Structural motifs in acetoacetanilides: the effect of a fluorine substituent

The structures of three fluoro-substituted acetoacetanilides, namely 2'-, 3'- and 4'-fluoro­acetoacetanilide, all C₁₀H₁₀FNO₂, are presented and discussed. We observe a planar structure with intramolecular hydrogen bonding when the F atom is in the ortho position of the aromatic ring, and a twisted structure with intermolecular hydrogen bonding when the F atom is in the meta or para positions. It can be predicted which of these two structural motifs will be adopted by considering the position of any aromatic substituents. In this regard, fluorine appears to mimic the steric effect of a larger substituent, which we attribute to its high electronegativity.

S1. Comment

Acetoacetanilides are common starting materials in the synthesis of azo pigments. Typically during synthesis of such a pigment, a diazonium salt component is added to a slightly acidic aqueous slurry of the anilide. Thus, the solid-state properties of the anilide may play a role in determining the final quality of the pigment. Acetoacetanilide, (I), and compounds derived from it by substitution around the aryl ring, thus give rise to a wide range of commercial azo pigments. Such azo pigments are of varying yellow and orange shades and moderate fastness properties, and find applications in a range of systems including the colouration of inks, paints and plastics (Herbst & Hunger, 1993).

We recently compared the structures of some commercially important acetoacetanilides with those of the monoazo pigments derived from them (Chisholm et al., 2000). To expand our knowledge of the packing motifs for such compounds further, we have prepared the fluorinated compounds 2'-fluoroacetoacetanilide, (II), 3'-fluoroacetoacetanilide, (III) and 4'-fluoroacetoacetanilide, (IV), and determined single-crystal structures for each of them. \sch

The presence of F in molecular crystals and its influence on crystal packing have been comparatively rarely studied [for examples, see Hayashi & Mori (1998) and Renak et al. (1999)], given the wealth of information available on the effect of the F atom in biological chemistry (Filler et al., 1993). The interactions of organic F with other atoms within a crystal lattice are weak, and indeed it has been observed that, when organically bonded, F hardly ever acts as a hydrogen-bond acceptor (Dunitz & Taylor, 1997). However, it is known that weak interactions can still play important roles in molecular recognition, self-assembly and other structural processes (MacDonald & Whitesides, 1994).

Each of the compounds (II), (III) and (IV) adopts a trans planar configuration at the amide (Figs. 1, 2 and 4). However, the nature of the hydrogen bonding present then defines the orientation of the ketone carbonyl with respect to the amide. In the ortho-substituted compound, (II), intramolecular hydrogen bonding between the ketone carbonyl and the amide N—H is present. This serves to give a planar arrangement, as shown by the pseudo-torsion angle between the two carbonyls [O1—C2—C4—O2 - 179.0 (2)°]. The meta- and para-substituted compounds, however, feature intermolecular hydrogen bonding between N—H and the amide carbonyl (Fig. 3). Here, the requirement to adopt a planar arrangement is lifted and the equivalent torsion angles are -62.2 (2)° for (III), and -64.0 (2) and -74.8 (2)° for the two independent conformations of (IV). A further difference is that, in (II), the aromatic ring plane is approximately coplanar with the amide plane, whilst both (III) and (IV) exhibit more twisted geometries (see torsion angles in Tables 1, 3 and 5).

Thus, the three compounds are differentiated by the relative conformation of both the aromatic and ketone groups with respect to the amide, and by differences in hydrogen bonding. Similar effects were observed in previous work (Chisholm et al., 2000) on methyl-substituted analogues. Therein, we rationalized that a methyl substituent ortho to the N—H group sterically disfavoured intermolecular interactions and forced the adoption of a sterically disfavoured planar conformation. That this is a disfavoured strained conformation is shown by a widening of the C2—C3—C4 angle, with values of 122.13 (9) and 122.5 (2)° in planar (II) and its methyl analogue, compared with 112.6 (2)° for (III), and 110.6 (1) or 110.2 (2)° for (IV). A steric explanation is less likely to be the case with F substitution, due to the similarity in van der Waals radii between H and F. In (II), an explanation may be the high electronegativity of F, which disfavours the approach of the O atom to form an intermolecular hydrogen bond. The coplanarity of the amide and the aromatic ring is stabilized by an F1···H1N close contact of 2.29 (2) Å. That this is attractive and not incidental may be indicated by the closure of the N1—C5—C10 angle to 117.2 (1)°. We find no evidence of intermolecular H···F interactions in any of these compounds.

In conclusion, the structures presented herein provide further evidence for two broad conformational motifs for acetoacetanilides, namely, a planar intramolecular hydrogen-bonded structure and a non-planar intermolecular hydrogen-bonded structure. Which motif is present is dependent on the position of the substituents on the phenyl ring. Whilst the small size of F may mitigate against steric effects, its high electronegativity may serve to mimic the effect of a larger group in preventing the close approach of a second molecule to form an intermolecular hydrogen bond.

