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Acta Crystallogr Sect E Struct Rep Online. 2008 June 1; 64(Pt 6): o1065.
Published online 2008 May 14. doi:  10.1107/S1600536808013160
PMCID: PMC2961494

(E)-4-Methyl-2-[(R)-1-phenyl­ethyl­imino­meth­yl]phenol

Abstract

In the title Schiff base, C16H17NO, the dihedral angle between the two aromatic rings is 63.59 (2)°. A strong intra­molecular O—H(...)N hydrogen bond is observed between the hydroxyl group and the imine N atom.

Related literature

For photochromism and thermochromism of Schiff bases, see: Cohen et al. (1964 [triangle]).

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Object name is e-64-o1065-scheme1.jpg

Experimental

Crystal data

  • C16H17NO
  • M r = 239.31
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-64-o1065-efi1.jpg
  • a = 20.342 (8) Å
  • b = 5.911 (2) Å
  • c = 14.551 (5) Å
  • β = 128.585 (4)°
  • V = 1367.7 (9) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 0.07 mm−1
  • T = 296 (2) K
  • 0.35 × 0.34 × 0.26 mm

Data collection

  • Bruker APEXII area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Sheldrick, 1997 [triangle]) T min = 0.971, T max = 0.986
  • 5952 measured reflections
  • 1726 independent reflections
  • 1609 reflections with I > 2σ(I)
  • R int = 0.034

Refinement

  • R[F 2 > 2σ(F 2)] = 0.033
  • wR(F 2) = 0.100
  • S = 1.08
  • 1726 reflections
  • 166 parameters
  • 1 restraint
  • H-atom parameters constrained
  • Δρmax = 0.16 e Å−3
  • Δρmin = −0.12 e Å−3

Data collection: APEX2 (Bruker, 2004 [triangle]); cell refinement: SAINT (Bruker, 2004 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: SHELXTL (Sheldrick, 2008 [triangle]); software used to prepare material for publication: SHELXL97.

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808013160/ci2590sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808013160/ci2590Isup2.hkl

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

Acknowledgments

This project was supported by the Talent Fund of Xi’an University of Architecture and Technology.

supplementary crystallographic information

Comment

Compounds presenting photochromism, a reversible colour change brought about in at least one direction, by the action of electromagnetic radiation, attract considerable attention from various fields of chemistry, physics and materials science as potential candidates for practical applications. For a long time, the Schiff bases of salicylaldehyde with aromatic amines (anils or N-salicylideneaniline derivatives) are recognized as such compounds, which undergo enol-keto tautomerism and present common features in their structures and reaction mechanisms. The Schiff base compounds show photochromism and thermochromism in the solid state by proton transfer from the hydroxyl O atom to the imine N atom (Cohen et al., 1964). The tautomerism involves proton transfer from the hydroxylic oxygen to the imino nitrogen atom that occurs intramolecularly via a six-membered ring, with the keto species showing bathochromically shifted spectra. Continuing our studies on the relation between the Schiff base geometry in the crystalline state and photochromism and/or thermochromism, we report presently on the crystal structure of the title compound.

The structure of the title molecule is illustrated in Fig. 1. It is a typical salicylaldehyde Schiff base with normal geometric parameters. The C8?N1 bond show the expected double-bond character. The molecule is not planar. The dihedral angle between the two aromatic rings is 63.59 (2)°. A strong intramolecular O—H···N hydrogen bond is observed between the hydroxyl group and the imine N atom (Table 1).

Experimental

(R)-1-Phenylethanamine (0.02 mol, 2.42 g) and 2-hydroxy-5-methylbenzaldehyde (0.02 mol, 2.72 g) were dissolved in ethanol and the solution was refluxed for 3 h. After evaporation, a crude product was obtained which was recrystallized twice from ethanol to give a pure yellow product (yield 82.5%). Calculated for C16H17NO: C 80.30, H 7.16, N 5.85%; found: C 80.18, H 7.42, N 5.54%.

Refinement

H atoms were placed in geometrically idealized positions (C—H = 0.93–0.98%A and O—H = 0.82 Å) and constrained to ride on their parent atoms, with Uiso(H) = 1.2Ueq(C) or 1.5Ueq(Cmethyl, O). In the absence of significant anomalous scattering, Friedel pairs were merged prior to the final refinement.

Figures

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

Crystal data

C16H17NOF000 = 512
Mr = 239.31Dx = 1.162 Mg m3
Monoclinic, C2Mo Kα radiation λ = 0.71073 Å
Hall symbol: C 2yCell parameters from 1435 reflections
a = 20.342 (8) Åθ = 1.0–27.6º
b = 5.911 (2) ŵ = 0.07 mm1
c = 14.551 (5) ÅT = 296 (2) K
β = 128.585 (4)ºBlock, yellow
V = 1367.7 (9) Å30.35 × 0.34 × 0.26 mm
Z = 4

