Diiodidobis[4-(4-nitro­benz­yl)pyridine-κN 1]zinc

Graham Smith; Urs D Wermuth; Michael L Williams

doi:10.1107/S1600536811005939

. 2011 Feb 23;67(Pt 3):m359. doi: 10.1107/S1600536811005939

Diiodidobis[4-(4-nitrobenzyl)pyridine-κN ¹]zinc

Graham Smith ^a,^*, Urs D Wermuth ^a, Michael L Williams ^b

PMCID: PMC3052165 PMID: 21522285

Abstract

The asymmetric unit of the title compound, [ZnI₂(C₁₂H₁₀N₂O₂)₂], obtained from the reaction of 4-(4-nitrobenzyl)pyridine with zinc(II) iodide, contains two independent discrete distorted tetrahedral complex units [Zn—I = 2.5472 (8)–2.5666 (7) Å and Zn—N = 2.044 (4)–2.052 (4) Å], which are essentially identical conformationally. The crystal used for measurement was a racemic twin.

Related literature

For the structures of some Zn^II–pyridine complexes, see: Le Querler et al. (1977 ▶); Pasaoglu et al. (2006 ▶); Fan & Wu (2006 ▶). For the structure of a mixed-ligand Pt^II complex with 4-(4-nitrobenzyl)pyridine, see: Chan et al. (1993 ▶).

Experimental

Crystal data

[ZnI₂(C₁₂H₁₀N₂O₂)₂]
M _r = 747.61
Orthorhombic,
a = 18.2091 (2) Å
b = 15.8998 (3) Å
c = 19.0327 (3) Å
V = 5510.37 (15) Å³
Z = 8
Mo Kα radiation
μ = 3.17 mm⁻¹
T = 200 K
0.40 × 0.22 × 0.15 mm

Data collection

Oxford Diffraction Gemini-S Ultra CCD detector diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2010 ▶) T _min = 0.865, T _max = 0.980
18536 measured reflections
10102 independent reflections
7499 reflections with I > 2σ(I)
R _int = 0.024

Refinement

R[F ² > 2σ(F ²)] = 0.032
wR(F ²) = 0.056
S = 0.89
10102 reflections
627 parameters
25 restraints
H-atom parameters not refined
Δρ_max = 0.63 e Å⁻³
Δρ_min = −0.47 e Å⁻³
Absolute structure: Flack (1983 ▶), 4516 Friedel pairs
Flack parameter: 0.430 (14)

Data collection: CrysAlis PRO (Oxford Diffraction, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶) within WinGX (Farrugia, 1999 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: PLATON.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811005939/ng5114sup1.cif

e-67-0m359-sup1.cif^{(37.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811005939/ng5114Isup2.hkl

e-67-0m359-Isup2.hkl^{(484.1KB, hkl)}

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

Acknowledgments

The authors acknowledge financial support from the Australian Research Committee, the Faculty of Science and Technology and the University Library, Queensland University of Technology, and the School of Biomolecular and Physical Sciences, Griffith University.

supplementary crystallographic information

Comment

The structures of complexes of ZnI₂ with pyridine and substituted pyridine ligands, of the type [ZnI₂(py)₂] are common in the crystallographic literature e.g. with pyridine (Le Querler et al., 1977), and with nicotinamide and isonicotinamide (Pasaoglu et al., 2006). These complexes are usually discrete with distorted tetrahedral stereochemistry. Polymeric complexes having similar stereochemistry are also formed with bifunctional pyridines such as 4,4'-bipyridine (Fan & Wu, 2006). We obtained the title compound [ZnI₂(C₁₂H₁₀N₂O₂)₂] (I) from the reaction of zinc(II) iodide with 4-(4-nitrobenzyl)pyridine (L) and the structure is reported here. This substituted pyridine has only occasionally been used as a ligand in metal complex formation e.g. in the mixed-ligand Pt^II complex with 2,9-diphenyl-1,10-phenanthroline (Chan et al., 1993).

In the structure of (I), the asymmetric unit contains two independent discrete distorted tetrahedral [ZnI₂L₂] complex units, involving Zn1 and Zn2 (Figs. 1, 2). The Zn—I range is 2.5472 (8)–2.5666 (7) Å, the Zn—N range is 2.044 (4)–2.052 (4) Å and the bond angle range about Zn is 98.99 (17)–119.96 (2)° (for I1—Zn1—I2 and N1A—Zn1—N1B, respectively). The two complex molecules are essentially identical conformationally and are related by pseudo-symmetry, being treated as a racemic twin in the structure refinement.

In the crystal packing of (I) there are only weak intermolecular aromatic C—H···O_nitro interactions [C5A—H···O41D, 3.211 (9) Å and C6B—H···O41B, 3.295 Å] but there are some aromatic ring π–π associations involving the C11B–C61B rings: ring centroid separation, 3.591 (3) Å; inter-ring dihedral angle, 3.46 (1)°] (Fig. 3).

Experimental

The title compound was synthesized by heating together under reflux for 10 minutes, 1 mmol of zinc(II) iodide and 2 mmol of 4-(4-nitrobenzyl)pyridine in 50 ml of 50% ethanol–water. After concentration to ca 30 ml, partial room temperature evaporation of the hot-filtered solution gave pale yellow flattened prisms of (I) from which a suitable specimen was cleaved for the X-ray analysis.