2-(p-Bromo­phenyl­hydrazono)-3-oxobutanoic acid

The skeleton, without hydrogen atoms, of the title mol­ecule, C₁₀H₉BrN₂O₃, is planar, and intramolecular N—H...O and O—H...O hydrogen bonds contribute to this planarity. The mol­ecules exist in the stereoisomeric Z form.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.011 Å
• R factor = 0.071
• wR factor = 0.186
• Data-to-parameter ratio = 13.0

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level B:



CHEMS_01  Alert B The sum formula contains elements in the wrong order.
          Br precedes C
          Sequence must be C, H, then alphabetical.

PLAT_031  Alert B Refined Extinction Parameter within Range ....       1.64 Sigma


 Alert Level C:



ABSTM_02  Alert C The ratio of expected to reported Tmax/Tmin(RR) is > 1.10
          Tmin and Tmax reported:      0.756     0.989
          Tmin and Tmax expected:      0.355     0.526
          RR =      1.133
          Please check that your absorption correction is appropriate.

REFLT_03
         From the CIF: _diffrn_reflns_theta_max           69.88
         From the CIF: _reflns_number_total               1912
         TEST2: Reflns within _diffrn_reflns_theta_max
         Count of symmetry unique reflns         2064
         Completeness (_total/calc)             92.64%
          Alert C: < 95% complete

General Notes



ABSTM_02  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      0.532
          Tmax scaled      0.526 Tmin scaled      0.402

REFLT_03
         From the CIF: _diffrn_reflns_theta_max           69.88
         From the CIF: _reflns_number_total               1912
         From the CIF: _diffrn_reflns_limit_ max hkl    8.    8.   11.
         From the CIF: _diffrn_reflns_limit_ min hkl    0.   -8.  -11.
         TEST1: Expected hkl limits for theta max
         Calculated maximum hkl    8.    8.   13.
         Calculated minimum hkl   -8.   -8.  -13.
          ALERT: Expected hkl max differ from CIF values


 0 Alert Level A = Potentially serious problem

 2 Alert Level B = Potential problem

 2 Alert Level C = Please check

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S1. Comment

As a part of our project to study the crystal structures of a series of phenylhydrazones and their stereochemistry, the crystal structure of the title compound, (I), has been determined. Earlier, this laboratory has reported two related structures, viz. 2-(2-methoxyphenylhydrazono)-3-oxobutanoic acid (Rani et al., 2002a) and 3-oxo-2-(phenylhydrazono)butanoic acid (Rani et al., 2002b), compound (I) being a Br derivative of the latter. The replacement of a H atom by a Br atom has effectively increased the volume of the cell by 24.92 ų per Br atom. The bond lengths and angles in (I) show normal values and are comparable with those observed in the two reported structures. The molecule is nearly planar, with atoms O1 and C10 displaced from the mean least-squares plane by −0.108 (5) and 0.127 (10) Å, respectively (on opposite sides). The planarity of the molecule is facilitated by the intramolecular hydrogen bonds. The N1—H1N bond is involved in the formation of a bifurcated hydrogen bond, the shorter interaction, called the major component (Steiner, 2002), is an intramolecular N1—H1N···O2 hydrogen bond with the carbonyl O atom of the carboxyl group, whereas the longer one, the minor component, is an intermolecular N1—H1N···O2(-x, 1 − y, 1 − z) hydrogen bond, which links two molecules via hydrogen-bond dimers across a centre of symmetry (Table 3). The carbonyl O atom of the carbomethoxy group is also involved in an intramolecular O1—H1O···O3 hydrogen bond with the carboxyl group (Fig. 1). Along the b-cell direction, the molecules related by inversion are stacked alternatively 3.419 (5) and 3.490 (5) Å apart, optimum distances for π–π stacking interactions. The short contacts observed in the structure are listed in Table 2. The distance O2···O2(-x, 1 − y, 1 − z) of 2.888 (8) Å is less than the sum of the van der Waals radii, but since the C8—O2 bond length is 1.217 (9) Å, O2 is the double-bonded carbonyl O atom, hence the O2···O2 contact must be regarded as a strong van der Waals interaction.

S2. Experimental

The title compound, (I), was prepared by the partial hydrolysis of ethyl 2-(2-bromophenylhydrazono)-3-oxobutyrate by the action of strong acids (Prasad et al., 1994) and was recrystallized from methanol at room temperature.

S3. Refinement

After checking their presence in the difference map, all the H atoms were placed at calculated positions and were allowed to ride on their respective parent atoms.

Computing details

Data collection: CAD-4 EXPRESS (Enraf-Nonius, 1994); cell refinement: CAD-4 EXPRESS; data reduction: MolEN (Fair, 1990); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97.

Figures

Fig. 1. An ORTEP-3 plot (Farrugia, 1997) of the title molecule, with 50% probability displacement ellipsoids for non-H atoms.

