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

Dang, F.-F.

doi:10.1107/S1600536808013160

organic compounds

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ISSN: 2056-9890

Volume 64| Part 6| June 2008| Page o1065

doi:10.1107/S1600536808013160

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

Fang-Fang Dang ^a ^*

^aSchool of Science, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
^*Correspondence e-mail: fangfangdang@yahoo.com.cn

(Received 23 April 2008; accepted 5 May 2008; online 14 May 2008)

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 ).

Experimental

Crystal data

C₁₆H₁₇NO
M_r = 239.31
Monoclinic, C 2
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 ) 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[F² > 2σ(F²)] = 0.033
wR(F²) = 0.100
S = 1.08
1726 reflections
166 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.16 e Å⁻³
Δρ_min = −0.12 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯N1	0.82	1.89	2.613 (2)	147

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

Supporting information

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

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

checkCIF report

Comment top

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).

Related literature top

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

Experimental top

(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%.

Computing details top

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

Figures top

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

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

Crystal data top

C₁₆H₁₇NO	F(000) = 512
M_r = 239.31	D_x = 1.162 Mg m⁻³
Monoclinic, C2	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: C 2y	Cell parameters from 1435 reflections
a = 20.342 (8) Å	θ = 1.0–27.6°
b = 5.911 (2) Å	µ = 0.07 mm⁻¹
c = 14.551 (5) Å	T = 296 K
β = 128.585 (4)°	Block, yellow
V = 1367.7 (9) Å³	0.35 × 0.34 × 0.26 mm
Z = 4

Data collection top

Bruker APEXII area-detector diffractometer	1726 independent reflections
Radiation source: fine-focus sealed tube	1609 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.034
ϕ and ω scans	θ_max = 27.6°, θ_min = 1.8°
Absorption correction: multi-scan (SADABS; Sheldrick, 1997)	h = −24→26
T_min = 0.971, T_max = 0.986	k = −7→7
5952 measured reflections	l = −18→18

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.033	H-atom parameters constrained
wR(F²) = 0.100	w = 1/[σ²(F_o²) + (0.0539P)² + 0.1688P] where P = (F_o² + 2F_c²)/3
S = 1.08	(Δ/σ)_max = 0.001
1726 reflections	Δρ_max = 0.16 e Å⁻³
166 parameters	Δρ_min = −0.12 e Å⁻³
1 restraint	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.023 (3)

Crystal data top

C₁₆H₁₇NO	V = 1367.7 (9) Å³
M_r = 239.31	Z = 4
Monoclinic, C2	Mo Kα radiation
a = 20.342 (8) Å	µ = 0.07 mm⁻¹
b = 5.911 (2) Å	T = 296 K
c = 14.551 (5) Å	0.35 × 0.34 × 0.26 mm
β = 128.585 (4)°

Data collection top

Bruker APEXII area-detector diffractometer	1726 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1997)	1609 reflections with I > 2σ(I)
T_min = 0.971, T_max = 0.986	R_int = 0.034
5952 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.033	1 restraint
wR(F²) = 0.100	H-atom parameters constrained
S = 1.08	Δρ_max = 0.16 e Å⁻³
1726 reflections	Δρ_min = −0.12 e Å⁻³
166 parameters

