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ISSN: 2056-9890
Volume 67| Part 8| August 2011| Pages m1152-m1153

Bis(μ-4-amino-3,5-di­methyl-4H-1,2,4-triazole-κ2N1:N2)bis­­(di­bromidozinc)

aScience College, Civil Aviation University of China, Tianjin 300300, People's Republic of China
*Correspondence e-mail: xzhu@cauc.edu.cn

(Received 6 July 2011; accepted 17 July 2011; online 30 July 2011)

The centrosymmetric dimeric title complex, [Zn2Br4(C4H8N4)2], is isotypic with its [Zn2Cl4(C4H8N4)2], [Zn2I4(C4H8N4)2] and [Co2Cl4(C4H8N4)2] analogues. The zinc atom is bonded to two N atoms belonging to triazole bridging rings and to two terminal bromide ligands, in a geometry close to tetra­hedral. Weak N—H⋯Br hydrogen bonds, with the amine functions as donor groups, are observed in the crystal structure, forming a three-dimensional supra­molecular network.

Related literature

For background to transition metal complexes of 1,2,4-triazole derivatives, see: Liu et al. (1999[Liu, J.-C., Fu, D.-G., Zhuang, J.-Z., Duan, C.-Y. & You, X.-Z. (1999). J. Chem. Soc. Dalton Trans. pp. 2337-2342.]). For the isotypic [Zn2Cl4(C4H8N4)2], [Zn2I4(C4H8N4)2] and [Co2Cl4(C4H8N4)2] analogues, see: Lavrenova et al. (1992[Lavrenova, L. G., Baidina, I. A., Ikorskii, V. N., Sheludyakova, L. A. & Larionov, S. V. (1992). Zh. Neorg. Khim. 37, 630-636.]); Zhang et al. (2011[Zhang, R., Chen, Q., Yang, X. & Wu, X. (2011). Acta Cryst. E67, m26.]); Gong et al. (2009[Gong, Y., Li, J., Zhou, Y., Qin, J. & Wu, X. (2009). Acta Cryst. E65, m791.]). For other related structures, see: Liu et al. (2003[Liu, J.-C., Guo, G.-C., Huang, J.-S. & You, X.-Z. (2003). Inorg. Chem. 42, 235-243.]); Zhao et al. (2002[Zhao, Q. H., Li, H. F., Chen, Z. D. & Fang, R. B. (2002). Inorg. Chim. Acta, 336, 142-146.]); Yi et al. (2004[Yi, L., Ding, B., Zhao, B., Cheng, P., Liao, D.-Z., Yan, S.-P. & Jiang, Z.-H. (2004). Inorg. Chem. 43, 33-43.]); Zhang et al. (2007[Zhang, Y.-M., Zhang, Y.-P., Li, B.-L. & Zhang, Y. (2007). Acta Cryst. C63, m120-m122.]).

[Scheme 1]

Experimental

Crystal data
  • [Zn2Br4(C4H8N4)2]

  • Mr = 674.67

  • Monoclinic, P 21 /c

  • a = 7.0344 (17) Å

  • b = 12.629 (3) Å

  • c = 11.456 (3) Å

  • β = 99.951 (6)°

  • V = 1002.4 (4) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 10.37 mm−1

  • T = 293 K

  • 0.48 × 0.20 × 0.16 mm

Data collection
  • Rigaku Mercury CCD diffractometer

  • Absorption correction: multi-scan (REQAB; Jacobson, 1998[Jacobson, R. (1998). REQAB. Private communication to the Rigaku Corporation, Tokyo, Japan.]) Tmin = 0.083, Tmax = 0.288

  • 9580 measured reflections

  • 1833 independent reflections

  • 1517 reflections with I > 2σ(I)

  • Rint = 0.054

Refinement
  • R[F2 > 2σ(F2)] = 0.052

  • wR(F2) = 0.148

  • S = 1.05

  • 1833 reflections

  • 110 parameters

  • 2 restraints

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.69 e Å−3

  • Δρmin = −0.97 e Å−3

Table 1
Selected geometric parameters (Å, °)

Zn1—N1 2.027 (6)
Zn1—N2i 2.025 (6)
Zn1—Br1 2.3523 (12)
Zn1—Br2 2.3625 (12)
N2i—Zn1—N1 107.5 (2)
N2i—Zn1—Br1 109.56 (16)
N1—Zn1—Br1 107.83 (17)
N2i—Zn1—Br2 109.48 (16)
N1—Zn1—Br2 108.79 (17)
Br1—Zn1—Br2 113.53 (5)
Symmetry code: (i) -x+2, -y+2, -z+1.

