3-[(E)-(4-Ethyl-phen-yl)imino-meth-yl]benzene-1,2-diol.

The title compound, C(15)H(15)NO(2), adopts the enol-imine tautomeric form. The dihedral angle between the two benzene rings is 48.1 (1)°. Intra-molecular O-H⋯N and O-H⋯O hydrogen bonds generate S(6) and S(5) ring motifs, respectively. In the crystal, mol-ecules are linked into centrosymmetric R(2) (2)(10) dimers via pairs of O-H⋯O hydrogen bonds and the dimers may interact through very weak by π-π inter-actions [centroid-centroid distance = 4.150 (1) Å]. The ethyl group is disordered over two orientations, with occupancies of 0.587 (11) and 0.413 (11).

Related literature

For the photochromic and thermochromic properties of Schiff base compounds, see: Elmali et al. (1999 ▶); Guha et al. (2000 ▶); Kletski et al. (1997 ▶); Kownacki et al. (1994 ▶); Zgierski et al. (2000 ▶). For Schiff base tautomerism, see: Alarcon et al. (1995 ▶); Dudek et al., (1966 ▶); Salman et al. (1991 ▶, 1993 ▶). For a related structure, see: Özek et al. (2009 ▶). For graph-set motifs, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C15H15NO2

M = 241.28

Triclinic,

a = 6.1893 (4) Å

b = 8.7704 (6) Å

c = 12.7605 (9) Å

α = 87.326 (6)°

β = 86.397 (6)°

γ = 69.394 (5)°

V = 646.85 (8) Å3

Z = 2

Mo Kα radiation

μ = 0.08 mm−1

T = 296 K

0.54 × 0.41 × 0.31 mm

Data collection

Stoe IPDS II diffractometer

Absorption correction: integration (X-RED32; Stoe & Cie, 2002 ▶) T min = 0.966, T max = 0.979

8683 measured reflections

2668 independent reflections

1896 reflections with I > 2σ(I)

R int = 0.042

Refinement

R[F 2 > 2σ(F 2)] = 0.051

wR(F 2) = 0.148

S = 1.03

2668 reflections

191 parameters

28 restraints

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.24 e Å−3

Δρmin = −0.13 e Å−3

Data collection: X-AREA (Stoe & Cie, 2002 ▶); cell refinement: X-AREA; 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 ▶).

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809029924/ci2862sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809029924/ci2862Isup2.hkl

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

C15H15NO2	Z = 2
Mr = 241.28	F(000) = 256
Triclinic, P1	Dx = 1.239 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.1893 (4) Å	Cell parameters from 8683 reflections
b = 8.7704 (6) Å	θ = 1.6–28.0°
c = 12.7605 (9) Å	µ = 0.08 mm−1
α = 87.326 (6)°	T = 296 K
β = 86.397 (6)°	Prism, red
γ = 69.394 (5)°	0.54 × 0.41 × 0.31 mm
V = 646.85 (8) Å3

Stoe IPDS II diffractometer	2668 independent reflections
Radiation source: fine-focus sealed tube	1896 reflections with I > 2σ(I)
graphite	Rint = 0.042
Detector resolution: 6.67 pixels mm-1	θmax = 26.5°, θmin = 1.6°
rotation method scans	h = −7→7
Absorption correction: integration (X-RED32; Stoe & Cie, 2002)	k = −11→11
Tmin = 0.966, Tmax = 0.979	l = −15→15
8683 measured reflections

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)] = 0.051	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.148	w = 1/[σ2(Fo2) + (0.0674P)2 + 0.1042P] where P = (Fo2 + 2Fc2)/3
S = 1.03	(Δ/σ)max = 0.001
2668 reflections	Δρmax = 0.24 e Å−3
191 parameters	Δρmin = −0.13 e Å−3
28 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.030 (7)

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.

