6-Bromo-2′-[4-(dimethyl­amino)benzyl­idene]nicotinohydrazide monohydrate

The asymmetric unit of the title compound, C₁₅H₁₅BrN₄O·H₂O, consists of a roughly planar Schiff base mol­ecule and a solvent water mol­ecule. The Schiff base mol­ecule displays a trans configuration with respect to the C=N double bond. The dihedral angle between the benzene and pyridine rings is 4.6 (2)°. In the crystal structure, mol­ecules are linked through inter­molecular O—H...O and O—H...N hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.035
• wR factor = 0.086
• Data-to-parameter ratio = 17.0

checkCIF/PLATON results

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Alert level C
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.95
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Alert level G
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S1. Comment

Schiff base compounds have been of great interest for a long time. These compounds play an important role in the development of coordination chemistry (Musie et al., 2001; Bernardo et al., 1996; Paul et al., 2002). Recently, we have reported a few Schiff base compounds (Yang, 2006a,b,c,d,e, 2007; Yang & Guo, 2006). As a further investigation of this work, the crystal structure of the title compound is reported here.

The title compound, C₁₅H₁₅BrN₄O·H₂O, consists of a roughly planar Schiff base molecule and a lattice water molecule (Fig. 1). The Schiff base molecule displays a trans configuration with respect to the C═N double bond. All the bond lengths are within normal ranges (Allen et al., 1987). The C7═N3 bond length of 1.279 (3) Å conforms to the value for a double bond. The bond length of 1.338 (3) Å between atoms C6 and N2 is intermediate between an N—N single bond and an N═N double bond, because of conjugation effects in the molecule. The dihedral angle between the benzene ring and the pyridine ring is 4.6 (2)°. In the crystal structure, molecules are linked through intermolecular O—H···O and O—H···N hydrogen bonds, forming tetrammers (Fig. 2).

Related literature

For related structures, see Yang (2006a,b,c,d,e, 2007); Yang & Guo (2006). For related literature, see: Allen et al. (1987); Bernardo et al. (1996); Musie et al. (2001); Paul et al. (2002).

S2. Experimental

4-Dimethylaminobenzaldehyde (0.1 mmol, 15.0 mg) and 5-bromonicotinic acid hydrazide (0.1 mmol, 21.6 mg) were dissolved in MeOH (10 ml). The mixture was stirred at room temperature to give a clear colorless solution. Crystals of the title compound were formed by gradual evaporation of the solvent over a period of 3 days at room temperature.

S3. Refinement

Atoms H2A, H2B and H2C were located in a difference Fourier map and refined isotropically, with O—H distances restrained to 0.85 (1) Å, N—H distance restrained to 0.90 (1) Å, H···H distance restrained to 1.37 (2) Å. Other H atoms were placed in idealized positions and constrained to ride on their parent atoms, with C—H distances of 0.93–0.96 Å, and with U_iso(H) = 1.2U_eq(C) and 1.5U_eq(methyl C).

Computing details

Data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a); molecular graphics: SHELXTL (Sheldrick, 1997b); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The structure of the title compound showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. Molecular packing as viewed along the b axis. Hydrogen bonds are shown as dashed lines.

6-Bromo-2'-[4-(dimethylamino)benzylidene]nicotinohydrazide monohydrate

Crystal data

C15H15BrN4O·H2O	F(000) = 744
Mr = 365.24	Dx = 1.538 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 10.535 (6) Å	Cell parameters from 2425 reflections
b = 12.363 (7) Å	θ = 2.5–24.3°
c = 12.889 (7) Å	µ = 2.62 mm^−1
β = 110.067 (6)°	T = 298 K
V = 1576.8 (15) Å^3	Block, colourless
Z = 4	0.23 × 0.22 × 0.20 mm

Data collection

Bruker SMART CCD diffractometer	3572 independent reflections
Radiation source: fine-focus sealed tube	2312 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.032
ω scans	θmax = 27.5°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −12→13
Tmin = 0.584, Tmax = 0.622	k = −10→15
9266 measured reflections	l = −16→16

