organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

2-[(4-Meth­oxy­phen­yl)imino­meth­yl]-4-nitro­phenol

aDepartment of Physics, Faculty of Arts and Sciences, Ondokuz Mayıs University, TR-55139 Kurupelit-Samsun, Turkey, and bDepartment of Chemistry, Faculty of Arts and Sciences, Ondokuz Mayıs University, 55139 Samsun, Turkey
*Correspondence e-mail: ikilic@omu.edu.tr

(Received 20 February 2009; accepted 5 March 2009; online 11 March 2009)

The title Schiff base compound, C14H12N2O4, is in an inter­mediate state between NH and OH tautomers. Apart from the intra­molecular O—H⋯N hydrogen bond, there are inter­molecular C—H⋯O hydrogen bonds, generating centrosymmetric R22(18) and R22(14) dimers.

Related literature

For a related structure, see: Karabıyık et al. (2007[Karabıyık, H., Güzel, B., Aygün, M., Boğa, G. & Büyükgüngör, O. (2007). Acta Cryst. C63, o215-o218.]). For geometric parameters, see: Allen et al. (1987[Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1-19.]); Glidewell et al. (2004[Glidewell, C., Low, J. N., Skakle, J. M. S. & Wardell, J. L. (2004). Acta Cryst. C60, o33-o34.]); Zeller & Hunter (2004[Zeller, M. & Hunter, A. D. (2004). Acta Cryst. C60, o415-o417.]).

[Scheme 1]

Experimental

Crystal data
  • C14H12N2O4

  • Mr = 272.26

  • Monoclinic, P 21 /c

  • a = 3.8883 (3) Å

  • b = 21.6202 (17) Å

  • c = 15.3127 (11) Å

  • β = 97.887 (1)°

  • V = 1275.10 (17) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.11 mm−1

  • T = 296 K

  • 0.80 × 0.22 × 0.21 mm

Data collection
  • Stoe IPDS-II diffractometer

  • Absorption correction: integration (X-RED; Stoe & Cie, 2002[Stoe & Cie (2002). X-AREA and X-RED32. Stoe & Cie, Darmstadt, Germany.]) Tmin = 0.945, Tmax = 0.982

  • 8242 measured reflections

  • 2501 independent reflections

  • 1710 reflections with I > 2σ(I)

  • Rint = 0.033

Refinement
  • R[F2 > 2σ(F2)] = 0.038

  • wR(F2) = 0.098

  • S = 1.02

  • 2501 reflections

  • 185 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.09 e Å−3

  • Δρmin = −0.14 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O1—H1⋯N1 1.25 (3) 1.38 (3) 2.5547 (18) 153 (2)
C7—H7⋯O3i 0.93 2.46 3.3014 (19) 151
C10—H10⋯O1ii 0.93 2.57 3.4605 (18) 160
Symmetry codes: (i) -x+1, -y+1, -z; (ii) -x, -y+1, -z+1.

Data collection: X-AREA (Stoe & Cie, 2002[Stoe & Cie (2002). X-AREA and X-RED32. Stoe & Cie, Darmstadt, Germany.]); cell refinement: X-AREA; data reduction: X-RED32 (Stoe & Cie, 2002[Stoe & Cie (2002). X-AREA and X-RED32. Stoe & Cie, Darmstadt, Germany.]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]); software used to prepare material for publication: WinGX (Farrugia, 1999[Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.]).

Supporting information


Comment top

Schiff base compounds can be classified by their photochromic and thermochromic characteristics. Photochromism and thermochromism produced by the reversible intramolecular proton transfer associated with a change in π-electron configuration. Schiff bases display two possible tautomeric forms, the phenol-imine and the keto-amine forms. We report here on the crystal structure of the title compound, 2-[(4-Methoxyphenyl)iminomethyl]-4-nitrophenylen-1-olate, (I). The molecular structure of the compound (I) is described as an intermediate state between NH and OH tautomers. The bond lengths of the compound are intermediate between single and double C—O (1.362 and 1.222 Å, respectively) and C—N bond lengths (1.339 and 1.279 Å, respectively), (Allen et al., 1987). In particular, C6—O1 bond length (1.318 Å) is significantly shorter than its expected value.