	x	y	z	Uiso*/Ueq	Occ. (<1)
C1	0.5280 (3)	0.5619 (2)	0.34375 (15)	0.0590 (5)
C2	0.3189 (3)	0.5824 (2)	0.40019 (14)	0.0557 (4)
C3	0.2107 (3)	0.7228 (2)	0.45769 (15)	0.0583 (5)
C4	0.3058 (3)	0.8430 (2)	0.45564 (17)	0.0664 (5)
H4	0.2322	0.9372	0.4932	0.080*
C5	0.5101 (4)	0.8250 (2)	0.39809 (18)	0.0717 (6)
H5	0.5719	0.9076	0.3964	0.086*
C6	0.6212 (4)	0.6859 (2)	0.34379 (17)	0.0700 (5)
H6	0.7600	0.6736	0.3065	0.084*
C7	0.6472 (3)	0.4135 (2)	0.28805 (15)	0.0636 (5)
H7	0.7913	0.3996	0.2554	0.076*
C8	0.6932 (3)	0.1541 (2)	0.23042 (15)	0.0629 (5)
C9	0.9261 (4)	0.0745 (3)	0.24457 (18)	0.0752 (6)
H9	1.0026	0.1169	0.2892	0.090*
C10	1.0450 (4)	−0.0671 (3)	0.1929 (2)	0.0914 (8)
H10	1.2010	−0.1202	0.2041	0.110*
C11	0.9377 (5)	−0.1323 (3)	0.1246 (2)	0.0994 (8)
C12	0.7038 (5)	−0.0553 (3)	0.1148 (2)	0.0949 (8)
H12	0.6263	−0.0994	0.0718	0.114*
C13	0.5816 (4)	0.0857 (3)	0.16706 (18)	0.0789 (6)
H13	0.4233	0.1347	0.1595	0.095*
C14A	1.0861 (17)	−0.2683 (8)	0.0432 (7)	0.120 (3)	0.587 (11)
H14A	0.9952	−0.2714	−0.0153	0.144*	0.587 (11)
H14B	1.2235	−0.2474	0.0164	0.144*	0.587 (11)
C15A	1.1473 (16)	−0.4208 (9)	0.1053 (5)	0.143 (3)	0.587 (11)
H15A	1.2155	−0.5112	0.0597	0.214*	0.587 (11)
H15B	1.0107	−0.4296	0.1409	0.214*	0.587 (11)
H15C	1.2558	−0.4216	0.1561	0.214*	0.587 (11)
C14B	1.0391 (18)	−0.3057 (11)	0.0870 (10)	0.116 (4)	0.413 (11)
H14C	1.0239	−0.3787	0.1441	0.139*	0.413 (11)
H14D	0.9493	−0.3172	0.0303	0.139*	0.413 (11)
C15B	1.273 (2)	−0.3543 (17)	0.0517 (11)	0.164 (5)	0.413 (11)
H15D	1.2997	−0.4273	−0.0053	0.246*	0.413 (11)
H15E	1.3686	−0.4085	0.1082	0.246*	0.413 (11)
H15F	1.3090	−0.2601	0.0282	0.246*	0.413 (11)
N1	0.5630 (3)	0.30067 (18)	0.28177 (13)	0.0637 (4)
O1	0.2152 (2)	0.46864 (15)	0.40254 (11)	0.0659 (4)
O2	0.0118 (2)	0.74271 (17)	0.51685 (13)	0.0749 (5)
H1	0.314 (5)	0.386 (3)	0.358 (2)	0.099 (8)*
H2	−0.027 (5)	0.655 (4)	0.515 (2)	0.111 (9)*