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)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.086	H atoms treated by a mixture of independent and constrained refinement
S = 1.01	w = 1/[σ^2(Fo^2) + (0.0367P)^2 + 0.2692P] where P = (Fo^2 + 2Fc^2)/3
3572 reflections	(Δ/σ)max < 0.001
210 parameters	Δρmax = 0.23 e Å^−3
4 restraints	Δρmin = −0.32 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	0.47397 (3)	0.42451 (2)	0.16814 (2)	0.06254 (13)
O1	0.6679 (2)	0.43639 (13)	0.61464 (15)	0.0656 (6)
O2	0.64188 (19)	0.03201 (13)	0.68079 (17)	0.0555 (5)
N1	0.5521 (2)	0.14776 (17)	0.35409 (18)	0.0521 (6)
N2	0.6671 (2)	0.26731 (15)	0.68069 (16)	0.0420 (5)
N3	0.7079 (2)	0.30497 (16)	0.78919 (16)	0.0424 (5)
N4	0.8832 (2)	0.31198 (18)	1.32054 (18)	0.0597 (6)
C1	0.6001 (2)	0.29484 (18)	0.48329 (19)	0.0373 (5)
C2	0.5636 (2)	0.36808 (19)	0.3968 (2)	0.0414 (6)
H2	0.5657	0.4420	0.4104	0.050*
C3	0.5239 (2)	0.32913 (19)	0.28971 (19)	0.0409 (6)
C4	0.5194 (2)	0.2193 (2)	0.2719 (2)	0.0481 (6)
H4	0.4923	0.1940	0.1996	0.058*
C5	0.5927 (2)	0.18524 (19)	0.4576 (2)	0.0457 (6)
H5	0.6172	0.1356	0.5153	0.055*
C6	0.6478 (2)	0.3389 (2)	0.5989 (2)	0.0422 (6)
C7	0.7264 (2)	0.2307 (2)	0.8620 (2)	0.0434 (6)
H7	0.7138	0.1589	0.8392	0.052*
C8	0.7665 (2)	0.25483 (18)	0.97939 (19)	0.0393 (5)
C9	0.7856 (2)	0.35918 (19)	1.0216 (2)	0.0437 (6)
H9	0.7731	0.4174	0.9734	0.052*
C10	0.8223 (2)	0.3783 (2)	1.1329 (2)	0.0457 (6)
H10	0.8330	0.4493	1.1584	0.055*
C11	0.8443 (2)	0.2932 (2)	1.20932 (19)	0.0427 (6)
C12	0.8246 (3)	0.1880 (2)	1.1664 (2)	0.0481 (6)
H12	0.8372	0.1294	1.2142	0.058*
C13	0.7868 (3)	0.17021 (19)	1.0544 (2)	0.0474 (6)
H13	0.7744	0.0995	1.0281	0.057*
C14	0.9084 (3)	0.2233 (3)	1.3982 (2)	0.0659 (8)
H14A	0.8265	0.1831	1.3854	0.099*
H14B	0.9390	0.2514	1.4722	0.099*
H14C	0.9765	0.1768	1.3886	0.099*
C15	0.9053 (4)	0.4204 (2)	1.3647 (3)	0.0746 (9)
H15A	0.9786	0.4529	1.3478	0.112*
H15B	0.9272	0.4178	1.4434	0.112*
H15C	0.8248	0.4626	1.3323	0.112*
H2A	0.648 (3)	0.1969 (10)	0.671 (2)	0.080*
H2B	0.7067 (18)	−0.006 (2)	0.720 (2)	0.080*
H2C	0.5687 (15)	−0.002 (2)	0.667 (3)	0.080*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0862 (2)	0.05148 (19)	0.04669 (17)	0.00208 (16)	0.01863 (15)	0.00658 (13)
O1	0.1116 (16)	0.0305 (10)	0.0472 (11)	−0.0100 (10)	0.0175 (11)	−0.0051 (8)
O2	0.0598 (12)	0.0307 (9)	0.0676 (13)	−0.0010 (9)	0.0110 (11)	0.0033 (9)
N1	0.0674 (15)	0.0320 (11)	0.0513 (14)	0.0002 (10)	0.0134 (11)	−0.0068 (10)
N2	0.0529 (13)	0.0318 (10)	0.0420 (12)	−0.0031 (10)	0.0172 (10)	−0.0042 (9)
N3	0.0514 (13)	0.0379 (11)	0.0389 (11)	−0.0020 (9)	0.0168 (10)	−0.0056 (9)
N4	0.0813 (17)	0.0547 (14)	0.0408 (13)	0.0002 (13)	0.0181 (12)	−0.0024 (11)
C1	0.0397 (13)	0.0300 (12)	0.0440 (13)	−0.0039 (10)	0.0166 (11)	−0.0041 (10)
C2	0.0464 (15)	0.0295 (12)	0.0489 (15)	−0.0009 (11)	0.0171 (12)	−0.0045 (11)
C3	0.0422 (14)	0.0391 (14)	0.0412 (13)	0.0008 (11)	0.0142 (11)	0.0018 (11)
C4	0.0557 (16)	0.0424 (15)	0.0433 (15)	−0.0006 (13)	0.0131 (12)	−0.0094 (12)
C5	0.0551 (16)	0.0354 (14)	0.0448 (14)	0.0013 (12)	0.0147 (12)	−0.0022 (11)
C6	0.0486 (15)	0.0347 (14)	0.0436 (14)	−0.0022 (11)	0.0161 (12)	−0.0030 (11)
C7	0.0456 (14)	0.0369 (14)	0.0492 (15)	−0.0025 (11)	0.0183 (12)	−0.0044 (12)
C8	0.0413 (13)	0.0370 (13)	0.0405 (13)	−0.0008 (11)	0.0153 (11)	−0.0002 (10)
C9	0.0538 (15)	0.0333 (13)	0.0448 (14)	−0.0003 (12)	0.0176 (12)	0.0049 (11)
C10	0.0555 (16)	0.0324 (13)	0.0503 (15)	0.0013 (12)	0.0194 (13)	−0.0044 (11)
C11	0.0412 (14)	0.0441 (14)	0.0428 (14)	0.0009 (11)	0.0144 (11)	0.0003 (11)
C12	0.0602 (17)	0.0350 (14)	0.0474 (15)	−0.0014 (12)	0.0163 (13)	0.0083 (11)
C13	0.0589 (16)	0.0297 (13)	0.0517 (16)	−0.0028 (12)	0.0168 (13)	−0.0021 (11)
C14	0.069 (2)	0.083 (2)	0.0444 (16)	−0.0051 (17)	0.0179 (14)	0.0074 (15)
C15	0.099 (2)	0.068 (2)	0.0534 (18)	0.0004 (18)	0.0211 (17)	−0.0172 (15)

