2,2-Dichloro-N-(3,4-dichloro­phen­yl)acetamide

The conformation of the N—H bond in the title compound, C₈H₅Cl₄NO, is syn to the 3-chloro substituent, in contrast to the anti conformation observed in N-(3,4-dichloro­phen­yl)­acetamide, 2,2-dichloro-N-(3-chloro­phen­yl)acetamide and 2,2,2-trichloro-N-(3,4-dichloro­phen­yl)acetamide. The bond parameters in the title compound are similar to those in other acetanilides. The mol­ecules are linked into zigzag chains running along the c axis through N—H...O hydrogen bonding.

Key indicators

• Single-crystal X-ray study
• T = 299 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.039
• wR factor = 0.106
• Data-to-parameter ratio = 14.3

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT061_ALERT_3_C Tmax/Tmin Range Test RR' too Large .............       0.75
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         C8

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

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

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S1. Comment

In the present work, the structure of N-(3,4-dichlorophenyl)-2,2- dichloroacetamide (34DCPDCA) has been determined to study the substituent effects on the structures of N-aromatic amides (Gowda et al., 2006; Gowda, Kozisek, Svoboda & Fuess, 2007; Gowda, Kožíšek, Tokarčík & Fuess, 2007). The conformation of the N—H bond in 34DCPDCA is syn to the 3-chloro substituent (Fig. 1), compared to the anti conformation observed in the chain unsubstituted N-(3,4-dichlorophenyl)- acetamide (34DCPA)(Jones et al., 1990), N-(3-chlorophenyl)- 2,2-dichloroacetamide (3CPDCA)(Gowda et al., 2006) and N-(3,4-dichlorophenyl)-2,2,2-trichloroacetamide (34DCPTCA)(Gowda, Kožíšek, Tokarčík & Fuess, 2007). The bond parameters in 34DCPDCA are similar to those in 34DCPA, 3CPDCA, 34DCPTCA and other acetanilides (Gowda et al., 2006; Gowda, Kozisek, Svoboda & Fuess, 2007; Gowda, Kožíšek, Tokarčík & Fuess, 2007). The molecules in 34DCPDCA are linked into chains via N—H···O hydrogen bonding (Fig.2).

Related literature

For related literature, see: Gowda et al. (2006); Gowda, Kozisek, Svoboda & Fuess, (2007); Gowda, Kožíšek, Tokarčík & Fuess (2007); Jones et al. (1990); Shilpa & Gowda (2007).

S2. Experimental

The title compound was prepared according to the literature method (Shilpa and Gowda, 2007). The purity of the compound was checked by determining its melting point. It was characterized by recording its infrared and NMR spectra (Shilpa and Gowda, 2007). Single crystals of the title compound were obtained from an ethanolic solution and used for X-ray diffraction studied at room temperature.

S3. Refinement

The amino H atom was located in difference map and was freely refined. The other H atoms were positioned with idealized geometry using a riding model (C—H = 0.93–0.98 Å). All H atoms bonded to C were refined with isotropic displacement parameters (set to 1.2 times of the U_eq of the parent atom).

Computing details

Data collection: CAD-4-PC (Enraf–Nonius, 1996); cell refinement: CAD-4-PC (Enraf–Nonius, 1996); data reduction: REDU4 (Stoe & Cie, 1987); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).

Figures

	Fig. 1. Molecular structure of the title compound showing the atom labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are represented as small spheres of arbitrary radii.
	Fig. 2. Molecular packing of the title compound with hydrogen bonding shown as dashed lines.