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N4—H4D⋯Br1ii 0.85 (2) 2.80 (7) 3.428 (7) 132 (8)
N4—H4E⋯Br2iii 0.86 (2) 2.93 (4) 3.748 (8) 161 (8)
Symmetry codes: (ii) [x-1, -y+{\script{3\over 2}}, z-{\script{1\over 2}}]; (iii) [x, -y+{\script{3\over 2}}, z-{\script{1\over 2}}].

Data collection: CrystalClear (Rigaku, 2005[Rigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.]); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

Transition metal complexes bridged by 1,2,4-triazole group can produce interesting structures and specific properties. Many attempts have been made to synthesize a variety of complexes with paramagnetic centers by using such ligands, and their structures and magnetic properties have been characterized (Liu et al., 1999). For 4-amino-3,5-dimethyl-1,2,4-triazole (admt), several CuII (Liu et al., 2003), CoII, NiII (Zhao et al., 2002; Gong et al., 2009), and CdII compounds (Yi et al., 2004) were synthesized. However, to the best of our knowledge, only two ZnII-admt compounds, [Zn2(admt)2Cl4] and [Zn2(admt)2I4] were synthesized (Lavrenova et al., 1992; Zhang et al., 2011). Here, we report the preparation and crystal structure of a dimeric ZnII complex of formula [Zn2(admt)2Br4].

The structure of the title compound is made up of neutral dimeric metallacycles. The title compound is isostructural to analogous complexes which were previously reported: [Zn2(admt)2Cl4], [Zn2(admt)2I4] and [Co2(admt)2Cl4] (Lavrenova et al., 1992; Zhang et al., 2011; Gong et al., 2009). In each dimeric metallacycle, as shown in Fig. 1, two ZnII centers are connected by two admt ligands, resulting in a discrete Zn2(admt)2 6-membered metallacycle, which represents the smallest closed cyclic structure with a 1:1 metal-to-ligand ratio. Two triazole rings are coplanar. Each ZnII center is four-coordinated with two N donors of two admt ligands [Zn1—N1: 2.027 (6) Å; Zn1—N2i (symmetry code i: 2-x, 2-y, 1-z): 2.025 (6) Å] and two Br- anions ligands [Zn1—Br1: 2.3523 (12) Å; Zn1—Br2: 2.3625 (12) Å], forming a distorted tetrahedral geometry. The Zn—N(triazole) bond lengths in the title compound are consistent with values in other Zn-triazole complexes (Zhang et al., 2007, 2011; Lavrenova et al., 1992). The N—Zn—N, N—Zn—Br and Br—Zn—Br bond angles in the title compound are in the range of 107.5 (2)° to 113.53 (5)°, near to the ideal tetrahedral value of ca 109.5°. The ligand admt is a 4-substituted 1,2,4-triazole and exhibits in the title compound the κ2N1:N2 bidentate bridging coordination mode. Two admt ligands bridge two ZnII ions to form a dimer with a Zn···Zn separation of 3.7781 (6) Å. For a 4-substituted 1,2,4-triazole, by blocking the N4 donor position through substitution, only the N1 monodentate (Zhang et al., 2007) and N1,N2-bidentate coordination modes are possible.

There are weak hydrogen bonding interactions between the H atoms of the amine NH2 groups and the Br- anions of adjacent dimers (N4—Br1ii = 3.428 (7) Å, N4—Br2iii = 3.748 (8) Å; symmetry codes: ii = 1-x, 3/2-y, z-1/2; iii = x, 3/2-y, z-1/2). The adjacent dimers are held together by N—H···Br hydrogen bonds to form a three-dimensional supramolecular network (Fig. 2). No obvious π···π stacking interactions between the triazole rings are observed in the crystal structure.

