4-(2-Chloro­phenyl­amino)-pent-3-en-2-one

In the title compound, C₁₁H₁₂ClNO, intra­molecular N—H...O hydrogen bonding is present. The dihedral angle between the benzene ring and the pentenone unit is 46.52 (5)°. In the crystal, C—H...O inter­actions between hydrogen atoms of the aryl moiety and two separate oxygen atoms occur, leading to a three-dimensional network.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.025
• wR factor = 0.068
• Data-to-parameter ratio = 17.9

checkCIF/PLATON results

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Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           26.99
           From the CIF: _reflns_number_total               2259
           Count of symmetry unique reflns         1329
           Completeness (_total/calc)            169.98%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured       930
           Fraction of Friedel pairs measured     0.700
           Are heavy atom types Z>Si present        yes
PLAT005_ALERT_5_G No _iucr_refine_instructions_details in CIF ....          ?
PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L=  0.600          4

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   0 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   3 ALERT level G = General information/check it is not something unexpected

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

The β-diketone compound AcacH (acetylacetone; or when coordinated acetylacetonato, acac^-) has been studied extensively, with a multitude of derivatives synthesized to date. One such derivative type, known as enaminoketones, contains both nitrogen and oxygen atoms with an unsaturated C═C bond, and is of interest in various fields including liquid crystals [Pyżuk et al. (1993)], fluorescence studies [Xia et al. (2008)], medicine [Tan et al. (2008)] and catalysis [Roodt & Steyn (2000); Brink et al. (2010)].

The title compound (Fig. 1) crystallizes in the orthorhombic space group P2₁2₁2₁ with Z = 4. This enaminoketone is a derivative of 4-(phenylamino)pent-3-en-2-one [PhonyH; Shaheen et al. (2006)]. Bond distances differ significantly from compounds coordinated to rhodium [Venter et al. (2012a); Damoense et al. (1994)], but share characteristics with other enaminoketones of this type [Venter et al. (2010; 2012b). An unsaturated bond in the pentenone backbone is indicated by the difference in distance between the C₂═C₃ bond [1.379 (2) Å] and the C₃–C₄ bond [1.428 (2) Å]. The distance, N₁₁···O₁₂, is greatly increased (~ 0.2 Å) upon coordination. Intramolecular N₁₁—H₁₁···O₁₂ bonding (D—A distance = 2.632 (2) Å was observed, as well as intermolecular interactions for C₁₁₃—H₁₁₃···O₁₂i [i = x-0.5, 0.5-y, 1-z; distance = 3.3536 (18) Å] and C₁₁₅—H₁₁₅···O₁₂ii [ii = x, y+1, z; distance = 3.3217 (18) Å]. These interactions are illustrated in Fig. 2. The dihedral angle between the benzene ring and pentenone moieties is 46.52 (5)° and is dependent on the position of the substituent on the benzene ring, where para substituents usually display the smallest angles (Venter et al., 2010).

Related literature

For synthetic background and similar compounds, see: Shaheen et al. (2006); Venter et al. (2010, 2012b). For applications, see: Brink et al. (2010); Pyżuk et al. (1993); Roodt & Steyn (2000); Tan et al. (2008); Xia et al. (2008). For related ligand systems, see: Damoense et al. (1994), Venter et al. (2012a).

S2. Experimental

A solution of acetylacetone (11.07 g, 0.1106 mol), 2-chloro-aniline (10.73 g, 0.1008 mol) and 2 drops of H₂SO₄ (conc.) in 150 ml benzene was refluxed for 6 h in a Dean-Stark trap, filtered and left to crystallize. Crystals suitable for X-ray diffraction were obtained in 17.86 g (94.32%) yield. This compound is stable in air and light over a period of several months.

S3. Refinement

The methyl and aromatic H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms, with C—H = 0.95 Å and 0.98 Å and U_iso(H) = 1.5U_eq(C) and 1.2U_eq(C), respectively. The methyl groups were generated to fit the difference electron density and the groups were then refined as rigid rotors.

Computing details

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. Molecular structure of the title compound. Displacement ellipsoids are drawn at the 50% probability level. Hydrogen atoms are shown as spheres of arbitrary radius.
	Fig. 2. Partially filled unit cell illustrating the intra- and intermolecular hydrogen bonding interactions in the title compound, indicated with dashed lines.