2,2-Dichloro-N-(3,4-dichlorophenyl)acetamide

Crystal data

C8H5Cl4NO	F(000) = 544
Mr = 272.93	Dx = 1.721 Mg m^−3
Monoclinic, P21/c	Cu Kα radiation, λ = 1.54180 Å
Hall symbol: -P 2ybc	Cell parameters from 25 reflections
a = 11.898 (5) Å	θ = 5.7–23.9°
b = 10.310 (3) Å	µ = 9.93 mm^−1
c = 9.212 (2) Å	T = 299 K
β = 111.23 (3)°	Prism, colourless
V = 1053.3 (6) Å^3	0.25 × 0.23 × 0.20 mm
Z = 4

Data collection

Enraf–Nonius CAD-4 diffractometer	1690 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.033
Graphite monochromator	θmax = 67.0°, θmin = 4.0°
ω/2θ scans	h = −14→14
Absorption correction: ψ scan (North et al., 1968)	k = −12→0
Tmin = 0.120, Tmax = 0.138	l = −10→4
2954 measured reflections	3 standard reflections every 120 min
1877 independent reflections	intensity decay: 1.0%

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)] = 0.039	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.106	w = 1/[σ^2(Fo^2) + (0.0454P)^2 + 0.967P] where P = (Fo^2 + 2Fc^2)/3
S = 1.07	(Δ/σ)max < 0.001
1877 reflections	Δρmax = 0.56 e Å^−3
131 parameters	Δρmin = −0.37 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0037 (5)

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
C1	0.3114 (2)	0.6392 (2)	0.1238 (3)	0.0323 (5)
C2	0.3922 (2)	0.6851 (3)	0.0593 (3)	0.0357 (5)
H2	0.3670	0.7446	−0.0220	0.043*
C3	0.5100 (2)	0.6426 (3)	0.1154 (3)	0.0388 (6)
C4	0.5474 (2)	0.5531 (3)	0.2341 (3)	0.0441 (6)
C5	0.4653 (3)	0.5052 (3)	0.2945 (3)	0.0467 (7)
H5	0.4901	0.4433	0.3732	0.056*
C6	0.3476 (2)	0.5471 (3)	0.2409 (3)	0.0400 (6)
H6	0.2932	0.5140	0.2828	0.048*
C7	0.1198 (2)	0.7060 (2)	0.1425 (3)	0.0330 (5)
C8	0.0002 (2)	0.7693 (3)	0.0475 (3)	0.0403 (6)
H8	0.0030	0.8002	−0.0517	0.048*
N1	0.19265 (18)	0.6887 (2)	0.0630 (2)	0.0339 (5)
H1N	0.174 (3)	0.720 (3)	−0.020 (4)	0.041*
O1	0.14306 (18)	0.6745 (2)	0.2774 (2)	0.0470 (5)
Cl1	0.60911 (7)	0.70548 (8)	0.03597 (11)	0.0602 (3)
Cl2	0.69516 (7)	0.50195 (9)	0.30933 (12)	0.0738 (3)
Cl3	−0.11360 (7)	0.65230 (11)	0.01221 (13)	0.0785 (3)
Cl4	−0.02442 (9)	0.90102 (9)	0.15321 (10)	0.0679 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0321 (12)	0.0373 (13)	0.0287 (11)	−0.0023 (10)	0.0124 (9)	−0.0040 (9)
C2	0.0330 (13)	0.0393 (13)	0.0371 (12)	0.0025 (10)	0.0155 (10)	0.0017 (10)
C3	0.0327 (13)	0.0401 (14)	0.0477 (14)	−0.0009 (10)	0.0195 (11)	−0.0059 (11)
C4	0.0361 (13)	0.0401 (14)	0.0497 (15)	0.0074 (11)	0.0079 (11)	−0.0067 (12)
C5	0.0548 (17)	0.0397 (15)	0.0413 (14)	0.0073 (12)	0.0122 (12)	0.0047 (11)
C6	0.0460 (14)	0.0402 (14)	0.0370 (13)	−0.0021 (11)	0.0188 (11)	0.0008 (11)
C7	0.0309 (12)	0.0394 (13)	0.0315 (12)	−0.0074 (10)	0.0146 (9)	−0.0060 (10)
C8	0.0336 (13)	0.0530 (16)	0.0383 (13)	−0.0014 (11)	0.0177 (11)	−0.0040 (11)
N1	0.0290 (10)	0.0485 (13)	0.0258 (9)	−0.0016 (9)	0.0120 (8)	0.0026 (9)
O1	0.0481 (11)	0.0659 (13)	0.0317 (9)	0.0038 (9)	0.0201 (8)	0.0024 (8)
Cl1	0.0420 (4)	0.0638 (5)	0.0887 (6)	0.0026 (3)	0.0403 (4)	0.0032 (4)
Cl2	0.0412 (4)	0.0708 (6)	0.0955 (7)	0.0202 (4)	0.0081 (4)	0.0067 (5)
Cl3	0.0354 (4)	0.0872 (7)	0.1111 (8)	−0.0204 (4)	0.0241 (4)	−0.0139 (6)
Cl4	0.0855 (6)	0.0608 (5)	0.0616 (5)	0.0230 (4)	0.0318 (4)	−0.0043 (4)