S2. Experimental

All starting materials were purchased from Aldrich and used as received, except for xylene (mixture of isomers), which was purified by washing with concentrated sulfuric acid and dried over anhydrous CaCl₂. The general synthesis of (II), (III) and (IV) was carried out as follows. A 250 ml three-necked round-bottomed flask was fitted with a magnetic stirrer, a dropping funnel, and a still head and condenser set for downward distillation. To this apparatus were added ethyl acetoacetate (12.9 g, 0.1 mol) and xylene (25 ml). The flask was heated in an oil bath at 420 K with stirring. The appropriate fluorinated aniline (0.09 mol) was then added via the dropping funnel and ethanol began to distil. The reaction was continued until the temperature at the still head dropped below the boiling point of ethanol. On cooling to room temperature, off-white crystalline needles formed, which were isolated by filtration and washed with a small amount of petroleum ether (333–353 K), with typical yields of 55–65%. For (II), m.p. 332–334 K; IR spectroscopic data (ν_max, Nujol, cm^-1): 1707 (C═O), 1675 (amide 1), 1620 (aromatic), 1551 (amide 2). For (III), m.p. 339–341 K; IR spectroscopic data (ν_max, Nujol, cm^-1): 1720 (C═O), 1663 (amide 1), 1614 (aromatic), 1548 (amide 2). For (IV), m.p. 364–366 K; IR spectroscopic data (ν_max, Nujol, cm^-1): 1720 (C═O), 1665 (amide 1), 1618 (aromatic), 1552 (amide 2).

S3. Refinement

In (III), all H atoms were refined isotropically. However, in (II) and (IV), only the amide H atom was refined isotropically, with all other H atoms being placed in calculated positions, with C—H = 0.95–0.99 Å Is this correct?, and refined in riding modes. The methyl H atoms in (II) were modelled as being rotationally disordered over two sites. The refined N—H distances were 0.872 (19)–0.892 (19) Å and the refined C—H distances were 0.90 (2)–1.018 (17) Å.

Computing details

For all compounds, data collection: DENZO (Otwinowski & Minor, 1997) and COLLECT (Nonius, 1998); cell refinement: DENZO and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. A view of the molecule of (II), showing the atom-numbering scheme and with the intramolecular contacts as dashed lines. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
	Fig. 2. A view of the molecular structure of (III). Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
	Fig. 3. The intermolecular hydrogen-bonding in (III), forming a molecular chain that propogates along the a direction. The atom labelled with an asterisk (*) is at symmetry position (x + 1/2, y, 1/2 - z).
	Fig. 4. A view of the asymmetric unit of (IV), showing the twisted nature of both crystallographically independent molecules and their atom-numbering schemes. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.

(II) 2'-fluoroacetoacetanilide

Crystal data

C10H10FNO2	F(000) = 408
Mr = 195.19	Dx = 1.416 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2169 reflections
a = 7.3215 (2) Å	θ = 1.7–27.5°
b = 12.0480 (3) Å	µ = 0.11 mm^−1
c = 10.5082 (3) Å	T = 150 K
β = 98.877 (1)°	Cut prism, colourless
V = 915.82 (4) Å^3	0.35 × 0.30 × 0.20 mm
Z = 4

Data collection

Nonius KappaCCD area-detector diffractometer	1812 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.015
Graphite monochromator	θmax = 27.5°, θmin = 2.8°
ϕ and ω scans	h = 0→9
3637 measured reflections	k = −15→14
2092 independent reflections	l = −13→13

