(E,E)-4,4′-Dichloro-2,2′-(1,1′-azino­diethyl­ene)diphenol

The title compound, C₁₈H₁₈Cl₂N₂O₂, was synthesized by the reaction of 1-(5-chloro-2-hydroxy­phen­yl)propan-1-one with hydrazine hydrate. The mol­ecule possesses a crystallographically imposed centre of symmetry at the midpoint of the N—N bond. Intra­molecular O—H...N hydrogen bonds, together with C—H...π inter­actions, help to stabilize the structure.

Key indicators

• Single-crystal X-ray study
• T = 273 K
• Mean [sigma](C-C)= 0.002 Å
• R factor = 0.032
• wR factor = 0.089
• Data-to-parameter ratio = 13.6

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S1. Comment

Recently, a number of azine compounds containing both a diimine linkage and N—N bonding have been investigated in terms of their crystallography and coordination chemistry (Kundu et al., 2005; Kesslen et al., 1999; Zheng et al., 2005;). As an extension of work on the structural characterization of azine derivatives,the title compound, (I),was synthesized and its crystal structure is reported here.

In the title compound, there is a crystallographic centre of symmetry at the midpoint of the N—N bond (Fig. 1). The molecule displays the (E, E) conformation with respect to the C7=N1 and its symmetry related C7ⁱ=N1ⁱ double bond (Fig 1.). This configuration agrees with those commonly found in similar compounds (Glaser et al., 1995; Hunig et al., 2000)·The crystal structure is stabilized by intramolecular O—H···N hydrogen bond and weak C—H···\p interactions. (Table 1. and Fig. 2).

Related literature

For related literature, see: Glaser et al. (1995); Hunig et al. (2000); Kesslen et al. (1999); Kundu et al. (2005); Zheng et al. (2005).

S2. Experimental

An ethanol solution (50 ml) of hydrazine (0.02 mol) and 1-(5-chloro-2-hydroxyphenyl)propan-1-one (0.04 mol) was refluxed and stirred for 5 h; the mixture was cooled and the resulting solid product, (I), was collected by filtration·Crystals suitable for single-crystal X-ray diffraction were grown by slow evaporation of a solution in 1,2-dichloroethane.

S3. Refinement

All H atoms were positioned geometrically and treated as riding on their parent atoms,with C—H(methyl) = 0.96 Å, C—H(methylene) = 0.97 Å,C—H(aromatic) = 0.93 Å, O—H = 0.82 Å and with U_iso(H) =1.5U_eq(C_methyl,O) and 1.2U_eq(C_aromatic,C_methylene).

Computing details

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and XP in SHELXTL (Sheldrick, 1997b); software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The molecular structure of compound (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. Dashed lines show intramolecular hydrogen bonds. [Symmetry code: (i) 1 - x, 1 - y, 1 - z].
	Fig. 2. View showing the C—H···π interactio. H bond is shown as dashed line.

(E,E)-4,4'-Dichloro-2,2'-(1,1'-azinodiethylene)diphenol

Crystal data

C18H18Cl2N2O2	F(000) = 380
Mr = 365.24	Dx = 1.412 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 4397 reflections
a = 9.3706 (3) Å	θ = 2.2–28.1°
b = 13.9089 (4) Å	µ = 0.39 mm^−1
c = 6.7640 (2) Å	T = 273 K
β = 103.021 (1)°	Plate, yellow
V = 858.92 (4) Å^3	0.33 × 0.23 × 0.11 mm
Z = 2

Data collection

Bruker APEXII CCD area-detector diffractometer	1507 independent reflections
Radiation source: fine-focus sealed tube	1352 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.022
φ and ω scans	θmax = 25.0°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	h = −10→11
Tmin = 0.882, Tmax = 0.958	k = −16→16
9653 measured reflections	l = −8→8

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.032	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.089	H-atom parameters constrained
S = 1.08	w = 1/[σ^2(Fo^2) + (0.0453P)^2 + 0.2176P] where P = (Fo^2 + 2Fc^2)/3
1507 reflections	(Δ/σ)max < 0.001
111 parameters	Δρmax = 0.17 e Å^−3
0 restraints	Δρmin = −0.29 e Å^−3

