6-Chloro-N′-(3,5-dibromo-2-hydroxy­benzyl­idene)­nicotinohydrazide

In the title compound, C₁₃H₈Br₂ClN₃O₂, the dihedral angle between the pyridine and benzene rings is 2.7 (4)°; an intra­molecular O—H...N hydrogen bond contributes to the conformation of the mol­ecule. In the crystal structure, inter­molecular N—H...O hydrogen bonds link mol­ecules into chains along the b-axis direction, while C—H...O and C—H...Cl inter­actions form head-to-tail chains in the ac plane.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.007 Å
• R factor = 0.046
• wR factor = 0.103
• Data-to-parameter ratio = 16.3

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT029_ALERT_3_B _diffrn_measured_fraction_theta_full Low .......       0.95

Alert level C
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.70
PLAT154_ALERT_1_C The su's on the Cell Angles are Equal  (x 10000)       3000 Deg.
PLAT341_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          7

Alert level G
ABSTM02_ALERT_3_G  When printed, the submitted absorption T values will be
            replaced by the scaled T values. Since the ratio of scaled T's
            is identical to the ratio of reported T values, the scaling
            does not imply a change to the absorption corrections used in
            the study.
            Ratio of Tmax expected/reported      0.701
            Tmax scaled      0.218 Tmin scaled      0.179
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          1

   0 ALERT level A = In general: serious problem
   1 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   2 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   4 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Schiff base compounds have received much attention in recent years. Some of the complexes have been found to have pharmacological and antitumor properties (Brückner et al., 2000; Harrop et al., 2003; Ren et al., 2002). As part of our research programme on the structure of Schiff base compounds (Diao et al., 2007; Diao, 2007; Li et al., 2007) we report here the structure of the title compound.

In the title compound, C₁₃H₈Br₂ClN₃O₂, (I), Fig. 1, the dihedral angle between the pyridine ring and the benzene ring is 2.7 (4) ° and an intramolecular O1—H1···N1 hydrogen bond contributes to the conformation of the molecule. In the crystal structure, intermolecular N2—H2···O2 hydrogen bonds link molecules into chains down b while C11–H11···O1, and C6–H6···Cl1 interactions form head-to-tail chains in the ac plane·(Table 1 and Fig. 2).

Related literature

For the biological properties of Schiff base compounds, see: Brückner et al. (2000); Harrop et al. (2003); Ren et al. (2002). For related structures, see: Diao (2007); Diao et al. (2007); Li et al. (2007).

S2. Experimental

3,5-Dibromosalicylaldehyde (1.0 mmol, 280.0 mg) and 6-chloronicotinic acid hydrazide (1.0 mmol, 171.3 mg) were dissolved in a methanol (70 ml). The mixture was stirred at reflux for 1 h and cooled to room temperature. After keeping the solution in air for three days, yellow block-like crystals were formed.

S3. Refinement

The crystals obtained were small and weakly diffracting so that the extent of diffraction observed is poor. H2 was located from a difference Fourier map and refined isotropically, with the N–H distance restrained to 0.90 (1) Å. Other H atoms were placed in calculated positions and constrained to ride on their parent atoms, with C–H distances of 0.93 Å, O–H distance of 0.82 Å, and with U_iso(H) = 1.2U_eq(C) and 1.5U_eq(O).

Computing details

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXTL (Bruker, 2000); program(s) used to refine structure: SHELXTL (Bruker, 2000); molecular graphics: SHELXTL (Bruker, 2000); software used to prepare material for publication: SHELXTL (Bruker, 2000).

Figures

	Fig. 1. The structure of (I) with displacement parameters drawn at the 30% probability level.
	Fig. 2. Crystal packing of (I) viewed along the b axis.

6-Chloro-N'-(3,5-dibromo-2-hydroxybenzylidene)nicotinohydrazide

Crystal data

C13H8Br2ClN3O2	Z = 2
Mr = 433.49	F(000) = 420
Triclinic, P1	Dx = 2.011 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 4.940 (1) Å	Cell parameters from 1135 reflections
b = 8.0750 (16) Å	θ = 2.4–24.3°
c = 18.598 (4) Å	µ = 5.85 mm^−1
α = 101.98 (3)°	T = 298 K
β = 90.88 (3)°	Block, yellow
γ = 98.93 (3)°	0.32 × 0.27 × 0.26 mm
V = 716.1 (3) Å^3

Data collection

Bruker SMART CCD area-detector diffractometer	3160 independent reflections
Radiation source: fine-focus sealed tube	2003 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.037
ω scans	θmax = 27.5°, θmin = 1.1°
Absorption correction: multi-scan (SADABS; Bruker, 2000)	h = −6→6
Tmin = 0.256, Tmax = 0.311	k = −10→10
6137 measured reflections	l = −24→23

