Dichlorido{N-[1-(pyrazin-2-yl)ethyl­idene-κN1]ethane-1,2-diamine-κ2N,N′}zinc

Liu, J.-C.; Li, M.; Mohammed Omer, A.S.; Wei, Y.; Guo, G.-Z.

doi:10.1107/S1600536811042115

metal-organic compounds

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Volume 67| Part 11| November 2011| Page m1555

doi:10.1107/S1600536811042115

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Dichlorido{N-[1-(pyrazin-2-yl)ethylidene-κN¹]ethane-1,2-diamine-κ²N,N′}zinc

Jia-Cheng Liu,^a ^* Meng Li,^a Abedelwahed Saeed Mohammed Omer,^a Yun Wei ^a and Guo-Zhe Guo ^a

^aCollege of Chemistry and Chemical Engineering, Key Laboratory of Eco-Environment-Related Polymer Materials of the Ministry of Education, Key Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu, Northwest Normal University, Lanzhou 730070, People's Republic of China
^*Correspondence e-mail: jcliu8@nwnu.edu.cn

(Received 1 October 2011; accepted 12 October 2011; online 22 October 2011)

The Zn^II atom in the title complex, [ZnCl₂(C₈H₁₂N₄)], is coordinated by two Cl atoms and three N atoms of the N-[1-(pyrazin-2-yl)ethylidene]ethane-1,2-diamine ligand, and displays a distorted square-pyramidal geometry with the apical position occupied by a Cl atom. In the crystal, intermolecular N—H⋯Cl and C—H⋯Cl hydrogen bonds link the molecules into a three-dimensional framework.

Related literature

For the use of dinucleating N-heterocyclic ligands in crystal engineering, see: Pascu et al. (2004 ). For metal complexes of Schiff base ligands in coordination chemictry, see: Coles et al. (1998 ); Gourbatsis et al. (1999 ).

Experimental

Crystal data

[ZnCl₂(C₈H₁₂N₄)]
M_r = 300.49
Triclinic, $[P \overline 1]$
a = 7.106 (5) Å
b = 8.976 (6) Å
c = 10.225 (6) Å
α = 69.566 (5)°
β = 73.434 (5)°
γ = 83.056 (5)°
V = 585.6 (6) Å³
Z = 2
Mo Kα radiation
μ = 2.53 mm⁻¹
T = 296 K
0.23 × 0.21 × 0.19 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008 ) T_min = 0.594, T_max = 0.646
4159 measured reflections
2129 independent reflections
1790 reflections with I > 2σ(I)
R_int = 0.027

Refinement

R[F² > 2σ(F²)] = 0.031
wR(F²) = 0.071
S = 1.08
2129 reflections
137 parameters
H-atom parameters constrained
Δρ_max = 0.31 e Å⁻³
Δρ_min = −0.38 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N4—H4B⋯Cl1ⁱ	0.90	2.77	3.531 (4)	143
N4—H4A⋯Cl2ⁱⁱ	0.90	2.81	3.534 (3)	139
C2—H2⋯Cl2ⁱⁱⁱ	0.93	2.81	3.672 (4)	155
C3—H3⋯Cl2^iv	0.93	2.80	3.704 (4)	164
C6—H6B⋯Cl1ⁱ	0.97	2.84	3.550 (4)	131
Symmetry codes: (i) -x+1, -y+1, -z+2; (ii) -x, -y+1, -z+2; (iii) -x+1, -y+1, -z+1; (iv) -x+1, -y+2, -z+1.

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); 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.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811042115/bh2386sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811042115/bh2386Isup2.hkl

checkCIF report

Comment top

Pyrazines themselves are well known dinucleating ligands and, as many dinucleating N-heterocyclic ligands, have attracted much attention from crystal engineers (Pascu et al., 2004). On the other hand, Schiff base ligands have played an integral role in the development of coordination chemistry since the late 19 th century. The finding that metal complexes of these ligands are ubiquitous reflects their facile synthesis, wide applications and the accessibility to diverse structural modifications (Coles et al., 1998; Gourbatsis et al., 1999). Herein, we report on the synthesis of an asymmetric Schiff base using 2-acetylpyrazine as precursor and we report its Zn^II complex.