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.033	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.094	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0485P)^2 + 0.2047P] where P = (Fo^2 + 2Fc^2)/3
2092 reflections	(Δ/σ)max < 0.001
132 parameters	Δρmax = 0.23 e Å^−3
0 restraints	Δρmin = −0.18 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
F1	0.41992 (9)	0.03293 (6)	0.70364 (6)	0.03238 (19)
O1	0.30657 (11)	−0.22681 (7)	0.57662 (7)	0.0297 (2)
O2	0.08600 (13)	−0.01994 (7)	0.26742 (8)	0.0392 (2)
N1	0.23391 (12)	−0.02392 (8)	0.47517 (8)	0.0230 (2)
H1N	0.2760 (18)	−0.0721 (13)	0.5359 (13)	0.035 (4)*
C1	0.23139 (18)	−0.38998 (10)	0.45386 (13)	0.0368 (3)
H1A	0.3195	−0.4259	0.5210	0.044*	0.50
H1B	0.2639	−0.4076	0.3691	0.044*	0.50
H1C	0.1064	−0.4170	0.4586	0.044*	0.50
H1D	0.1403	−0.4078	0.3781	0.044*	0.50
H1E	0.1960	−0.4260	0.5300	0.044*	0.50
H1F	0.3535	−0.4167	0.4405	0.044*	0.50
C2	0.23817 (14)	−0.26668 (9)	0.47362 (10)	0.0247 (2)
C3	0.15356 (14)	−0.19743 (9)	0.35946 (10)	0.0237 (2)
H3A	0.0227	−0.2206	0.3379	0.028*
H3B	0.2151	−0.2197	0.2859	0.028*
C4	0.15473 (14)	−0.07137 (9)	0.36299 (10)	0.0238 (2)
C5	0.25128 (13)	0.08929 (9)	0.50507 (10)	0.0216 (2)
C6	0.17827 (14)	0.17620 (9)	0.42532 (10)	0.0254 (2)
H6	0.1116	0.1606	0.3424	0.030*
C7	0.20264 (15)	0.28577 (10)	0.46671 (11)	0.0291 (3)
H7	0.1529	0.3443	0.4114	0.035*
C8	0.29858 (15)	0.31058 (10)	0.58765 (11)	0.0294 (3)
H8	0.3135	0.3856	0.6153	0.035*
C9	0.37292 (14)	0.22494 (10)	0.66822 (10)	0.0274 (3)
H9	0.4397	0.2405	0.7512	0.033*
C10	0.34798 (13)	0.11756 (9)	0.62566 (10)	0.0238 (2)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
F1	0.0349 (4)	0.0359 (4)	0.0231 (3)	0.0037 (3)	−0.0056 (3)	0.0024 (3)
O1	0.0346 (4)	0.0300 (4)	0.0222 (4)	0.0020 (3)	−0.0026 (3)	0.0014 (3)
O2	0.0557 (6)	0.0326 (5)	0.0236 (4)	0.0013 (4)	−0.0118 (4)	0.0025 (3)
N1	0.0255 (4)	0.0243 (5)	0.0180 (4)	0.0007 (3)	−0.0001 (3)	0.0017 (4)
C1	0.0407 (7)	0.0281 (6)	0.0391 (7)	0.0003 (5)	−0.0014 (5)	−0.0016 (5)
C2	0.0220 (5)	0.0269 (5)	0.0250 (5)	0.0009 (4)	0.0031 (4)	0.0003 (4)
C3	0.0228 (5)	0.0282 (6)	0.0194 (5)	−0.0005 (4)	0.0013 (4)	−0.0022 (4)
C4	0.0225 (5)	0.0297 (6)	0.0189 (5)	−0.0003 (4)	0.0024 (4)	0.0001 (4)
C5	0.0194 (4)	0.0260 (5)	0.0200 (5)	−0.0011 (4)	0.0047 (4)	−0.0004 (4)
C6	0.0269 (5)	0.0291 (6)	0.0200 (5)	0.0003 (4)	0.0033 (4)	0.0021 (4)
C7	0.0321 (6)	0.0278 (6)	0.0286 (6)	0.0013 (4)	0.0085 (5)	0.0034 (4)
C8	0.0292 (5)	0.0284 (6)	0.0323 (6)	−0.0042 (4)	0.0101 (5)	−0.0045 (5)
C9	0.0224 (5)	0.0358 (6)	0.0242 (5)	−0.0039 (4)	0.0043 (4)	−0.0063 (4)
C10	0.0198 (5)	0.0311 (6)	0.0201 (5)	0.0008 (4)	0.0022 (4)	0.0017 (4)

Geometric parameters (Å, º)

F1—C10	1.3621 (12)	C3—C4	1.5191 (15)
O1—C2	1.2189 (13)	C3—H3A	0.9900
O2—C4	1.2205 (13)	C3—H3B	0.9900
N1—C4	1.3571 (13)	C5—C10	1.3951 (14)
N1—C5	1.4011 (14)	C5—C6	1.3950 (15)
N1—H1N	0.883 (15)	C6—C7	1.3927 (16)
C1—C2	1.4997 (16)	C6—H6	0.9500
C1—H1A	0.9800	C7—C8	1.3865 (16)
C1—H1B	0.9800	C7—H7	0.9500
C1—H1C	0.9800	C8—C9	1.3912 (17)
C1—H1D	0.9800	C8—H8	0.9500
C1—H1E	0.9800	C9—C10	1.3718 (16)
C1—H1F	0.9800	C9—H9	0.9500
C2—C3	1.5131 (14)
C4—N1—C5	128.08 (9)	C2—C3—C4	122.13 (9)
C4—N1—H1N	113.9 (9)	C2—C3—H3A	106.8
C5—N1—H1N	118.0 (9)	C4—C3—H3A	106.8
C2—C1—H1A	109.5	C2—C3—H3B	106.8
C2—C1—H1B	109.5	C4—C3—H3B	106.8
H1A—C1—H1B	109.5	H3A—C3—H3B	106.6
C2—C1—H1C	109.5	O2—C4—N1	124.57 (11)
H1A—C1—H1C	109.5	O2—C4—C3	119.17 (10)
H1B—C1—H1C	109.5	N1—C4—C3	116.26 (9)
C2—C1—H1D	109.5	C10—C5—C6	117.14 (10)
H1A—C1—H1D	141.1	C10—C5—N1	117.20 (10)
H1B—C1—H1D	56.3	C6—C5—N1	125.66 (10)
H1C—C1—H1D	56.3	C7—C6—C5	120.34 (10)
C2—C1—H1E	109.5	C7—C6—H6	119.8
H1A—C1—H1E	56.3	C5—C6—H6	119.8
H1B—C1—H1E	141.1	C8—C7—C6	120.86 (11)
H1C—C1—H1E	56.3	C8—C7—H7	119.6
H1D—C1—H1E	109.5	C6—C7—H7	119.6
C2—C1—H1F	109.5	C7—C8—C9	119.55 (11)
H1A—C1—H1F	56.3	C7—C8—H8	120.2
H1B—C1—H1F	56.3	C9—C8—H8	120.2
H1C—C1—H1F	141.1	C10—C9—C8	118.76 (10)
H1D—C1—H1F	109.5	C10—C9—H9	120.6
H1E—C1—H1F	109.5	C8—C9—H9	120.6
O1—C2—C1	120.90 (10)	F1—C10—C9	119.35 (9)
O1—C2—C3	123.27 (10)	F1—C10—C5	117.30 (10)
C1—C2—C3	115.83 (9)	C9—C10—C5	123.35 (10)
O1—C2—C3—C4	2.63 (16)	C5—C6—C7—C8	−0.36 (16)
C1—C2—C3—C4	−178.15 (10)	C6—C7—C8—C9	0.60 (16)
C5—N1—C4—O2	0.84 (17)	C7—C8—C9—C10	−0.40 (16)
C5—N1—C4—C3	−179.04 (9)	C8—C9—C10—F1	−179.94 (9)
C2—C3—C4—O2	179.25 (10)	C8—C9—C10—C5	−0.04 (16)
C2—C3—C4—N1	−0.86 (14)	C6—C5—C10—F1	−179.82 (8)
C4—N1—C5—C10	−176.57 (9)	N1—C5—C10—F1	0.96 (13)
C4—N1—C5—C6	4.27 (17)	C6—C5—C10—C9	0.28 (15)
C10—C5—C6—C7	−0.08 (15)	N1—C5—C10—C9	−178.95 (9)
N1—C5—C6—C7	179.07 (9)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1	0.883 (15)	1.917 (16)	2.6869 (12)	144.7 (13)

