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Mol­ecules of the title compound, C11H10N2O, are effectively planar. In the crystal structure, they are stabilized primarily by electrostatic inter­actions, as the dipole moment of the mol­ecule is 4.56 D. In addition, the mol­ecules are linked by weak C—H...N and C—H...O hydrogen bonds. An analysis of bonding conditions in the mol­ecule was carried out using natural bond orbital (NBO) formalism.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270106025571/dn3022sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270106025571/dn3022Isup2.hkl
Contains datablock I

CCDC reference: 621279

Comment top

Push–pull olefines are interesting compounds, not only from a theoretical point of view but also for their interesting spectroscopic properties and numerous applications in organic synthesis (Hermecz et al., 1992; Patai, 1994, Milata & Ilavský, 1995). The structures of some of these compounds have been reported previously, e.g. by Lokaj et al. (1994) or Kettmann et al. (2000, 2004).

Aminomethylene derivatives or β,β-disubstituted aminoethylenes allow the study of the conformation of the –NH—CHgrouping or of the geometrical isomerism of the CHC double bond, due to the two non-equivalent substituents at the β-positions. If a β-substituent has at least one carbonyl group CO in the acetyl (COOMe) or m-ethoxycarbonyl (COOEt) substituent, the –NH—CHmoiety can also be stabilized by an intramolecular hydrogen bond between the NH H atoms and the O atom.

Some compounds of this type having at least one COOMe or COOEt group can be thermally or catalytically cyclized to form the corresponding 3-substituted-4-quinolones (Milata et al., 2000, Hooper, 2001, Coleman, 2004, Blondeau, 1999). If the starting compound does not bear either a COOMe or a COOEt group, cyclization can also take place through a cyano or other group. In this way, 4-aminoquinolines, interesting as antimalarial drugs and as an apoptosis agent, can also be prepared (Jantová et al., 2005). The precursors for 4-aminoquinolines are anilinoacrylonitriles, e.g. anilinomethylene derivatives of 3-oxobutanenitrile (cyanoacetone), propanedinitrile (malononitrile) or cyanoacetates. Against this background, we present here the crystal structure of the title compound, (I).

The structure of (I) is illustrated in Fig. 1. The molecules in the crystal structure are stabilized primarily by electrostatic interactions, as the calculated dipole moment of the molecule is 4.56 D. In addition, the molecules are linked by weak C—H···N and C—H···O hydrogen bonds (Table 1). The most prominent role in the hydrogen-bonding system is played by atom O1, which is an acceptor of one intra- and two intermoleclular hydrogen bonds. The intramolecular N2—H2···O1 hydrogen bond is, however, too long [2.6998 (18) Å] for an H-atom transfer along it. The molecule is almost planar, the largest deviation from planarity being 0.051 (2) Å for which atom?

Natural bond orbital (NBO) analysis (Foster & Weinhold, 1980) of the molecular electronic structure reveals that the bond orders are, for the majority of the bonds, very close to the expected values (Fig. 2). The exceptions are the N2—C5 and C5—C2 bonds, the bond orders of which are between a single and a double bond, indicating delocalization of electrons. A detailed analysis of the NBO results shows that the electron donor, a lone pair on atom N2, is connected through the C2C5 double bond to electron-withdrawing groups, i.e. –CO and –CN groups. As a result, the electrons from the lone pair are delocalized to a formally single N2—C5 bond, lending it a partially double-bond character. Furthermore, π-electrons from the C2C5 double bond are pulled toward the C2—C3 and C2—C1 bonds, which gain a slightly multiple character (Fig. 3). The expected geometrical consequences of this electron redistribution area shortening of the C5—N2 and C2—C3 bonds, an elongation of the C2—C5 bond and a planar structure of the moiety attached to the phenyl ring. The planarity of this moiety is further maintained by the intramolecular hydrogen bond N2—H2···O1. The geometry of an isolated molecule optimized at the B3LYP/6–31G** level is such that the C6'—C1'—N2—C5 torsion angle is ~13°, compared with ~1.8° found in the crystal. This difference cannot be unambiguously explained by the computational method itself, as the difference in energies between the optimal molecular structure and the planar one (0.1 kJ mol-1) is below the precision of the method.

The orientation of the anisotropic ellipsoid of C1 is unreasonable in its direction, indicating non-statistical uncertainty in the C1—N1 distance. The length of this bond [1.146 (3) Å] is in accordance with the value of 1.148 (2) Å found for a chemically similar push–pull family of compounds surveyed by Ziao et al. (2001). It is, however, remarkably longer than two independent –CN distances (1.135–1.136 Å) reported for anilinimethylenmalononitrile (Nasakin et al., 1992), which differs from (I) by just two –CN groups attached to the C2 analogue.