The molecular structure of the complex [ZnCl₂(C₈H₁₂N₄)] is shown in Fig. 1. The complex is a mononuclear, five-coordinate species. The central zinc ion is coordinated by two chloride and three N atoms. The Schiff base acts as a tridentate chelating ligand, giving two five-membered rings. The coordination geometry about zinc(II) is distorted square-pyramidal. Atoms N1, N3, N4 and Cl1 form the basal plane and atom Cl2 is in apical position. The effect of the chelate rings is clearly observed in the N1—Zn1—N3 and N3—Zn1—N4 bond angles, which deviate by 16.7 and 12.0°, respectively, from the ideal value (90°). As a result, the N1—Zn1—N4 axis is not linear [145.43 (10)°], significantly deviated from the ideal value of 180°. The Zn—N distances in the basal plane are 2.122 (3), 2.245 (2), and 2.117 (3) Å.

In the crystal packing (Fig. 2), N—H···Cl and C—H···Cl hydrogen bonds link the molecules into sheets, which interact weakly to form a 3D framework.

Related literature top

For the use of dinucleating N-heterocyclic ligands in crystal engineering, see: Pascu et al. (2004). For metal complexes of Schiff base ligands in coordination chemictry, see: Coles et al. (1998); Gourbatsis et al. (1999).

Experimental top

To 0.2 mmol (0.0328 g) of N-[1-(pyrazin-2-yl)ethylidene]ethane-1,2-diamine in 15 ml of methanol was added 0.2 mmol (0.0272 g) of ZnCl₂ in 10 ml of methanol, and the mixture was stirred at 333 K for 0.5 h. Upon free evaporation, single crystals suitable for XRD analysis were collected by filtration within two weeks (yield: 69%).

Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); 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. The structure of the title compound. Displacement ellipsoids are drawn at the 30% probability level. H atoms have been omitted for clarity.
	Fig. 2. The crystal packing of the title compound, viewed along the b axis. Hydrogen bonds are shown as dashed lines.

Dichlorido{N-[1-(pyrazin-2-yl)ethylidene-κN¹]ethane-1,2- diamine-κ²N,N'}zinc top

Crystal data top

[ZnCl₂(C₈H₁₂N₄)]	Z = 2
M_r = 300.49	F(000) = 304
Triclinic, P1	D_x = 1.704 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.106 (5) Å	Cell parameters from 1862 reflections
b = 8.976 (6) Å	θ = 2.2–26.4°
c = 10.225 (6) Å	µ = 2.53 mm⁻¹
α = 69.566 (5)°	T = 296 K
β = 73.434 (5)°	Block, colourless
γ = 83.056 (5)°	0.23 × 0.21 × 0.19 mm
V = 585.6 (6) Å³

Data collection top

Bruker APEXII CCD diffractometer	2129 independent reflections
Radiation source: fine-focus sealed tube	1790 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.027
ϕ and ω scans	θ_max = 25.5°, θ_min = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −8→8
T_min = 0.594, T_max = 0.646	k = −9→10
4159 measured reflections	l = −12→12

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)] = 0.031	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.071	H-atom parameters constrained
S = 1.08	w = 1/[σ²(F_o²) + (0.032P)²] where P = (F_o² + 2F_c²)/3
2129 reflections	(Δ/σ)_max = 0.001
137 parameters	Δρ_max = 0.31 e Å⁻³
0 restraints	Δρ_min = −0.38 e Å⁻³
0 constraints

Crystal data top

[ZnCl₂(C₈H₁₂N₄)]	γ = 83.056 (5)°
M_r = 300.49	V = 585.6 (6) Å³
Triclinic, P1	Z = 2
a = 7.106 (5) Å	Mo Kα radiation
b = 8.976 (6) Å	µ = 2.53 mm⁻¹
c = 10.225 (6) Å	T = 296 K
α = 69.566 (5)°	0.23 × 0.21 × 0.19 mm
β = 73.434 (5)°

Data collection top

Bruker APEXII CCD diffractometer	2129 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2008)	1790 reflections with I > 2σ(I)
T_min = 0.594, T_max = 0.646	R_int = 0.027
4159 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.031	0 restraints
wR(F²) = 0.071	H-atom parameters constrained
S = 1.08	Δρ_max = 0.31 e Å⁻³
2129 reflections	Δρ_min = −0.38 e Å⁻³
137 parameters

