (s, 6H).

2.3. Synthesis of complex 1

The ligand H4L (9.42 mg, 0.015 mmol) was dissolved in dichloromethane (2 mL). To stirring solution of Zn(OAc)2 (12.67 mg, 0.03 mmol) in methanol (2 mL) and Ho(OAc)3 (2.24 mg, 0.015 mmol) in methanol (2 mL) was added in drops solution of H4L in dichloromethane (2 mL) at room temperature. After about 15 min, the resulting solution turned clear. The mixed solution was filtered, and the filtrate was placed at room temperature for slow evaporation. Clear light colourless crystals were collected and washed with n-hexane. Finally, complex 1 was dried and collected. Yield: 51.3%. Anal. Calcd. for C40H43Cl2Zn2HoN4O17 (%): C, 39.43; H, 3.56; N, 4.60; Zn, 10.73; Ho, 13.54; Found: C, 39.62; H, 3.71; N, 4.45; Zn, 10.54; Ho, 13.39.

2.4. Synthesis of complex 2

To stirring solution of Zn(OAc)2 (4.51 mg, 0.02 mmol) in methanol (2 mL) and Er(OAc)3 (1.28 mg, 0.01 mmol) in methanol (2 mL) was added solution of H4L in methanol (2 mL) in a dropwise manner at room temperature. After about 15 min, the resulting solution turned clear. The mixed solution was filtered and stayed for ca. two weeks, after which clear light colorless crystals were gained.Yield: 50.4%. Anal. Calcd. for C38H37Zn2ErN4O16 (%): C, 41.35; H, 3.38; N, 5.08; Zn, 11.85; Er, 15.15; Found: C, 41.59; H, 3.42; N, 5.02; Zn, 12.15; Er, 15.46.

2.5. X-ray Structure Determinations for complexes 1 and 2

Intensity data of complexes 1 and 2 were collected on a SuperNova Dual, Cu at zero, Eos diffractometer with graphite monochromated Mo Kα radiation (λ = 0.71073 Å) at 293.78(10) and 293.18(10) K, respectively. Multiscan absorption corrections were applied. The structures were solved by Direct Methods and refined anisotropically using full-matrix least-squares methods on F2 with the SHELX-2014 program package. All non-hydrogen atoms were refined anisotropically. The positions of hydrogen atoms were calculated and isotropically fixed in the final refinement. Contributions to scattering due to these very large solvent accessible VOID(S) in structure were removed using the SQUEEZE routine of PLATON, the structures were then refined again using the data generated. The crystallographic and refinement parameter data including the structural determinations are listed in Table 1. Supplementary crystallographic data for this paper have been deposited at Cambridge Crystallographic Data Centre (CCDC Nos. 1825954 and 1825953 for complexes 1 and 2) and can be obtained free of charge via www.ccdc.cam.ac.uk/conts/retrieving.html.

3. Results and Discussion

Complexes 1 and 2 derived from a bis(salamo) ligand H4L were prepared and characterized by UV-Vis, IR, X-ray crystallography and fluorescence spectra.

3.1. IR Spectra

The main FT-IR spectral data for H4L and its corresponding metallic complexes 1 and 2 in the 500–4000 cm−1 region are delineated in Table 2.
In the FT-IR spectra, the phenolic O–H vibration band for H4L exhibited a strong characteristic absorption at 3167 cm−1. Nevertheless, this band disappeared, and a new O–H vibration band of methanol molecule was displayed at 3389 cm-1 in complex 1, which is in agreement with the result of the elementary analyses. However, this band disappeared in complex 2, indicating that the hydroxyl groups of phenolic and naphthalenediol of H4L are completely deprotonated and coordinated with the metal atoms, and the methanol solvent used is not involved in the coordination. A typical C=N stretching vibration band of H4L was detected at 1628 cm−1. Upon complexation, the C=N bands of complexes 1 and 2 appeared at 1601 and 1604 cm−1, respectively, which are both shifted to low frequencies, demonstrating the coordination of the C=N nitrogen atoms of the N2O2 binding sites with ZnII atoms [65]. The IR spectrum of H4L exhibited one absorption band at ca. 1253 cm−1, assignable to the Ar–O absorption band. Compared with H4L, the typical Ar–O stretching frequencies of complexes 1 and 2 occurred at 1220 and 1217 cm−1, respectively. This phenomenon can be explained by the formation of M–O bonds [67]. The results mentioned above show consistence with single crystal X-ray diffraction.

