1,2-Bis(2-chloro­benzyl­idene)hydrazine

Abstract

The title Schiff base compound, C₁₄H₁₀Cl₂N₂, crystallizes with one half-mol­ecule in the asymmetric unit. The mid-point of the N—N bond [1.418 (3) Å] lies on an inversion centre. The mol­ecular skeleton is approximately planar, the largest deviation from the mean plane being 0.143 (4) Å for the N-bonded C atom. The crystal packing exhibits no classical inter­molecular hydrogen bonds.

Related literature

For related literature, see: Alemi & Shaabani (2000 ▶); Alizadeh et al. (1999 ▶); Allen (2002 ▶).

Experimental

Crystal data

• C₁₄H₁₀Cl₂N₂

• M _r = 277.14

• Monoclinic,

• a = 3.9449 (17) Å

• b = 13.548 (6) Å

• c = 11.993 (5) Å

• β = 93.931 (6)°

• V = 639.5 (5) ų

• Z = 2

• Mo Kα radiation

• μ = 0.49 mm⁻¹

• T = 298 (2) K

• 0.29 × 0.25 × 0.17 mm

Data collection

• Bruker APEXII area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 2004 ▶) T _min = 0.871, T _max = 0.922

• 3767 measured reflections

• 1119 independent reflections

• 738 reflections with I > 2σ(I)

• R _int = 0.037

Refinement

• R[F ² > 2σ(F ²)] = 0.028

• wR(F ²) = 0.066

• S = 0.97

• 1119 reflections

• 82 parameters

• H-atom parameters constrained

• Δρ_max = 0.13 e Å⁻³

• Δρ_min = −0.14 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997 ▶); molecular graphics: ORTEPIII (Burnett & Johnson, 1996 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

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

supplementary crystallographic information

Comment

Schiff base ligands have significant importance in chemistry, especially in the development of Schiff base complexes, (Alizadeh et al., 1999). Schiff bases exhibiting olvent-dependent UV/vis spectra (solvatochromicity) can be suitable NLO (nonlinear optically active) materials (Alemi & Shaabani, 2000). In this paper, we report the synthesis and crystal structure of the title compound, (I).

The molecular structure of the title compound has crystallographically imposed inversion symmetry located in the middle of the N—N bond (Fig. 1). The molecule is approximately planar with the largest deviation from the plane being 0.143 (4) for C7. The C7—N1 of 1.272 (2)Å is indicative of a C?N double bond. The other C—N, C—Cl, and C—C distances show no remarkable features (Allen, 2002).

Experimental

Under nitrogen, a mixture of 2-chlorobenzaldehyde (2.8 g, 20 mmol), Na₂SO₄ (3.0 g) and hydrazine (30% in water, 10 mmol) in absolute ethanol (70 ml) was refluxed for about 3 h to yield a yellow precipitate. The product was collected by vacuum filtration and washed with ethanol. The crude solid was redissolved in CH₂Cl₂ (100 ml) and washed with water (2*10 ml)and brine(10 ml). After dried over Na₂SO₄, the solvent was removed under vacuum, and yellow solid was isolated in yield 90% (2.5 g). Colourless single crystals of the compound suitable for X-ray analysis were grown from CH₂Cl₂ and absolute ethanol(3:1) by slow evaporation of the solvent at room temperature over a period of about two weeks.

Refinement

All H atoms were placed in calculated positions (C—H = 0.93 Å) and refined using a riding model, with U_iso(H) = 1.2U_eq(C).

Figures

Fig. 1.

The molecular structure of (I) showing the atomic numbering scheme and 30% probability displacement ellipsoids [symmetry code (i):-x, 1 - y, 1 - z].

Crystal data

C14H10Cl2N2	F000 = 284
Mr = 277.14	Dx = 1.439 Mg m−3
Monoclinic, P21/c	Mo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1119 reflections
a = 3.9449 (17) Å	θ = 2.3–25.2º
b = 13.548 (6) Å	µ = 0.49 mm−1
c = 11.993 (5) Å	T = 298 (2) K
β = 93.931 (6)º	Block, colourless
V = 639.5 (5) Å3	0.29 × 0.25 × 0.17 mm
Z = 2

Data collection

Bruker APEXII area-detector diffractometer	1119 independent reflections
Radiation source: fine-focus sealed tube	738 reflections with I > 2σ(I)
Monochromator: graphite	Rint = 0.037
T = 298(2) K	θmax = 25.2º
φ and ω scan	θmin = 2.3º
Absorption correction: multi-scan(SADABS; Sheldrick, 2004)	h = −4→4
Tmin = 0.871, Tmax = 0.922	k = −16→16
3767 measured reflections	l = −13→14

