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Acta Crystallogr Sect E Struct Rep Online. 2009 November 1; 65(Pt 11): o2949.
Published online 2009 October 31. doi:  10.1107/S1600536809044560
PMCID: PMC2971260

2-Methyl-6-[2-(trifluoro­meth­yl)phenyl­imino­meth­yl]phenol

Abstract

The title compound, C15H12F3NO, is a Schiff base which adopts the phenol–imine tautomeric form in the solid state. The dihedral angle between the aromatic rings is 38.79 (5)°. The mol­ecular structure is stabilized by an intra­molecular O—H(...)N hydrogen bond, which generates an S(6) ring. In addition, there is an intra­molecular short C—H(...)F contact.

Related literature

For the biological properties of Schiff bases, see: Barton et al. (1979 [triangle]); Layer (1963 [triangle]); Ingold (1969 [triangle]) Taggi et al. (2002 [triangle]); Aydoğan et al. (2001 [triangle]). Schiff base compounds can be classified by their photochromic and thermochromic characteristics, see: Cohen et al. (1964 [triangle]); Moustakali-Mavridis et al. (1978 [triangle]). For the graph-set description of hydrogen bonds, see: Bernstein et al. (1995 [triangle]. For a related structure, see: Temel et al. (2007 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-65-o2949-scheme1.jpg

Experimental

Crystal data

  • C15H12F3NO
  • M r = 279.26
  • Orthorhombic, An external file that holds a picture, illustration, etc.
Object name is e-65-o2949-efi1.jpg
  • a = 8.1634 (3) Å
  • b = 11.8810 (6) Å
  • c = 13.4469 (7) Å
  • V = 1304.21 (11) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 0.12 mm−1
  • T = 293 K
  • 0.73 × 0.51 × 0.37 mm

Data collection

  • Stoe IPDS II diffractometer
  • Absorption correction: integration (X-RED32; Stoe & Cie, 2002 [triangle]) T min = 0.943, T max = 0.970
  • 14752 measured reflections
  • 1565 independent reflections
  • 1396 reflections with I > 2σ(I)
  • R int = 0.030

Refinement

  • R[F 2 > 2σ(F 2)] = 0.031
  • wR(F 2) = 0.081
  • S = 1.07
  • 1565 reflections
  • 187 parameters
  • H atoms treated by a mixture of independent and constrained refinement
  • Δρmax = 0.09 e Å−3
  • Δρmin = −0.15 e Å−3

Data collection: X-AREA (Stoe & Cie, 2002 [triangle]); cell refinement: X-AREA; data reduction: X-RED32 (Stoe & Cie, 2002 [triangle]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 [triangle]); software used to prepare material for publication: WinGX (Farrugia, 1999 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809044560/bt5114sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809044560/bt5114Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

This study was supported financially by the Research Center of Ondokuz Mayıs University (Project No. F-476). 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).

supplementary crystallographic information

Comment

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 phenol-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 phenol-imine and N—H···O in keto-amine tautomers.

In the title compound (Fig. 1), the molecular structure is not planar. The dihedral angle between the aromatic ring systems [C1/C6 and C9/C14] is 38.79 (5)°. It is also known that Schiff bases may exhibit thermochromism depending on the planarity or non-planarity, respectively (Moustakali-Mavridis et al., 1978).The O—H and C=N bond lengths confirm the phenol-imine form of the title compound. These distances agree with the corresponding distances in (E)-3-[2-(Trifluoromethyl)phenyliminomethyl]-benzene-1,2-diol (Temel et al., 2007), which is related structure. The imine group is coplanar with the C1—C6 aromatic ring system as it can be shown by the C2—C1—C8—N1 torsion angle is 1.67 (19)°.

The molecular structure is stabilized by intramolecular hydrogen bonds. An intramolecular O1—H1···N1 hydrogen bond (Fig. 1) generates a six-membered ring, producing an S(6) ring motif (Bernstein et al., 1995), resulting in approximate planarity of the molecular skeleton [O···N= 2.6187 (16) Å]. The crystal structure is further stabilized by intramolecular C—H···F hydrogen bond, namely C13—H13···F3. And also details of the hydrogen bond is shown in Table 1.