3.2. UV–Vis Spectra

In many studies, UV–Vis absorption spectra have been utilized to study the lanthanides complexes. In this study, the UV–Vis spectrum of H4L in CH3OH:CHCl3 (1:1) (1.0 × 10−5 mol L−1) with its corresponding complexes 1 and 2 in methanol/H2O (10:1) (1.0 × 10−3 mol L−1) were determined in the range of 250–550 nm. According to the previously reported results, the free ligand H4L has absorption peaks at about 269, 340, 360 and 374 nm. The former peak at 269 nm could be attributed to the π-π* transition of the benzene rings while the other peaks could be appointed to those of the oxime groups [65].
In the UV–Vis titration test, gradual addition of Zn(OAc)2 to H4L solution resulted in solution changes from yellow to colorless. In contrast to H4L, the peaks are bathochromically shifted. This phenomenon is owing to the reaction of H4L with ZnII ions. When ZnII ions were added in excess of 3 equiv, the absorbance no longer changed. The spectroscopic titration of H4L and Zn(OAc)2 obviously showed a 1:3 homo-trinuclear complex was formed which is shown in Figure 1a.
Then, upon the addition of 1 equiv of HoIII ions, the absorbance changed and showed two isoabsorptive points at about 298 and 380 nm. The titration test obviously showed that the stoichiometry ratio of the replacement reaction is 1:1 (inset of Figure 1b). Similar change was observed in complex 2, giving the same results and is shown in Figure 2.

3.3. Crystal Structure Description of complex 1

The determined crystal structure of complex 1 is depicted in Figure 3. From the Figure 3, complex 1 crystallizes in monoclinic system, consisting of two ZnII atoms, one HoIII atom, one deprotonated (L)4− unit, two μ2-acetate anions, one monodentate coordinated acetate anion, one coordinated methanol and one crystallizing dichloromethane molecules.
The X-ray diffraction analysis revealed that the Zn1 atom is surrounded by a N2O2 donor environment and is bonded to two nitrogen atoms (Zn1-N1, 2.140(4) Å and Zn1-N2, 2.157(4) Å) of the oxime groups, two oxygen (Zn1-O2, 2.154(3) Å and Zn1-O5, 2.053(3) Å) atoms of the phenolic groups, one oxygen atom of the μ2-acetate anion (Zn1-O12, 2.061(3) Å) and one oxygen atom (Zn1-O16, 2.088(3) Å) of the monodentate coordinated acetate anion (Table 3). Therefore, the Zn1 is six-coordinated and has octahedral coordination geometry [68]. The Zn1-O/N bond lengths are in the range of 1.950(3)–2.157(4) Å. Zn2 atom is five-coordinated and has a tetragonal pyramid geometry, which being calculated by τ value was estimated to be τ = 0.19 [64,65,68]. The Zn2 atom is linked by two nitrogen atoms (Zn2-N3, 2.100(3) Å and Zn2-N4, 2.054(3) Å) of the oxime groups, two oxygen (Zn2-O6, 1.991(3) Å and Zn2-O9, 2.045(3) Å) atoms of the phenolic group and the μ2-acetate anion (Zn2-O14, 1.986(3) Å). The Zn2-O/N bond lengths are in range of 1.986(3)–2.100(3) Å.
Meanwhile, the HoIII atom is nine-coordinated and has a mono-capped square antiprism coordination geometry. The HoIII atom located in O9 coordination sphere is coordinated with six oxygen atoms (Ho1-O1, 2.587(3) Å; Ho1-O2, 2.308(3) Å; Ho1-O5, 2.327(3) Å; Ho1-O6, 2.341(3) Å; Ho1-O9, 2.356(3) Å and Ho1-O10, 2.634(3) Å) from the phenolic oxygen and methoxy groups, two μ2-acetate oxygen atoms (Ho1-O11, 2.394(3) Å and Ho1-O13, 2.373(4) Å) and one oxygen atom (Ho1-O15, 2.460(3) Å) of the coordinated methanol molecule.
The hydrogen bonding and C-H···π interactions are summarized in Table 4. In the structure of complex 1, there are four pairs of intra-molecular O15-H15···O16, C8-H8B···O12, C9-H9B···O17 and C22-H22A···O14 hydrogen bonding in Figure 4 [69,70,71,72,73,74]. As illustrated in Figure 5, a 2D supra-molecular structure is interlinked via two significant intermolecular C15-H15A···O17 and C24-H24···O11 hydrogen bonding interactions are constructed. In addition, one significant C-H···π interaction (C8-H8A···Cg1 (C25-C30)) is built in Figure 6 [75,76,77,78].

