Tetra­aqua­tetra­kis{μ3-3,3′-[(E,E)-ethane-1,2-diylbis(nitrilo­methyl­idyne)]benzene-1,2-diolato}octa­zinc(II) N,N-dimethyl­formamide hexa­solvate

Qin-Juan Xu; Li-Rong Lin; Di Sun; Rong-Bin Huang; Lan-Sun Zheng

doi:10.1107/S1600536809046923

. 2009 Nov 11;65(Pt 12):m1559–m1560. doi: 10.1107/S1600536809046923

Tetraaquatetrakis{μ₃-3,3′-[(E,E)-ethane-1,2-diylbis(nitrilomethylidyne)]benzene-1,2-diolato}octazinc(II) N,N-dimethylformamide hexasolvate

Qin-Juan Xu ^a, Li-Rong Lin ^a,^*, Di Sun ^a, Rong-Bin Huang ^a, Lan-Sun Zheng ^b

PMCID: PMC2972079 PMID: 21578596

Abstract

The asymmetric unit of the title compound [Zn₈(C₁₆H₁₂N₂O₄)₄(H₂O)₄]·6C₃H₇NO, consists of eight Zn^II cations, four tetravalent anionic ligands, L ⁴⁻ (L ⁴⁻ = 3,3′-(1E,1′E)-(ethane-1,2-diylbis(azan-1-yl-1-ylidene))bis(methan-1-yl-1-ylidene)dibenzene-1,2-bis(olate), four coordinated water molecules and six N,N-dimethylformamide solvate molecules. The coordination complex comprises an octanuclear Zn^II unit with its Zn^II centers coordinated in two discrete distorted square-pyramidal geometries. Four Zn^II atoms each coordinate to two nitrogen atoms and two phenolate oxygen atoms from an individual L ⁴⁻ ligand and one coordinated water molecule. The other four Zn^II atoms each bind to five phenolate oxygen atoms from three different L ⁴⁻ ligands. In the crystal structure, the Zn^II complex unit, coordinated water molecules and dimethylformamide solvate molecules are linked via O—H⋯O and C—H⋯O hydrogen bonds. Molecules are connected by additional intermolecular O—H⋯O and C—H⋯O hydrogen bonds, forming an extensive three dimensional framework.

Related literature

For applications of Schiff base–metal compounds, see: Xu et al. (2007 ▶); Wu et al. (2006 ▶); Cametti et al. (2008 ▶); Shi et al. (2009 ▶); Dochnahl et al. (2006 ▶); Wu et al. (2007 ▶); Rai et al. (2009 ▶). For the luminescence properties of zinc complexes, see: Yu et al. (2007 ▶); Kaplunov et al. (2008 ▶). For the geometrical analysis of polyhedra with coordination number 5, see: Addison et al. (1984 ▶). For Zn and Cd complexes of similar flexible, multidentate Schiff base ligands, see: Sanmartín et al. (2000 ▶). For synthesis of the ligand, see: Casellato et al. (1991 ▶); Miyamoto et al. (2002 ▶). For other related structures, see: Eltayeb et al. (2008 ▶); Chen et al. (2009 ▶); Miyamoto et al. (2002 ▶). graphic file with name e-65-m1559-scheme1.jpg

Experimental

Crystal data

[Zn₈(C₁₆H₁₂N₂O₄)₄(H₂O)₄]·6C₃H₇NO
M _r = 2218.69
Triclinic,
a = 13.5451 (4) Å
b = 14.2114 (4) Å
c = 25.0620 (6) Å
α = 80.599 (2)°
β = 76.519 (2)°
γ = 72.734 (2)°
V = 4456.9 (2) Å³
Z = 2
Mo Kα radiation
μ = 2.20 mm⁻¹
T = 298 K
0.31 × 0.20 × 0.15 mm

Data collection

Oxford Diffraction Gemini S Ultra diffractometer
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008 ▶) T _min = 0.516, T _max = 0.719
51671 measured reflections
17430 independent reflections
13557 reflections with I > 2σ(I)
R _int = 0.027

