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Acta Cryst. (2008). E64, m732    [ doi:10.1107/S1600536808006466 ]

Bis(2-aminopyrimidine-[kappa]N1)dibromidozinc(II)

Y. Qu, S. M. Zhang, X. Z. Wu, H. Zhang and Z. D. Lin

Abstract top

The title compound, [ZnBr2(C4H5N3)2], is a mononuclear complex in which the ZnII ions have distorted tetrahedral coordination geometry. The ZnII 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 [pi]-[pi] interactions [centroid-centroid distance = 3.403 (3) Å].

Comment top

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 ZnII 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.

Related literature top

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

Experimental top

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%.

Refinement top

The H atoms bonded to C atoms were placed in calculated positions, and were allowed to ride on their parent C atoms, with a distance of 0.93 Å for aromatic H atoms and Uiso(H) = 1.2 times its parent atom. The H atoms of –NH2 were found from residue peaks in the difference map. The H atoms of the NH2 group were placed in geometrically calculated positions and the N—H distance restrained to 0.86 (2) Å. The isotropic displacement parameters were set equal to 1.5Ueq(parent N atom) for amino H atoms.

Computing details top

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT (Siemens, 1996); 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 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular components of (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level.
[Figure 2] Fig. 2. Crystal packing of (I) viewed along the a axis. The O–H···N and Br—H···N hydrogen bonding interactions are shown as dashed lines.
Bis(2-aminopyrimidine-κN1)dibromidozinc(II) top
Crystal data top
[ZnBr2(C4H5N3)2]Z = 2
Mr = 415.41F000 = 400
Triclinic, P1Dx = 2.060 Mg m−3
Hall symbol: -P 1Mo Kα radiation
λ = 0.71073 Å
a = 6.7912 (11) ÅCell parameters from 2800 reflections
b = 7.2197 (12) Åθ = 2.1–28.7º
c = 15.512 (3) ŵ = 7.79 mm−1
α = 81.060 (3)ºT = 292 (2) K
β = 83.823 (3)ºBlock, white
γ = 63.132 (2)º0.20 × 0.16 × 0.14 mm
V = 669.61 (19) Å3
Data collection top
Siemens SMART CCD area-detector
diffractometer		2342 independent reflections
Radiation source: fine-focus sealed tube1878 reflections with I > 2σ(I)
Monochromator: graphiteRint = 0.074
T = 292(2) Kθmax = 25.0º
φ and ω scansθmin = 2.7º
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)		h = −8→7
Tmin = 0.305, Tmax = 0.409k = −8→8
5351 measured reflectionsl = −18→18
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.041H-atom parameters constrained
wR(F2) = 0.110  w = 1/[σ2(Fo2) + (0.0639P)2]
where P = (Fo2 + 2Fc2)/3
S = 1.02(Δ/σ)max < 0.001
2342 reflectionsΔρmax = 0.80 e Å−3
156 parametersΔρmin = −0.68 e Å−3
Primary atom site location: structure-invariant direct methodsExtinction correction: none
Crystal data top
[ZnBr2(C4H5N3)2]γ = 63.132 (2)º
Mr = 415.41V = 669.61 (19) Å3
Triclinic, P1Z = 2
a = 6.7912 (11) ÅMo Kα
b = 7.2197 (12) ŵ = 7.79 mm−1
c = 15.512 (3) ÅT = 292 (2) K
α = 81.060 (3)º0.20 × 0.16 × 0.14 mm
β = 83.823 (3)º
Data collection top
Siemens SMART CCD area-detector
diffractometer		2342 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)		1878 reflections with I > 2σ(I)
Tmin = 0.305, Tmax = 0.409Rint = 0.074
5351 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.041156 parameters
wR(F2) = 0.110H-atom parameters constrained
S = 1.02Δρmax = 0.80 e Å−3
2342 reflectionsΔρmin = −0.68 e Å−3
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Br10.19184 (13)0.75744 (9)0.20800 (4)0.0660 (2)
Br20.57558 (9)0.19239 (9)0.31136 (4)0.0528 (2)
C10.2693 (11)0.1954 (8)0.0989 (3)0.0472 (14)
C2−0.0153 (14)0.2437 (10)0.0194 (4)0.0631 (18)
H2−0.06640.2230−0.02980.076*
C3−0.1718 (12)0.3635 (10)0.0799 (4)0.0613 (17)
H3−0.32310.41710.07370.074*
C4−0.0852 (11)0.3955 (9)0.1486 (4)0.0527 (15)
H4−0.18150.47670.19010.063*
C5−0.0098 (7)0.2696 (8)0.4074 (3)0.0322 (10)
C6−0.2637 (9)0.4775 (9)0.5028 (3)0.0470 (14)
H6−0.34390.49250.55590.056*
C7−0.2909 (8)0.6530 (9)0.4488 (4)0.0481 (14)
H7−0.39320.78480.46220.058*
C8−0.1607 (8)0.6272 (8)0.3737 (3)0.0452 (13)
H8−0.17380.74490.33570.054*
N10.1338 (8)0.3141 (7)0.1588 (2)0.0412 (10)
N20.1963 (11)0.1600 (8)0.0279 (3)0.0594 (14)
N30.4858 (9)0.1121 (9)0.1065 (3)0.0674 (16)
H3A0.51010.11350.15240.101*
H3B0.55060.15970.06070.101*
N4−0.0134 (6)0.4360 (6)0.3530 (2)0.0356 (9)
N5−0.1293 (7)0.2848 (7)0.4844 (3)0.0414 (10)
N60.1223 (8)0.0761 (7)0.3887 (3)0.0477 (11)
H6A0.16460.08020.34210.071*
H6B0.04490.00260.39500.071*
Zn10.22458 (9)0.41974 (8)0.25651 (3)0.0358 (2)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.1151 (6)0.0446 (4)0.0495 (4)−0.0468 (4)0.0003 (3)−0.0032 (3)
Br20.0431 (4)0.0522 (4)0.0541 (4)−0.0125 (3)0.0026 (3)−0.0125 (3)
C10.082 (5)0.042 (3)0.033 (3)−0.042 (3)0.011 (3)−0.011 (2)
C20.115 (6)0.062 (4)0.037 (3)−0.061 (4)−0.013 (3)0.002 (3)
C30.086 (5)0.067 (4)0.051 (4)−0.051 (4)−0.017 (3)0.005 (3)
C40.081 (5)0.050 (3)0.040 (3)−0.040 (3)−0.002 (3)−0.005 (3)
C50.027 (2)0.041 (3)0.027 (2)−0.014 (2)0.0021 (18)−0.007 (2)
C60.042 (3)0.068 (4)0.038 (3)−0.028 (3)0.009 (2)−0.024 (3)
C70.032 (3)0.050 (3)0.058 (3)−0.010 (3)0.009 (2)−0.024 (3)
C80.041 (3)0.037 (3)0.045 (3)−0.006 (2)0.001 (2)−0.007 (2)
N10.063 (3)0.049 (3)0.027 (2)−0.037 (2)0.0078 (19)−0.0118 (19)
N20.109 (5)0.058 (3)0.036 (3)−0.056 (3)0.004 (3)−0.015 (2)
N30.081 (4)0.090 (4)0.049 (3)−0.049 (3)0.023 (3)−0.041 (3)
N40.036 (2)0.038 (2)0.030 (2)−0.0123 (18)0.0025 (16)−0.0095 (18)
N50.040 (2)0.056 (3)0.030 (2)−0.023 (2)0.0061 (18)−0.011 (2)
N60.056 (3)0.044 (3)0.042 (3)−0.022 (2)0.014 (2)−0.011 (2)