Related literature top

For background to transition metal complexes of 1,2,4-triazole derivatives, see: Liu et al. (1999). For the isotypic [Zn2Cl4(C4H8N4)2], [Zn2I4(C4H8N4)2] and [Co2Cl4(C4H8N4)2] analogues, see: Lavrenova et al. (1992); Zhang et al. (2011); Gong et al. (2009). For other related structures, see: Liu et al. (2003); Zhao et al. (2002); Yi et al. (2004); Zhang et al. (2007).

Experimental top

To a solution of admtrz in EtOH was added one equivalent of ZnBr2 (aqueous solution) under stirring at room temperature. Then, the reaction mixture was filtered and colorless crystals suitable for structure determination were isolated by slow evaporation of the solvent at room temperature after a couple of weeks.

Refinement top

H atoms of the methyl groups were placed in idealized positions and refined as riding, with C—H distances of 0.96 Å and Uiso(H) = 1.5Ueq(parent C). H atoms bonded to N4 were located in a difference map and refined with N—H distances restrained to 0.85 (2) Å, and with Uiso(H) = 1.2Ueq(N4).

Computing details top

Data collection: CrystalClear (Rigaku, 2005); cell refinement: CrystalClear (Rigaku, 2005); data reduction: CrystalClear (Rigaku, 2005); 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. View of the title complex.
[Figure 2] Fig. 2. The crystal structure of the title complex.
Bis(µ-4-amino-3,5-dimethyl-4H-1,2,4-triazole- κ2N1:N2)bis(dibromidozinc) top
Crystal data top
[Zn2Br4(C4H8N4)2]F(000) = 640
Mr = 674.67Dx = 2.235 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71070 Å
Hall symbol: -P 2ybcCell parameters from 2994 reflections
a = 7.0344 (17) Åθ = 3.2–25.4°
b = 12.629 (3) ŵ = 10.37 mm1
c = 11.456 (3) ÅT = 293 K
β = 99.951 (6)°Block, colourless
V = 1002.4 (4) Å30.48 × 0.20 × 0.16 mm
Z = 2
Data collection top
Rigaku Mercury CCD
diffractometer
1833 independent reflections
Radiation source: fine-focus sealed tube1517 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.054
Detector resolution: 14.63 pixels mm-1θmax = 25.3°, θmin = 3.2°
ω scansh = 88
Absorption correction: multi-scan
(REQAB;Jacobson, 1998)
k = 1315
Tmin = 0.083, Tmax = 0.288l = 1313
9580 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.052Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.148H atoms treated by a mixture of independent and constrained refinement
S = 1.05 w = 1/[σ2(Fo2) + (0.084P)2 + 1.6395P]
where P = (Fo2 + 2Fc2)/3
1833 reflections(Δ/σ)max < 0.001
110 parametersΔρmax = 0.69 e Å3
2 restraintsΔρmin = 0.97 e Å3
0 constraints
Crystal data top
[Zn2Br4(C4H8N4)2]V = 1002.4 (4) Å3
Mr = 674.67Z = 2
Monoclinic, P21/cMo Kα radiation
a = 7.0344 (17) ŵ = 10.37 mm1
b = 12.629 (3) ÅT = 293 K
c = 11.456 (3) Å0.48 × 0.20 × 0.16 mm
β = 99.951 (6)°
Data collection top
Rigaku Mercury CCD
diffractometer
1833 independent reflections
Absorption correction: multi-scan
(REQAB;Jacobson, 1998)
1517 reflections with I > 2σ(I)
Tmin = 0.083, Tmax = 0.288Rint = 0.054
9580 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0522 restraints
wR(F2) = 0.148H atoms treated by a mixture of independent and constrained refinement
S = 1.05Δρmax = 0.69 e Å3
1833 reflectionsΔρmin = 0.97 e Å3