(III) 3'-fluoroacetoacetanilide

Crystal data

C10H10FNO2	F(000) = 816
Mr = 195.19	Dx = 1.380 Mg m^−3
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 2458 reflections
a = 9.4933 (3) Å	θ = 1.3–27.5°
b = 9.7792 (3) Å	µ = 0.11 mm^−1
c = 20.2345 (7) Å	T = 150 K
V = 1878.51 (11) Å^3	Cut plate, colourless
Z = 8	0.50 × 0.30 × 0.05 mm

Data collection

Nonius KappaCCD area-detector diffractometer	1387 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.044
Graphite monochromator	θmax = 27.5°, θmin = 2.9°
ϕ and ω scans	h = −12→12
3999 measured reflections	k = −12→12
2158 independent reflections	l = −26→26

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.104	All H-atom parameters refined
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0522P)^2 + 0.0664P] where P = (Fo^2 + 2Fc^2)/3
2158 reflections	(Δ/σ)max < 0.001
167 parameters	Δρmax = 0.18 e Å^−3
0 restraints	Δρmin = −0.21 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
F1	−0.03629 (9)	0.39731 (10)	0.08777 (4)	0.0366 (3)
O1	0.25883 (13)	0.13894 (13)	0.37141 (6)	0.0402 (3)
O2	0.06376 (10)	0.05021 (13)	0.24909 (5)	0.0363 (3)
N1	0.27845 (14)	0.09721 (14)	0.20457 (6)	0.0259 (3)
H1N	0.370 (2)	0.0787 (17)	0.2078 (8)	0.035 (5)*
C1	0.3917 (2)	−0.0507 (2)	0.40981 (10)	0.0386 (5)
H1A	0.366 (2)	−0.146 (3)	0.4141 (10)	0.062 (7)*
H1B	0.482 (3)	−0.056 (3)	0.3952 (11)	0.075 (8)*
H1C	0.394 (2)	−0.005 (2)	0.4517 (12)	0.064 (7)*
C2	0.30144 (16)	0.02397 (18)	0.36163 (8)	0.0273 (4)
C3	0.26651 (17)	−0.05238 (18)	0.29890 (8)	0.0253 (4)
H3A	0.3500 (18)	−0.0902 (17)	0.2826 (8)	0.029 (4)*
H3B	0.2102 (17)	−0.1299 (17)	0.3103 (8)	0.031 (5)*
C4	0.19230 (15)	0.03588 (17)	0.24888 (7)	0.0250 (4)
C5	0.23996 (14)	0.17868 (16)	0.14999 (7)	0.0232 (4)
C6	0.11316 (16)	0.24979 (17)	0.14672 (8)	0.0252 (4)
H6	0.0467 (16)	0.2441 (15)	0.1802 (7)	0.026 (4)*
C7	0.08714 (15)	0.32580 (17)	0.09095 (8)	0.0262 (4)
C8	0.17729 (17)	0.33549 (17)	0.03824 (8)	0.0292 (4)
H8	0.1454 (16)	0.3909 (17)	−0.0017 (9)	0.029 (4)*
C9	0.30320 (18)	0.26480 (19)	0.04270 (8)	0.0333 (4)
H9	0.3750 (16)	0.2711 (17)	0.0060 (8)	0.037 (5)*
C10	0.33527 (17)	0.18840 (18)	0.09780 (8)	0.0294 (4)
H10	0.4221 (19)	0.1432 (18)	0.1014 (8)	0.035 (5)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
F1	0.0276 (5)	0.0418 (6)	0.0404 (6)	0.0074 (5)	−0.0022 (4)	0.0064 (5)
O1	0.0564 (8)	0.0268 (7)	0.0372 (7)	0.0071 (6)	−0.0023 (6)	−0.0027 (6)
O2	0.0176 (6)	0.0546 (8)	0.0368 (7)	0.0003 (6)	0.0021 (5)	0.0094 (6)
N1	0.0163 (7)	0.0342 (9)	0.0271 (7)	0.0017 (6)	0.0008 (5)	0.0046 (6)
C1	0.0468 (12)	0.0337 (12)	0.0353 (11)	0.0021 (10)	−0.0108 (9)	0.0007 (10)
C2	0.0275 (8)	0.0253 (10)	0.0292 (8)	−0.0023 (8)	0.0023 (7)	0.0015 (7)
C3	0.0215 (8)	0.0245 (9)	0.0299 (9)	0.0012 (8)	0.0024 (7)	−0.0001 (7)
C4	0.0202 (8)	0.0279 (9)	0.0270 (8)	−0.0010 (7)	0.0013 (7)	−0.0020 (7)
C5	0.0211 (8)	0.0232 (9)	0.0252 (8)	−0.0028 (7)	−0.0011 (6)	−0.0021 (7)
C6	0.0214 (8)	0.0299 (10)	0.0244 (8)	−0.0006 (7)	0.0007 (7)	−0.0033 (8)
C7	0.0215 (8)	0.0261 (9)	0.0312 (9)	0.0007 (7)	−0.0048 (7)	−0.0042 (8)
C8	0.0361 (9)	0.0277 (9)	0.0239 (8)	−0.0005 (8)	−0.0011 (7)	−0.0002 (8)
C9	0.0365 (9)	0.0334 (10)	0.0299 (9)	0.0004 (8)	0.0094 (8)	−0.0006 (8)
C10	0.0244 (8)	0.0276 (10)	0.0361 (10)	0.0030 (8)	0.0056 (7)	−0.0001 (8)

