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

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ISSN: 2056-9890

2-[1-(3-Amino­phenyl­imino)­eth­yl]phenol

aDepartment of Chemistry, J. J. Strossmayer University, Osijek, Franje Kuhača 20, HR-31000 Osijek, Croatia, and bLaboratory of General and Inorganic Chemistry, Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, HR-10002 Zagreb, Croatia
*Correspondence e-mail: ablagus@kemija.unios.hr

(Received 14 April 2011; accepted 10 May 2011; online 14 May 2011)

The title compound, C14H14N2O, exists as the enol–imine tautomer. A strong intra­molecular hydrogen bond between O and N atoms forms a six-membered ring with an S(6) graph-set motif, which is approximately coplanar with the phenol ring, the inter­planar angle being 3.4 (3)°. In the crystal, inter­molecular C—H⋯O hydrogen bonds and N—H⋯π inter­actions link the mol­ecules into infinite chains along [100].

Related literature

For background to Schiff base compounds, see: Blagus & Kaitner (2007[Blagus, A. & Kaitner, B. (2007). J. Chem. Crystallogr. 37, 473-477.]); Blagus et al. (2010[Blagus, A., Cinčić, D., Friščić, T., Kaitner, B. & Stilinović, V. (2010). Maced. J. Chem. Chem. Eng. 29, 117-138.]). For the photochromic and thermochromic characteristics of Schiff bases, see: Hadjoudis & Mavridis (2004[Hadjoudis, E. & Mavridis, I. M. (2004). Chem. Soc. Rev. 33, 579-588.]). For graph-set notation of hydrogen bonds, see Bernstein et al. (1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]). For standard bond lengths, see: Allen et al. (1987[Allen, F. H., Kennard, O., Watson, D. G., Brammer, L. A. & Orpen, G. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1-19.]).

[Scheme 1]

Experimental

Crystal data
  • C14H14N2O

  • Mr = 226.27

  • Orthorhombic, P c a 21

  • a = 9.0625 (2) Å

  • b = 5.5777 (2) Å

  • c = 23.2349 (6) Å

  • V = 1174.48 (6) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.08 mm−1

  • T = 298 K

  • 0.6 × 0.5 × 0.4 mm

Data collection
  • Oxford Diffraction Xcalibur CCD diffractometer

  • 6829 measured reflections

  • 1317 independent reflections

  • 1145 reflections with I > 2σ(I)

  • Rint = 0.016

Refinement
  • R[F2 > 2σ(F2)] = 0.030

  • wR(F2) = 0.087

  • S = 1.10

  • 1317 reflections

  • 165 parameters

  • 1 restraint

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

  • Δρmax = 0.15 e Å−3

  • Δρmin = −0.11 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

Cg is the centroid of the C9–C14 ring.

D—H⋯A D—H H⋯A DA D—H⋯A
O1—H1⋯N1 1.04 (4) 1.59 (4) 2.540 (2) 150 (3)
C8—H8B⋯O1i 0.96 2.71 3.243 (3) 116
N2—H1N2⋯Cgi 0.90 (4) 2.71 (4) 3.457 (3) 142 (3)
Symmetry code: (i) [x+{\script{1\over 2}}, -y+1, z].

Data collection: CrysAlis CCD (Oxford Diffraction, 2003[Oxford Diffraction (2003). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Wrocław, Poland.]); cell refinement: CrysAlis RED (Oxford Diffraction, 2003[Oxford Diffraction (2003). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Wrocław, Poland.]); data reduction: CrysAlis RED; 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 (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.]), PARST97 (Nardelli, 1995[Nardelli, M. (1995). J. Appl. Cryst. 28, 659.]) and Mercury (Macrae et al., 2006[Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453-457.]).

Supporting information


Comment top

Schiff bases are some of the most widely used chelating ligands in the field of metal-organic coordination chemistry (Blagus et al., 2010). The Schiff bases derived from ortho hydroxy aldehydes or ketons and aromatic diamines often have photochromic and thermochromic characteristics (Hadjoudis & Mavridis 2004). In this work we report the preparation and the crystal and molecular structure of a novel ketimine Schiff base 2-[1-(3-aminophenylimino)ethyl]phenol (Scheme 1).

The presence of intramolecular O1–H···N1 hydrogen bond [2.540 (2) Å] shows unequivocally that the molecular conformation of compound (1) in the crystalline state is in the enol-imino form. As shown in Figure 2, the Schiff base molecules link mutually in an one-dimensional chain forming a graph-set motif C(5) in the notation of Bernstein et al., (1995) along the [100] direction through a C–H···O [3.243 (3) Å] intermolecular hydrogen bond. Another intermolecular connection between the same neighbouring molecules forms through the terminal primary N2-amino group N–H···π interaction [3.457 (3) Å; π refers to the C9—C14 aromatic system centroid). All bond lengths are within the standard values (Allen et al., 1987) and are comparable with the similar ketimine Schiff bases as cited above (Blagus & Kaitner, 2007).

