Bis[μ-1,2-bis­(1,2,4-triazol-4-yl)ethane]bis­[diiodidozinc(II)]

Abstract

In the title dinuclear complex, [Zn₂I₄(C₆H₈N₆)₂], two Zn^II atoms are bridged by two 1,2-bis­(1,2,4-triazol-4-yl)ethane (btre) ligands, forming a centrosymmetric metallacycle. The coordination geometry of the Zn^II ion is distorted tetra­hedral with the coordination sphere formed by two N atoms from the triazole rings of two symmetry-related btre ligands and two iodide ligands.

Related literature

For the isostructural zinc complexes [Zn₂(btre)₂ X ₄], where X = Cl, Br, see: Habit et al. (2009 ▶). For other triazole coordin­ation compounds, see: Haasnoot (2000 ▶); Li et al. (2003 ▶); Zhang et al. (2007 ▶); Zhu et al. (2004 ▶).

Experimental

Crystal data

• [Zn₂I₄(C₆H₈N₆)₂]

• M _r = 966.71

• Monoclinic,

• a = 20.241 (5) Å

• b = 7.3847 (14) Å

• c = 17.348 (4) Å

• β = 97.375 (5)°

• V = 2571.6 (9) ų

• Z = 4

• Mo Kα radiation

• μ = 6.69 mm⁻¹

• T = 293 K

• 0.59 × 0.21 × 0.20 mm

Data collection

• Rigaku Mercury CCD diffractometer

• Absorption correction: multi-scan (REQAB; Jacobson, 1998 ▶) T _min = 0.110, T _max = 0.348

• 11703 measured reflections

• 2339 independent reflections

• 2063 reflections with I > 2σ(I)

• R _int = 0.040

Refinement

• R[F ² > 2σ(F ²)] = 0.039

• wR(F ²) = 0.106

• S = 1.07

• 2339 reflections

• 136 parameters

• H-atom parameters constrained

• Δρ_max = 0.69 e Å⁻³

• Δρ_min = −1.31 e Å⁻³

Data collection: CrystalClear (Rigaku, 2000 ▶); 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

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

Table 1. Selected geometric parameters (Å, °).

Zn1—N1	2.017 (5)
Zn1—N4i	2.019 (5)
Zn1—I1	2.5479 (8)
Zn1—I2	2.5523 (9)

N1—Zn1—N4i	103.68 (19)
N1—Zn1—I1	108.78 (14)
N4i—Zn1—I1	112.08 (14)
N1—Zn1—I2	113.03 (14)
N4i—Zn1—I2	107.90 (14)
I1—Zn1—I2	111.19 (3)

Symmetry code: (i) .

supplementary crystallographic information

Comment

A large number of mononuclear, oligonuclear and polynuclear transition metal complexes of 1,2,4-triazole derivatives have been synthesized and characterized because of their magnetic properties and novel topologies (Haasnoot, 2000).

In our previous work, we synthesized several zinc^II complexes with 1,2-bis(1,2,4-triazol-1-yl)ethane (bte; Li et al., 2003; Zhang et al., 2007; Zhu et al., 2004). 1,2-Bis(1,2,4-triazol-4-yl)ethane (btre) is an isomer of 1,2-bis(1,2,4-triazol-1-yl)ethane. In the present work, we report here the preparation and crystal structure of a dimeric zinc^II complex, namely, [Zn(btre)I₂]₂ (I).

The crystal structure of (I) is built up from a neutral dimeric metallacycle. The dimer is centrosymmetric. As shown in Fig.1, in each dimer, two zinc^II centres are connected by two btre lignads resulting in a discrete Zn₂(btre)₂ 18-membered binuclear metallacycle.

Each zinc^II centre is four-coordinated by two N atoms of btre ligands and two I lignads (Table 1), forming a distorted tetrahedral geometry. Each btre exhibits a gauche conformation in (I). The N3—C5—C6—N6 torsion angle is 63.8 (7)°. The dihedral angle between the two triazole rings is 45.6 (2)°. The Zn···Zn separation via the bridging btre ligand is 7.755 (2) Å in (I), compared with the corresponding values of 7.8750 (2) Å in [Zn(btre)Cl₂]₂ and 7.7980 (5) Å in [Zn(btre)Br₂]₂ (Habit et al., 2009).

Experimental

10 ml of aqueous solution of ZnI₂ (1 mmol) was added to a tube, and 10 ml of MeOH solution of 1,2-bis(1,2,4-triazol-4-yl)ethane (btre) (1.0 mmol) was carefully added above the aqueous solution. Colourless crystals were obtained after about two weeks. Anal. Calcd. for C₁₂H₁₆I₄N₁₂Zn₂: C, 14.91; H, 1.67; N, 17.39%. Found: C, 14.82; H, 1.56; N, 17.31%.

Refinement

H atom were placed in idealized positions and refined as riding, with C—H distances of 0.93 (triazole) and 0.97Å (ethane), and with U_iso(H) = 1.2U_eq(C).

Figures

Fig. 1.