4-(2-Chlorophenylamino)-pent-3-en-2-one

Crystal data

C11H12ClNO	F(000) = 440
Mr = 209.67	Dx = 1.347 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 5717 reflections
a = 7.3264 (3) Å	θ = 2.7–28.3°
b = 8.7103 (4) Å	µ = 0.33 mm^−1
c = 16.1960 (7) Å	T = 100 K
V = 1033.55 (8) Å^3	Cuboid, yellow
Z = 4	0.6 × 0.42 × 0.21 mm

Data collection

Bruker APEXII CCD area-detector diffractometer	2259 independent reflections
Radiation source: fine-focus sealed tube	2211 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.032
ϕ and ω scans	θmax = 27.0°, θmin = 2.5°
Absorption correction: multi-scan (SADABS; Bruker, 2004)	h = −9→9
Tmin = 0.825, Tmax = 0.933	k = −11→11
17399 measured reflections	l = −20→19

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.025	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.068	w = 1/[σ^2(Fo^2) + (0.0376P)^2 + 0.2837P] where P = (Fo^2 + 2Fc^2)/3
S = 1.06	(Δ/σ)max = 0.013
2259 reflections	Δρmax = 0.21 e Å^−3
126 parameters	Δρmin = −0.24 e Å^−3
0 restraints	Absolute structure: Flack (1983), 932 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.01 (5)

Special details

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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 (Ų)

	x	y	z	Uiso*/Ueq
Cl12	0.00235 (5)	0.20519 (4)	0.531562 (19)	0.02339 (10)
N11	0.21805 (15)	0.28866 (14)	0.67897 (7)	0.0174 (2)
H11	0.2500 (8)	0.209 (2)	0.6556 (6)	0.027 (5)*
O12	0.33003 (14)	0.00171 (12)	0.68371 (6)	0.02136 (18)
C3	0.24678 (18)	0.14426 (16)	0.80149 (9)	0.0178 (3)
H3	0.2362	0.1411	0.8599	0.021*
C2	0.20915 (17)	0.28095 (16)	0.76209 (8)	0.0169 (3)
C111	0.18055 (18)	0.41335 (16)	0.62662 (8)	0.0166 (3)
C116	0.2464 (2)	0.56091 (16)	0.64159 (9)	0.0197 (3)
H116	0.3191	0.5797	0.6891	0.024*
C4	0.3006 (2)	0.00740 (18)	0.75983 (9)	0.02136 (18)
C113	0.04201 (19)	0.50725 (19)	0.49974 (9)	0.0229 (3)
H113	−0.0264	0.4881	0.451	0.027*
C5	0.3168 (2)	−0.13853 (17)	0.80936 (9)	0.0227 (3)
H5A	0.2032	−0.1974	0.8047	0.034*
H5B	0.339	−0.1131	0.8674	0.034*
H5C	0.4185	−0.2	0.7881	0.034*
C112	0.08035 (18)	0.38927 (17)	0.55421 (9)	0.0184 (3)
C115	0.20717 (19)	0.68074 (17)	0.58791 (9)	0.0226 (3)
H115	0.2505	0.7812	0.5996	0.027*
C1	0.1554 (2)	0.41966 (16)	0.81135 (9)	0.0203 (3)
H1A	0.2628	0.4845	0.8205	0.03*
H1B	0.1056	0.3871	0.8647	0.03*
H1C	0.0627	0.478	0.7811	0.03*
C114	0.1048 (2)	0.65395 (18)	0.51727 (9)	0.0243 (3)
H114	0.0776	0.7363	0.4808	0.029*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl12	0.02513 (17)	0.02720 (17)	0.01784 (17)	−0.00589 (15)	−0.00152 (14)	−0.00549 (12)
N11	0.0194 (5)	0.0181 (5)	0.0146 (5)	0.0016 (5)	−0.0004 (4)	−0.0024 (5)
O12	0.0232 (4)	0.0229 (4)	0.0180 (4)	−0.0007 (3)	0.0032 (3)	−0.0004 (3)
C3	0.0158 (6)	0.0234 (7)	0.0140 (7)	−0.0011 (5)	−0.0006 (5)	−0.0012 (5)
C2	0.0122 (6)	0.0218 (6)	0.0167 (6)	−0.0010 (5)	−0.0007 (5)	−0.0026 (5)
C111	0.0136 (6)	0.0216 (6)	0.0145 (6)	0.0013 (5)	0.0015 (5)	−0.0012 (5)
C116	0.0168 (6)	0.0224 (6)	0.0198 (7)	−0.0008 (5)	0.0010 (5)	−0.0028 (5)
C4	0.0232 (4)	0.0229 (4)	0.0180 (4)	−0.0007 (3)	0.0032 (3)	−0.0004 (3)
C113	0.0202 (7)	0.0333 (7)	0.0152 (6)	0.0025 (6)	0.0003 (5)	0.0019 (6)
C5	0.0211 (6)	0.0230 (7)	0.0241 (8)	0.0020 (6)	0.0011 (6)	0.0025 (6)
C112	0.0151 (6)	0.0236 (7)	0.0165 (7)	−0.0019 (5)	0.0026 (5)	−0.0027 (5)
C115	0.0212 (7)	0.0224 (7)	0.0242 (7)	−0.0013 (6)	0.0062 (5)	0.0008 (6)
C1	0.0212 (6)	0.0221 (7)	0.0175 (7)	0.0018 (5)	0.0007 (5)	−0.0032 (5)
C114	0.0228 (7)	0.0276 (7)	0.0224 (8)	0.0032 (6)	0.0042 (6)	0.0077 (6)