Geometric parameters (Å, º)

F1—C7	1.3661 (17)	C3—H3A	0.934 (17)
O1—C2	1.211 (2)	C3—H3B	0.956 (17)
O2—C4	1.2283 (16)	C5—C6	1.392 (2)
N1—C4	1.3536 (19)	C5—C10	1.394 (2)
N1—C5	1.4101 (19)	C6—C7	1.374 (2)
N1—H1N	0.892 (19)	C6—H6	0.927 (15)
C1—C2	1.489 (3)	C7—C8	1.371 (2)
C1—H1A	0.96 (2)	C8—C9	1.384 (2)
C1—H1B	0.90 (2)	C8—H8	1.018 (17)
C1—H1C	0.96 (2)	C9—C10	1.376 (2)
C2—C3	1.509 (2)	C9—H9	1.010 (16)
C3—C4	1.505 (2)	C10—H10	0.938 (18)
C4—N1—C5	127.78 (13)	N1—C4—C3	114.63 (13)
C4—N1—H1N	116.8 (11)	C6—C5—C10	119.44 (15)
C5—N1—H1N	115.2 (11)	C6—C5—N1	122.93 (13)
C2—C1—H1A	112.8 (12)	C10—C5—N1	117.63 (14)
C2—C1—H1B	110.8 (15)	C7—C6—C5	117.70 (14)
H1A—C1—H1B	102 (2)	C7—C6—H6	120.7 (9)
C2—C1—H1C	111.2 (12)	C5—C6—H6	121.6 (9)
H1A—C1—H1C	112.4 (18)	F1—C7—C8	117.61 (14)
H1B—C1—H1C	106.8 (19)	F1—C7—C6	118.03 (13)
O1—C2—C1	122.71 (16)	C8—C7—C6	124.36 (15)
O1—C2—C3	121.55 (15)	C7—C8—C9	117.00 (16)
C1—C2—C3	115.74 (15)	C7—C8—H8	117.9 (9)
C4—C3—C2	112.62 (14)	C9—C8—H8	125.0 (9)
C4—C3—H3A	112.8 (10)	C10—C9—C8	121.01 (15)
C2—C3—H3A	107.8 (10)	C10—C9—H9	118.7 (9)
C4—C3—H3B	110.8 (10)	C8—C9—H9	120.2 (9)
C2—C3—H3B	108.2 (10)	C9—C10—C5	120.47 (15)
H3A—C3—H3B	104.2 (14)	C9—C10—H10	120.9 (10)
O2—C4—N1	123.51 (14)	C5—C10—H10	118.7 (10)
O2—C4—C3	121.87 (14)
O1—C2—C3—C4	7.5 (2)	N1—C5—C6—C7	−179.94 (14)
C1—C2—C3—C4	−172.10 (16)	C5—C6—C7—F1	−179.16 (13)
C5—N1—C4—O2	−4.2 (3)	C5—C6—C7—C8	0.4 (2)
C5—N1—C4—C3	175.98 (14)	F1—C7—C8—C9	178.70 (14)
C2—C3—C4—O2	−86.77 (19)	C6—C7—C8—C9	−0.9 (3)
C2—C3—C4—N1	93.05 (16)	C7—C8—C9—C10	0.1 (3)
C4—N1—C5—C6	24.7 (2)	C8—C9—C10—C5	1.2 (3)
C4—N1—C5—C10	−156.07 (16)	C6—C5—C10—C9	−1.6 (2)
C10—C5—C6—C7	0.8 (2)	N1—C5—C10—C9	179.12 (14)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O2^i	0.89 (2)	2.05 (2)	2.903 (2)	158.9 (15)

Symmetry code: (i) x+1/2, y, −z+1/2.