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)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.103	H atoms treated by a mixture of independent and constrained refinement
S = 0.95	w = 1/[σ^2(Fo^2) + (0.0406P)^2] where P = (Fo^2 + 2Fc^2)/3
3160 reflections	(Δ/σ)max < 0.001
194 parameters	Δρmax = 0.74 e Å^−3
1 restraint	Δρmin = −0.48 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
Br1	0.64704 (10)	1.12018 (6)	0.38390 (3)	0.04623 (18)
Br2	−0.23098 (12)	0.65585 (7)	0.45596 (3)	0.0650 (2)
Cl1	−0.2558 (3)	0.61628 (17)	−0.30227 (7)	0.0535 (4)
O1	0.4050 (6)	0.9711 (4)	0.23082 (17)	0.0463 (8)
H1	0.3335	0.9344	0.1893	0.069*
O2	0.3840 (6)	0.7890 (5)	0.02625 (18)	0.0554 (10)
N1	0.0455 (7)	0.7899 (5)	0.1333 (2)	0.0392 (9)
N2	−0.0540 (7)	0.7455 (5)	0.0606 (2)	0.0374 (9)
N3	−0.2934 (7)	0.5806 (5)	−0.1668 (2)	0.0389 (9)
C1	0.0041 (9)	0.7871 (5)	0.2593 (2)	0.0370 (11)
C2	0.2486 (8)	0.9024 (5)	0.2799 (2)	0.0336 (10)
C3	0.3328 (8)	0.9506 (5)	0.3537 (3)	0.0366 (11)
C4	0.1922 (9)	0.8769 (5)	0.4061 (2)	0.0387 (11)
H4	0.2538	0.9074	0.4553	0.046*
C5	−0.0410 (9)	0.7572 (6)	0.3839 (2)	0.0390 (11)
C6	−0.1377 (9)	0.7133 (5)	0.3116 (3)	0.0391 (11)
H6	−0.2976	0.6344	0.2978	0.047*
C7	−0.0995 (9)	0.7370 (6)	0.1826 (3)	0.0394 (11)
H7	−0.2690	0.6675	0.1699	0.047*
C8	0.1354 (9)	0.7578 (6)	0.0096 (3)	0.0380 (11)
C9	0.0327 (8)	0.7262 (5)	−0.0682 (2)	0.0332 (10)
C10	0.1878 (9)	0.8054 (6)	−0.1171 (3)	0.0435 (12)
H10	0.3502	0.8798	−0.1006	0.052*
C11	0.1000 (10)	0.7732 (6)	−0.1896 (3)	0.0453 (12)
H11	0.1985	0.8260	−0.2232	0.054*
C12	−0.1389 (9)	0.6601 (6)	−0.2108 (2)	0.0369 (11)
C13	−0.2042 (9)	0.6156 (6)	−0.0962 (2)	0.0381 (11)
H13	−0.3088	0.5618	−0.0639	0.046*
H2	−0.234 (3)	0.750 (7)	0.056 (3)	0.080*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0403 (3)	0.0556 (3)	0.0381 (3)	−0.0031 (2)	−0.0101 (2)	0.0083 (2)
Br2	0.0754 (4)	0.0764 (4)	0.0414 (4)	−0.0097 (3)	0.0074 (3)	0.0246 (3)
Cl1	0.0615 (8)	0.0617 (8)	0.0335 (7)	−0.0032 (6)	−0.0119 (6)	0.0126 (6)
O1	0.0376 (19)	0.065 (2)	0.0302 (19)	−0.0083 (16)	−0.0008 (15)	0.0104 (18)
O2	0.0275 (19)	0.099 (3)	0.036 (2)	0.0031 (18)	−0.0058 (15)	0.0132 (19)
N1	0.033 (2)	0.056 (2)	0.028 (2)	0.0031 (18)	−0.0041 (17)	0.0094 (19)
N2	0.027 (2)	0.055 (2)	0.028 (2)	0.0040 (18)	−0.0028 (18)	0.0063 (19)
N3	0.039 (2)	0.044 (2)	0.030 (2)	−0.0025 (18)	−0.0045 (18)	0.0060 (18)
C1	0.036 (3)	0.044 (3)	0.031 (3)	0.004 (2)	0.000 (2)	0.009 (2)
C2	0.027 (2)	0.041 (3)	0.032 (3)	0.0000 (19)	0.001 (2)	0.010 (2)
C3	0.028 (2)	0.043 (3)	0.037 (3)	0.002 (2)	−0.004 (2)	0.009 (2)
C4	0.041 (3)	0.046 (3)	0.030 (3)	0.009 (2)	−0.001 (2)	0.009 (2)
C5	0.044 (3)	0.045 (3)	0.029 (3)	0.007 (2)	0.008 (2)	0.008 (2)
C6	0.038 (3)	0.037 (3)	0.039 (3)	−0.002 (2)	0.002 (2)	0.006 (2)
C7	0.033 (3)	0.046 (3)	0.035 (3)	0.002 (2)	−0.003 (2)	0.002 (2)
C8	0.035 (3)	0.044 (3)	0.034 (3)	0.003 (2)	−0.002 (2)	0.007 (2)
C9	0.029 (2)	0.042 (3)	0.028 (3)	0.006 (2)	−0.001 (2)	0.008 (2)
C10	0.033 (3)	0.057 (3)	0.036 (3)	−0.008 (2)	−0.004 (2)	0.011 (2)
C11	0.044 (3)	0.055 (3)	0.037 (3)	−0.002 (2)	0.006 (2)	0.017 (2)
C12	0.039 (3)	0.041 (3)	0.032 (3)	0.009 (2)	0.000 (2)	0.009 (2)
C13	0.038 (3)	0.045 (3)	0.028 (3)	−0.003 (2)	0.001 (2)	0.008 (2)

