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

Zhu, X.; Guo, Y.; Li, J.-G.; Wu, Y.

doi:10.1107/S1600536811028789

metal-organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

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

doi:10.1107/S1600536811028789

Open

access

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

Xia Zhu,^a ^* Ying Guo,^a Jian-Gang Li ^a and Yao Wu ^a

^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 ). 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

Crystal data

[Zn₂Br₄(C₄H₈N₄)₂]
M_r = 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 ) T_min = 0.083, T_max = 0.288
9580 measured reflections
1833 independent reflections
1517 reflections with I > 2σ(I)
R_int = 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
Δρ_max = 0.69 e Å⁻³
Δρ_min = −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	D⋯A	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 ); 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.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811028789/bh2370sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811028789/bh2370Isup2.hkl

checkCIF report

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 Cu^II (Liu et al., 2003), Co^II, Ni^II (Zhao et al., 2002; Gong et al., 2009), and Cd^II compounds (Yi et al., 2004) were synthesized. However, to the best of our knowledge, only two Zn^II-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 Zn^II 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 Zn^II 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 Zn^II 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 Zn^II 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.

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

	Fig. 1. View of the title complex.
	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
M_r = 674.67	D_x = 2.235 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71070 Å
Hall symbol: -P 2ybc	Cell parameters from 2994 reflections
a = 7.0344 (17) Å	θ = 3.2–25.4°
b = 12.629 (3) Å	µ = 10.37 mm⁻¹
c = 11.456 (3) Å	T = 293 K
β = 99.951 (6)°	Block, colourless
V = 1002.4 (4) Å³	0.48 × 0.20 × 0.16 mm
Z = 2

Data collection top

Rigaku Mercury CCD diffractometer	1833 independent reflections
Radiation source: fine-focus sealed tube	1517 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.054
Detector resolution: 14.63 pixels mm^-1	θ_max = 25.3°, θ_min = 3.2°
ω scans	h = −8→8
Absorption correction: multi-scan (REQAB;Jacobson, 1998)	k = −13→15
T_min = 0.083, T_max = 0.288	l = −13→13
9580 measured reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.052	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.148	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ²(F_o²) + (0.084P)² + 1.6395P] where P = (F_o² + 2F_c²)/3
1833 reflections	(Δ/σ)_max < 0.001
110 parameters	Δρ_max = 0.69 e Å⁻³
2 restraints	Δρ_min = −0.97 e Å⁻³
0 constraints

Crystal data top

[Zn₂Br₄(C₄H₈N₄)₂]	V = 1002.4 (4) Å³
M_r = 674.67	Z = 2
Monoclinic, P2₁/c	Mo Kα radiation
a = 7.0344 (17) Å	µ = 10.37 mm⁻¹
b = 12.629 (3) Å	T = 293 K
c = 11.456 (3) Å	0.48 × 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)
T_min = 0.083, T_max = 0.288	R_int = 0.054
9580 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.052	2 restraints
wR(F²) = 0.148	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	Δρ_max = 0.69 e Å⁻³
1833 reflections	Δρ_min = −0.97 e Å⁻³
110 parameters

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Zn1	0.91275 (11)	0.89737 (6)	0.59841 (7)	0.0379 (3)
Br1	1.05816 (13)	0.72906 (7)	0.61240 (10)	0.0726 (4)
Br2	0.66056 (12)	0.91347 (7)	0.70931 (9)	0.0638 (3)
N1	0.8048 (8)	0.9248 (4)	0.4253 (5)	0.0393 (13)
N2	0.8846 (8)	0.9908 (4)	0.3485 (5)	0.0372 (13)
N3	0.6514 (8)	0.9028 (4)	0.2457 (5)	0.0386 (13)
N4	0.5184 (11)	0.8698 (6)	0.1475 (6)	0.0541 (17)
H4D	0.408 (7)	0.881 (7)	0.166 (8)	0.06 (3)*
H4E	0.520 (13)	0.803 (2)	0.161 (8)	0.06 (3)*
C1	0.7888 (10)	0.9765 (5)	0.2415 (6)	0.0381 (15)
C2	0.6619 (10)	0.8725 (5)	0.3605 (6)	0.0398 (16)
C3	0.8174 (12)	1.0313 (6)	0.1318 (6)	0.0527 (19)
H3A	0.6998	1.0660	0.0969	0.079*
H3B	0.8526	0.9805	0.0768	0.079*
H3C	0.9184	1.0828	0.1503	0.079*
C4	0.5307 (13)	0.7968 (7)	0.4037 (8)	0.063 (2)
H4A	0.6048	0.7423	0.4489	0.094*
H4B	0.4473	0.7657	0.3374	0.094*
H4C	0.4544	0.8332	0.4528	0.094*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Zn1	0.0342 (5)	0.0373 (5)	0.0419 (5)	−0.0009 (3)	0.0058 (4)	0.0031 (3)
Br1	0.0570 (6)	0.0457 (6)	0.1112 (9)	0.0139 (4)	0.0036 (5)	0.0004 (4)
Br2	0.0528 (5)	0.0687 (6)	0.0770 (7)	−0.0005 (4)	0.0308 (5)	−0.0099 (4)
N1	0.038 (3)	0.039 (3)	0.040 (3)	−0.005 (2)	0.004 (3)	0.003 (2)
N2	0.037 (3)	0.038 (3)	0.035 (3)	−0.003 (2)	0.005 (3)	0.005 (2)
N3	0.036 (3)	0.039 (3)	0.037 (3)	−0.003 (2)	−0.002 (3)	−0.004 (2)
N4	0.053 (4)	0.058 (5)	0.048 (4)	−0.017 (4)	0.001 (3)	−0.008 (3)
C1	0.040 (4)	0.037 (4)	0.038 (4)	−0.002 (3)	0.009 (3)	0.000 (3)
C2	0.039 (3)	0.041 (4)	0.038 (4)	−0.009 (3)	0.003 (3)	0.003 (3)
C3	0.070 (5)	0.048 (5)	0.041 (4)	−0.001 (4)	0.013 (4)	0.004 (3)
C4	0.072 (6)	0.054 (5)	0.061 (5)	−0.025 (4)	0.005 (4)	0.002 (4)

Geometric parameters (Å, º) top

Zn1—N1	2.027 (6)	N4—H4D	0.85 (2)
Zn1—N2ⁱ	2.025 (6)	N4—H4E	0.86 (2)
Zn1—Br1	2.3523 (12)	C1—C3	1.478 (10)
Zn1—Br2	2.3625 (12)	C2—C4	1.472 (10)
N1—C2	1.320 (8)	C3—H3A	0.9600
N1—N2	1.398 (8)	C3—H3B	0.9600
N2—C1	1.305 (9)	C3—H3C	0.9600
N2—Zn1ⁱ	2.025 (6)	C4—H4A	0.9600
N3—C1	1.349 (9)	C4—H4B	0.9600
N3—C2	1.359 (9)	C4—H4C	0.9600
N3—N4	1.397 (9)

N2ⁱ—Zn1—N1	107.5 (2)	N2—C1—N3	108.6 (6)
N2ⁱ—Zn1—Br1	109.56 (16)	N2—C1—C3	127.6 (6)
N1—Zn1—Br1	107.83 (17)	N3—C1—C3	123.8 (6)
N2ⁱ—Zn1—Br2	109.48 (16)	N1—C2—N3	108.2 (6)
N1—Zn1—Br2	108.79 (17)	N1—C2—C4	126.7 (6)
Br1—Zn1—Br2	113.53 (5)	N3—C2—C4	125.1 (6)
C2—N1—N2	107.1 (5)	C1—C3—H3A	109.5
C2—N1—Zn1	125.8 (5)	C1—C3—H3B	109.5
N2—N1—Zn1	126.5 (4)	H3A—C3—H3B	109.5
C1—N2—N1	108.1 (5)	C1—C3—H3C	109.5
C1—N2—Zn1ⁱ	126.9 (5)	H3A—C3—H3C	109.5
N1—N2—Zn1ⁱ	124.4 (4)	H3B—C3—H3C	109.5
C1—N3—C2	108.0 (5)	C2—C4—H4A	109.5
C1—N3—N4	124.2 (6)	C2—C4—H4B	109.5
C2—N3—N4	127.7 (6)	H4A—C4—H4B	109.5
N3—N4—H4D	105 (6)	C2—C4—H4C	109.5
N3—N4—H4E	100 (6)	H4A—C4—H4C	109.5
H4D—N4—H4E	96 (8)	H4B—C4—H4C	109.5

N2ⁱ—Zn1—N1—C2	−176.0 (6)	Zn1ⁱ—N2—C1—C3	6.4 (11)
Br1—Zn1—N1—C2	66.0 (6)	C2—N3—C1—N2	1.2 (8)
Br2—Zn1—N1—C2	−57.5 (6)	N4—N3—C1—N2	178.3 (7)
N2ⁱ—Zn1—N1—N2	14.3 (7)	C2—N3—C1—C3	−177.7 (7)
Br1—Zn1—N1—N2	−103.7 (5)	N4—N3—C1—C3	−0.7 (11)
Br2—Zn1—N1—N2	132.7 (5)	N2—N1—C2—N3	0.6 (7)
C2—N1—N2—C1	0.1 (7)	Zn1—N1—C2—N3	−170.8 (5)
Zn1—N1—N2—C1	171.5 (5)	N2—N1—C2—C4	−177.4 (8)
C2—N1—N2—Zn1ⁱ	172.1 (5)	Zn1—N1—C2—C4	11.2 (11)
Zn1—N1—N2—Zn1ⁱ	−16.6 (8)	C1—N3—C2—N1	−1.1 (8)
N1—N2—C1—N3	−0.8 (8)	N4—N3—C2—N1	−178.1 (7)
Zn1ⁱ—N2—C1—N3	−172.6 (4)	C1—N3—C2—C4	176.9 (8)
N1—N2—C1—C3	178.1 (7)	N4—N3—C2—C4	0.0 (12)

Symmetry code: (i) −x+2, −y+2, −z+1.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	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+3/2, z−1/2; (iii) x, −y+3/2, z−1/2.

Experimental details

Crystal data
Chemical formula	[Zn₂Br₄(C₄H₈N₄)₂]
M_r	674.67
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	293
a, b, c (Å)	7.0344 (17), 12.629 (3), 11.456 (3)
β (°)	99.951 (6)
V (Å³)	1002.4 (4)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	10.37
Crystal size (mm)	0.48 × 0.20 × 0.16

Data collection
Diffractometer	Rigaku Mercury CCD diffractometer
Absorption correction	Multi-scan (REQAB;Jacobson, 1998)
T_min, T_max	0.083, 0.288
No. of measured, independent and observed [I > 2σ(I)] reflections	9580, 1833, 1517
R_int	0.054
(sin θ/λ)_max (Å⁻¹)	0.602

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.052, 0.148, 1.05
No. of reflections	1833
No. of parameters	110
No. of restraints	2
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	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—N1	2.027 (6)	Zn1—Br1	2.3523 (12)
Zn1—N2ⁱ	2.025 (6)	Zn1—Br2	2.3625 (12)

N2ⁱ—Zn1—N1	107.5 (2)	N2ⁱ—Zn1—Br2	109.48 (16)
N2ⁱ—Zn1—Br1	109.56 (16)	N1—Zn1—Br2	108.79 (17)
N1—Zn1—Br1	107.83 (17)	Br1—Zn1—Br2	113.53 (5)

Symmetry code: (i) −x+2, −y+2, −z+1.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	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+3/2, z−1/2; (iii) x, −y+3/2, z−1/2.

Acknowledgements

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

References

Gong, Y., Li, J., Zhou, Y., Qin, J. & Wu, X. (2009). Acta Cryst. E65, m791. Web of Science CSD CrossRef IUCr Journals Google Scholar
Jacobson, R. (1998). REQAB. Private communication to the Rigaku Corporation, Tokyo, Japan. Google Scholar
Lavrenova, L. G., Baidina, I. A., Ikorskii, V. N., Sheludyakova, L. A. & Larionov, S. V. (1992). Zh. Neorg. Khim. 37, 630–636. CAS Google Scholar
Liu, J.-C., Fu, D.-G., Zhuang, J.-Z., Duan, C.-Y. & You, X.-Z. (1999). J. Chem. Soc. Dalton Trans. pp. 2337–2342. Web of Science CSD CrossRef Google Scholar
Liu, J.-C., Guo, G.-C., Huang, J.-S. & You, X.-Z. (2003). Inorg. Chem. 42, 235–243. Web of Science CSD CrossRef PubMed CAS Google Scholar
Rigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Yi, L., Ding, B., Zhao, B., Cheng, P., Liao, D.-Z., Yan, S.-P. & Jiang, Z.-H. (2004). Inorg. Chem. 43, 33–43. Web of Science CSD CrossRef PubMed CAS Google Scholar
Zhang, R., Chen, Q., Yang, X. & Wu, X. (2011). Acta Cryst. E67, m26. Web of Science CrossRef IUCr Journals Google Scholar
Zhang, Y.-M., Zhang, Y.-P., Li, B.-L. & Zhang, Y. (2007). Acta Cryst. C63, m120–m122. Web of Science CSD CrossRef IUCr Journals Google Scholar
Zhao, Q. H., Li, H. F., Chen, Z. D. & Fang, R. B. (2002). Inorg. Chim. Acta, 336, 142–146. Web of Science CSD CrossRef CAS Google Scholar