(IV) 4'-fluoroacetoacetanilide

Crystal data

C10H10FNO2	F(000) = 816
Mr = 195.19	Dx = 1.360 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 4374 reflections
a = 4.9811 (1) Å	θ = 2.6–27.5°
b = 20.7383 (4) Å	µ = 0.11 mm^−1
c = 18.4869 (5) Å	T = 150 K
β = 93.021 (1)°	Cut needle, colourless
V = 1907.03 (7) Å^3	0.60 × 0.20 × 0.03 mm
Z = 8

Data collection

Nonius KappaCCD area-detector diffractometer	2728 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.035
Graphite monochromator	θmax = 27.5°, θmin = 3.0°
ϕ and ω scans	h = 0→6
8284 measured reflections	k = −26→26
4372 independent reflections	l = −23→23

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.113	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0486P)^2 + 0.3055P] where P = (Fo^2 + 2Fc^2)/3
4372 reflections	(Δ/σ)max = 0.001
263 parameters	Δρmax = 0.21 e Å^−3
0 restraints	Δρmin = −0.22 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
F1	0.1874 (2)	−0.01606 (5)	0.71536 (6)	0.0515 (3)
F2	1.0148 (2)	0.46448 (6)	0.60064 (6)	0.0530 (3)
O1	0.9201 (2)	0.31809 (6)	0.81717 (8)	0.0461 (4)
O2	1.0559 (2)	0.17888 (6)	0.86595 (6)	0.0364 (3)
O3	0.2814 (3)	0.13101 (8)	0.49571 (9)	0.0657 (5)
O4	0.1370 (2)	0.23385 (6)	0.61212 (6)	0.0350 (3)
N1	0.9707 (3)	0.17207 (7)	0.74406 (8)	0.0280 (3)
N2	0.2276 (3)	0.29041 (7)	0.51023 (8)	0.0286 (3)
C1	1.3117 (3)	0.37529 (9)	0.78825 (11)	0.0398 (5)
H1A	1.3244	0.3822	0.7361	0.060*
H1B	1.4925	0.3704	0.8111	0.060*
H1C	1.2227	0.4124	0.8095	0.060*
C2	1.1525 (3)	0.31581 (8)	0.80048 (9)	0.0286 (4)
C3	1.2890 (3)	0.25125 (8)	0.79085 (9)	0.0283 (4)
H3A	1.3519	0.2480	0.7411	0.034*
H3B	1.4477	0.2479	0.8252	0.034*
C4	1.0979 (3)	0.19680 (8)	0.80404 (9)	0.0270 (4)
C5	0.7702 (3)	0.12322 (8)	0.74025 (8)	0.0256 (4)
C6	0.7142 (4)	0.08381 (9)	0.79735 (9)	0.0368 (4)
H6	0.8108	0.0888	0.8427	0.044*
C7	0.5166 (4)	0.03679 (9)	0.78881 (10)	0.0407 (5)
H7	0.4771	0.0094	0.8280	0.049*
C8	0.3803 (3)	0.03054 (9)	0.72346 (10)	0.0345 (4)
C9	0.4310 (4)	0.06848 (10)	0.66580 (10)	0.0430 (5)
H9	0.3345	0.0627	0.6206	0.052*
C10	0.6262 (3)	0.11563 (9)	0.67451 (9)	0.0384 (5)
H10	0.6621	0.1431	0.6351	0.046*
C11	−0.1344 (4)	0.08412 (9)	0.45956 (12)	0.0467 (5)
H11A	−0.0231	0.0489	0.4424	0.070*
H11B	−0.2555	0.0993	0.4197	0.070*
H11C	−0.2405	0.0686	0.4992	0.070*
C12	0.0416 (3)	0.13803 (9)	0.48593 (9)	0.0351 (4)
C13	−0.0893 (3)	0.20255 (8)	0.50039 (9)	0.0298 (4)
H13A	−0.1350	0.2246	0.4539	0.036*
H13B	−0.2577	0.1956	0.5254	0.036*
C14	0.0998 (3)	0.24434 (8)	0.54685 (9)	0.0272 (4)
C15	0.4270 (3)	0.33405 (8)	0.53680 (8)	0.0270 (4)