Experimental top

The title compound can be readily prepared by nucleophilic vinylic substitution of 2-m-ethoxy-3-oxobutanenitrile (2-m-ethoxymethylene cyanoacetone) with aniline, as described by Černuchová et al. (2005). Crystals were obtained by recrystallization from which solvent?

Refinement top

H atoms were refined isotropically for the X-ray data and constrained to ideal geometry using an appropriate riding model. The C—H distance was kept fixed at 1.00 Å for tertiary H atoms and at 0.99 Å for secondary H atoms. For the hydroxyl groups, the O—H distance (0.84 Å) and C—O—H angle (109.5°) were kept fixed, while the torsion angle was allowed to refine, with the starting position based on the circular Fourier synthesis.

Molecular calculations were carried out at the B3LYP/6–31G** level of theory using GAUSSIAN98 (Frisch et al., 1998). NBO (natural bond order) calclulations were carried out using the NBO program (Glendening et al. 1993) included in the GAUSSIAN package.

Theoretical investigation of hydrogen bonds in the crystal was performed using the Vienna ab initio simulation package VASP for the studied compound (Kresse & Furthmüller, 1996; Kresse & Hafner, 1993). The calculations were based on density functional theory (DFT) with periodic boundary conditions (Jones & Gunnarsson, 1989) using generalized gradient approximation (GGA) in the exchange-correlation function (Perdew et al. 1992). The interactions between ions and electrons were described using the projector-augemented wave method (PAW) (Kresse & Joubert 1999), with a plane wave cut-off of 400 eV. The optimization of the structure was carried out by the method of conjugated gradients in 4k (Should this be 4000?) points (Teter et al. 1989; Bylander et al. 1990).

Computing details top

Data collection: SMART (Siemens, 1995); cell refinement: SAINT (Siemens, 1995); data reduction: SAINT and SADABS (Sheldrick, 2002); program(s) used to solve structure: SHELXTL (Bruker, 2001); program(s) used to refine structure: SHELXTL; molecular graphics: DIAMOND (Brandenburg, 2000); software used to prepare material for publication: PLATON (Spek, 2003).