2-(p-Bromophenylhydrazono)-3-oxobutanoic acid

Crystal data

C10H9BrN2O3	Z = 2
Mr = 285.10	F(000) = 284
Triclinic, P1	Dx = 1.743 Mg m^−3
Hall symbol: -P 1	Cu Kα radiation, λ = 1.54180 Å
a = 7.058 (4) Å	Cell parameters from 25 reflections
b = 7.126 (3) Å	θ = 17.7–39.9°
c = 11.311 (6) Å	µ = 5.14 mm^−1
α = 77.05 (3)°	T = 293 K
β = 86.35 (4)°	Elongated plate, light yellow
γ = 78.47 (5)°	0.25 × 0.19 × 0.13 mm
V = 543.1 (5) Å^3

Data collection

Enraf-Nonius CAD-4 diffractometer	1171 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.026
Graphite monochromator	θmax = 69.9°, θmin = 4.0°
ω–2θ scans	h = 0→8
Absorption correction: ψ scan (North at el., 1968)	k = −8→8
Tmin = 0.756, Tmax = 0.989	l = −11→11
2079 measured reflections	3 standard reflections every 1 hr min
1912 independent reflections	intensity decay: 0.0%

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.071	H-atom parameters constrained
wR(F^2) = 0.186	w = 1/[σ^2(Fo^2) + (0.1211P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.90	(Δ/σ)max = 0.001
1912 reflections	Δρmax = 1.11 e Å^−3
147 parameters	Δρmin = −0.91 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0018 (11)

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
Br	0.92940 (15)	0.12344 (13)	0.13951 (8)	0.0729 (5)
O1	−0.0291 (8)	0.4290 (8)	0.8160 (5)	0.0663 (14)
H1O	0.0430	0.4131	0.8729	0.080*
O2	−0.0050 (8)	0.3976 (8)	0.6254 (5)	0.0690 (15)
O3	0.2778 (9)	0.3219 (9)	0.9413 (5)	0.0757 (16)
N1	0.3493 (10)	0.3007 (8)	0.5359 (5)	0.0552 (15)
H1N	0.2291	0.3418	0.5189	0.083*
N2	0.4070 (10)	0.2778 (8)	0.6462 (5)	0.0566 (16)
C1	0.4867 (12)	0.2573 (9)	0.4446 (6)	0.0512 (18)
C2	0.4237 (13)	0.2738 (10)	0.3306 (6)	0.061 (2)
H2	0.2925	0.3119	0.3143	0.073*
C3	0.5549 (12)	0.2340 (10)	0.2396 (7)	0.060 (2)
H3	0.5125	0.2447	0.1617	0.072*
C4	0.7473 (12)	0.1788 (9)	0.2643 (6)	0.0529 (18)
C5	0.8127 (13)	0.1655 (11)	0.3788 (6)	0.062 (2)
H5	0.9442	0.1292	0.3947	0.074*
C6	0.6808 (13)	0.2066 (10)	0.4696 (6)	0.058 (2)
H6	0.7229	0.1999	0.5470	0.069*
C7	0.2884 (12)	0.3141 (9)	0.7348 (6)	0.0521 (18)
C8	0.0739 (13)	0.3820 (10)	0.7206 (7)	0.060 (2)
C9	0.3764 (13)	0.2826 (11)	0.8530 (7)	0.062 (2)
C10	0.5880 (13)	0.2057 (14)	0.8624 (8)	0.081 (3)
H10A	0.6363	0.2423	0.9297	0.122*
H10B	0.6521	0.2597	0.7890	0.122*
H10C	0.6124	0.0653	0.8748	0.122*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br	0.0948 (8)	0.0673 (6)	0.0556 (6)	−0.0121 (4)	0.0116 (4)	−0.0181 (4)
O1	0.070 (4)	0.084 (4)	0.046 (3)	−0.014 (3)	0.001 (3)	−0.014 (3)
O2	0.079 (4)	0.087 (4)	0.041 (3)	−0.017 (3)	−0.010 (3)	−0.010 (2)
O3	0.099 (5)	0.092 (4)	0.040 (3)	−0.026 (3)	0.001 (3)	−0.016 (3)
N1	0.077 (4)	0.052 (3)	0.041 (4)	−0.018 (3)	0.002 (3)	−0.013 (2)
N2	0.088 (5)	0.047 (3)	0.036 (4)	−0.019 (3)	0.003 (3)	−0.006 (2)
C1	0.075 (5)	0.034 (3)	0.046 (4)	−0.016 (3)	0.004 (4)	−0.008 (3)
C2	0.087 (6)	0.059 (4)	0.040 (4)	−0.017 (4)	−0.007 (4)	−0.014 (3)
C3	0.084 (6)	0.056 (4)	0.041 (4)	−0.008 (4)	−0.004 (4)	−0.016 (3)
C4	0.074 (5)	0.037 (3)	0.046 (4)	−0.002 (3)	0.008 (3)	−0.014 (3)
C5	0.083 (6)	0.060 (4)	0.040 (4)	−0.004 (4)	−0.012 (4)	−0.010 (3)
C6	0.088 (6)	0.059 (4)	0.027 (4)	−0.021 (4)	−0.012 (4)	−0.005 (3)
C7	0.086 (6)	0.043 (3)	0.030 (4)	−0.022 (4)	−0.005 (3)	−0.004 (3)
C8	0.081 (6)	0.051 (4)	0.047 (4)	−0.019 (4)	−0.004 (4)	−0.004 (3)
C9	0.087 (6)	0.062 (4)	0.039 (4)	−0.024 (4)	−0.005 (4)	−0.004 (3)
C10	0.079 (7)	0.099 (7)	0.060 (6)	−0.016 (5)	−0.017 (5)	−0.002 (5)