C16	0.5582 (3)	0.32950 (9)	0.60445 (9)	0.0360 (4)
H16	0.5132	0.2958	0.6365	0.043*
C17	0.7553 (3)	0.37394 (9)	0.62576 (10)	0.0391 (5)
H17	0.8437	0.3713	0.6725	0.047*
C18	0.8198 (3)	0.42101 (9)	0.57919 (10)	0.0359 (4)
C19	0.6977 (4)	0.42670 (10)	0.51170 (10)	0.0468 (5)
H19	0.7480	0.4600	0.4798	0.056*
C20	0.5000 (4)	0.38311 (9)	0.49074 (10)	0.0424 (5)
H20	0.4122	0.3867	0.4440	0.051*
H1N	1.012 (3)	0.1881 (9)	0.7014 (10)	0.034 (5)*
H2N	0.178 (3)	0.2956 (9)	0.4644 (11)	0.036 (5)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
F1	0.0435 (6)	0.0401 (7)	0.0708 (8)	−0.0167 (5)	0.0005 (5)	−0.0092 (6)
F2	0.0561 (7)	0.0519 (8)	0.0511 (7)	−0.0256 (6)	0.0039 (5)	−0.0096 (6)
O1	0.0258 (7)	0.0412 (8)	0.0721 (10)	0.0028 (6)	0.0112 (6)	0.0058 (7)
O2	0.0486 (7)	0.0381 (8)	0.0221 (6)	−0.0084 (6)	−0.0017 (5)	0.0008 (5)
O3	0.0300 (8)	0.0649 (11)	0.1011 (13)	0.0088 (7)	−0.0071 (7)	−0.0276 (9)
O4	0.0387 (7)	0.0434 (8)	0.0227 (7)	−0.0092 (6)	−0.0006 (5)	0.0078 (5)
N1	0.0331 (8)	0.0309 (9)	0.0203 (7)	−0.0050 (6)	0.0036 (6)	0.0005 (6)
N2	0.0334 (8)	0.0331 (9)	0.0192 (8)	−0.0037 (6)	−0.0018 (6)	0.0035 (6)
C1	0.0304 (10)	0.0319 (11)	0.0571 (13)	0.0004 (8)	0.0009 (8)	−0.0009 (9)
C2	0.0253 (9)	0.0310 (11)	0.0290 (9)	0.0000 (7)	−0.0042 (6)	0.0008 (7)
C3	0.0261 (8)	0.0302 (10)	0.0285 (9)	−0.0014 (7)	0.0001 (7)	−0.0022 (7)
C4	0.0285 (8)	0.0276 (10)	0.0249 (9)	0.0021 (7)	0.0010 (6)	−0.0025 (7)
C5	0.0280 (8)	0.0232 (10)	0.0259 (9)	0.0006 (7)	0.0025 (6)	−0.0025 (7)
C6	0.0445 (10)	0.0370 (11)	0.0286 (10)	−0.0098 (9)	−0.0025 (7)	0.0018 (8)
C7	0.0502 (11)	0.0355 (12)	0.0370 (11)	−0.0127 (9)	0.0073 (8)	0.0026 (9)
C8	0.0286 (9)	0.0252 (10)	0.0497 (12)	−0.0045 (7)	0.0035 (8)	−0.0082 (8)
C9	0.0453 (11)	0.0437 (13)	0.0385 (11)	−0.0102 (9)	−0.0114 (8)	−0.0039 (9)
C10	0.0468 (11)	0.0404 (12)	0.0274 (10)	−0.0095 (9)	−0.0031 (8)	0.0049 (8)
C11	0.0444 (11)	0.0359 (12)	0.0593 (13)	−0.0001 (9)	−0.0001 (9)	−0.0036 (10)
C12	0.0335 (10)	0.0410 (12)	0.0306 (10)	0.0010 (8)	0.0014 (7)	−0.0009 (8)
C13	0.0273 (8)	0.0358 (11)	0.0260 (9)	−0.0013 (8)	−0.0007 (6)	0.0024 (8)
C14	0.0260 (8)	0.0310 (10)	0.0245 (9)	0.0023 (7)	0.0020 (6)	0.0027 (7)
C15	0.0277 (9)	0.0284 (10)	0.0251 (9)	0.0024 (7)	0.0043 (7)	−0.0008 (7)
C16	0.0390 (10)	0.0403 (12)	0.0284 (10)	−0.0069 (9)	−0.0021 (7)	0.0075 (8)
C17	0.0395 (10)	0.0471 (13)	0.0302 (10)	−0.0078 (9)	−0.0026 (8)	−0.0001 (9)
C18	0.0354 (10)	0.0340 (11)	0.0387 (11)	−0.0086 (8)	0.0054 (8)	−0.0100 (9)
C19	0.0624 (13)	0.0410 (13)	0.0372 (11)	−0.0179 (10)	0.0044 (9)	0.0079 (9)
C20	0.0540 (12)	0.0438 (13)	0.0287 (10)	−0.0139 (10)	−0.0033 (8)	0.0084 (9)