Refinement

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.028	H-atom parameters constrained
wR(F2) = 0.066	w = 1/[σ2(Fo2) + (0.03P)2] where P = (Fo2 + 2Fc2)/3
S = 0.97	(Δ/σ)max = 0.001
1119 reflections	Δρmax = 0.13 e Å−3
82 parameters	Δρmin = −0.14 e Å−3
Primary atom site location: structure-invariant direct methods	Extinction correction: none

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.47589 (13)	0.61367 (3)	0.83542 (4)	0.0708 (2)
C1	0.0082 (4)	0.75417 (13)	0.57454 (14)	0.0566 (5)
H1	−0.0887	0.7395	0.5036	0.068*
C7	0.1598 (4)	0.57711 (12)	0.59883 (13)	0.0500 (4)
H7	0.3006	0.5310	0.6361	0.060*
C6	0.1555 (4)	0.67868 (12)	0.64024 (13)	0.0458 (4)
C4	0.2921 (4)	0.80006 (13)	0.78504 (14)	0.0595 (5)
H4	0.3884	0.8156	0.8558	0.071*
C5	0.2958 (4)	0.70373 (12)	0.74636 (13)	0.0499 (4)
C3	0.1449 (5)	0.87235 (13)	0.71780 (17)	0.0653 (5)
H3	0.1408	0.9370	0.7436	0.078*
C2	0.0033 (5)	0.85042 (13)	0.61264 (16)	0.0644 (5)
H2	−0.0950	0.9000	0.5676	0.077*
N1	−0.0248 (4)	0.55045 (9)	0.51295 (11)	0.0567 (4)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Cl1	0.0842 (4)	0.0692 (3)	0.0563 (3)	0.0015 (3)	−0.0145 (2)	−0.0021 (2)
C1	0.0631 (12)	0.0559 (11)	0.0499 (11)	−0.0027 (9)	−0.0024 (9)	−0.0033 (8)
C7	0.0549 (12)	0.0494 (10)	0.0449 (10)	−0.0040 (8)	−0.0021 (8)	−0.0021 (8)
C6	0.0446 (11)	0.0467 (10)	0.0464 (9)	−0.0065 (8)	0.0050 (8)	−0.0043 (8)
C4	0.0617 (13)	0.0614 (12)	0.0552 (11)	−0.0110 (10)	0.0037 (9)	−0.0167 (9)
C5	0.0483 (11)	0.0529 (10)	0.0482 (10)	−0.0053 (8)	0.0015 (8)	−0.0020 (8)
C3	0.0707 (14)	0.0491 (11)	0.0767 (13)	−0.0049 (10)	0.0103 (11)	−0.0142 (10)
C2	0.0714 (15)	0.0538 (12)	0.0681 (12)	0.0018 (9)	0.0058 (10)	0.0023 (10)
N1	0.0687 (10)	0.0462 (8)	0.0539 (9)	−0.0061 (8)	−0.0050 (8)	−0.0069 (7)

Geometric parameters (Å, °)

Cl1—C5	1.7406 (16)	C4—C3	1.372 (2)
C1—C2	1.382 (2)	C4—C5	1.385 (2)
C1—C6	1.393 (2)	C4—H4	0.9300
C1—H1	0.9300	C3—C2	1.376 (3)
C7—N1	1.272 (2)	C3—H3	0.9300
C7—C6	1.463 (2)	C2—H2	0.9300
C7—H7	0.9300	N1—N1i	1.418 (2)
C6—C5	1.394 (2)
C2—C1—C6	121.35 (16)	C5—C4—H4	120.4
C2—C1—H1	119.3	C4—C5—C6	121.48 (15)
C6—C1—H1	119.3	C4—C5—Cl1	117.90 (13)
N1—C7—C6	121.49 (15)	C6—C5—Cl1	120.60 (13)
N1—C7—H7	119.3	C4—C3—C2	120.89 (17)
C6—C7—H7	119.3	C4—C3—H3	119.6
C1—C6—C5	117.48 (15)	C2—C3—H3	119.6
C1—C6—C7	120.82 (14)	C3—C2—C1	119.50 (17)
C5—C6—C7	121.70 (15)	C3—C2—H2	120.3
C3—C4—C5	119.29 (16)	C1—C2—H2	120.3
C3—C4—H4	120.4	C7—N1—N1i	111.78 (16)

Symmetry codes: (i) −x, −y+1, −z+1.

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7···Cl1	0.93	2.69	3.060 (2)	105