The molecular structure of 2-[(4-Methoxyphenyl)iminomethyl]-4- nitrophenylen-1-olate is shown in Fig. 1. The conformation is stabilized by an intramolecular O—H···N hydrogen bond. It is a well known fact that H atoms participating in intramolecular hydrogen bonds in Schiff bases are rather mobile. The molecule can be regarded as having an intermediate state between its canonical OH and NH forms, and therefore the O1—H1 bond (1.246 Å) remains somewhat longer than its expected value. On the other hand, the C3—N2 bond length [1.4521 (18) Å] in title compound is as expected and also is in agreement with the corresponding distances [1.4671 (18) Å (Zeller & Hunter, 2004) and 1.456 (4) Å (Glidewell et al., 2004)] for compounds that contain a nitro group.

The molecule is nearly planar and the dihedral angle between the two benzene rings is 3.28 (7) Å. The crystal packing is stabilized by intermolecular C—H···O hydrogen bonds generating centrosymmetric R22(18) and R22(14) dimers.

Related literature top

For a related structure, see: Karabıyık et al. (2007). For geometric parameters, see: Allen et al. (1987); Glidewell et al. (2004); Zeller & Hunter (2004).

Experimental top

The compound 2-[(4-Methoxyphenyl)iminomethyl]-4-nitrophenylen-1-olate was prepared by reflux a mixture of a solution containing 2-Hydroxy-5-nitrobenzaldehyde(0.0574 g 0.34 mmol) in 20 ml e thanol and a solution containing p-Anisidine (0.0423 g 0.34 mmol) in 20 ml e thanol. The reaction mixture was stirred for 1 hunder reflux. The crystals of (E)-2-[(4-Methoxyphenylimino)methyl]-4-nitrophenol suitable for X-ray analysis were obtained from ethylalcohol by slow evaporation (yield % 41; m.p.445–446 K).

Refinement top

All H atoms (expect for H1) were positioned geometrically and treated using a riding model, fixing the bond lengths at 0.93 and 0.96 Å for CH(aromatic) and CH3, respectively. The displacement parameters of the H atoms were constrained as Uiso(H) = 1.2Ueq(Caromatic) or 1.5Ueq(Cmethyl). The position of the H1 atom was obtained from a difference map and this atom was refined freely.

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, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound showing the atom-numbering scheme and diplacement ellipsoids at the %50 probability.
[Figure 2] Fig. 2. The crystal packing of the title compound. Intermolecular hydrogen bonds are shown as dashed lines.
2-[(4-Methoxyphenyl)iminomethyl]-4-nitrophenol top
Crystal data top
C14H12N2O4F(000) = 568
Mr = 272.26Dx = 1.418 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 12745 reflections
a = 3.8883 (3) Åθ = 1.6–28.9°
b = 21.6202 (17) ŵ = 0.11 mm1
c = 15.3127 (11) ÅT = 296 K
β = 97.887 (1)°Prism, orange
V = 1275.10 (17) Å30.80 × 0.22 × 0.21 mm
Z = 4
Data collection top
Stoe IPDS-II
diffractometer
2501 independent reflections
Radiation source: fine-focus sealed tube1710 reflections with I > 2σ(I)
Plane graphite monochromatorRint = 0.033
Detector resolution: 6.67 pixels mm-1θmax = 26.0°, θmin = 1.6°
rotation method scansh = 44
Absorption correction: integration
(X-RED; Stoe & Cie, 2002)
k = 2622
Tmin = 0.945, Tmax = 0.982l = 1818
8242 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)] = 0.038Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.098H atoms treated by a mixture of independent and constrained refinement
S = 1.02 w = 1/[σ2(Fo2) + (0.0543P)2]
where P = (Fo2 + 2Fc2)/3
2501 reflections(Δ/σ)max = 0.001
185 parametersΔρmax = 0.09 e Å3
0 restraintsΔρmin = 0.14 e Å3
Crystal data top
C14H12N2O4V = 1275.10 (17) Å3
Mr = 272.26Z = 4
Monoclinic, P21/cMo Kα radiation
a = 3.8883 (3) ŵ = 0.11 mm1
b = 21.6202 (17) ÅT = 296 K
c = 15.3127 (11) Å0.80 × 0.22 × 0.21 mm
β = 97.887 (1)°
Data collection top
Stoe IPDS-II
diffractometer
2501 independent reflections
Absorption correction: integration
(X-RED; Stoe & Cie, 2002)
1710 reflections with I > 2σ(I)
Tmin = 0.945, Tmax = 0.982Rint = 0.033
8242 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0380 restraints
wR(F2) = 0.098H atoms treated by a mixture of independent and constrained refinement
S = 1.02Δρmax = 0.09 e Å3
2501 reflectionsΔρmin = 0.14 e Å3
185 parameters
Special details top