Geometric parameters (Å, º)

Cl12—C112	1.7412 (15)	C4—C5	1.508 (2)
N11—C2	1.3494 (18)	C113—C112	1.383 (2)
N11—C111	1.4049 (18)	C113—C114	1.387 (2)
N11—H11	0.8243	C113—H113	0.95
O12—C4	1.2524 (18)	C5—H5A	0.98
C3—C2	1.3787 (19)	C5—H5B	0.98
C3—C4	1.425 (2)	C5—H5C	0.98
C3—H3	0.95	C115—C114	1.388 (2)
C2—C1	1.5005 (19)	C115—H115	0.95
C111—C116	1.3942 (19)	C1—H1A	0.98
C111—C112	1.3994 (19)	C1—H1B	0.98
C116—C115	1.389 (2)	C1—H1C	0.98
C116—H116	0.95	C114—H114	0.95
C2—N11—C111	129.12 (13)	C4—C5—H5A	109.5
C2—N11—H11	115.4	C4—C5—H5B	109.5
C111—N11—H11	115.4	H5A—C5—H5B	109.5
C2—C3—C4	123.95 (13)	C4—C5—H5C	109.5
C2—C3—H3	118	H5A—C5—H5C	109.5
C4—C3—H3	118	H5B—C5—H5C	109.5
N11—C2—C3	119.67 (12)	C113—C112—C111	121.98 (13)
N11—C2—C1	120.21 (13)	C113—C112—Cl12	118.89 (11)
C3—C2—C1	120.11 (12)	C111—C112—Cl12	119.13 (11)
C116—C111—C112	117.74 (13)	C114—C115—C116	120.12 (13)
C116—C111—N11	122.69 (12)	C114—C115—H115	119.9
C112—C111—N11	119.50 (12)	C116—C115—H115	119.9
C115—C116—C111	120.82 (13)	C2—C1—H1A	109.5
C115—C116—H116	119.6	C2—C1—H1B	109.5
C111—C116—H116	119.6	H1A—C1—H1B	109.5
O12—C4—C3	123.13 (14)	C2—C1—H1C	109.5
O12—C4—C5	118.48 (14)	H1A—C1—H1C	109.5
C3—C4—C5	118.35 (13)	H1B—C1—H1C	109.5
C112—C113—C114	119.11 (14)	C113—C114—C115	120.18 (14)
C112—C113—H113	120.4	C113—C114—H114	119.9
C114—C113—H113	120.4	C115—C114—H114	119.9
C111—N11—C2—C3	177.99 (12)	C114—C113—C112—C111	0.1 (2)
C111—N11—C2—C1	−0.9 (2)	C114—C113—C112—Cl12	−179.63 (11)
C4—C3—C2—N11	1.8 (2)	C116—C111—C112—C113	−1.8 (2)
C4—C3—C2—C1	−179.31 (13)	N11—C111—C112—C113	−178.91 (12)
C2—N11—C111—C116	46.2 (2)	C116—C111—C112—Cl12	177.84 (10)
C2—N11—C111—C112	−136.84 (15)	N11—C111—C112—Cl12	0.77 (17)
C112—C111—C116—C115	2.6 (2)	C111—C116—C115—C114	−1.5 (2)
N11—C111—C116—C115	179.53 (13)	C112—C113—C114—C115	1.1 (2)
C2—C3—C4—O12	4.7 (2)	C116—C115—C114—C113	−0.3 (2)
C2—C3—C4—C5	−173.14 (12)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N11—H11···O12	0.82	1.95	2.6317 (16)	139
C113—H113···O12^i	0.95	2.42	3.3536 (18)	166
C115—H115···O12^ii	0.95	2.43	3.3217 (18)	157

Symmetry codes: (i) x−1/2, −y+1/2, −z+1; (ii) x, y+1, z.