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	−0.00768 (5)	0.36471 (3)	1.03985 (8)	0.0643 (2)
O1	0.58588 (12)	0.37295 (8)	0.90005 (17)	0.0499 (3)
H1	0.5916	0.4059	0.8016	0.075*
N1	0.48939 (13)	0.47487 (9)	0.58463 (18)	0.0384 (3)
C1	0.16828 (19)	0.36915 (10)	0.9962 (2)	0.0433 (4)
C2	0.28142 (19)	0.32278 (11)	1.1277 (2)	0.0473 (4)
H2	0.2641	0.2898	1.2396	0.057*
C3	0.41983 (19)	0.32587 (11)	1.0916 (2)	0.0470 (4)
H3	0.4961	0.2947	1.1801	0.056*
C4	0.44800 (17)	0.37479 (10)	0.9253 (2)	0.0385 (3)
C5	0.33229 (15)	0.42224 (9)	0.7891 (2)	0.0351 (3)
C6	0.19278 (16)	0.41832 (10)	0.8310 (2)	0.0402 (3)
H6	0.1152	0.4496	0.7453	0.048*
C7	0.35581 (15)	0.47347 (9)	0.6084 (2)	0.0354 (3)
C8	0.23007 (16)	0.52225 (11)	0.4663 (2)	0.0419 (4)
H8A	0.1402	0.4879	0.4673	0.050*
H8B	0.2457	0.5198	0.3294	0.050*
C9	0.2138 (2)	0.62645 (13)	0.5253 (3)	0.0613 (5)
H9A	0.2073	0.6295	0.6648	0.092*
H9B	0.1265	0.6530	0.4409	0.092*
H9C	0.2973	0.6626	0.5076	0.092*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0603 (3)	0.0673 (3)	0.0767 (4)	−0.0043 (2)	0.0394 (3)	0.0087 (2)
O1	0.0403 (6)	0.0577 (7)	0.0509 (7)	0.0051 (5)	0.0086 (5)	0.0132 (5)
N1	0.0386 (7)	0.0399 (6)	0.0387 (6)	0.0025 (5)	0.0127 (5)	0.0059 (5)
C1	0.0519 (9)	0.0366 (8)	0.0471 (9)	−0.0037 (6)	0.0229 (7)	−0.0017 (6)
C2	0.0658 (11)	0.0397 (8)	0.0399 (8)	−0.0032 (7)	0.0193 (7)	0.0032 (6)
C3	0.0567 (10)	0.0432 (9)	0.0388 (8)	0.0014 (7)	0.0059 (7)	0.0052 (6)
C4	0.0407 (8)	0.0346 (7)	0.0398 (8)	−0.0004 (6)	0.0083 (6)	−0.0022 (6)
C5	0.0394 (8)	0.0301 (7)	0.0369 (7)	−0.0012 (6)	0.0110 (6)	−0.0012 (5)
C6	0.0414 (8)	0.0371 (7)	0.0440 (8)	0.0018 (6)	0.0133 (6)	0.0019 (6)
C7	0.0368 (8)	0.0331 (7)	0.0367 (7)	−0.0003 (5)	0.0094 (6)	−0.0018 (5)
C8	0.0354 (8)	0.0501 (8)	0.0406 (8)	0.0004 (6)	0.0092 (6)	0.0068 (6)
C9	0.0636 (12)	0.0553 (11)	0.0637 (12)	0.0208 (8)	0.0116 (9)	0.0072 (8)

Geometric parameters (Å, º)

Cl1—C1	1.7404 (17)	C4—C5	1.417 (2)
O1—C4	1.3410 (19)	C5—C6	1.400 (2)
O1—H1	0.8200	C5—C7	1.4738 (19)
N1—C7	1.2976 (18)	C6—H6	0.9300
N1—N1^i	1.393 (2)	C7—C8	1.504 (2)
C1—C6	1.373 (2)	C8—C9	1.520 (2)
C1—C2	1.381 (2)	C8—H8A	0.9700
C2—C3	1.374 (2)	C8—H8B	0.9700
C2—H2	0.9300	C9—H9A	0.9600
C3—C4	1.390 (2)	C9—H9B	0.9600
C3—H3	0.9300	C9—H9C	0.9600
C4—O1—H1	109.5	C1—C6—H6	119.4
C7—N1—N1^i	115.44 (14)	C5—C6—H6	119.4
C6—C1—C2	120.81 (15)	N1—C7—C5	116.02 (12)
C6—C1—Cl1	119.62 (13)	N1—C7—C8	123.55 (13)
C2—C1—Cl1	119.57 (12)	C5—C7—C8	120.41 (12)
C3—C2—C1	119.32 (14)	C7—C8—C9	111.89 (13)
C3—C2—H2	120.3	C7—C8—H8A	109.2
C1—C2—H2	120.3	C9—C8—H8A	109.2
C2—C3—C4	121.22 (15)	C7—C8—H8B	109.2
C2—C3—H3	119.4	C9—C8—H8B	109.2
C4—C3—H3	119.4	H8A—C8—H8B	107.9
O1—C4—C3	117.23 (13)	C8—C9—H9A	109.5
O1—C4—C5	122.97 (13)	C8—C9—H9B	109.5
C3—C4—C5	119.78 (14)	H9A—C9—H9B	109.5
C6—C5—C4	117.58 (13)	C8—C9—H9C	109.5
C6—C5—C7	120.52 (13)	H9A—C9—H9C	109.5
C4—C5—C7	121.90 (13)	H9B—C9—H9C	109.5
C1—C6—C5	121.28 (14)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N1	0.82	1.83	2.5513 (16)	146
C2—H2···Cg1^ii	0.93	2.68	3.496 (2)	147

Symmetry code: (ii) x, −y−1/2, z−1/2.