supplementary materials


bt6911 scheme

Acta Cryst. (2013). E69, o1085    [ doi:10.1107/S1600536813015407 ]

2-{(E)-[(2-Methyl-3-nitrophenyl)imino]methyl}-4-nitrophenol

H. Tanak, F. Togurman, S. Kalecik, N. Dege and M. Yavuz

Abstract top

The title compound, C14H11N3O5, is a Schiff base that adopts the enol-imine tautomeric form in the solid state. The dihedral angle between the aromatic rings is 37.4 (3)° and the dihedral angles between the nitro groups and their attached rings are 4.0 (6) and 46.2 (8)°. The molecular structure is stabilized by an intramolecular O-H...N hydrogen bond, which generates an S(6) ring motif. In the crystal, molecules are linked by C-H...O interactions, forming a two-dimensional network parallel to the bc plane.

Comment top

Schiff bases, i.e., compounds having a double C=N bond, are used as starting materials in the synthesis of important drugs, such as antibiotics and antiallergic, antiphlogistic, and antitumor substances (Barton et al., 1979; Layer, 1963; Ingold 1969). On the industrial scale, they have a wide range of applications, such as dyes and pigments (Taggi et al., 2002). Schiff bases have also been employed as ligands for the complexation of metal ions (Aydoğan et al., 2001). There are two characteristic properties of Schiff bases, viz. Photochromism and thermochromism (Cohen et al., 1964). In general, Schiff bases display two possible tautomeric forms, the enol-imine (OH) and the keto-amine (NH) forms. Depending on the tautomers, two types of intramolecular hydrogen bonds are observed in Schiff bases: O—H···N in enol-imine and N—H···O in keto-amine tautomers (Tanak et al., 2010).

In the title crystal structure (Fig. 1), the molecules of the title compound are not planar. The dihedral angle between the aromatic ring systems is 37.4 (3)°. The imino group is coplanar with the hydroxyphenyl ring as it can be shown by the C2—C1—C7—N2 torsion angle [-1.6 (8)°]. The C—O and C=N bond lengths confirm the enol-imine form of the title compound. The length of the C7=N2 double bond is 1.269 (7) Å It is consistent with the related structure (Tanak, 2011). It is also known that Schiff bases may exhibit thermochromism depending on the planarity or non-planarity of the molecule, respectively (Moustakali-Mavridis et al., 1978).

The molecular structure is stabilized by an intramolecular hydrogen bond. The phenol H atom forms a strong intramolecular hydrogen bond with the imine N atom (Fig. 1) generating an S(6) ring motif (Bernstein et al., 1995). In the crystal structure, molecules are linked together by intermolecular C—H···O interactions (Fig. 2).

Related literature top

For the biological properties of Schiff bases, see: Aydoğan et al. (2001); Taggi et al. (2002); Barton & Ollis (1979); Layer (1963); Ingold (1969); Cohen et al. (1964); Moustakali-Mavridis et al. (1978). For tautomeric forms of Schiff base compounds, see: Tanak et al. (2010). For hydrogen-bond motifs, see: Bernstein et al. (1995). For a related structure, see: Tanak (2011).

Experimental top

2-hydroxy-5-nitrobenzaldehyde (0.0138 g, 0.0822 mmol) was added to a solution of 2-methyl-3-nitroaniline (0.0125 g, 0.0822 mmol) in ethanol (100 ml). The reaction mixture was stirred for 24 h under reflux. Single crystals suitable for X-ray analysis were obtained from ethyl alcohol by slow evaporation (yield 52%; m.p.485–487 K).

Refinement top

All H atoms were positioned geometrically and treated using a riding model, fixing the bond lengths at 0.82 Å for OH, at 0.93 Å for aromatic CH, at 0.96 Å for CH3. The displacement parameters of the H atoms were constrained as Uiso(H)= 1.2Ueq(1.5Ueqfor methyl) of the parent atom.