Experimental. 168 frames, detector distance = 100 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
H10.080 (7)0.5420 (15)0.3247 (17)0.159 (9)*
C10.1593 (4)0.54973 (7)0.17787 (9)0.0525 (4)
C20.1968 (4)0.55582 (7)0.08919 (9)0.0551 (4)
H20.29590.52400.06030.066*
C30.0878 (4)0.60869 (7)0.04447 (9)0.0537 (4)
C40.0560 (4)0.65778 (8)0.08562 (10)0.0615 (4)
H40.12800.69330.05410.074*
C50.0899 (4)0.65300 (8)0.17316 (10)0.0639 (4)
H50.18150.68600.20140.077*
C60.0109 (4)0.59926 (7)0.22101 (9)0.0566 (4)
C70.2677 (4)0.49350 (7)0.22438 (9)0.0569 (4)
H70.36800.46200.19510.068*
C80.3240 (4)0.43228 (7)0.35558 (9)0.0532 (4)
C90.2812 (4)0.43386 (7)0.44334 (9)0.0591 (4)
H90.19540.46970.46610.071*
C100.3611 (4)0.38411 (8)0.49849 (9)0.0594 (4)
H100.33000.38630.55760.071*
C110.4880 (4)0.33088 (7)0.46477 (9)0.0554 (4)
C120.5339 (4)0.32849 (8)0.37667 (10)0.0654 (4)
H120.62060.29270.35410.078*
C130.4526 (4)0.37842 (8)0.32228 (9)0.0627 (4)
H130.48360.37620.26320.075*
C140.5188 (5)0.27857 (8)0.60288 (10)0.0719 (5)
H14A0.59160.23970.62950.108*
H14B0.27600.28460.60590.108*
H14C0.64950.31140.63390.108*
N10.2277 (3)0.48627 (6)0.30559 (7)0.0567 (3)
N20.1205 (4)0.61313 (7)0.04865 (8)0.0617 (3)
O10.0338 (3)0.59470 (6)0.30459 (7)0.0713 (3)
O20.5770 (3)0.27862 (5)0.51285 (7)0.0696 (3)
O30.2895 (3)0.57320 (6)0.08103 (7)0.0806 (4)
O40.0247 (4)0.65529 (6)0.09199 (7)0.0860 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0452 (8)0.0534 (9)0.0586 (8)0.0031 (7)0.0055 (6)0.0084 (6)
C20.0523 (9)0.0528 (9)0.0607 (8)0.0028 (7)0.0094 (7)0.0089 (7)
C30.0515 (9)0.0527 (9)0.0560 (8)0.0061 (7)0.0040 (6)0.0060 (6)
C40.0566 (9)0.0532 (9)0.0721 (10)0.0006 (8)0.0001 (7)0.0049 (7)
C50.0640 (10)0.0580 (10)0.0692 (9)0.0066 (8)0.0079 (7)0.0129 (7)
C60.0483 (9)0.0590 (10)0.0619 (9)0.0026 (7)0.0051 (6)0.0121 (7)
C70.0521 (9)0.0580 (10)0.0610 (9)0.0009 (7)0.0090 (6)0.0106 (7)
C80.0478 (8)0.0545 (9)0.0572 (8)0.0005 (7)0.0069 (6)0.0073 (6)
C90.0586 (9)0.0595 (10)0.0604 (9)0.0067 (8)0.0127 (7)0.0117 (7)
C100.0589 (9)0.0651 (10)0.0553 (8)0.0024 (8)0.0114 (7)0.0094 (7)
C110.0476 (8)0.0576 (10)0.0605 (8)0.0018 (7)0.0055 (6)0.0051 (7)
C120.0732 (11)0.0570 (10)0.0671 (9)0.0064 (8)0.0132 (7)0.0126 (7)
C130.0708 (11)0.0648 (10)0.0538 (8)0.0036 (8)0.0129 (7)0.0099 (7)
C140.0777 (12)0.0709 (11)0.0676 (10)0.0007 (10)0.0113 (8)0.0033 (8)
N10.0550 (8)0.0589 (8)0.0562 (7)0.0001 (6)0.0078 (5)0.0069 (5)
N20.0646 (8)0.0566 (8)0.0632 (8)0.0096 (7)0.0058 (6)0.0036 (6)
O10.0835 (9)0.0729 (8)0.0594 (6)0.0080 (6)0.0166 (5)0.0120 (5)
O20.0800 (8)0.0604 (7)0.0687 (7)0.0070 (6)0.0115 (5)0.0007 (5)