Experimental

A solution of 3-methylsalicylaldehyde (0.0233 g, 0.1711 mmol) in ethanol (10 ml) was added to a solution of 2-Triflouromethylaniline (0.0275 g, 0.1711 mmol) in ethanol (20 ml). The reaction mixture was stirred for 2 h underreflux. Single crystals suitable for X-ray analysis were obtained from ethylalcohol by slow evaporation (yield 69%; m.p.408–410 K).

Refinement

C-bound H atoms were positioned geometrically and refined using a riding model, with C—H = 0.93–0.96 Å and Uiso(H) = 1.2–1.5Ueq(C). The position of the H1 atom was obtained from a difference map and this atom was refined freely. Friedel pairs were merged in the final refinement because the value of the absolute structure parameter (Flack, 1983) is meaningless.

Figures

Fig. 1.
The molecular structure of the title compound, showing the atom-numbering scheme and 30% probability diplacement ellipsoids.

Crystal data

C15H12F3NOF(000) = 576
Mr = 279.26Dx = 1.422 Mg m3
Orthorhombic, P212121Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 19471 reflections
a = 8.1634 (3) Åθ = 1.5–28.0°
b = 11.8810 (6) ŵ = 0.12 mm1
c = 13.4469 (7) ÅT = 293 K
V = 1304.21 (11) Å3Prism, light yellow
Z = 40.73 × 0.51 × 0.37 mm

Data collection

Stoe IPDS II diffractometer1565 independent reflections
Radiation source: fine-focus sealed tube1396 reflections with I > 2σ(I)
graphiteRint = 0.030
Detector resolution: 6.67 pixels mm-1θmax = 26.5°, θmin = 2.3°
rotation method scansh = −10→10
Absorption correction: integration (X-RED32; Stoe & Cie, 2002)k = −14→14
Tmin = 0.943, Tmax = 0.970l = −16→16
14752 measured reflections

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.031Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.081H atoms treated by a mixture of independent and constrained refinement
S = 1.07w = 1/[σ2(Fo2) + (0.0562P)2 + 0.0179P] where P = (Fo2 + 2Fc2)/3
1565 reflections(Δ/σ)max < 0.001
187 parametersΔρmax = 0.09 e Å3
0 restraintsΔρmin = −0.15 e Å3

Special details

Experimental. 270 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)