Computing details top

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA (Stoe & Cie, 2002); data reduction: X-RED32 (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: WinGX (Farrugia, 2012).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, showing the atom-numbering scheme and 30% probability diplacement ellipsoids. The intramolecular hydrogen bond is shown as a dashed line.
[Figure 2] Fig. 2. The crystal packing of the title compound. Hydrogen bonds are shown as dashed lines.
2-{(E)-[(2-Methyl-3-nitrophenyl)imino]methyl}-4-nitrophenol top
Crystal data top
C14H11N3O5F(000) = 624
Mr = 301.26Dx = 1.470 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 6502 reflections
a = 3.754 (5) Åθ = 1.6–26.2°
b = 15.696 (5) ŵ = 0.11 mm1
c = 23.149 (5) ÅT = 296 K
β = 93.491 (5)°Stick, yellow
V = 1361.5 (19) Å30.46 × 0.20 × 0.05 mm
Z = 4
Data collection top
Stoe IPDS II
diffractometer
2538 independent reflections
Radiation source: fine-focus sealed tube923 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.181
Detector resolution: 6.67 pixels mm-1θmax = 25.7°, θmin = 1.6°
rotation method scansh = 44
Absorption correction: integration
(X-RED32; Stoe & Cie, 2002)
k = 1819
Tmin = 0.600, Tmax = 0.976l = 2228
7609 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.095Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.229H-atom parameters constrained
S = 0.97 w = 1/[σ2(Fo2) + (0.0591P)2]
where P = (Fo2 + 2Fc2)/3
2538 reflections(Δ/σ)max < 0.001
199 parametersΔρmax = 0.23 e Å3
0 restraintsΔρmin = 0.25 e Å3
Crystal data top
C14H11N3O5V = 1361.5 (19) Å3
Mr = 301.26Z = 4
Monoclinic, P21/cMo Kα radiation
a = 3.754 (5) ŵ = 0.11 mm1
b = 15.696 (5) ÅT = 296 K
c = 23.149 (5) Å0.46 × 0.20 × 0.05 mm
β = 93.491 (5)°
Data collection top
Stoe IPDS II
diffractometer
2538 independent reflections
Absorption correction: integration
(X-RED32; Stoe & Cie, 2002)
923 reflections with I > 2σ(I)
Tmin = 0.600, Tmax = 0.976Rint = 0.181
7609 measured reflectionsθmax = 25.7°
Refinement top
R[F2 > 2σ(F2)] = 0.095H-atom parameters constrained
wR(F2) = 0.229Δρmax = 0.23 e Å3
S = 0.97Δρmin = 0.25 e Å3
2538 reflectionsAbsolute structure: ?
199 parametersAbsolute structure parameter: ?
0 restraintsRogers parameter: ?
Special details top