Data collection

Bruker APEXII area-detector diffractometer1726 independent reflections
Radiation source: fine-focus sealed tube1609 reflections with I > 2σ(I)
Monochromator: graphiteRint = 0.034
T = 296(2) Kθmax = 27.6º
[var phi] and ω scansθmin = 1.8º
Absorption correction: multi-scan(SADABS; Sheldrick, 1997)h = −24→26
Tmin = 0.971, Tmax = 0.986k = −7→7
5952 measured reflectionsl = −18→18

Refinement

Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.033H-atom parameters constrained
wR(F2) = 0.100  w = 1/[σ2(Fo2) + (0.0539P)2 + 0.1688P] where P = (Fo2 + 2Fc2)/3
S = 1.08(Δ/σ)max = 0.001
1726 reflectionsΔρmax = 0.16 e Å3
166 parametersΔρmin = −0.12 e Å3
1 restraintExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.023 (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 (Å2)

xyzUiso*/Ueq
O10.40281 (8)−0.3392 (2)−0.02219 (12)0.0730 (4)
H10.4410−0.26530.03420.110*
N10.47315 (9)0.0034 (2)0.12256 (11)0.0538 (3)
C10.32941 (11)−0.2272 (3)−0.07580 (15)0.0532 (4)
C20.25597 (12)−0.3196 (3)−0.17537 (17)0.0641 (5)
H20.2577−0.4590−0.20350.077*
C30.18064 (12)−0.2067 (4)−0.23274 (16)0.0637 (5)
H30.1323−0.2725−0.29900.076*
C40.17441 (11)0.0028 (3)−0.19481 (15)0.0573 (4)
C50.24764 (10)0.0946 (3)−0.09567 (14)0.0525 (4)
H50.24510.2337−0.06820.063*
C60.32532 (10)−0.0142 (3)−0.03530 (13)0.0475 (3)
C70.09140 (12)0.1267 (4)−0.2595 (2)0.0782 (6)
H7A0.10060.2860−0.25970.117*
H7B0.06740.0999−0.22100.117*
H7C0.05360.0729−0.33910.117*
C80.40074 (10)0.0940 (3)0.06644 (13)0.0509 (4)
H80.39590.23360.09120.061*
C90.54666 (10)0.1249 (3)0.22409 (14)0.0548 (4)
H90.52680.26030.23900.066*
C100.60292 (14)0.1982 (4)0.19397 (19)0.0727 (5)
H10A0.57400.30840.13200.109*
H10B0.61660.06920.16870.109*
H10C0.65370.26330.26220.109*
C110.58971 (10)−0.0289 (3)0.33046 (13)0.0519 (4)
C120.62976 (13)−0.2262 (4)0.33758 (17)0.0664 (5)
H120.6319−0.26230.27720.080*
C130.66655 (14)−0.3697 (4)0.4330 (2)0.0802 (6)
H130.6936−0.50020.43660.096*
C140.66345 (14)−0.3215 (5)0.52172 (19)0.0864 (7)
H140.6876−0.41930.58530.104*
C150.62443 (17)−0.1278 (6)0.51633 (19)0.0894 (8)
H150.6226−0.09390.57710.107*
C160.58746 (13)0.0192 (4)0.42139 (16)0.0696 (5)
H160.56120.15020.41910.083*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
O10.0677 (7)0.0529 (7)0.0784 (9)0.0080 (6)0.0357 (7)−0.0145 (7)
N10.0630 (8)0.0471 (7)0.0489 (6)0.0001 (6)0.0337 (6)−0.0041 (6)
C10.0620 (9)0.0425 (8)0.0575 (8)0.0013 (7)0.0385 (7)−0.0019 (7)
C20.0730 (10)0.0470 (9)0.0696 (10)−0.0048 (9)0.0432 (9)−0.0123 (9)
C30.0608 (9)0.0626 (11)0.0617 (10)−0.0105 (9)0.0352 (8)−0.0081 (9)
C40.0601 (9)0.0568 (9)0.0627 (9)0.0030 (8)0.0421 (8)0.0094 (8)
C50.0650 (9)0.0448 (8)0.0604 (9)0.0031 (7)0.0453 (8)0.0026 (7)
C60.0610 (8)0.0407 (7)0.0508 (7)0.0016 (6)0.0398 (7)0.0022 (6)
C70.0649 (10)0.0782 (15)0.0904 (13)0.0100 (11)0.0479 (10)0.0140 (12)
C80.0671 (9)0.0418 (7)0.0516 (8)0.0007 (7)0.0409 (7)−0.0026 (7)
C90.0647 (9)0.0460 (8)0.0528 (8)−0.0027 (7)0.0362 (7)−0.0084 (7)
C100.0849 (12)0.0704 (12)0.0686 (11)−0.0137 (11)0.0507 (10)−0.0019 (10)
C110.0539 (8)0.0520 (9)0.0493 (7)−0.0096 (7)0.0320 (6)−0.0094 (7)
C120.0769 (11)0.0587 (10)0.0629 (10)0.0032 (9)0.0433 (9)−0.0030 (9)
C130.0765 (12)0.0642 (12)0.0738 (12)0.0015 (11)0.0341 (10)0.0061 (11)
C140.0861 (14)0.0835 (16)0.0554 (10)−0.0224 (13)0.0273 (10)0.0057 (11)
C150.1092 (17)0.1044 (19)0.0575 (11)−0.0279 (16)0.0535 (12)−0.0134 (13)
C160.0833 (12)0.0720 (12)0.0616 (9)−0.0097 (10)0.0492 (9)−0.0132 (10)

