trans-Diaqua­bis{1,3-bis­[5-(2-pyrid­yl)-2H-tetra­zol-2-yl]propane}zinc(II) bis­(perchlorate)

Hugo Gallardo; Fernando Molin; Adailton J Bortoluzzi; Ademir Neves

doi:10.1107/S1600536808006703

. 2008 Mar 14;64(Pt 4):m541–m542. doi: 10.1107/S1600536808006703

trans-Diaquabis{1,3-bis[5-(2-pyridyl)-2H-tetrazol-2-yl]propane}zinc(II) bis(perchlorate)

Hugo Gallardo ^a,^*, Fernando Molin ^a, Adailton J Bortoluzzi ^a, Ademir Neves ^a

PMCID: PMC2960969 PMID: 21202000

Abstract

The Zn^II ion in the title compound, [Zn(C₁₅H₁₄N₁₀)(H₂O)₂](ClO₄)₂, lies on a centre of symmetry. The distorted N₄O₂ octahedral coordination environment around the Zn atom is composed of two 1,3-bis[5-(2-pyridyl)-2H-tetrazol-2-yl]propane ligands (L1) and two water molecules, coordinated in trans positions. The ligand acts as a typical bidentate chelating ligand through one of its 2-pyridyl-2H-tetrazole units, forming a five-membered Zn—N—C—C—N metallacycle with a small N—Zn—N bite angle [77.40 (8)°]. The other 2-pyridyl-2H-tetrazole unit remains uncoordinated. The average Zn—N distance (2.156 Å) is somewhat longer than the distance between the Zn^II center and the aqua ligand [2.108 (2) Å]. The coordinated pyridyl-tetrazoyl rings are quasi-coplanar, making a dihedral angle of 1.9 (2)°, while the uncoordinated rings show a larger interplanar angle of 21.3 (2)°. The flexible propane spacer displays a zigzag chain. Intermolecular O—H⋯N and O—H⋯O interactions result in two-dimensional polymeric structures parallel to (100). Two C atoms of the spacer are disordered over two positions, with site occupancy factors of ca 0.85 and 0.15.

Related literature

For related literature, see: Fan et al. (2005 ▶); Gallardo et al. (2001 ▶, 2004 ▶); Gong et al. (2004 ▶); Mizukami et al. (2005 ▶); Rodríguez-Diéguez et al. (2007 ▶); Wang et al. (2005 ▶).

Experimental

Crystal data

[Zn(C₁₅H₁₄N₁₀)(H₂O)₂](ClO₄)₂
M _r = 969.03
Monoclinic,
a = 7.378 (3) Å
b = 13.354 (3) Å
c = 20.764 (4) Å
β = 99.25 (2)°
V = 2019.2 (10) Å³
Z = 2
Mo Kα radiation
μ = 0.82 mm⁻¹
T = 293 (2) K
0.50 × 0.46 × 0.20 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: ψ scan (North et al., 1968 ▶) T _min = 0.682, T _max = 0.853
3873 measured reflections
3576 independent reflections
2826 reflections with I > 2σ(I)
R _int = 0.016
3 standard reflections every 200 reflections intensity decay: 1%

Refinement

R[F ² > 2σ(F ²)] = 0.035
wR(F ²) = 0.097
S = 1.06
3576 reflections
305 parameters
3 restraints
H-atom parameters constrained
Δρ_max = 0.30 e Å⁻³
Δρ_min = −0.41 e Å⁻³

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994 ▶); cell refinement: SET4 in CAD-4 EXPRESS; data reduction: HELENA (Spek, 1996 ▶); program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2003 ▶) and Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: SHELXL97 and publCIF (Westrip, 2008 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808006703/bg2168sup1.cif

e-64-0m541-sup1.cif^{(20.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808006703/bg2168Isup2.hkl

e-64-0m541-Isup2.hkl^{(171.8KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Zn1—O1W	2.1079 (18)
Zn1—N17	2.149 (2)
Zn1—N11	2.170 (2)

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Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1W—H1WA⋯O11	0.86	2.01	2.869 (3)	172
O1W—H1WB⋯N21ⁱ	0.86	1.97	2.833 (3)	178

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação de Apoio à Pesquisa Científica e Tecnológica do Estado de Santa Catarina (FAPESC), Financiadora de Estudos e Projetos (FINEP) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).

supplementary crystallographic information

Comment

New compounds for the research of supramolecular chemistry and crystal engineering have been extensively described in the literature in the last few years (Wang et al., 2005; Fan et al., 2005; Rodríguez-Diéguez et al., 2007). Self-assembly processes involving organic ligands and metal ions have attracted much attention from the point of view of the development of novel functional materials with unique electronic, magnetic, catalytic and optical properties. However, while an accurate prediction of the overall crystal structure of such materials is not often an easy task, the introduction of rational organic ligands acting as building blocks has been recognized as a crucial synthetic strategy to overcome such difficulties. The syntheses of aromatic molecules containing nitrogen donor groups and which are interconnected by different type of spacers, such as conformationally rigid or flexible molecular skeletons, have been widely utilized as building blocks (Mizukami et al., 2005; Gallardo et al., 2001; Gong et al., 2004).

The synthesis and X-ray crystal structure of the ligand 1,3-Bis-[(2-pyridyl)-2H-tetrazol-5-yl]propane (L1) has been described previously (Gallardo et al., 2004). We report herein the title cation complex [Zn(L1)₂(H₂O)₂]²⁺. The Zn^II atom lies on a center of symmetry and its distorted octahedral coordination is achieved through the interaction with four nitrogen atoms of two trans L1 ligands, defining the equatorial plane and two water molecules in apical positions (Fig. 1). The basal Zn1—N17 (2.149 (2) Å) and Zn1—N11 (2.170 (2) Å) distances are somewhat larger than the apical ones (Zn1—O1W: (2.108 (2) Å). Some conformational differences in the structure of the two 2-pyridyl-2H-tetrazoyl units in the L1 ligand can be observed: the coordination of the pyridyl and tetrazoyl rings of one of the units to the metal center imposes structural rigidity in this moiety, and the rings become rings quasi coplanar with an interplanar angle of 1.9 (2)°. The N11—C10—C16 angle (113.5 (2)°) is smaller than the expected value due to the restriction of the five-membered chelate ring. On the other hand, in the uncoordinated unit the bond the corresponding rings are free to rotate around C20—C26 and the interplanar angle between angle climbs up to 21.3 (2)°. Besides, the N21—C20—C26 angle (116.6 (2)°) is significantly larger than the one in the coordinated unit. A two-dimensional polymeric structure parallel to (100) is formed by intermolecular O—H···N interactions (Fig. 2). Finally, the perchlorate counterion is also connected to the polymeric structure by a O—H···O interaction.

Experimental

Ligand L1 (obtained as described in Gallardo et al., 2004) was added to a suspension of Zn(ClO)₄.6H₂O in Ethanol and stirred at 50°C for 30 min. The white product was filtered off and recrystallized from isopropyl alcohol/water (1:1) affording white crystals. Yield: 61%. Elemental analysis. Calc. C₃₀H₃₂Cl₂N₂₀O₁₀Zn: C 37.18, H 3.33, N 28.91%. Found: C 37.27, H 3.29, N 28.98%.