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

	x	y	z	U_iso*/U_eq
Zn1	0.31700 (5)	0.62496 (4)	0.82328 (3)	0.03108 (13)
C1	0.6706 (5)	0.5945 (4)	0.5517 (3)	0.0429 (8)
H1	0.6344	0.4897	0.5783	0.051*
C2	0.8103 (5)	0.6600 (4)	0.4227 (3)	0.0478 (9)
H2	0.8639	0.5976	0.3645	0.057*
C3	0.7916 (4)	0.8893 (4)	0.4693 (3)	0.0348 (7)
H3	0.8318	0.9926	0.4442	0.042*
C4	0.6524 (4)	0.8264 (3)	0.5984 (3)	0.0271 (6)
C5	0.5617 (4)	0.9145 (3)	0.7031 (3)	0.0281 (6)
C6	0.3104 (4)	0.9118 (3)	0.9186 (3)	0.0343 (7)
H6A	0.2748	1.0230	0.8787	0.041*
H6B	0.3952	0.9032	0.9804	0.041*
C7	0.1281 (5)	0.8162 (4)	1.0050 (3)	0.0425 (8)
H7A	0.0788	0.8336	1.0974	0.051*
H7B	0.0269	0.8504	0.9533	0.051*
C8	0.6519 (5)	1.0628 (4)	0.6874 (4)	0.0496 (9)
H8A	0.5599	1.1201	0.7425	0.074*
H8B	0.6865	1.1277	0.5874	0.074*
H8C	0.7678	1.0363	0.7222	0.074*
Cl1	0.37658 (13)	0.35645 (9)	0.88661 (9)	0.0501 (2)
Cl2	0.07883 (12)	0.68599 (9)	0.70197 (9)	0.0431 (2)
N1	0.5878 (3)	0.6794 (3)	0.6377 (2)	0.0322 (6)
N2	0.8705 (4)	0.8072 (3)	0.3791 (3)	0.0438 (7)
N3	0.4131 (3)	0.8493 (3)	0.8015 (2)	0.0285 (5)
N4	0.1750 (4)	0.6466 (3)	1.0283 (3)	0.0460 (7)
H4A	0.0645	0.5900	1.0682	0.055*
H4B	0.2545	0.6102	1.0879	0.055*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Zn1	0.0306 (2)	0.0258 (2)	0.0363 (2)	−0.00363 (14)	−0.00618 (14)	−0.01066 (15)
C1	0.0433 (19)	0.0373 (19)	0.054 (2)	−0.0035 (15)	−0.0081 (16)	−0.0252 (16)
C2	0.047 (2)	0.057 (2)	0.047 (2)	0.0034 (17)	−0.0056 (16)	−0.0320 (18)
C3	0.0337 (17)	0.0355 (18)	0.0349 (16)	−0.0028 (13)	−0.0075 (13)	−0.0118 (14)
C4	0.0207 (14)	0.0295 (16)	0.0344 (16)	0.0014 (12)	−0.0101 (12)	−0.0130 (13)
C5	0.0256 (15)	0.0276 (16)	0.0315 (15)	0.0008 (12)	−0.0089 (12)	−0.0096 (13)
C6	0.0387 (17)	0.0318 (17)	0.0327 (16)	−0.0005 (13)	−0.0035 (13)	−0.0158 (13)
C7	0.0397 (19)	0.044 (2)	0.0408 (18)	−0.0042 (15)	0.0049 (14)	−0.0212 (16)
C8	0.049 (2)	0.046 (2)	0.055 (2)	−0.0185 (17)	0.0033 (17)	−0.0267 (17)
Cl1	0.0558 (6)	0.0267 (4)	0.0641 (6)	0.0026 (4)	−0.0167 (4)	−0.0108 (4)
Cl2	0.0419 (5)	0.0377 (5)	0.0505 (5)	−0.0055 (3)	−0.0203 (4)	−0.0077 (4)
N1	0.0312 (13)	0.0299 (14)	0.0373 (13)	−0.0033 (11)	−0.0055 (11)	−0.0150 (11)
N2	0.0402 (16)	0.0513 (18)	0.0404 (15)	−0.0058 (13)	−0.0001 (12)	−0.0225 (14)
N3	0.0296 (13)	0.0262 (13)	0.0313 (13)	0.0009 (10)	−0.0064 (11)	−0.0128 (11)
N4	0.0535 (18)	0.0400 (17)	0.0384 (15)	−0.0155 (14)	0.0007 (13)	−0.0111 (13)