Zn10.0478 (4)0.0332 (3)0.0277 (3)−0.0190 (3)0.0045 (2)−0.0081 (2)
Geometric parameters (Å, °) top
Br1—Zn12.3528 (9)C5—N51.360 (6)
Br2—Zn12.3593 (8)C6—N51.330 (7)
C1—N31.324 (8)C6—C71.354 (8)
C1—N11.340 (7)C6—H60.9300
C1—N21.358 (7)C7—C81.368 (8)
C2—N21.295 (9)C7—H70.9300
C2—C31.401 (10)C8—N41.353 (6)
C2—H20.9300C8—H80.9300
C3—C41.368 (8)N1—Zn12.060 (4)
C3—H30.9300N3—H3A0.7500
C4—N11.347 (8)N3—H3B0.9006
C4—H40.9300N4—Zn12.056 (4)
C5—N61.333 (6)N6—H6A0.7500
C5—N41.348 (6)N6—H6B0.8901
N3—C1—N1119.5 (5)N4—C8—H8119.0
N3—C1—N2117.2 (5)C7—C8—H8119.0
N1—C1—N2123.2 (6)C1—N1—C4117.6 (5)
N2—C2—C3124.1 (6)C1—N1—Zn1126.4 (4)
N2—C2—H2118.0C4—N1—Zn1115.4 (3)
C3—C2—H2118.0C2—N2—C1117.5 (6)
C4—C3—C2114.9 (7)C1—N3—H3A109.5
C4—C3—H3122.5C1—N3—H3B111.2
C2—C3—H3122.5H3A—N3—H3B120.6
N1—C4—C3122.7 (6)C5—N4—C8116.8 (4)
N1—C4—H4118.6C5—N4—Zn1124.1 (3)
C3—C4—H4118.6C8—N4—Zn1118.1 (4)
N6—C5—N4120.2 (4)C6—N5—C5116.2 (5)
N6—C5—N5116.0 (5)C5—N6—H6A109.5
N4—C5—N5123.8 (4)C5—N6—H6B109.0
N5—C6—C7123.9 (5)H6A—N6—H6B108.2
N5—C6—H6118.0N4—Zn1—N1101.97 (16)
C7—C6—H6118.0N4—Zn1—Br1109.63 (11)
C6—C7—C8116.9 (5)N1—Zn1—Br1109.06 (12)
C6—C7—H7121.6N4—Zn1—Br2108.97 (11)
C8—C7—H7121.6N1—Zn1—Br2114.70 (13)
N4—C8—C7122.1 (5)Br1—Zn1—Br2112.00 (3)
N2—C2—C3—C42.8 (9)C7—C8—N4—C53.9 (7)
C2—C3—C4—N1−1.5 (9)C7—C8—N4—Zn1−164.7 (4)
N5—C6—C7—C8−4.1 (8)C7—C6—N5—C52.0 (7)
C6—C7—C8—N41.0 (8)N6—C5—N5—C6−179.1 (4)
N3—C1—N1—C4−179.8 (5)N4—C5—N5—C63.5 (7)
N2—C1—N1—C42.2 (8)C5—N4—Zn1—N179.9 (4)
N3—C1—N1—Zn19.2 (7)C8—N4—Zn1—N1−112.3 (4)
N2—C1—N1—Zn1−168.8 (4)C5—N4—Zn1—Br1−164.6 (3)
C3—C4—N1—C1−0.8 (8)C8—N4—Zn1—Br13.2 (4)
C3—C4—N1—Zn1171.2 (5)C5—N4—Zn1—Br2−41.7 (4)
C3—C2—N2—C1−1.5 (9)C8—N4—Zn1—Br2126.0 (3)
N3—C1—N2—C2−179.1 (5)C1—N1—Zn1—N4−149.6 (4)
N1—C1—N2—C2−1.1 (8)C4—N1—Zn1—N439.2 (4)
N6—C5—N4—C8176.3 (4)C1—N1—Zn1—Br194.5 (4)
N5—C5—N4—C8−6.3 (7)C4—N1—Zn1—Br1−76.7 (4)
N6—C5—N4—Zn1−15.8 (6)C1—N1—Zn1—Br2−32.1 (5)
N5—C5—N4—Zn1161.6 (3)C4—N1—Zn1—Br2156.8 (3)
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
C8—H8···Br2i0.932.873.651 (5)142
N6—H6B···N5ii0.892.472.996 (6)119
N3—H3A···Br20.752.743.480 (5)170
Symmetry codes: (i) x−1, y+1, z; (ii) −x, −y, −z+1.
Table 1
Selected geometric parameters (Å) top
Br1—Zn12.3528 (9)N1—Zn12.060 (4)
Br2—Zn12.3593 (8)N4—Zn12.056 (4)
Table 2
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
C8—H8···Br2i0.932.873.651 (5)142
N6—H6B···N5ii0.892.472.996 (6)119
N3—H3A···Br20.752.743.480 (5)170
Symmetry codes: (i) x−1, y+1, z; (ii) −x, −y, −z+1.
Acknowledgements top

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).

references
References top

Bourne, S. A., Kilkenny, M. & Nassimbeni, L. R. (2001). Dalton Trans. pp. 1176–1179.

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Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Siemens (1996). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.