	U11	U22	U33	U12	U13	U23
C1	0.0606 (11)	0.0534 (10)	0.0622 (11)	−0.0192 (8)	−0.0047 (9)	0.0012 (8)
C2	0.0577 (10)	0.0463 (9)	0.0641 (11)	−0.0189 (8)	−0.0078 (8)	−0.0009 (7)
C3	0.0546 (10)	0.0491 (9)	0.0695 (12)	−0.0150 (8)	−0.0065 (8)	−0.0049 (8)
C4	0.0681 (12)	0.0502 (10)	0.0818 (13)	−0.0197 (9)	−0.0128 (10)	−0.0079 (9)
C5	0.0766 (13)	0.0580 (11)	0.0896 (15)	−0.0339 (10)	−0.0112 (11)	0.0003 (10)
C6	0.0674 (12)	0.0667 (12)	0.0807 (14)	−0.0301 (10)	−0.0005 (10)	0.0004 (10)
C7	0.0628 (11)	0.0606 (11)	0.0638 (12)	−0.0185 (9)	0.0036 (9)	−0.0008 (9)
C8	0.0712 (12)	0.0564 (10)	0.0585 (11)	−0.0195 (9)	0.0014 (9)	−0.0034 (8)
C9	0.0736 (13)	0.0669 (12)	0.0793 (14)	−0.0156 (10)	−0.0063 (10)	−0.0143 (10)
C10	0.0826 (16)	0.0733 (14)	0.1042 (19)	−0.0078 (12)	−0.0029 (13)	−0.0206 (13)
C11	0.112 (2)	0.0714 (14)	0.104 (2)	−0.0159 (14)	−0.0015 (15)	−0.0307 (13)
C12	0.117 (2)	0.0750 (15)	0.0955 (18)	−0.0321 (15)	−0.0172 (15)	−0.0207 (13)
C13	0.0826 (15)	0.0695 (13)	0.0861 (15)	−0.0265 (11)	−0.0127 (12)	−0.0062 (11)
C14A	0.144 (6)	0.085 (4)	0.129 (5)	−0.042 (4)	0.014 (4)	0.013 (3)
C15A	0.182 (7)	0.098 (5)	0.114 (4)	−0.007 (4)	0.007 (4)	−0.021 (3)
C14B	0.137 (6)	0.059 (5)	0.136 (7)	−0.016 (4)	0.034 (5)	−0.044 (5)
C15B	0.156 (8)	0.135 (7)	0.185 (9)	−0.036 (6)	0.038 (7)	−0.029 (6)
N1	0.0668 (10)	0.0559 (9)	0.0655 (10)	−0.0181 (7)	0.0016 (7)	−0.0054 (7)
O1	0.0642 (8)	0.0517 (7)	0.0840 (10)	−0.0234 (6)	0.0090 (7)	−0.0149 (6)
O2	0.0646 (9)	0.0587 (8)	0.1033 (12)	−0.0236 (7)	0.0119 (7)	−0.0265 (7)