Geometric parameters (Å, º) top

Zn1—N4	2.117 (3)	C5—N3	1.266 (3)
Zn1—N3	2.122 (3)	C5—C8	1.485 (4)
Zn1—N1	2.245 (2)	C6—N3	1.467 (3)
Zn1—Cl2	2.2807 (14)	C6—C7	1.510 (4)
Zn1—Cl1	2.2862 (16)	C6—H6A	0.9700
C1—N1	1.329 (4)	C6—H6B	0.9700
C1—C2	1.387 (4)	C7—N4	1.468 (4)
C1—H1	0.9300	C7—H7A	0.9700
C2—N2	1.320 (4)	C7—H7B	0.9700
C2—H2	0.9300	C8—H8A	0.9600
C3—N2	1.337 (4)	C8—H8B	0.9600
C3—C4	1.381 (4)	C8—H8C	0.9600
C3—H3	0.9300	N4—H4A	0.9000
C4—N1	1.335 (3)	N4—H4B	0.9000
C4—C5	1.505 (4)

N4—Zn1—N3	77.98 (9)	N3—C6—H6B	110.0
N4—Zn1—N1	145.43 (10)	C7—C6—H6B	110.0
N3—Zn1—N1	73.32 (8)	H6A—C6—H6B	108.4
N4—Zn1—Cl2	104.77 (9)	N4—C7—C6	109.6 (2)
N3—Zn1—Cl2	104.26 (7)	N4—C7—H7A	109.8
N1—Zn1—Cl2	100.68 (8)	C6—C7—H7A	109.8
N4—Zn1—Cl1	100.56 (8)	N4—C7—H7B	109.8
N3—Zn1—Cl1	146.85 (7)	C6—C7—H7B	109.8
N1—Zn1—Cl1	93.29 (7)	H7A—C7—H7B	108.2
Cl2—Zn1—Cl1	108.03 (3)	C5—C8—H8A	109.5
N1—C1—C2	120.9 (3)	C5—C8—H8B	109.5
N1—C1—H1	119.5	H8A—C8—H8B	109.5
C2—C1—H1	119.5	C5—C8—H8C	109.5
N2—C2—C1	122.8 (3)	H8A—C8—H8C	109.5
N2—C2—H2	118.6	H8B—C8—H8C	109.5
C1—C2—H2	118.6	C1—N1—C4	117.2 (2)
N2—C3—C4	122.5 (3)	C1—N1—Zn1	128.1 (2)
N2—C3—H3	118.7	C4—N1—Zn1	113.90 (17)
C4—C3—H3	118.7	C2—N2—C3	115.7 (3)
N1—C4—C3	120.8 (2)	C5—N3—C6	122.9 (2)
N1—C4—C5	115.2 (2)	C5—N3—Zn1	121.79 (19)
C3—C4—C5	124.0 (3)	C6—N3—Zn1	114.89 (17)
N3—C5—C8	125.8 (3)	C7—N4—Zn1	106.93 (18)
N3—C5—C4	114.5 (2)	C7—N4—H4A	110.3
C8—C5—C4	119.6 (2)	Zn1—N4—H4A	110.3
N3—C6—C7	108.4 (2)	C7—N4—H4B	110.3
N3—C6—H6A	110.0	Zn1—N4—H4B	110.3
C7—C6—H6A	110.0	H4A—N4—H4B	108.6