3.4. Crystal Structure Description of complex 2

The structure of complex 2 is illustrated in Figure 7. It crystallizes in monoclinic system. The asymmetric trinuclear structure is similar to complex 1 and contains two ZnII atoms, one ErIII atom, one deprotonated (L)4‒ unit, two μ2-acetate anions and one crystallizing acetate anions. The ZnII atom (Zn1 or Zn1i) is five-coordinated with two oxime nitrogen (Zn1-N1, 2.084(3) Å and Zn1-N2, 2.057(3) Å) atoms, two phenol oxygen (Zn1-O2, 2.029(3) Å and Zn1-O5, 2.012(2) Å) atoms and one oxygen (Zn1-O6, 1.984(2) Å) atom of the μ2-acetate anion (Table 5) [68]. So, the ZnII atoms (Zn1 and Zn1i) possess tetragonal pyramid geometries, which calculated by τ values were estimated to be τ (Zn1 and Zn1i) = 0.14 [68]. The ErIII atom located in O8 coordination sphere is coordinated with six oxygen atoms (Er1-O1, 2.484(3) Å; Er1-O1i, 2.484(3) Å; Er1-O2, 2.318(2) Å; Er1-O2i, 2.318(2) Å; Er1-O5, 2.288(2) Å and Er1-O5i, 2.288(2) Å) from one deprotonated (L)4− moiety and two μ2-acetate oxygen atoms (Er1-O7, 2.281(2) Å and Er1-O7i, 2.281(2) Å). Therefore, the ErIII atom is eight-coordinated and has the geometry of square antiprism. The distances between Er1 atom and the phenolic oxygen (O2, O5, O2i and O5i) atoms of the (L)4− unit are ranged from 2.288(2) to 2.318(2) Å, which are clearly shorter than those of the methoxy groups (Er1-O1, 2.484(3) Å and Er1-O1i,2.484(3) Å).
The hydrogen bonding and π···π interactions are summarized in Table 6. In the structure of complex 2, there is one pairs of intra-molecular C9-H9A···O6 hydrogen bonding and one significant intermolecular C10-H10B···O9 hydrogen bonding interactions in Figure 8. As illustrated in Figure 9, the space skeleton of complex 2 adopts a 3D supra-molecular structure by the hydrogen bonding and π···π stacking interactions [71,72,73].

3.5. Fluorescence Properties

Recently, some Salamo-type lanthanide complexes have been reported to perform excellent fluorescence properties [21,24,32]. ZnII components have been applied as lanthanide fluorescence sensitizers.
The emission spectra of H4L in CH3OH:CHCl3 (v/v = 1:1) solution and its corresponding metallic complexes 1 and 2 in methanol solution were measured in detail. As shown in Figure 10, H4L exhibited an emission peak at ca. 442 nm upon excitation at ca. 350 nm, which could be attributed to the intra-ligand π-π* transition [59]. Whereas, upon excitation at ca. 350 nm, complexes 1 and 2 showed relatively strong emission peaks at about 447 and 448 nm, respectively. These relatively intense emission peaks are bathochromically shifted, which could be assigned to ligand-to-metal charge transfer (LMCT) transitions [62,65].

4. Conclusions

In summary, two new hetero-trinuclear complexes, ZnII-HoIII (1) and ZnII-ErIII (2) derived from a bis(salamo) C-shape ligand H4L were prepared and characterized. Using a controlled design and introduction of methanol molecules, the UV–Vis titration test of complexes 1 and 2 showed that the stoichiometric ratio of ligand to ZnII and LnIII (Ln = Ho and Er) ions are both 1:2:1. Complex 1 has 1D supra-molecular structure formed by the C-H···π stacking interactions, and 2D supra-molecular structure by the hydrogen bonding interactions. Meanwhile, a large 3D supra-molecular structure of complex 2 is also built by hydrogen bonding and π···π stacking interactions. In addition, the fluorescence spectra of complexes 1 and 2 showed relatively strong emission peaks, and exhibited bathochromic shifts compared to ligand H4L, respectively.