Related literature top

For background to Schiff base compounds, see: Blagus & Kaitner (2007); Blagus et al. (2010). For the photochromic and thermochromic characteristics of Schiff bases, see: Hadjoudis & Mavridis (2004). For graph-set notation of hydrogen bonds, see Bernstein et al. (1995). For standard bond lengths, see: Allen et al. (1987).

Experimental top

The title compound was prepared by refluxing a methanolic solution of m-phenylendiamine (540 mg, 5 mmol) and 2-hydroxyacetophenone (1.25 ml, 10 mmol) for 4 h at the temperature of 80 °C. The water formed during the reaction was removed by a Dean-Stark trap. After cooling, the brown solid precipitate was filtered. Diffraction quality crystals were obtained by slow evaporation from ether solution.

Refinement top

All N- and O-bound H atoms were located in the difference Fourier map. The position and the isotropic thermal parameters of N-bound H atoms were refined, while the O-bound H atom was treated as riding atom. Aromatic H atoms were placed in calculated positions and treated as riding on their parent C atoms with C—H = 0.93 Å and Uiso(H) = 1.2 Ueq(C) for Csp2. In the absence of significant anomalous scattering effects Friedel pairs have been merged.

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2003); cell refinement: CrysAlis RED (Oxford Diffraction, 2003); data reduction: CrysAlis RED (Oxford Diffraction, 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999), PARST97 (Nardelli, 1995) and Mercury (Macrae et al., 2006).