A dimeric structure of the title compound. Displacement ellipsoids are drawn at the 30% probability level (symmetry code for atoms A: -x+1/2, -y+1/2, -z+1).

Fig. 2.

Crystal packing of the title compound viewed along the [010] direction.

Crystal data

[Zn2I4(C6H8N6)2]	F(000) = 1776
Mr = 966.71	Dx = 2.497 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71070 Å
Hall symbol: -c 2yc	Cell parameters from 4578 reflections
a = 20.241 (5) Å	θ = 3.1–25.4°
b = 7.3847 (14) Å	µ = 6.69 mm−1
c = 17.348 (4) Å	T = 293 K
β = 97.375 (5)°	Block, yellow
V = 2571.6 (9) Å3	0.59 × 0.21 × 0.20 mm
Z = 4

Data collection

Rigaku Mercury CCD diffractometer	2339 independent reflections
Radiation source: fine-focus sealed tube	2063 reflections with I > 2σ(I)
graphite	Rint = 0.040
ω scans	θmax = 25.3°, θmin = 3.1°
Absorption correction: multi-scan (REQAB; Jacobson, 1998)	h = −23→24
Tmin = 0.110, Tmax = 0.348	k = −8→8
11703 measured reflections	l = −20→20

Refinement

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)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.106	H-atom parameters constrained
S = 1.07	w = 1/[σ2(Fo2) + (0.0585P)2 + 4.1632P] where P = (Fo2 + 2Fc2)/3
2339 reflections	(Δ/σ)max = 0.001
136 parameters	Δρmax = 0.69 e Å−3
0 restraints	Δρmin = −1.31 e Å−3

Special details

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

	x	y	z	Uiso*/Ueq
Zn1	0.13008 (3)	−0.08434 (9)	0.58428 (4)	0.0339 (2)
I1	0.05228 (2)	0.08983 (6)	0.66190 (3)	0.04764 (18)
I2	0.09753 (2)	−0.41797 (6)	0.57188 (3)	0.05286 (19)
N1	0.1311 (2)	0.0385 (7)	0.4806 (3)	0.0372 (11)
N2	0.1752 (3)	−0.0096 (9)	0.4306 (3)	0.0571 (15)
N3	0.1084 (2)	0.2012 (7)	0.3770 (2)	0.0340 (10)
N4	0.2741 (2)	0.5707 (6)	0.3664 (3)	0.0375 (11)
N5	0.2601 (3)	0.6027 (9)	0.2874 (3)	0.0580 (17)
N6	0.1672 (2)	0.5550 (7)	0.3363 (3)	0.0365 (11)
C1	0.0918 (3)	0.1627 (8)	0.4480 (3)	0.0361 (13)
H1A	0.0573	0.2171	0.4702	0.043*
C2	0.1604 (4)	0.0924 (10)	0.3697 (4)	0.0543 (19)
H2A	0.1831	0.0903	0.3264	0.065*
C3	0.2178 (3)	0.5456 (8)	0.3934 (3)	0.0389 (14)
H3A	0.2135	0.5241	0.4453	0.047*
C4	0.1964 (4)	0.5905 (10)	0.2722 (4)	0.057 (2)
H4A	0.1732	0.6044	0.2227	0.069*
C5	0.0761 (3)	0.3322 (10)	0.3219 (3)	0.0466 (16)
H5A	0.0282	0.3217	0.3209	0.056*
H5B	0.0867	0.3030	0.2704	0.056*
C6	0.0963 (3)	0.5244 (9)	0.3406 (4)	0.0441 (15)
H6A	0.0702	0.6049	0.3045	0.053*
H6B	0.0867	0.5535	0.3926	0.053*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Zn1	0.0336 (4)	0.0388 (4)	0.0292 (4)	−0.0052 (3)	0.0042 (3)	0.0017 (3)
I1	0.0509 (3)	0.0455 (3)	0.0502 (3)	−0.00351 (19)	0.0210 (2)	−0.00607 (18)
I2	0.0723 (4)	0.0381 (3)	0.0476 (3)	−0.01108 (19)	0.0055 (2)	−0.00284 (17)
N1	0.042 (3)	0.040 (3)	0.031 (2)	−0.002 (2)	0.011 (2)	0.002 (2)
N2	0.057 (4)	0.071 (4)	0.047 (3)	0.020 (3)	0.020 (3)	0.015 (3)
N3	0.033 (2)	0.040 (3)	0.028 (2)	−0.005 (2)	0.0016 (19)	0.004 (2)
N4	0.035 (3)	0.047 (3)	0.030 (2)	−0.004 (2)	0.004 (2)	0.004 (2)
N5	0.042 (3)	0.102 (5)	0.029 (3)	−0.005 (3)	0.002 (2)	0.010 (3)
N6	0.031 (2)	0.046 (3)	0.032 (2)	−0.002 (2)	0.002 (2)	0.008 (2)
C1	0.037 (3)	0.038 (3)	0.035 (3)	−0.004 (3)	0.010 (3)	0.001 (3)
C2	0.066 (4)	0.067 (5)	0.034 (3)	0.008 (4)	0.019 (3)	0.010 (3)
C3	0.041 (3)	0.044 (3)	0.032 (3)	−0.004 (3)	0.007 (3)	0.001 (3)
C4	0.050 (4)	0.089 (6)	0.031 (3)	−0.007 (4)	−0.001 (3)	0.017 (3)
C5	0.037 (3)	0.068 (4)	0.032 (3)	−0.012 (3)	−0.007 (3)	0.009 (3)
C6	0.034 (3)	0.058 (4)	0.040 (3)	0.007 (3)	0.003 (3)	0.016 (3)

Geometric parameters (Å, °)

Zn1—N1	2.017 (5)	N5—C4	1.285 (9)
Zn1—N4i	2.019 (5)	N6—C3	1.333 (7)
Zn1—I1	2.5479 (8)	N6—C4	1.351 (8)
Zn1—I2	2.5523 (9)	N6—C6	1.463 (7)
N1—C1	1.296 (7)	C1—H1A	0.9300
N1—N2	1.369 (7)	C2—H2A	0.9300
N2—C2	1.301 (8)	C3—H3A	0.9300
N3—C2	1.342 (8)	C4—H4A	0.9300
N3—C1	1.350 (7)	C5—C6	1.502 (9)
N3—C5	1.455 (8)	C5—H5A	0.9700
N4—C3	1.301 (7)	C5—H5B	0.9700
N4—N5	1.384 (7)	C6—H6A	0.9700
N4—Zn1i	2.019 (5)	C6—H6B	0.9700
N1—Zn1—N4i	103.68 (19)	N3—C1—H1A	125.2
N1—Zn1—I1	108.78 (14)	N2—C2—N3	111.8 (5)
N4i—Zn1—I1	112.08 (14)	N2—C2—H2A	124.1
N1—Zn1—I2	113.03 (14)	N3—C2—H2A	124.1
N4i—Zn1—I2	107.90 (14)	N4—C3—N6	110.5 (5)
I1—Zn1—I2	111.19 (3)	N4—C3—H3A	124.7
C1—N1—N2	108.7 (5)	N6—C3—H3A	124.7
C1—N1—Zn1	129.1 (4)	N5—C4—N6	112.3 (6)
N2—N1—Zn1	122.1 (4)	N5—C4—H4A	123.9
C2—N2—N1	105.3 (5)	N6—C4—H4A	123.9
C2—N3—C1	104.5 (5)	N3—C5—C6	113.5 (5)
C2—N3—C5	128.9 (5)	N3—C5—H5A	108.9
C1—N3—C5	126.6 (5)	C6—C5—H5A	108.9
C3—N4—N5	107.7 (5)	N3—C5—H5B	108.9
C3—N4—Zn1i	133.9 (4)	C6—C5—H5B	108.9
N5—N4—Zn1i	118.4 (4)	H5A—C5—H5B	107.7
C4—N5—N4	105.3 (5)	N6—C6—C5	112.1 (5)
C3—N6—C4	104.2 (5)	N6—C6—H6A	109.2
C3—N6—C6	128.2 (5)	C5—C6—H6A	109.2
C4—N6—C6	127.5 (5)	N6—C6—H6B	109.2
N1—C1—N3	109.6 (5)	C5—C6—H6B	109.2
N1—C1—H1A	125.2	H6A—C6—H6B	107.9
N4i—Zn1—N1—C1	−131.9 (5)	C1—N3—C2—N2	0.9 (8)
I1—Zn1—N1—C1	−12.5 (5)	C5—N3—C2—N2	−178.9 (6)
I2—Zn1—N1—C1	111.5 (5)	N5—N4—C3—N6	1.5 (7)
N4i—Zn1—N1—N2	51.5 (5)	Zn1i—N4—C3—N6	177.6 (4)
I1—Zn1—N1—N2	171.0 (4)	C4—N6—C3—N4	−0.9 (7)
I2—Zn1—N1—N2	−65.0 (5)	C6—N6—C3—N4	176.2 (6)
C1—N1—N2—C2	1.0 (8)	N4—N5—C4—N6	0.9 (8)
Zn1—N1—N2—C2	178.2 (5)	C3—N6—C4—N5	−0.1 (8)
C3—N4—N5—C4	−1.4 (7)	C6—N6—C4—N5	−177.1 (6)
Zn1i—N4—N5—C4	−178.3 (5)	C2—N3—C5—C6	−101.4 (8)
N2—N1—C1—N3	−0.4 (7)	C1—N3—C5—C6	78.8 (7)
Zn1—N1—C1—N3	−177.4 (4)	C3—N6—C6—C5	−93.3 (7)
C2—N3—C1—N1	−0.3 (7)	C4—N6—C6—C5	83.1 (8)
C5—N3—C1—N1	179.6 (5)	N3—C5—C6—N6	63.8 (7)
N1—N2—C2—N3	−1.2 (9)

Symmetry codes: (i) −x+1/2, −y+1/2, −z+1.