xyzUiso*/Ueq
C10.5950 (2)0.12366 (13)0.48589 (13)0.0521 (4)
C20.7604 (2)0.09829 (14)0.46506 (13)0.0521 (4)
C30.8634 (3)0.05379 (15)0.53818 (15)0.0589 (5)
C40.7966 (3)0.03487 (16)0.63136 (16)0.0669 (5)
H40.86260.00390.68060.080*
C50.6363 (3)0.06007 (18)0.65389 (16)0.0725 (6)
H50.59600.04710.71760.087*
C60.5366 (3)0.10426 (16)0.58227 (15)0.0653 (5)
H60.42850.12170.59770.078*
C71.0381 (3)0.0287 (2)0.51468 (19)0.0804 (6)
H7A1.09720.09790.50640.121*
H7B1.0440−0.01440.45440.121*
H7C1.0857−0.01370.56820.121*
C80.4855 (2)0.16517 (13)0.41041 (14)0.0536 (4)
H80.37830.18260.42800.064*
C90.4144 (2)0.21161 (13)0.24725 (14)0.0525 (4)
C100.2558 (3)0.16864 (15)0.24564 (17)0.0638 (5)
H100.22270.11810.29450.077*
C110.1481 (3)0.20022 (18)0.1726 (2)0.0757 (6)
H110.04270.17050.17200.091*
C120.1946 (3)0.27551 (18)0.10000 (19)0.0747 (6)
H120.12020.29760.05140.090*
C130.3510 (3)0.31792 (17)0.09962 (16)0.0661 (5)
H130.38270.36810.05020.079*
C140.4618 (2)0.28640 (13)0.17241 (14)0.0541 (4)
C150.6310 (3)0.33225 (16)0.17122 (15)0.0625 (5)
N10.53021 (19)0.17904 (11)0.31975 (11)0.0530 (3)
O10.82427 (18)0.11539 (13)0.37360 (11)0.0671 (4)
F10.67184 (18)0.38548 (12)0.25515 (11)0.0888 (4)
F20.74444 (17)0.25364 (12)0.15746 (12)0.0872 (4)
F30.65390 (18)0.40802 (13)0.09842 (12)0.0930 (5)
H10.738 (4)0.141 (2)0.335 (2)0.097 (9)*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
C10.0552 (10)0.0460 (7)0.0550 (9)−0.0031 (7)0.0000 (8)−0.0035 (7)
C20.0568 (10)0.0468 (7)0.0528 (9)−0.0038 (7)−0.0010 (8)−0.0033 (7)
C30.0606 (11)0.0518 (8)0.0644 (11)−0.0035 (8)−0.0118 (9)−0.0052 (8)
C40.0800 (15)0.0577 (9)0.0631 (11)−0.0075 (9)−0.0180 (11)0.0033 (8)
C50.0891 (16)0.0757 (11)0.0528 (11)−0.0107 (11)0.0015 (11)0.0036 (9)
C60.0685 (12)0.0689 (10)0.0584 (10)−0.0042 (10)0.0059 (10)−0.0013 (9)
C70.0621 (13)0.0903 (14)0.0889 (16)0.0081 (11)−0.0139 (13)−0.0037 (13)
C80.0492 (10)0.0487 (7)0.0630 (10)0.0005 (7)0.0041 (8)−0.0018 (7)
C90.0490 (9)0.0471 (7)0.0613 (10)0.0058 (7)−0.0018 (8)−0.0009 (7)
C100.0527 (11)0.0570 (9)0.0816 (13)0.0005 (8)−0.0025 (10)0.0039 (10)
C110.0528 (11)0.0695 (11)0.1048 (17)0.0025 (9)−0.0140 (12)−0.0067 (12)
C120.0711 (14)0.0692 (11)0.0837 (14)0.0144 (11)−0.0227 (12)−0.0005 (11)
C130.0706 (13)0.0599 (10)0.0678 (12)0.0109 (9)−0.0078 (10)0.0059 (9)
C140.0559 (10)0.0478 (7)0.0586 (10)0.0070 (7)−0.0011 (8)−0.0010 (7)
C150.0604 (11)0.0620 (10)0.0652 (11)0.0010 (8)0.0044 (9)0.0072 (9)
N10.0483 (8)0.0525 (7)0.0583 (8)0.0029 (6)−0.0018 (7)0.0025 (6)
O10.0530 (8)0.0886 (9)0.0596 (8)0.0050 (7)0.0044 (7)0.0051 (7)
F10.0835 (10)0.0967 (9)0.0861 (9)−0.0323 (8)0.0002 (8)−0.0127 (7)
F20.0565 (7)0.0926 (8)0.1124 (11)0.0123 (7)0.0131 (7)0.0079 (8)
F30.0857 (9)0.0928 (8)0.1004 (10)−0.0116 (8)0.0083 (8)0.0376 (8)

Geometric parameters (Å, °)