Refinement

R[F ² > 2σ(F ²)] = 0.030
wR(F ²) = 0.074
S = 1.04
17430 reflections
1184 parameters
H-atom parameters constrained
Δρ_max = 0.62 e Å⁻³
Δρ_min = −0.38 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2008 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2008 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg 2008 ▶); software used to prepare material for publication: SHELXL97 and publCIF (Westrip, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809046923/sj2663sup1.cif

e-65-m1559-sup1.cif^{(76KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809046923/sj2663Isup2.hkl

e-65-m1559-Isup2.hkl^{(851.8KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O8W—H81W⋯O4	0.85	1.89	2.720 (3)	163
O8W—H82W⋯O2A	0.85	1.70	2.545 (3)	172
O7W—H21W⋯O5	0.85	1.84	2.677 (3)	167
O7W—H22W⋯O1D	0.85	1.76	2.604 (3)	173
O6W—H61W⋯O2	0.85	1.88	2.723 (3)	174
O6W—H62W⋯O2C	0.85	1.73	2.569 (3)	170
O5W—H51W⋯O6	0.85	1.89	2.731 (3)	171
O5W—H52W⋯O2B	0.85	1.77	2.612 (2)	171
C13A—H13A⋯O4ⁱ	0.93	2.52	3.339 (4)	148
C10D—H10D⋯O1	0.93	2.47	3.294 (4)	147
C13—H13⋯O4B	0.93	2.59	3.514 (4)	175

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Symmetry code: (i) Inline graphic .

Acknowledgments

This work was supported by the National Basic Research Program of China (973 Program, 2007CB815301) and the Science & Technology Innovation Project of Xiamen University (No. K70025).

supplementary crystallographic information

Comment

Schiff base metal compounds have attracted great interest due to their significant potential applications in luminescent materials, ion recognition, biological processes and catalysis (Xu et al., 2007; Wu et al., 2006; Cametti et al., 2008; Shi et al., 2009; Dochnahl et al., 2006; Wu et al., 2007; Rai et al., 2009). In particular, the luminescence properties of zinc compounds make them potentially useful as LED materials (Yu et al., 2007; Kaplunov et al., 2008). Herein we report the structure of an octanuclear zinc^II complex which exhibits strong fluorescence in the solid state.

The X-ray diffraction study shows that Zn^II cations are coordinated in two different distorted square-pyramidal geometries viz. ZnN₂O₃ and ZnO₅. Four Zn^II cations (Zn5, Zn6, Zn7, Zn8) each coordinate to two N atoms and two O atoms from an L^4- which lie in the square plane; the O atom from a coordinated water molecule occupies the vertex position. These Zn—O and Zn—N bond lengths fall within the ranges 1.9821 (17)–2.0468 (18) Å and 2.055 (2)–2.102 (2) Å respectively. The other four inner Zn^II cations (Zn1, Zn2, Zn3, Zn4) are coordinated by five O atoms from three different L^4- ligands. For these the Zn—O bond lengths range from 1.9556 (17) to 2.1604 (18) Å. Distortion of the square pyramids is indicated by the calculated τ values (Addison et al., 1984), the average of which are 0.4446 and 0.7089 for the ZnN₂O₃ and ZnO₅ square-pyramids respectively (for an ideal square-pyramidal geometry, τ = 0). Flexibility, versatility and high µ-O bridging ability of the ligands are the crucial factors in forming the octanuclear unit (Sanmartín et al., 2000). Bond lengths and angles in I fall in the normal ranges and are comparable with those for related structures (Eltayeb et al., 2008; Chen et al., 2009; Miyamoto et al., 2002).

In the crystal structure intermolecular O—H···O, C—H···O hydrogen bonds among the water molecules, solvent molecules and the Zn(II) complex unit form an extensive three dimensional supramolecular structure.

Experimental

The ligand 3,3'-(1E,1'E)-(ethane-1,2-diylbis(azan-1-yl-1-ylidene)) bis(methan-1-yl-1-ylidene)dibenzene-1,2-diol (L) was prepared according to the literature (Casellato et al., 1991; Miyamoto et al., 2002). The title compound (I) was synthesized by mixing L (0.030 g, 0.1 mmol) with zinc acetate dihydrate(0.047 g, 0.2 mmol) in DMF (15 mL). The solution was refluxed with stirring for 5 h, to yield a clear brown solution which was filtered and allowed to evaporate slowly at room temperature for two weeks to give brown block-shaped crystals of I.