C1—C2	1.399 (3)	C11—C12	1.376 (4)
C1—C6	1.399 (3)	C11—C14B	1.514 (7)
C1—C7	1.445 (3)	C11—C14A	1.603 (8)
C2—O1	1.361 (2)	C12—C13	1.379 (3)
C2—C3	1.395 (2)	C12—H12	0.93
C3—O2	1.364 (2)	C13—H13	0.93
C3—C4	1.375 (3)	C14A—C15A	1.464 (11)
C4—C5	1.385 (3)	C14A—H14A	0.97
C4—H4	0.93	C14A—H14B	0.97
C5—C6	1.367 (3)	C15A—H15A	0.96
C5—H5	0.93	C15A—H15B	0.96
C6—H6	0.93	C15A—H15C	0.96
C7—N1	1.278 (2)	C14B—C15B	1.405 (15)
C7—H7	0.93	C14B—H14C	0.97
C8—C13	1.378 (3)	C14B—H14D	0.97
C8—C9	1.382 (3)	C15B—H15D	0.96
C8—N1	1.419 (2)	C15B—H15E	0.96
C9—C10	1.375 (3)	C15B—H15F	0.96
C9—H9	0.93	O1—H1	0.95 (3)
C10—C11	1.383 (4)	O2—H2	0.88 (3)
C10—H10	0.93
C2—C1—C6	118.93 (17)	C10—C11—C14A	121.0 (4)
C2—C1—C7	120.31 (17)	C11—C12—C13	121.7 (2)
C6—C1—C7	120.76 (18)	C11—C12—H12	119.2
O1—C2—C3	117.70 (17)	C13—C12—H12	119.2
O1—C2—C1	122.45 (16)	C8—C13—C12	120.2 (2)
C3—C2—C1	119.85 (16)	C8—C13—H13	119.9
O2—C3—C4	119.15 (17)	C12—C13—H13	119.9
O2—C3—C2	121.02 (16)	C15A—C14A—C11	104.1 (6)
C4—C3—C2	119.83 (18)	C15A—C14A—H14A	110.9
C3—C4—C5	120.55 (18)	C11—C14A—H14A	110.9
C3—C4—H4	119.7	C15A—C14A—H14B	110.9
C5—C4—H4	119.7	C11—C14A—H14B	110.9
C6—C5—C4	120.14 (19)	H14A—C14A—H14B	109.0
C6—C5—H5	119.9	C14A—C15A—H15A	109.5
C4—C5—H5	119.9	C14A—C15A—H15B	109.5
C5—C6—C1	120.7 (2)	H15A—C15A—H15B	109.5
C5—C6—H6	119.7	C14A—C15A—H15C	109.5
C1—C6—H6	119.7	H15A—C15A—H15C	109.5
N1—C7—C1	122.76 (18)	H15B—C15A—H15C	109.5
N1—C7—H7	118.6	C15B—C14B—C11	114.5 (9)
C1—C7—H7	118.6	C15B—C14B—H14C	108.6
C13—C8—C9	118.79 (18)	C11—C14B—H14C	108.6
C13—C8—N1	118.77 (19)	C15B—C14B—H14D	108.6
C9—C8—N1	122.40 (18)	C11—C14B—H14D	108.6
C10—C9—C8	120.3 (2)	H14C—C14B—H14D	107.6
C10—C9—H9	119.9	C14B—C15B—H15D	109.5
C8—C9—H9	119.9	C14B—C15B—H15E	109.5
C9—C10—C11	121.5 (2)	H15D—C15B—H15E	109.5
C9—C10—H10	119.3	C14B—C15B—H15F	109.5
C11—C10—H10	119.3	H15D—C15B—H15F	109.5
C12—C11—C10	117.4 (2)	H15E—C15B—H15F	109.5
C12—C11—C14B	116.2 (5)	C7—N1—C8	120.19 (17)
C10—C11—C14B	123.6 (5)	C2—O1—H1	103.8 (15)
C12—C11—C14A	120.4 (4)	C3—O2—H2	111.0 (18)
C6—C1—C2—O1	178.84 (17)	C9—C10—C11—C12	−3.7 (4)
C7—C1—C2—O1	−2.3 (3)	C9—C10—C11—C14B	−164.1 (6)
C6—C1—C2—C3	−1.9 (3)	C9—C10—C11—C14A	164.1 (4)
C7—C1—C2—C3	177.02 (17)	C10—C11—C12—C13	2.8 (4)
O1—C2—C3—O2	2.1 (3)	C14B—C11—C12—C13	164.7 (6)
C1—C2—C3—O2	−177.26 (17)	C14A—C11—C12—C13	−165.0 (4)
O1—C2—C3—C4	−178.37 (17)	C9—C8—C13—C12	−3.3 (3)
C1—C2—C3—C4	2.3 (3)	N1—C8—C13—C12	179.0 (2)
O2—C3—C4—C5	178.65 (18)	C11—C12—C13—C8	0.6 (4)
C2—C3—C4—C5	−0.9 (3)	C12—C11—C14A—C15A	−109.9 (7)
C3—C4—C5—C6	−0.9 (3)	C10—C11—C14A—C15A	82.7 (8)
C4—C5—C6—C1	1.4 (3)	C14B—C11—C14A—C15A	−21.5 (12)
C2—C1—C6—C5	0.0 (3)	C12—C11—C14B—C15B	151.7 (11)
C7—C1—C6—C5	−178.83 (18)	C10—C11—C14B—C15B	−47.7 (16)
C2—C1—C7—N1	4.6 (3)	C14A—C11—C14B—C15B	45.5 (13)
C6—C1—C7—N1	−176.53 (19)	C1—C7—N1—C8	−176.85 (17)
C13—C8—C9—C10	2.5 (3)	C13—C8—N1—C7	−139.4 (2)
N1—C8—C9—C10	−179.9 (2)	C9—C8—N1—C7	43.0 (3)
C8—C9—C10—C11	1.1 (4)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N1	0.95 (3)	1.72 (3)	2.596 (2)	152 (2)
O2—H2···O1	0.88 (3)	2.29 (3)	2.7307 (19)	111 (2)
O2—H2···O1i	0.88 (3)	2.06 (3)	2.818 (2)	143 (2)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯N1	0.95 (3)	1.72 (3)	2.596 (2)	152 (2)
O2—H2⋯O1	0.88 (3)	2.29 (3)	2.7307 (19)	111 (2)
O2—H2⋯O1i	0.88 (3)	2.06 (3)	2.818 (2)	143 (2)

Symmetry code: (i) .