Bis(2-amino­pyrimidine-κN 1)dibromidozinc(II)

Yang Qu; Shi Ming Zhang; Xian Zong Wu; Huan Zhang; Zhi Dong Lin

doi:10.1107/S1600536808006466

. 2008 Apr 30;64(Pt 5):m732. doi: 10.1107/S1600536808006466

Bis(2-aminopyrimidine-κN ¹)dibromidozinc(II)

Yang Qu ^a,^*, Shi Ming Zhang ^a, Xian Zong Wu ^a, Huan Zhang ^a, Zhi Dong Lin ^b

PMCID: PMC2961077 PMID: 21202255

Abstract

The title compound, [ZnBr₂(C₄H₅N₃)₂], is a mononuclear complex in which the Zn^II ions have distorted tetrahedral coordination geometry. The Zn^II ion binds to two N atoms from two different 2-aminopyrimidine ligands and two bromide ions. N—H⋯N hydrogen bonds link the molecules to form a one-dimensional supramolecular structure. The supramolecular chains are parallel to each other and N—H⋯Br hydrogen bonds link them into a two-dimensional network in the ac plane. Additionally, there are strong π–π interactions [centroid–centroid distance = 3.403 (3) Å].

Related literature

For related literature, see: Bourne et al. (2001 ▶); Etter et al. (1990 ▶); Lin & Zeng (2007 ▶); Pon et al. (1997 ▶).

Experimental

Crystal data

[ZnBr₂(C₄H₅N₃)₂]
M _r = 415.41
Triclinic,
a = 6.7912 (11) Å
b = 7.2197 (12) Å
c = 15.512 (3) Å
α = 81.060 (3)°
β = 83.823 (3)°
γ = 63.132 (2)°
V = 669.61 (19) Å³
Z = 2
Mo Kα radiation
μ = 7.79 mm⁻¹
T = 292 (2) K
0.20 × 0.16 × 0.14 mm

Data collection

Siemens SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.305, T _max = 0.408 (expected range = 0.251–0.336)
5351 measured reflections
2342 independent reflections
1878 reflections with I > 2σ(I)
R _int = 0.073

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.110
S = 1.02
2342 reflections
156 parameters
H-atom parameters constrained
Δρ_max = 0.80 e Å⁻³
Δρ_min = −0.69 e Å⁻³

Data collection: SMART (Siemens, 1996 ▶); cell refinement: SAINT (Siemens, 1996 ▶); data reduction: SAINT; 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 global, I. DOI: 10.1107/S1600536808006466/rn2036sup1.cif

e-64-0m732-sup1.cif^{(16.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808006466/rn2036Isup2.hkl

e-64-0m732-Isup2.hkl^{(115.1KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Br1—Zn1	2.3528 (9)
Br2—Zn1	2.3593 (8)
N1—Zn1	2.060 (4)
N4—Zn1	2.056 (4)

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C8—H8⋯Br2ⁱ	0.93	2.87	3.651 (5)	142
N6—H6B⋯N5ⁱⁱ	0.89	2.47	2.996 (6)	119
N3—H3A⋯Br2	0.75	2.74	3.480 (5)	170

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

The authors are grateful for financial support from the Bureau of Science and Technology of Wuhan City, Hubei Province, People’s Republic of China (grant No. 20055003059-28).

supplementary crystallographic information

Comment

Recently, the design of molecular architecture with pyrimidine and bipyrimidine has aroused interest in the fields of coordination, bioinorganic and magnetochemistry (Pon et al., 1997).

In our laboratory, analogous crystals have been obtained from the interaction of zinc(lI) chloride with 2-aminopyrimidine (Lin & Zeng, 2007). As an extension of this work, we report the crystal structure of the title compound, (I), bis(2-aminopyrimidine)-zinc(II) bromide. Compound I contains discrete L₂CuBr₂ molecules (L: 2-aminopyrimidine). The Zn^II ion is coordinated by two N atoms from two different 2-aminopyrimidine ligands and two Br anions, giving distorted tetrahedral coordination geometry [mean Zn—N = 2.058 (8) Å and mean Zn—Br = 2.356 (4) Å]. The bond lengths and angles of Zn—N and Zn—Br (Table 1) are within the expected ranges (Bourne et al., 2001).

In the crystal structure, N—H···N hydrogen bonds and N—H···Br hydrogen bonds (Table 2) help to establish the crystal packing. The 2-aminopyrimidine molecules form N—H···N hydrogen bonds, resulting in eight membered ring graph-set motif, [R²₂(8)] (Etter et al., 1990). The N—H···N hydrogen bonds bind the neighboring 2-aminopyrimidine molecules to form a zigzag one-dimensional ribbon structure. The supramolecular ribbons are parallel to each other and N—H···Br hydrogen bonds link them into a two-dimensional network. The close distance, 3.403 (3) Å, between the centroids of two rings (N4,N5,C5,C6,C7,C8 and its symmetry equivalent at -x,1 - y,1 - z) indicates that there are also strong π -π interactions.

Experimental

10 ml e thanol solution containing ZnBr₂ (0.5 mmol) and 2-aminopyrimidine (1.0 mmol) was stirred at room temperature for 12 h and then filtered. The filtrate was kept at room temperature in the dark for two weeks to give white crystals of (I). The crystals were isolated and washed three times with ethanol and dried in a vacuum desiccator using anhydrous CaCl₂. Analysis calculated for C₈N₆H₁₀ Zn Br₂: C 23.13, N 20.23, H 2.43%; found: C 23.19, N 20.46,H 2.61%.