Supplementary Materials

Supplementary File 1

Author Contributions

W.-K.D. supervised the project and contributed materials/reagents/analysis tools; X.-Y.D., Q.-P.K. and X.-Y.L. performed the experiments.

Acknowledgments

This work was supported by the National Natural Science Foundation of China (21761018) and the Program for Excellent Team of Scientific Research in Lanzhou Jiaotong University (201706), both of which are gratefully acknowledged.

Conflicts of Interest

The authors declare no conflict of interest.

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Crystals 08 00230 sch001a 550Crystals 08 00230 sch001b 550
Scheme 1. Synthetic routes to H4L and its complexes.
Scheme 1. Synthetic routes to H4L and its complexes.
Crystals 08 00230 sch001aCrystals 08 00230 sch001b
Crystals 08 00230 g001a 550Crystals 08 00230 g001b 550
Figure 1. (a) UV-Vis spectral changes of H4L (1.0 × 10−5 M) upon the addition of ZnII (1.0 × 10−3 M) ions; (b) UV-Vis spectral changes of [LZn3]2+ upon the addition of HoIII (1.0 × 10−3 M) ions.
Figure 1. (a) UV-Vis spectral changes of H4L (1.0 × 10−5 M) upon the addition of ZnII (1.0 × 10−3 M) ions; (b) UV-Vis spectral changes of [LZn3]2+ upon the addition of HoIII (1.0 × 10−3 M) ions.
Crystals 08 00230 g001aCrystals 08 00230 g001b
Crystals 08 00230 g002a 550Crystals 08 00230 g002b 550
Figure 2. (a) UV–Vis spectral changes of H4L (1.0 × 10−5 M) upon the addition of ZnII (1.0 × 10−3 M) ions; (b) UV–Vis spectral changes of [LZn3]2+ upon the addition of ErIII (1.0 × 10−3 M) ions.
Figure 2. (a) UV–Vis spectral changes of H4L (1.0 × 10−5 M) upon the addition of ZnII (1.0 × 10−3 M) ions; (b) UV–Vis spectral changes of [LZn3]2+ upon the addition of ErIII (1.0 × 10−3 M) ions.
Crystals 08 00230 g002aCrystals 08 00230 g002b
Crystals 08 00230 g003 550
Figure 3. (a) View of the crystal structure of complex 1; (b) Coordination polyhedrons for ZnII and HoIII atoms.
Figure 3. (a) View of the crystal structure of complex 1; (b) Coordination polyhedrons for ZnII and HoIII atoms.
Crystals 08 00230 g003
Crystals 08 00230 g004 550
Figure 4. Intra-molecular O-H···O and C-H···O hydrogen bonding of complex 1.
Figure 4. Intra-molecular O-H···O and C-H···O hydrogen bonding of complex 1.
Crystals 08 00230 g004
Crystals 08 00230 g005 550
Figure 5. View of 2D supra-molecular structure of complex 1 by the intermolecular O-H···O and C-H···O hydrogen bonding interactions.
Figure 5. View of 2D supra-molecular structure of complex 1 by the intermolecular O-H···O and C-H···O hydrogen bonding interactions.
Crystals 08 00230 g005
Crystals 08 00230 g006 550
Figure 6. View of 1D supra-molecular structure via C-H···π interactions in complex 1.
Figure 6. View of 1D supra-molecular structure via C-H···π interactions in complex 1.
Crystals 08 00230 g006
Crystals 08 00230 g007 550
Figure 7. (a)The crystal structure of complex 2; (b) Coordination polyhedrons for ZnII and ErIII atoms.