110 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Zn10.91275 (11)0.89737 (6)0.59841 (7)0.0379 (3)
Br11.05816 (13)0.72906 (7)0.61240 (10)0.0726 (4)
Br20.66056 (12)0.91347 (7)0.70931 (9)0.0638 (3)
N10.8048 (8)0.9248 (4)0.4253 (5)0.0393 (13)
N20.8846 (8)0.9908 (4)0.3485 (5)0.0372 (13)
N30.6514 (8)0.9028 (4)0.2457 (5)0.0386 (13)
N40.5184 (11)0.8698 (6)0.1475 (6)0.0541 (17)
H4D0.408 (7)0.881 (7)0.166 (8)0.06 (3)*
H4E0.520 (13)0.803 (2)0.161 (8)0.06 (3)*
C10.7888 (10)0.9765 (5)0.2415 (6)0.0381 (15)
C20.6619 (10)0.8725 (5)0.3605 (6)0.0398 (16)
C30.8174 (12)1.0313 (6)0.1318 (6)0.0527 (19)
H3A0.69981.06600.09690.079*
H3B0.85260.98050.07680.079*
H3C0.91841.08280.15030.079*
C40.5307 (13)0.7968 (7)0.4037 (8)0.063 (2)
H4A0.60480.74230.44890.094*
H4B0.44730.76570.33740.094*
H4C0.45440.83320.45280.094*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Zn10.0342 (5)0.0373 (5)0.0419 (5)0.0009 (3)0.0058 (4)0.0031 (3)
Br10.0570 (6)0.0457 (6)0.1112 (9)0.0139 (4)0.0036 (5)0.0004 (4)
Br20.0528 (5)0.0687 (6)0.0770 (7)0.0005 (4)0.0308 (5)0.0099 (4)
N10.038 (3)0.039 (3)0.040 (3)0.005 (2)0.004 (3)0.003 (2)
N20.037 (3)0.038 (3)0.035 (3)0.003 (2)0.005 (3)0.005 (2)
N30.036 (3)0.039 (3)0.037 (3)0.003 (2)0.002 (3)0.004 (2)
N40.053 (4)0.058 (5)0.048 (4)0.017 (4)0.001 (3)0.008 (3)
C10.040 (4)0.037 (4)0.038 (4)0.002 (3)0.009 (3)0.000 (3)
C20.039 (3)0.041 (4)0.038 (4)0.009 (3)0.003 (3)0.003 (3)
C30.070 (5)0.048 (5)0.041 (4)0.001 (4)0.013 (4)0.004 (3)
C40.072 (6)0.054 (5)0.061 (5)0.025 (4)0.005 (4)0.002 (4)
Geometric parameters (Å, º) top
Zn1—N12.027 (6)N4—H4D0.85 (2)
Zn1—N2i2.025 (6)N4—H4E0.86 (2)
Zn1—Br12.3523 (12)C1—C31.478 (10)
Zn1—Br22.3625 (12)C2—C41.472 (10)
N1—C21.320 (8)C3—H3A0.9600
N1—N21.398 (8)C3—H3B0.9600
N2—C11.305 (9)C3—H3C0.9600
N2—Zn1i2.025 (6)C4—H4A0.9600
N3—C11.349 (9)C4—H4B0.9600
N3—C21.359 (9)C4—H4C0.9600
N3—N41.397 (9)
N2i—Zn1—N1107.5 (2)N2—C1—N3108.6 (6)
N2i—Zn1—Br1109.56 (16)N2—C1—C3127.6 (6)
N1—Zn1—Br1107.83 (17)N3—C1—C3123.8 (6)
N2i—Zn1—Br2109.48 (16)N1—C2—N3108.2 (6)
N1—Zn1—Br2108.79 (17)N1—C2—C4126.7 (6)
Br1—Zn1—Br2113.53 (5)N3—C2—C4125.1 (6)
C2—N1—N2107.1 (5)C1—C3—H3A109.5
C2—N1—Zn1125.8 (5)C1—C3—H3B109.5
N2—N1—Zn1126.5 (4)H3A—C3—H3B109.5
C1—N2—N1108.1 (5)C1—C3—H3C109.5
C1—N2—Zn1i126.9 (5)H3A—C3—H3C109.5
N1—N2—Zn1i124.4 (4)H3B—C3—H3C109.5
C1—N3—C2108.0 (5)C2—C4—H4A109.5
C1—N3—N4124.2 (6)C2—C4—H4B109.5
C2—N3—N4127.7 (6)H4A—C4—H4B109.5
N3—N4—H4D105 (6)C2—C4—H4C109.5
N3—N4—H4E100 (6)H4A—C4—H4C109.5
H4D—N4—H4E96 (8)H4B—C4—H4C109.5
N2i—Zn1—N1—C2176.0 (6)Zn1i—N2—C1—C36.4 (11)
Br1—Zn1—N1—C266.0 (6)C2—N3—C1—N21.2 (8)
Br2—Zn1—N1—C257.5 (6)N4—N3—C1—N2178.3 (7)
N2i—Zn1—N1—N214.3 (7)C2—N3—C1—C3177.7 (7)
Br1—Zn1—N1—N2103.7 (5)N4—N3—C1—C30.7 (11)
Br2—Zn1—N1—N2132.7 (5)N2—N1—C2—N30.6 (7)
C2—N1—N2—C10.1 (7)Zn1—N1—C2—N3170.8 (5)
Zn1—N1—N2—C1171.5 (5)N2—N1—C2—C4177.4 (8)
C2—N1—N2—Zn1i172.1 (5)Zn1—N1—C2—C411.2 (11)
Zn1—N1—N2—Zn1i16.6 (8)C1—N3—C2—N11.1 (8)
N1—N2—C1—N30.8 (8)N4—N3—C2—N1178.1 (7)
Zn1i—N2—C1—N3172.6 (4)C1—N3—C2—C4176.9 (8)
N1—N2—C1—C3178.1 (7)N4—N3—C2—C40.0 (12)
Symmetry code: (i) x+2, y+2, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N4—H4D···Br1ii0.85 (2)2.80 (7)3.428 (7)132 (8)
N4—H4E···Br2iii0.86 (2)2.93 (4)3.748 (8)161 (8)
Symmetry codes: (ii) x1, y+3/2, z1/2; (iii) x, y+3/2, z1/2.