Experimental. 215 frames, detector distance = 130 mm

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 (Å2) top
xyzUiso*/Ueq
O30.7299 (11)0.2631 (3)0.1412 (2)0.0806 (15)
H20.73920.22520.16560.121*
O20.0339 (12)0.0664 (4)0.0715 (2)0.0844 (15)
N20.6571 (12)0.1125 (4)0.1845 (2)0.0592 (14)
N10.1412 (12)0.1407 (4)0.0677 (2)0.0635 (15)
C130.6662 (13)0.0823 (4)0.2872 (3)0.0533 (16)
O10.1280 (16)0.1866 (4)0.1100 (3)0.110 (2)
C10.4754 (13)0.1458 (4)0.0866 (3)0.0536 (16)
C70.5162 (13)0.0880 (4)0.1361 (3)0.0579 (17)
H70.43710.03210.13210.070*
C100.8803 (16)0.0853 (5)0.2670 (3)0.0689 (19)
H100.94920.14110.26000.083*
C110.8347 (15)0.0593 (5)0.3228 (3)0.0677 (18)
H110.87080.09670.35370.081*
C50.2981 (13)0.1707 (4)0.0126 (3)0.0559 (16)
C60.3326 (13)0.1173 (4)0.0339 (3)0.0564 (16)
H60.25860.06100.02990.068*
C120.7342 (14)0.0238 (5)0.3314 (3)0.0610 (18)
O40.8401 (14)0.1172 (4)0.4082 (2)0.1012 (18)
N30.7006 (16)0.0501 (5)0.3918 (3)0.0765 (17)
C40.4026 (15)0.2570 (5)0.0082 (3)0.068 (2)
H40.37670.29330.04000.082*
C20.5843 (14)0.2325 (5)0.0912 (3)0.0608 (18)
C90.8248 (14)0.0294 (5)0.2215 (3)0.0643 (18)
H90.86360.04720.18400.077*
C30.5415 (16)0.2853 (5)0.0436 (3)0.0676 (19)
H30.61030.34210.04720.081*
O50.5514 (16)0.0028 (5)0.4243 (3)0.114 (2)
C80.7111 (12)0.0532 (4)0.2312 (3)0.0535 (16)
C140.5391 (16)0.1734 (4)0.2969 (3)0.0726 (19)
H14A0.50930.20230.26040.109*
H14B0.71280.20290.32160.109*
H14C0.31530.17200.31490.109*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O30.091 (3)0.065 (4)0.083 (4)0.017 (2)0.011 (3)0.012 (3)
O20.107 (3)0.066 (4)0.079 (4)0.024 (3)0.002 (3)0.005 (3)
N20.056 (3)0.057 (4)0.064 (4)0.002 (2)0.003 (3)0.007 (3)
N10.074 (3)0.059 (5)0.058 (4)0.002 (3)0.005 (3)0.003 (3)
C130.051 (3)0.049 (4)0.060 (4)0.001 (3)0.001 (3)0.007 (3)
O10.165 (5)0.086 (5)0.075 (4)0.011 (4)0.013 (3)0.018 (3)
C10.049 (3)0.049 (5)0.062 (4)0.005 (3)0.001 (3)0.001 (3)
C70.051 (3)0.053 (5)0.069 (5)0.000 (3)0.002 (3)0.005 (4)
C100.078 (4)0.051 (5)0.076 (5)0.007 (3)0.005 (4)0.002 (4)
C110.076 (4)0.055 (5)0.071 (5)0.004 (3)0.005 (3)0.003 (4)
C50.052 (3)0.051 (5)0.064 (5)0.001 (3)0.002 (3)0.006 (4)
C60.056 (3)0.047 (4)0.066 (5)0.006 (3)0.001 (3)0.001 (4)
C120.055 (3)0.063 (5)0.064 (5)0.002 (3)0.006 (3)0.007 (4)
O40.115 (4)0.089 (5)0.099 (4)0.007 (3)0.004 (3)0.027 (3)
N30.083 (4)0.071 (5)0.074 (5)0.010 (3)0.005 (3)0.002 (4)
C40.061 (4)0.054 (5)0.090 (6)0.003 (3)0.002 (4)0.003 (4)
C20.056 (3)0.063 (5)0.062 (5)0.003 (3)0.005 (3)0.008 (4)
C90.058 (3)0.061 (5)0.073 (5)0.003 (3)0.003 (3)0.015 (4)
C30.076 (4)0.054 (5)0.072 (5)0.005 (3)0.002 (4)0.000 (4)
O50.140 (5)0.112 (6)0.093 (5)0.012 (4)0.027 (4)0.023 (4)
C80.040 (3)0.060 (5)0.059 (5)0.005 (3)0.006 (3)0.001 (4)
C140.077 (4)0.060 (5)0.081 (5)0.015 (3)0.001 (3)0.011 (4)
Geometric parameters (Å, º) top
O3—C21.339 (7)C11—C121.375 (9)
O3—H20.8200C11—H110.9300
O2—N11.235 (7)C5—C61.364 (9)
N2—C71.269 (7)C5—C41.412 (9)
N2—C81.430 (8)C6—H60.9300
N1—O11.214 (7)C12—N31.469 (9)
N1—C51.451 (8)O4—N31.228 (8)
C13—C121.388 (9)N3—O51.217 (8)
C13—C81.395 (8)C4—C31.353 (9)
C13—C141.528 (9)C4—H40.9300
C1—C61.377 (8)C2—C31.382 (9)
C1—C21.423 (9)C9—C81.388 (9)
C1—C71.462 (9)C9—H90.9300
C7—H70.9300C3—H30.9300
C10—C111.374 (9)C14—H14A0.9600
C10—C91.377 (9)C14—H14B0.9600
C10—H100.9300C14—H14C0.9600
C2—O3—H2109.5C11—C12—N3116.4 (6)
C7—N2—C8120.2 (6)C13—C12—N3119.5 (7)
O1—N1—O2120.5 (6)O5—N3—O4122.4 (8)
O1—N1—C5120.7 (7)O5—N3—C12119.0 (7)
O2—N1—C5118.8 (6)O4—N3—C12118.5 (7)
C12—C13—C8116.2 (6)C3—C4—C5118.0 (7)
C12—C13—C14123.7 (6)C3—C4—H4121.0
C8—C13—C14120.0 (6)C5—C4—H4121.0
C6—C1—C2118.1 (6)O3—C2—C3119.7 (7)
C6—C1—C7120.7 (6)O3—C2—C1120.6 (6)
C2—C1—C7121.2 (6)C3—C2—C1119.7 (6)
N2—C7—C1121.6 (6)C10—C9—C8120.3 (7)
N2—C7—H7119.2C10—C9—H9119.8
C1—C7—H7119.2C8—C9—H9119.8
C11—C10—C9120.5 (7)C4—C3—C2122.0 (7)
C11—C10—H10119.7C4—C3—H3119.0
C9—C10—H10119.7C2—C3—H3119.0
C10—C11—C12118.0 (7)C9—C8—C13120.8 (6)
C10—C11—H11121.0C9—C8—N2121.1 (6)
C12—C11—H11121.0C13—C8—N2118.0 (6)
C6—C5—C4121.3 (6)C13—C14—H14A109.5
C6—C5—N1120.5 (6)C13—C14—H14B109.5
C4—C5—N1118.1 (6)H14A—C14—H14B109.5
C5—C6—C1120.9 (6)C13—C14—H14C109.5
C5—C6—H6119.6H14A—C14—H14C109.5
C1—C6—H6119.6H14B—C14—H14C109.5
C11—C12—C13124.0 (7)
C8—N2—C7—C1176.5 (5)C11—C12—N3—O4132.5 (6)
C6—C1—C7—N2177.9 (5)C13—C12—N3—O447.3 (8)
C2—C1—C7—N21.6 (8)C6—C5—C4—C30.5 (8)
C9—C10—C11—C120.3 (9)N1—C5—C4—C3178.6 (5)
O1—N1—C5—C6176.0 (6)C6—C1—C2—O3179.0 (5)
O2—N1—C5—C61.3 (8)C7—C1—C2—O30.5 (8)
O1—N1—C5—C46.0 (8)C6—C1—C2—C30.6 (8)
O2—N1—C5—C4176.8 (5)C7—C1—C2—C3179.9 (5)
C4—C5—C6—C10.9 (9)C11—C10—C9—C82.0 (9)
N1—C5—C6—C1178.9 (5)C5—C4—C3—C20.4 (9)
C2—C1—C6—C50.3 (8)O3—C2—C3—C4178.6 (6)
C7—C1—C6—C5179.2 (5)C1—C2—C3—C40.9 (9)
C10—C11—C12—C131.9 (9)C10—C9—C8—C132.8 (8)
C10—C11—C12—N3177.9 (5)C10—C9—C8—N2179.1 (5)
C8—C13—C12—C111.1 (8)C12—C13—C8—C91.3 (7)
C14—C13—C12—C11177.3 (6)C14—C13—C8—C9179.7 (5)
C8—C13—C12—N3178.7 (5)C12—C13—C8—N2177.6 (5)
C14—C13—C12—N33.0 (8)C14—C13—C8—N23.9 (7)
C11—C12—N3—O544.0 (8)C7—N2—C8—C939.8 (7)
C13—C12—N3—O5136.2 (6)C7—N2—C8—C13143.9 (5)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O3—H2···N20.821.852.589 (8)149
C6—H6···O2i0.932.503.333 (9)149
C4—H4···O4ii0.932.593.274 (9)131
Symmetry codes: (i) x, y, z; (ii) x, y+1/2, z1/2.