O30.0992 (10)0.0787 (9)0.0677 (7)0.0089 (7)0.0251 (6)0.0054 (6)
O40.1139 (11)0.0697 (8)0.0719 (7)0.0082 (8)0.0038 (6)0.0113 (6)
Geometric parameters (Å, º) top
C1—C21.3917 (19)C9—C101.376 (2)
C1—C61.421 (2)C9—H90.9300
C1—C71.442 (2)C10—C111.380 (2)
C2—C31.370 (2)C10—H100.9300
C2—H20.9300C11—O21.3669 (18)
C3—C41.390 (2)C11—C121.386 (2)
C3—N21.4521 (18)C12—C131.374 (2)
C4—C51.369 (2)C12—H120.9300
C4—H40.9300C13—H130.9300
C5—C61.401 (2)C14—O21.4275 (17)
C5—H50.9300C14—H14A0.9600
C6—O11.3186 (16)C14—H14B0.9600
C7—N11.2837 (17)C14—H14C0.9600
C7—H70.9300N1—H11.38 (3)
C8—C91.3770 (19)N2—O41.2196 (17)
C8—C131.391 (2)N2—O31.2297 (16)
C8—N11.4177 (19)O1—H11.25 (3)
C2—C1—C6119.07 (14)C9—C10—C11118.97 (14)
C2—C1—C7119.93 (13)C9—C10—H10120.5
C6—C1—C7121.01 (13)C11—C10—H10120.5
C3—C2—C1120.01 (14)O2—C11—C10124.40 (13)
C3—C2—H2120.0O2—C11—C12115.88 (14)
C1—C2—H2120.0C10—C11—C12119.71 (15)
C2—C3—C4121.78 (14)C13—C12—C11120.75 (15)
C2—C3—N2118.91 (13)C13—C12—H12119.6
C4—C3—N2119.31 (14)C11—C12—H12119.6
C5—C4—C3119.01 (15)C12—C13—C8119.99 (14)
C5—C4—H4120.5C12—C13—H13120.0
C3—C4—H4120.5C8—C13—H13120.0
C4—C5—C6121.16 (15)O2—C14—H14A109.5
C4—C5—H5119.4O2—C14—H14B109.5
C6—C5—H5119.4H14A—C14—H14B109.5
O1—C6—C5120.34 (14)O2—C14—H14C109.5
O1—C6—C1120.71 (14)H14A—C14—H14C109.5
C5—C6—C1118.95 (13)H14B—C14—H14C109.5
N1—C7—C1121.00 (14)C7—N1—C8124.42 (13)
N1—C7—H7119.5C7—N1—H1102.0 (11)
C1—C7—H7119.5C8—N1—H1133.6 (11)
C9—C8—C13118.42 (15)O4—N2—O3122.58 (14)
C9—C8—N1116.64 (13)O4—N2—C3119.16 (14)
C13—C8—N1124.94 (13)O3—N2—C3118.24 (14)
C10—C9—C8122.15 (15)C6—O1—H1102.6 (12)
C10—C9—H9118.9C11—O2—C14117.30 (13)
C8—C9—H9118.9
C6—C1—C2—C30.7 (2)C8—C9—C10—C110.1 (2)
C7—C1—C2—C3178.72 (14)C9—C10—C11—O2179.88 (14)
C1—C2—C3—C41.2 (2)C9—C10—C11—C120.3 (2)
C1—C2—C3—N2178.21 (12)O2—C11—C12—C13179.99 (15)
C2—C3—C4—C50.1 (2)C10—C11—C12—C130.4 (2)
N2—C3—C4—C5179.23 (13)C11—C12—C13—C80.3 (2)
C3—C4—C5—C61.3 (2)C9—C8—C13—C120.1 (2)
C4—C5—C6—O1177.85 (14)N1—C8—C13—C12179.22 (15)
C4—C5—C6—C11.7 (2)C1—C7—N1—C8179.33 (13)
C2—C1—C6—O1178.89 (13)C9—C8—N1—C7176.31 (14)
C7—C1—C6—O10.6 (2)C13—C8—N1—C74.5 (2)
C2—C1—C6—C50.7 (2)C2—C3—N2—O4168.40 (14)
C7—C1—C6—C5179.89 (14)C4—C3—N2—O411.0 (2)
C2—C1—C7—N1178.28 (13)C2—C3—N2—O310.2 (2)
C6—C1—C7—N11.2 (2)C4—C3—N2—O3170.37 (14)
C13—C8—C9—C100.0 (2)C10—C11—O2—C143.0 (2)
N1—C8—C9—C10179.19 (14)C12—C11—O2—C14177.33 (14)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···N11.25 (3)1.38 (3)2.5547 (18)153 (2)
C7—H7···O3i0.932.463.3014 (19)151
C10—H10···O1ii0.932.573.4605 (18)160
Symmetry codes: (i) x+1, y+1, z; (ii) x, y+1, z+1.