Figures top
[Figure 1] Fig. 1. ORTEPIII molecular structure of (I) showing our atom-labelling scheme. Thermal ellipsoids are drawn at the 50% probability level. The intramolecular hydrogen bonds O—H···N is shown as thin line.
[Figure 2] Fig. 2. Chains formed in the crystals of the title compound along the [100] direction. All intermolecular interactions are represented by dotted lines. The red spheres represent the centroids of C9—C14 aromatic rings.
2-[1-(3-Aminophenylimino)ethyl]phenol top
Crystal data top
C14H14N2OF(000) = 480
Mr = 226.27Dx = 1.280 Mg m3
Orthorhombic, Pca21Mo Kα radiation, λ = 0.71069 Å
Hall symbol: P 2c -2acCell parameters from 1145 reflections
a = 9.0625 (2) Åθ = 4–27°
b = 5.5777 (2) ŵ = 0.08 mm1
c = 23.2349 (6) ÅT = 298 K
V = 1174.48 (6) Å3Prism, yellow
Z = 40.6 × 0.5 × 0.4 mm
Data collection top
Oxford Diffraction Xcalibur CCD
diffractometer
1145 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.016
Graphite monochromatorθmax = 27.0°, θmin = 4.1°
ω scansh = 1111
6829 measured reflectionsk = 75
1317 independent reflectionsl = 2928
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.030H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.087 w = 1/[σ2(Fo2) + (0.0469P)2 + 0.130P]
where P = (Fo2 + 2Fc2)/3
S = 1.10(Δ/σ)max < 0.001
1317 reflectionsΔρmax = 0.15 e Å3
165 parametersΔρmin = 0.11 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: 0.027 (5)
Crystal data top
C14H14N2OV = 1174.48 (6) Å3
Mr = 226.27Z = 4
Orthorhombic, Pca21Mo Kα radiation
a = 9.0625 (2) ŵ = 0.08 mm1
b = 5.5777 (2) ÅT = 298 K
c = 23.2349 (6) Å0.6 × 0.5 × 0.4 mm
Data collection top
Oxford Diffraction Xcalibur CCD
diffractometer
1145 reflections with I > 2σ(I)
6829 measured reflectionsRint = 0.016
1317 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0301 restraint
wR(F2) = 0.087H atoms treated by a mixture of independent and constrained refinement
S = 1.10Δρmax = 0.15 e Å3
1317 reflectionsΔρmin = 0.11 e Å3
165 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
xyzUiso*/Ueq
O10.41349 (19)0.5690 (3)0.29685 (8)0.0596 (5)
H10.468 (4)0.505 (6)0.2607 (17)0.089*
N10.5638 (2)0.3031 (3)0.23025 (7)0.0440 (4)
N20.8305 (3)0.5261 (4)0.05762 (11)0.0656 (6)
C10.5491 (2)0.2236 (4)0.33034 (9)0.0402 (4)
C20.4534 (2)0.4203 (4)0.33965 (9)0.0448 (5)
C30.3969 (3)0.4621 (5)0.39453 (11)0.0588 (6)
H30.33600.59370.40080.071*
C40.4300 (3)0.3117 (5)0.43923 (11)0.0638 (7)
H40.38910.33930.47530.077*
C50.5235 (3)0.1192 (5)0.43119 (10)0.0619 (6)
H50.54730.01950.46190.074*
C60.5814 (3)0.0761 (4)0.37718 (10)0.0515 (5)
H60.64350.05480.37190.062*
C70.60706 (19)0.1706 (4)0.27231 (9)0.0395 (4)
C80.7137 (2)0.0334 (4)0.26549 (11)0.0510 (5)
H8A0.66400.18210.27300.076*
H8B0.79370.01410.29220.076*
H8C0.75160.03440.22690.076*
C90.6061 (2)0.2535 (4)0.17224 (9)0.0426 (4)
C100.6998 (2)0.4088 (4)0.14395 (9)0.0452 (5)
H100.73750.54140.16330.054*
C110.7386 (2)0.3685 (4)0.08652 (9)0.0458 (4)
C120.6800 (2)0.1690 (4)0.05828 (10)0.0509 (5)
H120.70450.13960.02010.061*
C130.5863 (3)0.0158 (5)0.08685 (10)0.0548 (5)
H130.54860.11720.06770.066*
C140.5470 (3)0.0563 (4)0.14380 (11)0.0514 (5)
H140.48230.04680.16260.062*
H1N20.874 (4)0.635 (7)0.0803 (14)0.077*
H2N20.864 (4)0.481 (6)0.0229 (18)0.077*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0719 (11)0.0573 (10)0.0494 (9)0.0216 (8)0.0010 (8)0.0010 (8)
N10.0465 (9)0.0483 (9)0.0371 (8)0.0038 (8)0.0003 (7)0.0028 (7)
N20.0719 (14)0.0692 (14)0.0558 (12)0.0132 (12)0.0135 (11)0.0016 (11)
C10.0351 (8)0.0468 (10)0.0388 (9)0.0034 (8)0.0023 (8)0.0033 (9)
C20.0452 (10)0.0489 (11)0.0403 (10)0.0001 (9)0.0012 (9)0.0043 (9)
C30.0604 (13)0.0658 (15)0.0501 (13)0.0077 (12)0.0057 (11)0.0125 (11)
C40.0667 (15)0.0847 (19)0.0399 (11)0.0016 (14)0.0037 (11)0.0071 (12)
C50.0690 (15)0.0746 (16)0.0422 (12)0.0035 (13)0.0036 (11)0.0072 (12)
C60.0516 (12)0.0554 (12)0.0476 (12)0.0028 (10)0.0052 (10)0.0019 (10)
C70.0344 (8)0.0432 (10)0.0408 (10)0.0028 (8)0.0019 (8)0.0030 (8)
C80.0471 (11)0.0523 (11)0.0535 (12)0.0087 (9)0.0006 (10)0.0015 (10)
C90.0435 (9)0.0474 (10)0.0369 (9)0.0052 (9)0.0014 (8)0.0037 (8)
C100.0480 (10)0.0438 (10)0.0439 (10)0.0002 (9)0.0042 (9)0.0038 (9)
C110.0429 (9)0.0512 (10)0.0435 (10)0.0038 (9)0.0001 (8)0.0014 (9)
C120.0527 (12)0.0614 (13)0.0385 (10)0.0034 (11)0.0016 (9)0.0074 (10)
C130.0600 (13)0.0576 (12)0.0467 (12)0.0058 (11)0.0009 (10)0.0142 (11)
C140.0517 (12)0.0537 (12)0.0489 (11)0.0068 (10)0.0020 (10)0.0039 (10)
Geometric parameters (Å, º) top
O1—C21.345 (3)C5—H50.9300
O1—H11.04 (4)C6—H60.9300
N1—C71.286 (3)C7—C81.501 (3)
N1—C91.428 (3)C8—H8A0.9600
N2—C111.385 (3)C8—H8B0.9600
N2—H1N20.89 (4)C8—H8C0.9600
N2—H2N20.90 (4)C9—C101.380 (3)
C1—C61.395 (3)C9—C141.391 (3)
C1—C21.415 (3)C10—C111.398 (3)
C1—C71.477 (3)C10—H100.9300
C2—C31.394 (3)C11—C121.397 (3)
C3—C41.368 (4)C12—C131.376 (3)
C3—H30.9300C12—H120.9300
C4—C51.380 (4)C13—C141.389 (3)
C4—H40.9300C13—H130.9300
C5—C61.381 (4)C14—H140.9300
C2—O1—H1105 (2)C1—C7—C8118.49 (18)
C7—N1—C9121.61 (17)C7—C8—H8A109.5
C11—N2—H1N2114 (2)C7—C8—H8B109.5
C11—N2—H2N2117 (2)H8A—C8—H8B109.5
H1N2—N2—H2N2125 (3)C7—C8—H8C109.5
C6—C1—C2117.80 (19)H8A—C8—H8C109.5
C6—C1—C7121.29 (18)H8B—C8—H8C109.5
C2—C1—C7120.85 (18)C10—C9—C14120.5 (2)
O1—C2—C3118.3 (2)C10—C9—N1119.53 (18)
O1—C2—C1122.01 (19)C14—C9—N1119.9 (2)
C3—C2—C1119.7 (2)C9—C10—C11120.56 (19)
C4—C3—C2120.7 (2)C9—C10—H10119.7
C4—C3—H3119.6C11—C10—H10119.7
C2—C3—H3119.6N2—C11—C12120.4 (2)
C3—C4—C5120.6 (2)N2—C11—C10120.8 (2)
C3—C4—H4119.7C12—C11—C10118.8 (2)
C5—C4—H4119.7C13—C12—C11120.2 (2)
C4—C5—C6119.5 (2)C13—C12—H12119.9
C4—C5—H5120.3C11—C12—H12119.9
C6—C5—H5120.3C12—C13—C14121.1 (2)
C5—C6—C1121.7 (2)C12—C13—H13119.4
C5—C6—H6119.1C14—C13—H13119.4
C1—C6—H6119.1C13—C14—C9118.9 (2)
N1—C7—C1118.05 (17)C13—C14—H14120.6
N1—C7—C8123.46 (19)C9—C14—H14120.6
C6—C1—C2—O1178.5 (2)C6—C1—C7—C85.7 (3)
C7—C1—C2—O11.2 (3)C2—C1—C7—C8177.18 (17)
C6—C1—C2—C30.9 (3)C7—N1—C9—C10111.9 (2)
C7—C1—C2—C3178.1 (2)C7—N1—C9—C1471.2 (3)
O1—C2—C3—C4177.8 (2)C14—C9—C10—C110.9 (3)
C1—C2—C3—C41.6 (4)N1—C9—C10—C11177.75 (19)
C2—C3—C4—C51.9 (4)C9—C10—C11—N2178.9 (2)
C3—C4—C5—C61.4 (4)C9—C10—C11—C120.3 (3)
C4—C5—C6—C10.7 (4)N2—C11—C12—C13178.6 (2)
C2—C1—C6—C50.4 (3)C10—C11—C12—C130.1 (3)
C7—C1—C6—C5177.7 (2)C11—C12—C13—C140.5 (4)
C9—N1—C7—C1175.40 (18)C12—C13—C14—C91.0 (4)
C9—N1—C7—C85.0 (3)C10—C9—C14—C131.3 (3)
C6—C1—C7—N1174.69 (19)N1—C9—C14—C13178.1 (2)
C2—C1—C7—N12.5 (3)
Hydrogen-bond geometry (Å, º) top
Cg is the centroid of the C9–C14 ring.
D—H···AD—HH···AD···AD—H···A
O1—H1···N11.04 (4)1.59 (4)2.540 (2)150 (3)
C8—H8B···O1i0.962.713.243 (3)116
N2—H1N2···Cgi0.90 (4)2.71 (4)3.457 (3)142 (3)
Symmetry code: (i) x+1/2, y+1, z.