Experimental details

Crystal data
Chemical formulaC14H11N3O5
Mr301.26
Crystal system, space groupMonoclinic, P21/c
Temperature (K)296
a, b, c (Å)3.754 (5), 15.696 (5), 23.149 (5)
β (°) 93.491 (5)
V3)1361.5 (19)
Z4
Radiation typeMo Kα
µ (mm1)0.11
Crystal size (mm)0.46 × 0.20 × 0.05
Data collection
DiffractometerStoe IPDS II
diffractometer
Absorption correctionIntegration
(X-RED32; Stoe & Cie, 2002)
Tmin, Tmax0.600, 0.976
No. of measured, independent and
observed [I > 2σ(I)] reflections
7609, 2538, 923
Rint0.181
(sin θ/λ)max1)0.610
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.095, 0.229, 0.97
No. of reflections2538
No. of parameters199
No. of restraints0
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.23, 0.25

Computer programs: X-AREA (Stoe & Cie, 2002), X-RED32 (Stoe & Cie, 2002), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 2012), WinGX (Farrugia, 2012).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O3—H2···N20.821.852.589 (8)148.7
C6—H6···O2i0.932.503.333 (9)149.1
C4—H4···O4ii0.932.593.274 (9)131.1
Symmetry codes: (i) x, y, z; (ii) x, y+1/2, z1/2.
Acknowledgements top

The authors acknowledge the Faculty of Arts and Sciences, Ondokuz Mayıs University, Turkey, for the use of the Stoe IPDS II diffractometer (purchased under grant No. F279 of the University Research Fund).

references
References top

Aydoğan, F., Öcal, N., Turgut, Z. & Yolaçan, C. (2001). Bull. Korean Chem. Soc. 22, 476–480.

Barton, D. & Ollis, W. D. (1979). Comprehensive Organic Chemistry, vol 2. Oxford: Pergamon.

Bernstein, J., Davies, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573.

Cohen, M. D., Schmidt, G. M. J. & Flavian, S. (1964). J. Chem. Soc. pp. 2041–2051.

Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.

Ingold, C. K. (1969). Structure and Mechanism in Organic Chemistry, 2nd ed. Ithaca: Cornell University Press.

Layer, R. W. (1963). Chem. Rev. 63, 489–510.

Moustakali-Mavridis, I., Hadjoudis, E. & Mavridis, A. (1978). Acta Cryst. B34, 3709–3715.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Stoe & Cie (2002). X-AREA and X-RED32. Stoe & Cie, Darmstadt, Germany.

Taggi, A. E., Hafez, A. M., Wack, H., Young, B., Ferraris, D. & Lectka, T. (2002). J. Am. Chem. Soc. 124, 6626–6635.

Tanak, H. (2011). J. Phys. Chem. A, 115, 13865–13876.

Tanak, H., Agar, A. & Yavuz, M. (2010). J. Mol. Model. 16, 577–587.