Geometric parameters (Å, º)

F1—C8	1.3655 (19)	C7—C8	1.360 (3)
F2—C18	1.3685 (19)	C7—H7	0.9500
O1—C2	1.2146 (19)	C8—C9	1.359 (3)
O2—C4	1.2317 (19)	C9—C10	1.382 (2)
O3—C12	1.208 (2)	C9—H9	0.9500
O4—C14	1.2304 (18)	C10—H10	0.9500
N1—C4	1.349 (2)	C11—C12	1.487 (3)
N1—C5	1.422 (2)	C11—H11A	0.9800
N1—H1N	0.889 (18)	C11—H11B	0.9800
N2—C14	1.350 (2)	C11—H11C	0.9800
N2—C15	1.413 (2)	C12—C13	1.518 (3)
N2—H2N	0.876 (19)	C13—C14	1.513 (2)
C1—C2	1.490 (2)	C13—H13A	0.9900
C1—H1A	0.9800	C13—H13B	0.9900
C1—H1B	0.9800	C15—C16	1.383 (2)
C1—H1C	0.9800	C15—C20	1.387 (2)
C2—C3	1.517 (2)	C16—C17	1.388 (2)
C3—C4	1.505 (2)	C16—H16	0.9500
C3—H3A	0.9900	C17—C18	1.351 (3)
C3—H3B	0.9900	C17—H17	0.9500
C5—C6	1.375 (2)	C18—C19	1.364 (3)
C5—C10	1.387 (2)	C19—C20	1.377 (3)
C6—C7	1.389 (2)	C19—H19	0.9500
C6—H6	0.9500	C20—H20	0.9500
C4—N1—C5	127.60 (14)	C9—C10—C5	120.68 (17)
C4—N1—H1N	117.8 (12)	C9—C10—H10	119.7
C5—N1—H1N	114.6 (11)	C5—C10—H10	119.7
C14—N2—C15	128.37 (14)	C12—C11—H11A	109.5
C14—N2—H2N	117.2 (12)	C12—C11—H11B	109.5
C15—N2—H2N	114.4 (12)	H11A—C11—H11B	109.5
C2—C1—H1A	109.5	C12—C11—H11C	109.5
C2—C1—H1B	109.5	H11A—C11—H11C	109.5
H1A—C1—H1B	109.5	H11B—C11—H11C	109.5
C2—C1—H1C	109.5	O3—C12—C11	121.33 (18)
H1A—C1—H1C	109.5	O3—C12—C13	120.69 (17)
H1B—C1—H1C	109.5	C11—C12—C13	117.98 (15)
O1—C2—C1	121.89 (16)	C14—C13—C12	110.15 (13)
O1—C2—C3	120.23 (15)	C14—C13—H13A	109.6
C1—C2—C3	117.88 (14)	C12—C13—H13A	109.6
C4—C3—C2	110.61 (13)	C14—C13—H13B	109.6
C4—C3—H3A	109.5	C12—C13—H13B	109.6
C2—C3—H3A	109.5	H13A—C13—H13B	108.1
C4—C3—H3B	109.5	O4—C14—N2	124.49 (15)
C2—C3—H3B	109.5	O4—C14—C13	120.82 (15)
H3A—C3—H3B	108.1	N2—C14—C13	114.62 (14)
O2—C4—N1	123.60 (16)	C16—C15—C20	118.58 (16)
O2—C4—C3	121.12 (14)	C16—C15—N2	124.10 (15)
N1—C4—C3	115.21 (14)	C20—C15—N2	117.29 (14)
C6—C5—C10	119.25 (16)	C15—C16—C17	120.30 (16)
C6—C5—N1	123.77 (14)	C15—C16—H16	119.9
C10—C5—N1	116.98 (15)	C17—C16—H16	119.9
C5—C6—C7	120.09 (16)	C18—C17—C16	119.14 (16)
C5—C6—H6	120.0	C18—C17—H17	120.4
C7—C6—H6	120.0	C16—C17—H17	120.4
C8—C7—C6	119.03 (17)	C17—C18—C19	122.40 (17)
C8—C7—H7	120.5	C17—C18—F2	118.69 (16)
C6—C7—H7	120.5	C19—C18—F2	118.90 (17)
C7—C8—C9	122.46 (16)	C18—C19—C20	118.56 (18)
C9—C8—F1	118.85 (16)	C18—C19—H19	120.7
C7—C8—F1	118.69 (17)	C20—C19—H19	120.7
C8—C9—C10	118.48 (17)	C19—C20—C15	121.01 (17)
C8—C9—H9	120.8	C19—C20—H20	119.5
C10—C9—H9	120.8	C15—C20—H20	119.5
O1—C2—C3—C4	0.5 (2)	O3—C12—C13—C14	−16.8 (2)
C1—C2—C3—C4	−179.02 (15)	C11—C12—C13—C14	163.15 (16)
C5—N1—C4—O2	0.7 (3)	C15—N2—C14—O4	1.4 (3)
C5—N1—C4—C3	−176.31 (14)	C15—N2—C14—C13	−175.66 (15)
C2—C3—C4—O2	−81.11 (19)	C12—C13—C14—O4	−75.38 (19)
C2—C3—C4—N1	95.98 (17)	C12—C13—C14—N2	101.76 (17)
C4—N1—C5—C6	−14.2 (3)	C14—N2—C15—C16	11.2 (3)
C4—N1—C5—C10	166.01 (16)	C14—N2—C15—C20	−170.91 (16)
C10—C5—C6—C7	0.4 (3)	C20—C15—C16—C17	1.0 (3)
N1—C5—C6—C7	−179.36 (16)	N2—C15—C16—C17	178.89 (16)
C5—C6—C7—C8	−0.1 (3)	C15—C16—C17—C18	−1.0 (3)
C6—C7—C8—C9	0.3 (3)	C16—C17—C18—C19	0.1 (3)
C6—C7—C8—F1	179.61 (15)	C16—C17—C18—F2	−179.85 (16)
C7—C8—C9—C10	−0.8 (3)	C17—C18—C19—C20	0.6 (3)
F1—C8—C9—C10	179.86 (16)	F2—C18—C19—C20	−179.43 (17)
C8—C9—C10—C5	1.1 (3)	C18—C19—C20—C15	−0.5 (3)
C6—C5—C10—C9	−0.9 (3)	C16—C15—C20—C19	−0.3 (3)
N1—C5—C10—C9	178.83 (16)	N2—C15—C20—C19	−178.31 (17)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O4^i	0.89 (2)	2.03 (2)	2.914 (2)	172.0 (16)
N2—H2N···O2^ii	0.88 (2)	1.96 (2)	2.830 (2)	171.2 (18)

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