Experimental details

Crystal data
Chemical formulaC14H12N2O4
Mr272.26
Crystal system, space groupMonoclinic, P21/c
Temperature (K)296
a, b, c (Å)3.8883 (3), 21.6202 (17), 15.3127 (11)
β (°) 97.887 (1)
V3)1275.10 (17)
Z4
Radiation typeMo Kα
µ (mm1)0.11
Crystal size (mm)0.80 × 0.22 × 0.21
Data collection
DiffractometerStoe IPDS-II
diffractometer
Absorption correctionIntegration
(X-RED; Stoe & Cie, 2002)
Tmin, Tmax0.945, 0.982
No. of measured, independent and
observed [I > 2σ(I)] reflections
8242, 2501, 1710
Rint0.033
(sin θ/λ)max1)0.617
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.038, 0.098, 1.02
No. of reflections2501
No. of parameters185
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.09, 0.14

Computer programs: X-AREA (Stoe & Cie, 2002), X-RED32 (Stoe & Cie, 2002), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···N11.25 (3)1.38 (3)2.5547 (18)153 (2)
C7—H7···O3i0.932.463.3014 (19)151
C10—H10···O1ii0.932.573.4605 (18)160
Symmetry codes: (i) x+1, y+1, z; (ii) x, y+1, z+1.
 

Acknowledgements

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

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First citationZeller, M. & Hunter, A. D. (2004). Acta Cryst. C60, o415–o417.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar

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