N1—C1—C2—N2	0.9 (5)	C1—C2—N2—C3	1.6 (5)
N2—C3—C4—N1	−1.1 (4)	C4—C3—N2—C2	−1.5 (4)
N2—C3—C4—C5	179.4 (3)	C8—C5—N3—C6	−1.6 (5)
N1—C4—C5—N3	−11.6 (4)	C4—C5—N3—C6	176.5 (2)
C3—C4—C5—N3	167.8 (3)	C8—C5—N3—Zn1	−173.7 (2)
N1—C4—C5—C8	166.6 (3)	C4—C5—N3—Zn1	4.4 (3)
C3—C4—C5—C8	−13.9 (4)	C7—C6—N3—C5	173.4 (3)
N3—C6—C7—N4	43.0 (3)	C7—C6—N3—Zn1	−13.9 (3)
C2—C1—N1—C4	−3.5 (5)	N4—Zn1—N3—C5	162.1 (2)
C2—C1—N1—Zn1	165.3 (2)	N1—Zn1—N3—C5	1.6 (2)
C3—C4—N1—C1	3.6 (4)	Cl2—Zn1—N3—C5	−95.5 (2)
C5—C4—N1—C1	−176.9 (3)	Cl1—Zn1—N3—C5	71.1 (3)
C3—C4—N1—Zn1	−166.8 (2)	N4—Zn1—N3—C6	−10.6 (2)
C5—C4—N1—Zn1	12.7 (3)	N1—Zn1—N3—C6	−171.1 (2)
N4—Zn1—N1—C1	147.8 (3)	Cl2—Zn1—N3—C6	91.80 (19)
N3—Zn1—N1—C1	−177.1 (3)	Cl1—Zn1—N3—C6	−101.6 (2)
Cl2—Zn1—N1—C1	−75.2 (3)	C6—C7—N4—Zn1	−51.8 (3)
Cl1—Zn1—N1—C1	33.8 (3)	N3—Zn1—N4—C7	33.3 (2)
N4—Zn1—N1—C4	−43.1 (3)	N1—Zn1—N4—C7	67.6 (3)
N3—Zn1—N1—C4	−8.02 (18)	Cl2—Zn1—N4—C7	−68.5 (2)
Cl2—Zn1—N1—C4	93.82 (19)	Cl1—Zn1—N4—C7	179.54 (19)
Cl1—Zn1—N1—C4	−157.14 (19)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N4—H4B···Cl1ⁱ	0.90	2.77	3.531 (4)	143
N4—H4A···Cl2ⁱⁱ	0.90	2.81	3.534 (3)	139
C2—H2···Cl2ⁱⁱⁱ	0.93	2.81	3.672 (4)	155
C3—H3···Cl2^iv	0.93	2.80	3.704 (4)	164
C6—H6B···Cl1ⁱ	0.97	2.84	3.550 (4)	131

Symmetry codes: (i) −x+1, −y+1, −z+2; (ii) −x, −y+1, −z+2; (iii) −x+1, −y+1, −z+1; (iv) −x+1, −y+2, −z+1.

Experimental details

Crystal data
Chemical formula	[ZnCl₂(C₈H₁₂N₄)]
M_r	300.49
Crystal system, space group	Triclinic, P1
Temperature (K)	296
a, b, c (Å)	7.106 (5), 8.976 (6), 10.225 (6)
α, β, γ (°)	69.566 (5), 73.434 (5), 83.056 (5)
V (Å³)	585.6 (6)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	2.53
Crystal size (mm)	0.23 × 0.21 × 0.19

Data collection
Diffractometer	Bruker APEXII CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2008)
T_min, T_max	0.594, 0.646
No. of measured, independent and observed [I > 2σ(I)] reflections	4159, 2129, 1790
R_int	0.027
(sin θ/λ)_max (Å⁻¹)	0.606

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.031, 0.071, 1.08
No. of reflections	2129
No. of parameters	137
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.31, −0.38

Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N4—H4B···Cl1ⁱ	0.90	2.77	3.531 (4)	142.9
N4—H4A···Cl2ⁱⁱ	0.90	2.81	3.534 (3)	138.7
C2—H2···Cl2ⁱⁱⁱ	0.93	2.81	3.672 (4)	154.5
C3—H3···Cl2^iv	0.93	2.80	3.704 (4)	163.8
C6—H6B···Cl1ⁱ	0.97	2.84	3.550 (4)	130.9

Symmetry codes: (i) −x+1, −y+1, −z+2; (ii) −x, −y+1, −z+2; (iii) −x+1, −y+1, −z+1; (iv) −x+1, −y+2, −z+1.

Acknowledgements

This work was supported by the NSFC (No. 20871099) and the Natural Science Foundation of Gansu (No. 0710RJZA113).

References

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