Experimental details

Crystal data
Chemical formula[Zn2Br4(C4H8N4)2]
Mr674.67
Crystal system, space groupMonoclinic, P21/c
Temperature (K)293
a, b, c (Å)7.0344 (17), 12.629 (3), 11.456 (3)
β (°) 99.951 (6)
V3)1002.4 (4)
Z2
Radiation typeMo Kα
µ (mm1)10.37
Crystal size (mm)0.48 × 0.20 × 0.16
Data collection
DiffractometerRigaku Mercury CCD
diffractometer
Absorption correctionMulti-scan
(REQAB;Jacobson, 1998)
Tmin, Tmax0.083, 0.288
No. of measured, independent and
observed [I > 2σ(I)] reflections
9580, 1833, 1517
Rint0.054
(sin θ/λ)max1)0.602
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.052, 0.148, 1.05
No. of reflections1833
No. of parameters110
No. of restraints2
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.69, 0.97

Computer programs: CrystalClear (Rigaku, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Selected geometric parameters (Å, º) top
Zn1—N12.027 (6)Zn1—Br12.3523 (12)
Zn1—N2i2.025 (6)Zn1—Br22.3625 (12)
N2i—Zn1—N1107.5 (2)N2i—Zn1—Br2109.48 (16)
N2i—Zn1—Br1109.56 (16)N1—Zn1—Br2108.79 (17)
N1—Zn1—Br1107.83 (17)Br1—Zn1—Br2113.53 (5)
Symmetry code: (i) x+2, y+2, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N4—H4D···Br1ii0.85 (2)2.80 (7)3.428 (7)132 (8)
N4—H4E···Br2iii0.86 (2)2.93 (4)3.748 (8)161 (8)
Symmetry codes: (ii) x1, y+3/2, z1/2; (iii) x, y+3/2, z1/2.
 

Acknowledgements

This work was supported by the fund of the Civil Aviation University of China (grant No. 2010kys07)

References

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Volume 67| Part 8| August 2011| Pages m1152-m1153
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