Geometric parameters (Å, °)

O1—C11.350 (2)C8—H80.93
O1—H10.82C9—C111.516 (2)
N1—C81.274 (2)C9—C101.522 (3)
N1—C91.476 (2)C9—H90.98
C1—C21.389 (2)C10—H10A0.96
C1—C61.414 (2)C10—H10B0.96
C2—C31.377 (3)C10—H10C0.96
C2—H20.93C11—C161.382 (2)
C3—C41.394 (3)C11—C121.389 (3)
C3—H30.93C12—C131.383 (3)
C4—C51.383 (2)C12—H120.93
C4—C71.514 (3)C13—C141.362 (4)
C5—C61.397 (2)C13—H130.93
C5—H50.93C14—C151.367 (4)
C6—C81.457 (2)C14—H140.93
C7—H7A0.96C15—C161.390 (4)
C7—H7B0.96C15—H150.93
C7—H7C0.96C16—H160.93
C1—O1—H1109.4N1—C9—C10108.95 (14)
C8—N1—C9118.78 (15)C11—C9—C10113.93 (15)
O1—C1—C2119.47 (15)N1—C9—H9108.6
O1—C1—C6121.80 (15)C11—C9—H9108.6
C2—C1—C6118.71 (15)C10—C9—H9108.6
C3—C2—C1120.53 (17)C9—C10—H10A109.5
C3—C2—H2119.7C9—C10—H10B109.5
C1—C2—H2119.7H10A—C10—H10B109.5
C2—C3—C4122.18 (18)C9—C10—H10C109.5
C2—C3—H3118.9H10A—C10—H10C109.5
C4—C3—H3118.9H10B—C10—H10C109.5
C5—C4—C3117.16 (17)C16—C11—C12117.99 (18)
C5—C4—C7121.14 (18)C16—C11—C9120.77 (17)
C3—C4—C7121.69 (18)C12—C11—C9121.20 (15)
C4—C5—C6122.38 (16)C13—C12—C11121.01 (18)
C4—C5—H5118.8C13—C12—H12119.5
C6—C5—H5118.8C11—C12—H12119.5
C5—C6—C1119.04 (15)C14—C13—C12120.5 (2)
C5—C6—C8119.88 (15)C14—C13—H13119.8
C1—C6—C8121.07 (15)C12—C13—H13119.8
C4—C7—H7A109.5C13—C14—C15119.3 (2)
C4—C7—H7B109.5C13—C14—H14120.3
H7A—C7—H7B109.5C15—C14—H14120.3
C4—C7—H7C109.5C14—C15—C16121.0 (2)
H7A—C7—H7C109.5C14—C15—H15119.5
H7B—C7—H7C109.5C16—C15—H15119.5
N1—C8—C6122.04 (15)C11—C16—C15120.2 (2)
N1—C8—H8119.0C11—C16—H16119.9
C6—C8—H8119.0C15—C16—H16119.9
N1—C9—C11108.04 (14)
O1—C1—C2—C3−178.86 (18)C1—C6—C8—N10.4 (2)
C6—C1—C2—C3−0.5 (3)C8—N1—C9—C11123.36 (15)
C1—C2—C3—C40.3 (3)C8—N1—C9—C10−112.39 (18)
C2—C3—C4—C5−0.2 (3)N1—C9—C11—C16−110.20 (17)
C2—C3—C4—C7179.20 (18)C10—C9—C11—C16128.59 (19)
C3—C4—C5—C60.5 (2)N1—C9—C11—C1267.34 (19)
C7—C4—C5—C6−178.95 (15)C10—C9—C11—C12−53.9 (2)
C4—C5—C6—C1−0.8 (2)C16—C11—C12—C13−0.2 (3)
C4—C5—C6—C8178.08 (14)C9—C11—C12—C13−177.84 (18)
O1—C1—C6—C5179.05 (16)C11—C12—C13—C140.7 (3)
C2—C1—C6—C50.8 (2)C12—C13—C14—C15−0.8 (3)
O1—C1—C6—C80.2 (2)C13—C14—C15—C160.5 (4)
C2—C1—C6—C8−178.06 (16)C12—C11—C16—C15−0.1 (3)
C9—N1—C8—C6179.41 (13)C9—C11—C16—C15177.52 (19)
C5—C6—C8—N1−178.41 (14)C14—C15—C16—C110.0 (3)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
O1—H1···N10.821.892.613 (2)147

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: CI2590).

References

  • Bruker (2004). APEX2 and SAINT Bruker AXS Inc., Madison, Wisconsin, USA.
  • Cohen, M. D., Schmidt, G. M. J. & Flavian, S. (1964). J. Chem. Soc. pp. 2041–2043.
  • Sheldrick, G. M. (1997). SADABS University of Göttingen, Germany.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]

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