Geometric parameters (Å, º)

Br—C4	1.901 (7)	C3—C4	1.365 (11)
O1—C8	1.330 (9)	C3—H3	0.9300
O1—H1O	0.8200	C4—C5	1.379 (10)
O2—C8	1.217 (9)	C5—C6	1.383 (11)
O3—C9	1.233 (9)	C5—H5	0.9300
N1—N2	1.302 (8)	C6—H6	0.9300
N1—C1	1.414 (9)	C7—C9	1.462 (10)
N1—H1N	0.8600	C7—C8	1.502 (12)
N2—C7	1.302 (9)	C9—C10	1.487 (12)
C1—C2	1.362 (10)	C10—H10A	0.9600
C1—C6	1.376 (11)	C10—H10B	0.9600
C2—C3	1.380 (10)	C10—H10C	0.9600
C2—H2	0.9300
Br···O1^i	3.547 (6)	N1···C6^i	3.461 (9)
Br···O3^ii	3.513 (7)	N2···C1^i	3.459 (9)
O1···C2^iii	3.413 (10)	N2···C4^v	3.550 (9)
O1···C10^iv	3.358 (11)	C3···C9^i	3.491 (11)
O2···O2^iii	2.888 (8)	C4···C7^v	3.569 (10)
O2···C2^iii	3.469 (10)	C5···C8^i	3.406 (11)
O2···C6^iv	3.558 (10)
C8—O1—H1O	109.5	C6—C5—H5	120.3
N2—N1—C1	119.2 (7)	C1—C6—C5	119.4 (7)
N2—N1—H1N	120.4	C1—C6—H6	120.3
C1—N1—H1N	120.4	C5—C6—H6	120.3
C7—N2—N1	122.5 (7)	N2—C7—C9	115.8 (8)
C2—C1—C6	120.8 (7)	N2—C7—C8	123.6 (6)
C2—C1—N1	118.8 (8)	C9—C7—C8	120.6 (7)
C6—C1—N1	120.4 (7)	O2—C8—O1	120.3 (8)
C1—C2—C3	119.9 (8)	O2—C8—C7	122.1 (7)
C1—C2—H2	120.0	O1—C8—C7	117.6 (7)
C3—C2—H2	120.0	O3—C9—C7	120.7 (8)
C4—C3—C2	119.7 (7)	O3—C9—C10	121.3 (7)
C4—C3—H3	120.2	C7—C9—C10	118.0 (8)
C2—C3—H3	120.2	C9—C10—H10A	109.5
C3—C4—C5	120.8 (7)	C9—C10—H10B	109.5
C3—C4—Br	120.0 (5)	H10A—C10—H10B	109.5
C5—C4—Br	119.2 (6)	C9—C10—H10C	109.5
C4—C5—C6	119.3 (8)	H10A—C10—H10C	109.5
C4—C5—H5	120.3	H10B—C10—H10C	109.5
C1—N1—N2—C7	−179.7 (6)	C4—C5—C6—C1	0.9 (11)
N2—N1—C1—C2	177.3 (6)	N1—N2—C7—C9	−179.5 (6)
N2—N1—C1—C6	−5.2 (9)	N1—N2—C7—C8	1.2 (10)
C6—C1—C2—C3	1.9 (11)	N2—C7—C8—O2	4.0 (11)
N1—C1—C2—C3	179.4 (6)	C9—C7—C8—O2	−175.3 (7)
C1—C2—C3—C4	−0.2 (11)	N2—C7—C8—O1	−174.7 (6)
C2—C3—C4—C5	−1.1 (11)	C9—C7—C8—O1	6.0 (10)
C2—C3—C4—Br	180.0 (5)	N2—C7—C9—O3	176.4 (6)
C3—C4—C5—C6	0.7 (11)	C8—C7—C9—O3	−4.2 (11)
Br—C4—C5—C6	179.7 (5)	N2—C7—C9—C10	−2.4 (10)
C2—C1—C6—C5	−2.2 (10)	C8—C7—C9—C10	176.9 (7)
N1—C1—C6—C5	−179.7 (6)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O2	0.86	2.01	2.656 (9)	131
N1—H1N···O2^iii	0.86	2.53	3.252 (9)	142
O1—H1O···O3	0.82	1.81	2.555 (8)	150

Symmetry code: (iii) −x, −y+1, −z+1.