Special details top

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

	x	y	z	U_iso*/U_eq
O1	0.40281 (8)	−0.3392 (2)	−0.02219 (12)	0.0730 (4)
H1	0.4410	−0.2653	0.0342	0.110*
N1	0.47315 (9)	0.0034 (2)	0.12256 (11)	0.0538 (3)
C1	0.32941 (11)	−0.2272 (3)	−0.07580 (15)	0.0532 (4)
C2	0.25597 (12)	−0.3196 (3)	−0.17537 (17)	0.0641 (5)
H2	0.2577	−0.4590	−0.2035	0.077*
C3	0.18064 (12)	−0.2067 (4)	−0.23274 (16)	0.0637 (5)
H3	0.1323	−0.2725	−0.2990	0.076*
C4	0.17441 (11)	0.0028 (3)	−0.19481 (15)	0.0573 (4)
C5	0.24764 (10)	0.0946 (3)	−0.09567 (14)	0.0525 (4)
H5	0.2451	0.2337	−0.0682	0.063*
C6	0.32532 (10)	−0.0142 (3)	−0.03530 (13)	0.0475 (3)
C7	0.09140 (12)	0.1267 (4)	−0.2595 (2)	0.0782 (6)
H7A	0.1006	0.2860	−0.2597	0.117*
H7B	0.0674	0.0999	−0.2210	0.117*
H7C	0.0536	0.0729	−0.3391	0.117*
C8	0.40074 (10)	0.0940 (3)	0.06644 (13)	0.0509 (4)
H8	0.3959	0.2336	0.0912	0.061*
C9	0.54666 (10)	0.1249 (3)	0.22409 (14)	0.0548 (4)
H9	0.5268	0.2603	0.2390	0.066*
C10	0.60292 (14)	0.1982 (4)	0.19397 (19)	0.0727 (5)
H10A	0.5740	0.3084	0.1320	0.109*
H10B	0.6166	0.0692	0.1687	0.109*
H10C	0.6537	0.2633	0.2622	0.109*
C11	0.58971 (10)	−0.0289 (3)	0.33046 (13)	0.0519 (4)
C12	0.62976 (13)	−0.2262 (4)	0.33758 (17)	0.0664 (5)
H12	0.6319	−0.2623	0.2772	0.080*
C13	0.66655 (14)	−0.3697 (4)	0.4330 (2)	0.0802 (6)
H13	0.6936	−0.5002	0.4366	0.096*
C14	0.66345 (14)	−0.3215 (5)	0.52172 (19)	0.0864 (7)
H14	0.6876	−0.4193	0.5853	0.104*
C15	0.62443 (17)	−0.1278 (6)	0.51633 (19)	0.0894 (8)
H15	0.6226	−0.0939	0.5771	0.107*
C16	0.58746 (13)	0.0192 (4)	0.42139 (16)	0.0696 (5)
H16	0.5612	0.1502	0.4191	0.083*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0677 (7)	0.0529 (7)	0.0784 (9)	0.0080 (6)	0.0357 (7)	−0.0145 (7)
N1	0.0630 (8)	0.0471 (7)	0.0489 (6)	0.0001 (6)	0.0337 (6)	−0.0041 (6)
C1	0.0620 (9)	0.0425 (8)	0.0575 (8)	0.0013 (7)	0.0385 (7)	−0.0019 (7)
C2	0.0730 (10)	0.0470 (9)	0.0696 (10)	−0.0048 (9)	0.0432 (9)	−0.0123 (9)
C3	0.0608 (9)	0.0626 (11)	0.0617 (10)	−0.0105 (9)	0.0352 (8)	−0.0081 (9)
C4	0.0601 (9)	0.0568 (9)	0.0627 (9)	0.0030 (8)	0.0421 (8)	0.0094 (8)
C5	0.0650 (9)	0.0448 (8)	0.0604 (9)	0.0031 (7)	0.0453 (8)	0.0026 (7)
C6	0.0610 (8)	0.0407 (7)	0.0508 (7)	0.0016 (6)	0.0398 (7)	0.0022 (6)
C7	0.0649 (10)	0.0782 (15)	0.0904 (13)	0.0100 (11)	0.0479 (10)	0.0140 (12)
C8	0.0671 (9)	0.0418 (7)	0.0516 (8)	0.0007 (7)	0.0409 (7)	−0.0026 (7)
C9	0.0647 (9)	0.0460 (8)	0.0528 (8)	−0.0027 (7)	0.0362 (7)	−0.0084 (7)
C10	0.0849 (12)	0.0704 (12)	0.0686 (11)	−0.0137 (11)	0.0507 (10)	−0.0019 (10)
C11	0.0539 (8)	0.0520 (9)	0.0493 (7)	−0.0096 (7)	0.0320 (6)	−0.0094 (7)
C12	0.0769 (11)	0.0587 (10)	0.0629 (10)	0.0032 (9)	0.0433 (9)	−0.0030 (9)
C13	0.0765 (12)	0.0642 (12)	0.0738 (12)	0.0015 (11)	0.0341 (10)	0.0061 (11)
C14	0.0861 (14)	0.0835 (16)	0.0554 (10)	−0.0224 (13)	0.0273 (10)	0.0057 (11)
C15	0.1092 (17)	0.1044 (19)	0.0575 (11)	−0.0279 (16)	0.0535 (12)	−0.0134 (13)
C16	0.0833 (12)	0.0720 (12)	0.0616 (9)	−0.0097 (10)	0.0492 (9)	−0.0132 (10)

Geometric parameters (Å, º) top

O1—C1	1.350 (2)	C8—H8	0.93
O1—H1	0.82	C9—C11	1.516 (2)
N1—C8	1.274 (2)	C9—C10	1.522 (3)
N1—C9	1.476 (2)	C9—H9	0.98
C1—C2	1.389 (2)	C10—H10A	0.96
C1—C6	1.414 (2)	C10—H10B	0.96
C2—C3	1.377 (3)	C10—H10C	0.96
C2—H2	0.93	C11—C16	1.382 (2)
C3—C4	1.394 (3)	C11—C12	1.389 (3)
C3—H3	0.93	C12—C13	1.383 (3)
C4—C5	1.383 (2)	C12—H12	0.93
C4—C7	1.514 (3)	C13—C14	1.362 (4)
C5—C6	1.397 (2)	C13—H13	0.93
C5—H5	0.93	C14—C15	1.367 (4)
C6—C8	1.457 (2)	C14—H14	0.93
C7—H7A	0.96	C15—C16	1.390 (4)
C7—H7B	0.96	C15—H15	0.93
C7—H7C	0.96	C16—H16	0.93