Geometric parameters (Å, º)

Br1—C3	1.896 (4)	C2—C3	1.386 (6)
Br2—C5	1.898 (4)	C3—C4	1.386 (6)
Cl1—C12	1.734 (4)	C4—C5	1.381 (6)
O1—C2	1.355 (5)	C4—H4	0.9300
O1—H1	0.8200	C5—C6	1.375 (6)
O2—C8	1.236 (5)	C6—H6	0.9300
N1—C7	1.275 (5)	C7—H7	0.9300
N1—N2	1.386 (5)	C8—C9	1.482 (6)
N2—C8	1.350 (6)	C9—C13	1.380 (6)
N2—H2	0.896 (10)	C9—C10	1.391 (6)
N3—C12	1.323 (5)	C10—C11	1.369 (6)
N3—C13	1.337 (5)	C10—H10	0.9300
C1—C6	1.387 (6)	C11—C12	1.372 (6)
C1—C2	1.400 (6)	C11—H11	0.9300
C1—C7	1.461 (6)	C13—H13	0.9300
C2—O1—H1	109.5	C1—C6—H6	120.1
C7—N1—N2	119.4 (4)	N1—C7—C1	119.1 (4)
C8—N2—N1	115.8 (4)	N1—C7—H7	120.4
C8—N2—H2	128 (4)	C1—C7—H7	120.4
N1—N2—H2	112 (4)	O2—C8—N2	121.9 (4)
C12—N3—C13	115.9 (4)	O2—C8—C9	121.1 (4)
C6—C1—C2	119.9 (4)	N2—C8—C9	117.0 (4)
C6—C1—C7	119.0 (4)	C13—C9—C10	117.3 (4)
C2—C1—C7	121.0 (4)	C13—C9—C8	123.7 (4)
O1—C2—C3	118.4 (4)	C10—C9—C8	118.9 (4)
O1—C2—C1	122.8 (4)	C11—C10—C9	119.6 (4)
C3—C2—C1	118.8 (4)	C11—C10—H10	120.2
C4—C3—C2	121.3 (4)	C9—C10—H10	120.2
C4—C3—Br1	119.2 (3)	C10—C11—C12	117.6 (4)
C2—C3—Br1	119.5 (3)	C10—C11—H11	121.2
C5—C4—C3	118.7 (4)	C12—C11—H11	121.2
C5—C4—H4	120.7	N3—C12—C11	125.3 (4)
C3—C4—H4	120.7	N3—C12—Cl1	115.9 (3)
C6—C5—C4	121.3 (4)	C11—C12—Cl1	118.8 (4)
C6—C5—Br2	120.3 (3)	N3—C13—C9	124.3 (4)
C4—C5—Br2	118.4 (4)	N3—C13—H13	117.8
C5—C6—C1	119.8 (4)	C9—C13—H13	117.8
C5—C6—H6	120.1

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2···O2^i	0.90 (1)	2.05 (2)	2.929 (5)	166 (5)
O1—H1···N1	0.82	1.85	2.565 (5)	146
C6—H6···Cl1^ii	0.93	2.77	3.662 (5)	161
C11—H11···O1^iii	0.93	2.38	3.160 (5)	142

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