μ-Actetato-1:2κ2 O:O′-tribromido-2κ3 Br-(5,5,7,12,12,14-hexa­methyl-1,4,8,11-tetra­aza­cyclo­tetra­deca-1,7-diene-1κ4 N)dizinc(II)

HuaFeng Li; FeiFei Shi; Rong Rong

doi:10.1107/S1600536810033702

. 2010 Sep 30;66(Pt 10):m1338. doi: 10.1107/S1600536810033702

μ-Actetato-1:2κ² O:O′-tribromido-2κ³ Br-(5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-1,7-diene-1κ⁴ N)dizinc(II)

HuaFeng Li ^a, FeiFei Shi ^a,^*, Rong Rong ^b

PMCID: PMC2983256 PMID: 21587467

Abstract

In the title compound, [Zn₂Br₃(CH₃COO)(C₁₆H₃₂N₄)], one Zn^II atom has a distorted square-planar coordination formed by the four macrocyclic N atoms with an acetate O atom in the apical position and the other Zn^II atom has a tetrahedral coordination environment formed by three Br atoms and one O acetate atom. The two Zn^II atoms are linked by an acetate bridge. In the crystal, molecules are linked into centrosymmetric dimers with graph-set motifs R ₂ ²(16) by an N—H⋯Br interaction. The molecular configuration is stabilized by an intramolecular N—H⋯Br hydrogen bond.

Related literature

For related macrocyclic complexes, see: Whimp et al. (1970 ▶); Yang (2005 ▶); Tebbe et al. (1985 ▶). The unsubstituted parent compound exists in the zwitterionic form, see: Spirlet et al. (1991 ▶); Maurya et al. (1991 ▶). For the preparation of the precursor complex C₁₆H₃₂N₄·2HBr·2H₂O, see: Hay et al. (1975 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

[Zn₂Br₃(C₂H₃O₂)(C₁₆H₃₂N₄)]
M _r = 709.97
Monoclinic,
a = 10.2964 (8) Å
b = 13.6985 (13) Å
c = 18.5235 (18) Å
β = 92.280 (1)°
V = 2610.6 (4) Å³
Z = 4
Mo Kα radiation
μ = 6.45 mm⁻¹
T = 298 K
0.43 × 0.42 × 0.22 mm

Data collection

Rigaku SCXmini diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ▶) T _min = 0.240, T _max = 0.428
13032 measured reflections
4608 independent reflections
2923 reflections with I > 2σ(I)
R _int = 0.038

Refinement

R[F ² > 2σ(F ²)] = 0.032
wR(F ²) = 0.067
S = 0.88
4608 reflections
269 parameters
H-atom parameters constrained
Δρ_max = 0.57 e Å⁻³
Δρ_min = −0.55 e Å⁻³

Data collection: CrystalClear (Rigaku, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810033702/bx2283sup1.cif

e-66-m1338-sup1.cif^{(21.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810033702/bx2283Isup2.hkl

e-66-m1338-Isup2.hkl^{(225.8KB, 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
N3—H3⋯Br2ⁱ	0.91	2.80	3.549 (3)	140
N1—H1⋯Br1	0.91	2.74	3.641 (3)	171

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Symmetry code: (i) Inline graphic .

supplementary crystallographic information

Comment

The structures of several related macrocyclic complexes have been reported (Whimp et al., 1970; Yang, 2005; Tebbe et al., 1985). The unsubstituted parent compound exists in the zwitterionic form (Maurya et al., 1991; Spirlet et al., 1991). The zinc teraazamacrocyclic complex cation, [Zn(C₁₆H₃₂N₄)] ²⁺, can combine with different anions to form many kinds of structures.

We herein report the crystal structure of a new compound synthesized by reaction of Zn(CH₃COO)₂.2H₂O and the complex C₁₈H₃₂N₄.2HBr.2H₂O, Fig.1. The structural analysis reveals that the title complex is formed by a discrete neutral dinuclear C₁₈H₃₅N₄O₂Br₃Zn₂ molecule consisting of two Zn atoms bridged by an acetate with the distance of 6.512 (1) Å between the them. Zn(1) is five-coordinated by the four macrocyclic N atoms with acetate O atom as an apical ligand while that the other Zn atom is in a tetrahedron coordinate environment formed by three bromine atoms and one O acetate atom. The average Zn—N(amine) bond distance of 2.1546 (5)Å and Zn—N(imine) bond distance of 2.0582 (5) Å). The average Zn—Br bond distance of 2.4070 (6) Å, the Zn(1)—O(1) bond distance of` 2.0030 (1) Å and the Zn(2)—O(2) bond distance of` 1.9967 (1) Å). In the crystal the molecules are linked into centrosymmetric dimers with graph-set notation R²₂(16) motifs by a N—H···Br interaction, centred at [1/2,1/2,0] (Bernstein et al., 1995), Fig. 2. The molecular conformation is stabilized by one intramolecular N—H···Br hydrogen bond. Table 1.

Experimental

All chemicals were of reagent grade and were used as received without further purification. The precursor complex C₁₈H₃₂N₄.2HBr.2H₂O was prepared by the literature method (Hay et al.,1975). To a 10 ml me thanol solution of Zn(CH₃COO)₂.2H₂O(0.2 mmol,0.039 g), a 5 ml methanol solution of C₁₈H₃₂N₄.2HBr.2H₂O (0.2 mmol,0.0957 g) was added dropwise with stirring. The resulting solution was continuously stirred for about 30 min. Colourless crystals suitable for X-ray analysis were obtained by slow evaporation at room temperature over several days.