C1—C61.400 (3)C9—C101.392 (3)
C1—C21.411 (3)C9—C141.397 (2)
C1—C81.440 (3)C9—N11.412 (2)
C2—O11.351 (2)C10—C111.371 (3)
C2—C31.398 (3)C10—H100.9300
C3—C41.385 (3)C11—C121.377 (3)
C3—C71.491 (3)C11—H110.9300
C4—C51.376 (3)C12—C131.373 (3)
C4—H40.9300C12—H120.9300
C5—C61.366 (3)C13—C141.385 (3)
C5—H50.9300C13—H130.9300
C6—H60.9300C14—C151.484 (3)
C7—H7A0.9600C15—F21.328 (2)
C7—H7B0.9600C15—F11.336 (2)
C7—H7C0.9600C15—F31.343 (2)
C8—N11.283 (2)O1—H10.93 (3)
C8—H80.9300
C6—C1—C2118.34 (18)C10—C9—C14118.66 (18)
C6—C1—C8119.82 (18)C10—C9—N1122.19 (17)
C2—C1—C8121.82 (16)C14—C9—N1119.10 (17)
O1—C2—C3117.71 (18)C11—C10—C9120.5 (2)
O1—C2—C1121.19 (17)C11—C10—H10119.8
C3—C2—C1121.10 (18)C9—C10—H10119.8
C4—C3—C2117.4 (2)C10—C11—C12120.6 (2)
C4—C3—C7122.4 (2)C10—C11—H11119.7
C2—C3—C7120.1 (2)C12—C11—H11119.7
C5—C4—C3122.6 (2)C13—C12—C11119.8 (2)
C5—C4—H4118.7C13—C12—H12120.1
C3—C4—H4118.7C11—C12—H12120.1
C6—C5—C4119.7 (2)C12—C13—C14120.4 (2)
C6—C5—H5120.2C12—C13—H13119.8
C4—C5—H5120.2C14—C13—H13119.8
C5—C6—C1120.9 (2)C13—C14—C9120.02 (19)
C5—C6—H6119.6C13—C14—C15120.06 (17)
C1—C6—H6119.6C9—C14—C15119.91 (16)
C3—C7—H7A109.5F2—C15—F1106.04 (18)
C3—C7—H7B109.5F2—C15—F3105.81 (17)
H7A—C7—H7B109.5F1—C15—F3105.28 (16)
C3—C7—H7C109.5F2—C15—C14113.09 (15)
H7A—C7—H7C109.5F1—C15—C14113.39 (17)
H7B—C7—H7C109.5F3—C15—C14112.55 (17)
N1—C8—C1122.48 (18)C8—N1—C9120.06 (16)
N1—C8—H8118.8C2—O1—H1105.5 (18)
C1—C8—H8118.8
C6—C1—C2—O1−179.82 (16)C9—C10—C11—C12−0.5 (3)
C8—C1—C2—O12.1 (2)C10—C11—C12—C131.2 (3)
C6—C1—C2—C30.7 (2)C11—C12—C13—C14−0.7 (3)
C8—C1—C2—C3−177.39 (15)C12—C13—C14—C9−0.4 (3)
O1—C2—C3—C4−179.06 (16)C12—C13—C14—C15179.73 (18)
C1—C2—C3—C40.5 (2)C10—C9—C14—C131.1 (2)
O1—C2—C3—C71.1 (3)N1—C9—C14—C13178.90 (16)
C1—C2—C3—C7−179.41 (17)C10—C9—C14—C15−179.04 (17)
C2—C3—C4—C5−1.2 (3)N1—C9—C14—C15−1.3 (2)
C7—C3—C4—C5178.6 (2)C13—C14—C15—F2−116.15 (19)
C3—C4—C5—C60.8 (3)C9—C14—C15—F264.0 (2)
C4—C5—C6—C10.4 (3)C13—C14—C15—F1123.08 (19)
C2—C1—C6—C5−1.1 (3)C9—C14—C15—F1−56.8 (2)
C8—C1—C6—C5176.98 (17)C13—C14—C15—F33.7 (3)
C6—C1—C8—N1−176.38 (16)C9—C14—C15—F3−176.13 (16)
C2—C1—C8—N11.6 (3)C1—C8—N1—C9175.06 (14)
C14—C9—C10—C11−0.7 (3)C10—C9—N1—C8−39.7 (2)
N1—C9—C10—C11−178.38 (17)C14—C9—N1—C8142.65 (17)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
O1—H1···N10.93 (3)1.77 (3)2.619 (2)151 (3)
C13—H13···F30.932.362.694 (3)101

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: BT5114).

References

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  • Temel, E., Albayrak, Ç., Odabaşoğlu, M. & Büyükgüngör, O. (2007). Acta Cryst. E63, o374–o376.

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