Figures top
[Figure 1] Fig. 1. A view of the title compound, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
[Figure 2] Fig. 2. Wiberg bond orders (bold) and natural charges (italics), in |e| calculated for an isolated molecule using NBO formalism. The arrows indicate predicted electron-density transfers.
[Figure 3] Fig. 3. Possible resonance structures of the title compound. Due to the large electron-withdrawing effect of the –CN group, the structure in the middle is more favoured than the structure on the right.
2-Anilinomethylene-3-oxobutanenitrile top
Crystal data top
C11H10N2OF(000) = 392
Mr = 186.21Dx = 1.337 Mg m3
MonoclinicP21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 3832 reflections
a = 13.3968 (5) Åθ = 2.5–28.3°
b = 5.0656 (2) ŵ = 0.09 mm1
c = 14.3402 (5) ÅT = 173 K
β = 108.027 (1)°Plate, colourless
V = 925.39 (6) Å30.22 × 0.14 × 0.02 mm
Z = 4
Data collection top
Siemens SMART CCD area-detector
diffractometer
2298 independent reflections
Radiation source: fine-focus sealed tube1514 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.058
ω scansθmax = 28.3°, θmin = 2.5°
Absorption correction: multi-scan
(SADABS; Sheldrick, 2002)
h = 1717
Tmin = 0.981, Tmax = 0.998k = 66
11777 measured reflectionsl = 1919
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.049Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.124H-atom parameters constrained
S = 1.01 w = 1/[σ2(Fo2) + (0.0469P)2 + 0.4176P]
where P = (Fo2 + 2Fc2)/3
2298 reflections(Δ/σ)max < 0.001
138 parametersΔρmax = 0.23 e Å3
0 restraintsΔρmin = 0.20 e Å3
Crystal data top
C11H10N2OV = 925.39 (6) Å3
Mr = 186.21Z = 4
MonoclinicP21/nMo Kα radiation
a = 13.3968 (5) ŵ = 0.09 mm1
b = 5.0656 (2) ÅT = 173 K
c = 14.3402 (5) Å0.22 × 0.14 × 0.02 mm
β = 108.027 (1)°
Data collection top
Siemens SMART CCD area-detector
diffractometer
2298 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2002)
1514 reflections with I > 2σ(I)
Tmin = 0.981, Tmax = 0.998Rint = 0.058
11777 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0490 restraints
wR(F2) = 0.124H-atom parameters constrained
S = 1.01Δρmax = 0.23 e Å3
2298 reflectionsΔρmin = 0.20 e Å3
138 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
O10.67933 (10)0.2241 (2)0.24657 (9)0.0322 (3)
N10.46017 (13)0.7039 (3)0.38484 (12)0.0370 (4)
N20.70389 (11)0.0019 (3)0.42341 (10)0.0246 (3)
H20.72250.00520.36980.039 (6)*
C10.51670 (14)0.5495 (4)0.37132 (12)0.0266 (4)
C20.58884 (13)0.3636 (3)0.35315 (12)0.0236 (4)
C30.61516 (13)0.3801 (3)0.26250 (12)0.0244 (4)
C40.56435 (15)0.5905 (4)0.18958 (13)0.0300 (4)
H4A0.59630.76180.21310.057 (7)*
H4B0.48910.59710.18170.056 (7)*
H4C0.57450.54990.12630.072 (8)*
C50.63359 (13)0.1822 (3)0.42662 (12)0.0257 (4)
H50.61200.18770.48380.026 (5)*
C1'0.75197 (13)0.1813 (3)0.49913 (12)0.0237 (4)
C2'0.82515 (13)0.3544 (3)0.48329 (12)0.0266 (4)
H2'0.84230.34670.42380.032 (5)*
C3'0.87319 (14)0.5385 (4)0.55440 (13)0.0295 (4)
H3'0.92330.65740.54340.034 (5)*
C4'0.84890 (14)0.5509 (4)0.64126 (13)0.0300 (4)
H4'0.88230.67690.69000.038 (6)*
C5'0.77585 (15)0.3789 (4)0.65649 (13)0.0321 (4)
H5'0.75890.38760.71600.040 (6)*
C6'0.72658 (14)0.1931 (4)0.58621 (13)0.0294 (4)
H6'0.67620.07540.59730.035 (5)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0385 (7)0.0299 (7)0.0311 (7)0.0080 (6)0.0150 (6)0.0017 (6)
N10.0367 (9)0.0417 (10)0.0366 (9)0.0088 (8)0.0169 (8)0.0052 (8)
N20.0281 (7)0.0247 (8)0.0211 (7)0.0004 (6)0.0076 (6)0.0007 (6)
C10.0263 (9)0.0285 (9)0.0246 (9)0.0018 (8)0.0075 (7)0.0039 (7)
C20.0223 (8)0.0226 (8)0.0251 (9)0.0012 (7)0.0061 (7)0.0014 (7)
C30.0229 (8)0.0219 (8)0.0265 (9)0.0040 (7)0.0050 (7)0.0016 (7)
C40.0331 (10)0.0282 (10)0.0288 (10)0.0026 (8)0.0097 (8)0.0050 (8)
C50.0257 (9)0.0264 (9)0.0253 (9)0.0030 (7)0.0081 (7)0.0017 (7)
C1'0.0241 (9)0.0210 (8)0.0232 (8)0.0040 (7)0.0034 (7)0.0008 (7)
C2'0.0277 (9)0.0272 (9)0.0249 (9)0.0023 (7)0.0082 (8)0.0012 (7)
C3'0.0272 (9)0.0267 (9)0.0331 (10)0.0020 (8)0.0072 (8)0.0010 (8)
C4'0.0302 (9)0.0255 (9)0.0302 (10)0.0001 (8)0.0032 (8)0.0054 (8)
C5'0.0365 (10)0.0348 (10)0.0257 (9)0.0005 (8)0.0107 (8)0.0051 (8)
C6'0.0310 (10)0.0279 (9)0.0301 (10)0.0015 (8)0.0106 (8)0.0002 (8)
Geometric parameters (Å, º) top
O1—C31.240 (2)C5—H50.9500
N1—C11.146 (2)C1'—C2'1.385 (2)
N2—C51.323 (2)C1'—C6'1.393 (2)
N2—C1'1.422 (2)C2'—C3'1.385 (2)
N2—H20.8800C2'—H2'0.9500
C1—C21.430 (2)C3'—C4'1.383 (3)
C2—C51.387 (2)C3'—H3'0.9500
C2—C31.451 (2)C4'—C5'1.377 (3)
C3—C41.501 (2)C4'—H4'0.9500
C4—H4A0.9800C5'—C6'1.388 (2)
C4—H4B0.9800C5'—H5'0.9500
C4—H4C0.9800C6'—H6'0.9500
C5—N2—C1'125.67 (15)C2'—C1'—C6'120.09 (16)
C5—N2—H2117.2C2'—C1'—N2117.65 (15)
C1'—N2—H2117.2C6'—C1'—N2122.25 (15)
N1—C1—C2178.10 (19)C1'—C2'—C3'119.78 (16)
C5—C2—C1117.11 (15)C1'—C2'—H2'120.1
C5—C2—C3123.44 (15)C3'—C2'—H2'120.1
C1—C2—C3119.38 (15)C2'—C3'—C4'120.55 (17)
O1—C3—C2120.19 (15)C2'—C3'—H3'119.7
O1—C3—C4121.00 (15)C4'—C3'—H3'119.7
C2—C3—C4118.80 (15)C5'—C4'—C3'119.42 (17)
C3—C4—H4A109.5C5'—C4'—H4'120.3
C3—C4—H4B109.5C3'—C4'—H4'120.3
H4A—C4—H4B109.5C6'—C5'—C4'121.03 (17)
C3—C4—H4C109.5C6'—C5'—H5'119.5
H4A—C4—H4C109.5C4'—C5'—H5'119.5
H4B—C4—H4C109.5C5'—C6'—C1'119.13 (17)
N2—C5—C2125.18 (16)C5'—C6'—H6'120.4
N2—C5—H5117.4C1'—C6'—H6'120.4
C2—C5—H5117.4
C5—C2—C3—O11.3 (3)C6'—C1'—C2'—C3'0.2 (2)
C1—C2—C3—O1178.42 (16)N2—C1'—C2'—C3'179.24 (15)
C5—C2—C3—C4177.99 (16)C1'—C2'—C3'—C4'0.1 (3)
C1—C2—C3—C40.9 (2)C2'—C3'—C4'—C5'0.3 (3)
C1'—N2—C5—C2178.55 (16)C3'—C4'—C5'—C6'0.2 (3)
C1—C2—C5—N2177.92 (16)C4'—C5'—C6'—C1'0.1 (3)
C3—C2—C5—N20.8 (3)C2'—C1'—C6'—C5'0.3 (3)
C5—N2—C1'—C2'179.24 (16)N2—C1'—C6'—C5'179.31 (16)
C5—N2—C1'—C6'1.7 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2···O10.882.042.6998 (18)131
C2—H2···O1i0.952.403.302 (2)159
C4—H4A···O1ii0.982.573.545 (2)171
C5—H5···N1iii0.952.433.365 (2)167
Symmetry codes: (i) x+3/2, y1/2, z+1/2; (ii) x, y+1, z; (iii) x+1, y+1, z+1.