Figure 7. (a)The crystal structure of complex 2; (b) Coordination polyhedrons for ZnII and ErIII atoms.
Crystals 08 00230 g007
Crystals 08 00230 g008 550
Figure 8. View of 1D supra-molecular structure of complex 2 by the hydrogen bonding interactions.
Figure 8. View of 1D supra-molecular structure of complex 2 by the hydrogen bonding interactions.
Crystals 08 00230 g008
Crystals 08 00230 g009 550
Figure 9. View of 3D supra-molecular structure of complex 2 by the hydrogen bonding and π···π stacking interactions.
Figure 9. View of 3D supra-molecular structure of complex 2 by the hydrogen bonding and π···π stacking interactions.
Crystals 08 00230 g009
Crystals 08 00230 g010 550
Figure 10. Emission spectra of H4L and its complexes 1 and 2.
Figure 10. Emission spectra of H4L and its complexes 1 and 2.
Crystals 08 00230 g010
Table
Table 1. Crystal and refinement parameter data for complexes 1 and 2.
Table 1. Crystal and refinement parameter data for complexes 1 and 2.
Complex12
FormulaC40H43Cl2Zn2HoN4O17C38H37Zn2ErN4O16
Formula weight1218.351103.71
Temperature (K)293.78(10)293.18(10)
Wavelength (Å)0.710730.71073
Crystal systemMonoclinicMonoclinic
Space groupP21/cI2/c
Unit cell dimensions
a (Å)12.6372(2)7.8033(4)
b (Å)13.68094(19)30.0645(18)
c (Å)26.7692(5)20.5938(10)
α (°)9090
β (°)103.494(2)93.545(4)
γ (°)9090
V (Å3)4500.33(14)4822.1(4)
Z44
Dc (g cm−3)1.7981.520
μ (mm−1)2.9952.777
F (000)24322196
Crystal size (mm)0.31 × 0.32 × 0.350.20 × 0.22 × 0.24
θ Range (°)3.7820–28.10601.199–28.8430
−15≤ h ≤ 14−10≤ h ≤ 10
Index ranges−16 ≤ k ≤ 16−40 ≤ k ≤ 35
−33 ≤ l ≤ 32−25 ≤ l ≤ 25
Reflections collected26,90019,152
Independent reflections85845715
Rint0.0350.019
Completeness96.06%99.70%
Data/restraints/parameters8584/3/6044642/4/296
GOF1.0401.017
Final R1, wR2 indices0.0337, 0.07460.0309, 0.0927
R1, wR2 indices (all data)0.0455, 0.08140.0398, 0.0945
Largest differences peak and hole (e Å−3)0.809/−0.8541.330/−0.960
Table
Table 2. Main FT-IR spectral data of H4L and its complexes 1and 2 (cm−1).
Table 2. Main FT-IR spectral data of H4L and its complexes 1and 2 (cm−1).
Compoundν(O–H)ν(C=N)ν(Ar–O)ν(C=C)
H4L3167162812531374
Complex 13389160112201316
Complex 2-160412171314
Table
Table 3. Selected bond lengths (Å) and angles (°) for complex 1.
Table 3. Selected bond lengths (Å) and angles (°) for complex 1.
Bond Lengths
Zn1-O22.154(3)Zn1-O51.950(3)Zn1-O122.061(3)
Zn1-O162.088(3)Zn1-N12.140(4)Zn1-N22.157(4)
Zn2-O61.991(3)Zn2-O92.045(3)Zn2-O141.986(3)
Zn2-N32.100(3)Zn2-N42.054(3)Ho1-O12.587(3)
Ho1-O22.308(3)Ho1-O52.327(3)Ho1-O62.341(3)
Ho1-O92.356(3)Ho1-O102.634(3)Ho1-O112.394(3)
Ho1-O132.373(4)Ho1-O152.460(3)
Bond Angles
O1-Ho1-O263.07(9)O1-Ho1-O5129.30(9)O1-Ho1-O6144.05(9)
O1-Ho1-O9111.59(9)O1-Ho1-O1065.13(9)O1-Ho1-O11117.67(9)
O1-Ho1-O1368.67(9)O1-Ho1-O1572.96(10)O2-Ho1-O573.40(9)
O2-Ho1-O6138.15(9)O2-Ho1-O9148.88(9)O1-Ho1-O1090.44(9)
O2-Ho1-O1175.84(9)O2-Ho1-O13125.83(10)O2-Ho1-O1574.04(11)
O5-Ho1-O665.45(9)O5-Ho1-O9119.11(10)O5-Ho1-O10142.08(9)