Geometric parameters (Å, º)

Br1—C3	1.886 (2)	C5—H5	0.9300
O1—C6	1.229 (3)	C7—C8	1.455 (3)
O2—H2B	0.837 (10)	C7—H7	0.9300
O2—H2C	0.841 (10)	C8—C9	1.388 (3)
N1—C4	1.331 (3)	C8—C13	1.390 (3)
N1—C5	1.337 (3)	C9—C10	1.372 (3)
N2—C6	1.338 (3)	C9—H9	0.9300
N2—N3	1.394 (3)	C10—C11	1.405 (3)
N2—H2A	0.893 (10)	C10—H10	0.9300
N3—C7	1.279 (3)	C11—C12	1.401 (4)
N4—C11	1.369 (3)	C12—C13	1.378 (3)
N4—C15	1.444 (3)	C12—H12	0.9300
N4—C14	1.446 (3)	C13—H13	0.9300
C1—C2	1.384 (3)	C14—H14A	0.9600
C1—C5	1.391 (3)	C14—H14B	0.9600
C1—C6	1.501 (3)	C14—H14C	0.9600
C2—C3	1.384 (3)	C15—H15A	0.9600
C2—H2	0.9300	C15—H15B	0.9600
C3—C4	1.376 (3)	C15—H15C	0.9600
C4—H4	0.9300
H2B—O2—H2C	111 (2)	C9—C8—C13	117.4 (2)
C4—N1—C5	118.1 (2)	C9—C8—C7	123.3 (2)
C6—N2—N3	118.75 (19)	C13—C8—C7	119.3 (2)
C6—N2—H2A	124.3 (19)	C10—C9—C8	121.4 (2)
N3—N2—H2A	116.7 (19)	C10—C9—H9	119.3
C7—N3—N2	114.4 (2)	C8—C9—H9	119.3
C11—N4—C15	121.3 (2)	C9—C10—C11	121.6 (2)
C11—N4—C14	121.0 (2)	C9—C10—H10	119.2
C15—N4—C14	117.7 (2)	C11—C10—H10	119.2
C2—C1—C5	117.9 (2)	N4—C11—C12	121.4 (2)
C2—C1—C6	117.9 (2)	N4—C11—C10	121.7 (2)
C5—C1—C6	124.2 (2)	C12—C11—C10	116.9 (2)
C1—C2—C3	118.7 (2)	C13—C12—C11	120.8 (2)
C1—C2—H2	120.6	C13—C12—H12	119.6
C3—C2—H2	120.6	C11—C12—H12	119.6
C4—C3—C2	119.4 (2)	C12—C13—C8	121.9 (2)
C4—C3—Br1	119.66 (19)	C12—C13—H13	119.0
C2—C3—Br1	120.92 (18)	C8—C13—H13	119.0
N1—C4—C3	122.6 (2)	N4—C14—H14A	109.5
N1—C4—H4	118.7	N4—C14—H14B	109.5
C3—C4—H4	118.7	H14A—C14—H14B	109.5
N1—C5—C1	123.2 (2)	N4—C14—H14C	109.5
N1—C5—H5	118.4	H14A—C14—H14C	109.5
C1—C5—H5	118.4	H14B—C14—H14C	109.5
O1—C6—N2	123.2 (2)	N4—C15—H15A	109.5
O1—C6—C1	120.0 (2)	N4—C15—H15B	109.5
N2—C6—C1	116.8 (2)	H15A—C15—H15B	109.5
N3—C7—C8	122.1 (2)	N4—C15—H15C	109.5
N3—C7—H7	118.9	H15A—C15—H15C	109.5
C8—C7—H7	118.9	H15B—C15—H15C	109.5

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2C···N1^i	0.84 (1)	2.17 (2)	2.948 (3)	154 (3)
O2—H2B···N3^ii	0.84 (1)	2.52 (2)	3.180 (3)	136 (3)
O2—H2B···O1^ii	0.84 (1)	2.21 (2)	2.956 (3)	149 (3)
N2—H2A···O2	0.89 (1)	2.05 (1)	2.921 (3)	167 (3)

Symmetry codes: (i) −x+1, −y, −z+1; (ii) −x+3/2, y−1/2, −z+3/2.