Experimental details

Crystal data
Chemical formulaC11H10N2O
Mr186.21
Crystal system, space groupMonoclinicP21/n
Temperature (K)173
a, b, c (Å)13.3968 (5), 5.0656 (2), 14.3402 (5)
β (°) 108.027 (1)
V3)925.39 (6)
Z4
Radiation typeMo Kα
µ (mm1)0.09
Crystal size (mm)0.22 × 0.14 × 0.02
Data collection
DiffractometerSiemens SMART CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 2002)
Tmin, Tmax0.981, 0.998
No. of measured, independent and
observed [I > 2σ(I)] reflections
11777, 2298, 1514
Rint0.058
(sin θ/λ)max1)0.667
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.049, 0.124, 1.01
No. of reflections2298
No. of parameters138
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.23, 0.20

Computer programs: SMART (Siemens, 1995), SAINT (Siemens, 1995), SAINT and SADABS (Sheldrick, 2002), SHELXTL (Bruker, 2001), SHELXTL, DIAMOND (Brandenburg, 2000), PLATON (Spek, 2003).

Hydrogen-bonding geometry (Å, °). The values in the second of each pair of rows are from the solid-state density functional theory calculation top
D—H···AD—HH···AD···AD—H···A
N2-H2···O10.882.042.6998 (18)130.7
1.041.812.6490134.6
C2'-H2'···O1i0.952.403.302 (3)159.1
1.092.203.2783167.2
C4-H4A···O1ii0.982.573.545 (2)170.9
1.102.403.4897168.9
C5-H5···N1iii0.952.433.365 (2)167.2
1.092.253.3300170.3
C6'-H6'···N10.952.693.635 (4)173.5
1.092.463.5393172.6
Symmetry codes: (i) 3/2-x, y-1/2, 1/2-z; (ii) x, 1+y, z; (iii) 1-x, 1-y, 1-z;
 

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