O5-Ho1-O1171.99(9)O5-Ho1-O13126.72(10)O5-Ho1-O1571.10(11)
O6-Ho1-O965.39(9)O6-Ho1-O10127.09(9)O6-Ho1-O1197.72(10)
O6-Ho1-O1377.01(10)O6-Ho1-O1585.55(11)O9-Ho1-O1061.88(9)
O9-Ho1-O1181.36(9)O9-Ho1-O1371.93(10)O9-Ho1-O15135.89(11)
O10-Ho1-O1170.84(9)O10-Ho1-O1390.68(9)O10-Ho1-O15137.86(11)
O11-Ho1-O13152.58(10)O11-Ho1-O15137.49(11)O13-Ho1-O1569.55(12)
Table
Table 4. Hydrogen bonding (Å, °) and C-H···π interactions for complex 1.
Table 4. Hydrogen bonding (Å, °) and C-H···π interactions for complex 1.
D-H···AD···AH···AD-H···A
O15-H15···O162.603(5)1.80(3)152
C8-H8B···O123.250(6)2.40146
C9-H9B···O173.469(7)2.50178
C22-H22A···O143.297(6)2.37160
C15-H15A···O173.478(7)2.56169
C24-H24···O113.278(5)2.38162
D-X···AD-AX···AD-X···A
C8-H8A···Cg13.727(6)2.79163
Note: Cg1 = C25–C26–C27–C28–C29–C30.
Table
Table 5. Selected bond lengths (Å) and angles (°) for complex 2.
Table 5. Selected bond lengths (Å) and angles (°) for complex 2.
Bond Lengths
Zn1-O22.029(3)Zn1-O52.012(2)Zn1-O61.984(2)
Zn1-N12.084(3)Zn1-N22.057(3)Er1-O12.484(3)
Er1-O22.318(2)Er1-O52.288(2)Er1-O72.281(2)
Bond Angles
O1-Er1-O264.33(9)O1-Er1-O5120.36(9)O1-Er1-O7122.83(10)
O1-Er1-O1i67.20(10)O1-Er1-O2i97.15(9)O1-Er1-O5i151.02(9)
O1-Er1-O7i74.67(10)O2-Er1-O566.80(9)O2-Er1-O780.66(9)
O1i-Er1-O297.15(9)O2-Er1-O2i158.64(10)O2-Er1-O5i134.51(9)
O2-Er1-O7i102.95(9)O5-Er1-O778.84(9)O1i-Er1-O5151.02(9)
O5-Er1-O5i68.10(9)O5-Er1-O7i85.26(9)O7-Er1-O7i160.81(10)
Symmetry code: i: 1 − x, y, 3/2 − z.
Table
Table 6. Hydrogen bonding (Å, °) and π···π stacking interactions for complex 2.
Table 6. Hydrogen bonding (Å, °) and π···π stacking interactions for complex 2.
D-H···AD···AH···AD-H···A
C9-H9A···O63.553(5)2.60162
C10-H10B···O93.171(6)2.33142
Ring1 Ring2DCC(Å)CgI-perp(Å)CgJ-perp(Å)
Cg1 Cg24.289(2)3.7112(15)−3.7033(17)
Note: Cg1 = C12–C13–C13i–C12i–C14i–C14; Cg2 = C14–C15–C16–C16i–C15i–C14i; DCC = distance between ring centroids; CgI-perp = perpendicular distance of Cg(I) from ring J; CgJ-perp = perpendicular distance of Cg(J) from Ring 1.

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Dong, X.-Y.; Zhao, Q.; Kang, Q.-P.; Li, X.-Y.; Dong, W.-K. Self-Assembly of 3d-4f ZnII-LnIII (Ln = Ho and Er) Bis(salamo)-Based Complexes: Controlled Syntheses, Structures and Fluorescence Properties. Crystals 2018, 8, 230. https://doi.org/10.3390/cryst8050230

AMA Style

Dong X-Y, Zhao Q, Kang Q-P, Li X-Y, Dong W-K. Self-Assembly of 3d-4f ZnII-LnIII (Ln = Ho and Er) Bis(salamo)-Based Complexes: Controlled Syntheses, Structures and Fluorescence Properties. Crystals. 2018; 8(5):230. https://doi.org/10.3390/cryst8050230

Chicago/Turabian Style

Dong, Xiu-Yan, Qing Zhao, Quan-Peng Kang, Xiao-Yan Li, and Wen-Kui Dong. 2018. "Self-Assembly of 3d-4f ZnII-LnIII (Ln = Ho and Er) Bis(salamo)-Based Complexes: Controlled Syntheses, Structures and Fluorescence Properties" Crystals 8, no. 5: 230. https://doi.org/10.3390/cryst8050230

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