C1—O1—H1	109.4	N1—C9—C10	108.95 (14)
C8—N1—C9	118.78 (15)	C11—C9—C10	113.93 (15)
O1—C1—C2	119.47 (15)	N1—C9—H9	108.6
O1—C1—C6	121.80 (15)	C11—C9—H9	108.6
C2—C1—C6	118.71 (15)	C10—C9—H9	108.6
C3—C2—C1	120.53 (17)	C9—C10—H10A	109.5
C3—C2—H2	119.7	C9—C10—H10B	109.5
C1—C2—H2	119.7	H10A—C10—H10B	109.5
C2—C3—C4	122.18 (18)	C9—C10—H10C	109.5
C2—C3—H3	118.9	H10A—C10—H10C	109.5
C4—C3—H3	118.9	H10B—C10—H10C	109.5
C5—C4—C3	117.16 (17)	C16—C11—C12	117.99 (18)
C5—C4—C7	121.14 (18)	C16—C11—C9	120.77 (17)
C3—C4—C7	121.69 (18)	C12—C11—C9	121.20 (15)
C4—C5—C6	122.38 (16)	C13—C12—C11	121.01 (18)
C4—C5—H5	118.8	C13—C12—H12	119.5
C6—C5—H5	118.8	C11—C12—H12	119.5
C5—C6—C1	119.04 (15)	C14—C13—C12	120.5 (2)
C5—C6—C8	119.88 (15)	C14—C13—H13	119.8
C1—C6—C8	121.07 (15)	C12—C13—H13	119.8
C4—C7—H7A	109.5	C13—C14—C15	119.3 (2)
C4—C7—H7B	109.5	C13—C14—H14	120.3
H7A—C7—H7B	109.5	C15—C14—H14	120.3
C4—C7—H7C	109.5	C14—C15—C16	121.0 (2)
H7A—C7—H7C	109.5	C14—C15—H15	119.5
H7B—C7—H7C	109.5	C16—C15—H15	119.5
N1—C8—C6	122.04 (15)	C11—C16—C15	120.2 (2)
N1—C8—H8	119.0	C11—C16—H16	119.9
C6—C8—H8	119.0	C15—C16—H16	119.9
N1—C9—C11	108.04 (14)

O1—C1—C2—C3	−178.86 (18)	C1—C6—C8—N1	0.4 (2)
C6—C1—C2—C3	−0.5 (3)	C8—N1—C9—C11	123.36 (15)
C1—C2—C3—C4	0.3 (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—C7	179.20 (18)	C10—C9—C11—C16	128.59 (19)
C3—C4—C5—C6	0.5 (2)	N1—C9—C11—C12	67.34 (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—C8	178.08 (14)	C9—C11—C12—C13	−177.84 (18)
O1—C1—C6—C5	179.05 (16)	C11—C12—C13—C14	0.7 (3)
C2—C1—C6—C5	0.8 (2)	C12—C13—C14—C15	−0.8 (3)
O1—C1—C6—C8	0.2 (2)	C13—C14—C15—C16	0.5 (4)
C2—C1—C6—C8	−178.06 (16)	C12—C11—C16—C15	−0.1 (3)
C9—N1—C8—C6	179.41 (13)	C9—C11—C16—C15	177.52 (19)
C5—C6—C8—N1	−178.41 (14)	C14—C15—C16—C11	0.0 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N1	0.82	1.89	2.613 (2)	147

Experimental details

Crystal data
Chemical formula	C₁₆H₁₇NO
M_r	239.31
Crystal system, space group	Monoclinic, C2
Temperature (K)	296
a, b, c (Å)	20.342 (8), 5.911 (2), 14.551 (5)
β (°)	128.585 (4)
V (Å³)	1367.7 (9)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.07
Crystal size (mm)	0.35 × 0.34 × 0.26

Data collection
Diffractometer	Bruker APEXII area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1997)
T_min, T_max	0.971, 0.986
No. of measured, independent and observed [I > 2σ(I)] reflections	5952, 1726, 1609
R_int	0.034
(sin θ/λ)_max (Å⁻¹)	0.652

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.033, 0.100, 1.08
No. of reflections	1726
No. of parameters	166
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.16, −0.12

Computer programs: APEX2 (Bruker, 2004), SAINT (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N1	0.82	1.89	2.613 (2)	147

Acknowledgements

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

References

Bruker (2004). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Cohen, M. D., Schmidt, G. M. J. & Flavian, S. (1964). J. Chem. Soc. pp. 2041–2043. CrossRef Web of Science Google Scholar
Sheldrick, G. M. (1997). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar