Home Crystal structure of tetrakis(μ2-acetato-κ2O:O′)-bis{[(E)-2,6-diisopropyl-N-(pyridin-3-ylmethylene)aniline]copper (II)}, C44H56Cu2N4O8
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Crystal structure of tetrakis(μ2-acetato-κ2O:O′)-bis{[(E)-2,6-diisopropyl-N-(pyridin-3-ylmethylene)aniline]copper (II)}, C44H56Cu2N4O8

  • Eric M. Njogu , Bernard Omondi EMAIL logo and Vincent O. Nyamori
Published/Copyright: February 27, 2018

Abstract

C44H56Cu2N4O8, monoclinic, P21/c (no. 14), a = 11.1061(10) Å, b = 20.5117(17) Å, c = 9.8185(9) Å, β = 101.302(2)°, V = 2193.27(15) Å3, Z = 2, Rgt(F) = 0.0283, wRref(F2) = 0.0753, T = 100 K.

CCDC no.: 1824267

The crystal structure is shown in the figure. Tables 1 and 2 contain details on crystal structure and measurement conditions and a list of the atoms including atomic coordinates and displacement parameters.

Table 1:

Data collection and handling.

Crystal:Block, blue
Size:0.32 × 0.25 × 0.18 mm
Wavelength:Mo radiation (0.71073 Å)
μ:1.02 mm−1
Diffractometer, scan mode:Bruker APEX-II, φ and ω-scans (0.5° scan width)
2θmax, completeness:28.7°, >98%
N(hkl)measured, N(hkl)unique, Rint:25678, 5527, 0.032
Criterion for Iobs, N(hkl)gt:Iobs > 2 σ(Iobs), 4676
N(param)refined:264
Programs:Bruker programs [1], SHELX [2], WinGX and ORTEP [3]
Table 2:

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2).

AtomxyzUiso*/Ueq
C10.42735(14)0.84025(8)0.25417(17)0.0194(3)
H10.36120.87040.24410.023*
C20.42480(15)0.78620(8)0.33738(18)0.0221(3)
H20.35780.77930.38280.027*
C30.52134(14)0.74203(8)0.35381(16)0.0181(3)
H30.52160.70460.41090.022*
C40.61768(13)0.75361(7)0.28516(15)0.0135(3)
C50.61223(13)0.80931(7)0.20224(15)0.0135(3)
H50.67750.81720.15470.016*
C60.72206(13)0.70754(7)0.30142(15)0.0148(3)
H60.72630.67270.36590.018*
C70.90572(13)0.66830(7)0.24978(15)0.0136(3)
C81.00373(13)0.67256(7)0.36445(15)0.0140(3)
C91.10227(14)0.62954(8)0.36973(15)0.0159(3)
H91.17000.63220.44540.019*
C101.10367(14)0.58314(8)0.26750(16)0.0171(3)
H101.17070.55370.27440.021*
C111.00621(14)0.57998(8)0.15483(16)0.0170(3)
H111.00730.54820.08470.020*
C120.90718(13)0.62247(7)0.14292(15)0.0145(3)
C130.79870(14)0.61684(8)0.02196(16)0.0201(3)
H130.76170.66120.00370.024*
C140.83619(17)0.59318(10)−0.11184(17)0.0272(4)
H14A0.76330.5904−0.18620.041*
H14B0.89490.6240−0.13870.041*
H14C0.87440.5501−0.09620.041*
C150.70070(17)0.57193(11)0.0607(2)0.0331(4)
H15A0.63130.5687−0.01790.050*
H15B0.73580.52850.08340.050*
H15C0.67220.58980.14140.050*
C161.00516(14)0.71915(8)0.48554(16)0.0167(3)
H160.93250.74870.46150.020*
C171.12142(15)0.76140(9)0.51546(18)0.0246(4)
H17A1.11810.79040.59390.037*
H17B1.19390.73320.53840.037*
H17C1.12660.78750.43320.037*
C180.99229(17)0.67992(9)0.61509(17)0.0243(3)
H18A0.99320.70970.69330.036*
H18B0.91460.65580.59670.036*
H18C1.06080.64920.63800.036*
C190.71767(13)0.98619(7)−0.03791(15)0.0146(3)
C200.84622(14)0.98026(8)−0.06287(18)0.0203(3)
H20A0.86881.0205−0.10570.030*
H20B0.85100.9434−0.12500.030*
H20C0.90290.97310.02580.030*
C210.57472(13)1.06026(8)0.22624(16)0.0169(3)
C220.61568(16)1.09716(9)0.36129(17)0.0257(4)
H22A0.62371.06680.43950.039*
H22B0.55471.13060.37020.039*
H22C0.69511.11800.36130.039*
N10.51943(11)0.85205(6)0.18668(13)0.0145(2)
N20.80586(11)0.71351(6)0.23143(13)0.0148(3)
O10.56977(11)0.99928(6)0.23156(11)0.0228(3)
O20.67803(10)0.94048(6)0.02725(13)0.0231(3)
O30.45062(12)0.90597(6)−0.11736(12)0.0265(3)
O40.34195(10)0.96346(6)0.08361(13)0.0216(2)
Cu10.51172(2)0.94417(2)0.06731(2)0.01267(6)

Source of material

The title compound was prepared though reaction of copper(II) acetate monohydrate (0.4045 g, 2 mmol) and (E)-2,6-diisopropyl-N-(pyridin-3-ylmethylene)aniline (0.5348 g, 2 mmol) in ethanol for 12 h. A sky blue precipitate was obtained that was disolved in dichloromethane and layered with hexane to give crystals. Yield 0.7556 g 84%.

Experimental details

All hydrogen atoms were placed in idealized positions and refined in riding models with Uiso assigned the values of 1.2 times those of their parent atoms and the distances of C—H were constrained to 0.93 Å for all the aromatic H atoms, 0.96 Å for methyl hydrogens and 0.98 Å for methine hydrogen.

Discussion

The title compound is a discrete complex bearing the centrosymmetric dinuclear copper(II) paddle wheel unit where four acetate ligands bridge the copper(II) ions. The axial positions are occupied by a N atom of (E)-2,6-diisopropyl-N-(pyridin-3-ylmethylene)aniline ligand, as shown in the figure. This paddle wheel has been previously reported in copper(II) acetate complexes [4, 5] . The distance between the bridged copper(II) ions is 2.6317(4) Å, typically for dimeric copper(II) carboxylates [6]. The copper(II) ions are slightly displaced from the basal plane of the four acetate O atoms by a distance of 0.198 Å towards the pyridine nitrogen, a trend that has also been reported [7]. The copper(II) ions are thus in a distorted square bipyramidal geometrical environment courtesy of the aforementioned coordination [8]. The asymmetric unit of the title compound bears half of the complex, i.e. one copper(II) ion, one (E)-2,6-diisopropyl-N-(pyridin-3-ylmethylene)aniline ligand and two acetate groups, the other half of the molecule is generated by −x + 1, −y + 2, −z symmetry. The phenyl and pyridyl rings are not coplanar and the angle between the mean planes of the phenyl ring including the imine N atom to that of the pyridyl ring including the imine C atom is 82.00(4)°. This angle is clearly larger than that reported for the free ligand, i.e. 60.00° [9]. The azomethine (C=N) bond length in the complex is 1.267(2) Å, similar to the one in the ligand 1.270(1) Å [9]. The two C—N bonds in the pyridyl moiety of the complex are 1.35 and 1.34 Å, slightly longer than their equivalent bonds in the pyridyl moiety of the free ligand [9]. The N(1)—Cu(1), O(1)—Cu(1) and O(2)—Cu(1) bond distances are 2.2162(13), 1.9716(11) and 1.9639(11) Å, respectively, which are similar to those of previously reported copper(II) complexes [10, 11] .

Acknowledgements

We acknowledge the University of KwaZulu-Natal and National Research Foundation of South Africa for financial support for Eric N Njogu.

References

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Received: 2017-10-9
Accepted: 2018-2-15
Published Online: 2018-2-27
Published in Print: 2018-5-24

©2018 Eric M. Njogu et al., published by De Gruyter, Berlin/Boston

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

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