Experimental details

Crystal data
Chemical formulaC14H14N2O
Mr226.27
Crystal system, space groupOrthorhombic, Pca21
Temperature (K)298
a, b, c (Å)9.0625 (2), 5.5777 (2), 23.2349 (6)
V3)1174.48 (6)
Z4
Radiation typeMo Kα
µ (mm1)0.08
Crystal size (mm)0.6 × 0.5 × 0.4
Data collection
DiffractometerOxford Diffraction Xcalibur CCD
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
6829, 1317, 1145
Rint0.016
(sin θ/λ)max1)0.639
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.030, 0.087, 1.10
No. of reflections1317
No. of parameters165
No. of restraints1
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.15, 0.11

Computer programs: CrysAlis CCD (Oxford Diffraction, 2003), CrysAlis RED (Oxford Diffraction, 2003), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997), WinGX (Farrugia, 1999), PARST97 (Nardelli, 1995) and Mercury (Macrae et al., 2006).

Hydrogen-bond geometry (Å, º) top
Cg is the centroid of the C9–C14 ring.
D—H···AD—HH···AD···AD—H···A
O1—H1···N11.04 (4)1.59 (4)2.540 (2)150 (3)
C8—H8B···O1i0.9602.7123.243 (3)116
N2—H1N2···Cgi0.90 (4)2.71 (4)3.457 (3)142 (3)
Symmetry code: (i) x+1/2, y+1, z.
 

Acknowledgements

Financial support by the Ministry of Science, Education and Sport of the Republic of Croatia is gratefully acknowledged (grant No. 119–1193079–3069).

References

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