Geometric parameters (Å, º)

C1—C6	1.384 (4)	C5—H5	0.9300
C1—C2	1.384 (4)	C6—H6	0.9300
C1—N1	1.413 (3)	C7—O1	1.215 (3)
C2—C3	1.378 (4)	C7—N1	1.334 (3)
C2—H2	0.9300	C7—C8	1.521 (4)
C3—C4	1.376 (4)	C8—Cl3	1.754 (3)
C3—Cl1	1.723 (3)	C8—Cl4	1.756 (3)
C4—C5	1.378 (4)	C8—H8	0.9800
C4—Cl2	1.723 (3)	N1—H1N	0.78 (3)
C5—C6	1.375 (4)
C6—C1—C2	120.0 (2)	C5—C6—C1	119.0 (2)
C6—C1—N1	122.8 (2)	C5—C6—H6	120.5
C2—C1—N1	117.2 (2)	C1—C6—H6	120.5
C3—C2—C1	120.1 (2)	O1—C7—N1	125.0 (2)
C3—C2—H2	120.0	O1—C7—C8	121.4 (2)
C1—C2—H2	120.0	N1—C7—C8	113.6 (2)
C4—C3—C2	120.2 (2)	C7—C8—Cl3	108.0 (2)
C4—C3—Cl1	121.1 (2)	C7—C8—Cl4	108.81 (17)
C2—C3—Cl1	118.7 (2)	Cl3—C8—Cl4	111.21 (14)
C3—C4—C5	119.3 (2)	C7—C8—H8	109.6
C3—C4—Cl2	120.9 (2)	Cl3—C8—H8	109.6
C5—C4—Cl2	119.8 (2)	Cl4—C8—H8	109.6
C6—C5—C4	121.4 (3)	C7—N1—C1	125.8 (2)
C6—C5—H5	119.3	C7—N1—H1N	118 (2)
C4—C5—H5	119.3	C1—N1—H1N	115 (2)
C6—C1—C2—C3	−2.3 (4)	C2—C1—C6—C5	1.8 (4)
N1—C1—C2—C3	178.7 (2)	N1—C1—C6—C5	−179.3 (2)
C1—C2—C3—C4	0.9 (4)	O1—C7—C8—Cl3	−69.7 (3)
C1—C2—C3—Cl1	−178.1 (2)	N1—C7—C8—Cl3	109.7 (2)
C2—C3—C4—C5	0.9 (4)	O1—C7—C8—Cl4	51.1 (3)
Cl1—C3—C4—C5	180.0 (2)	N1—C7—C8—Cl4	−129.4 (2)
C2—C3—C4—Cl2	−178.3 (2)	O1—C7—N1—C1	−4.4 (4)
Cl1—C3—C4—Cl2	0.7 (3)	C8—C7—N1—C1	176.2 (2)
C3—C4—C5—C6	−1.4 (4)	C6—C1—N1—C7	32.8 (4)
Cl2—C4—C5—C6	177.8 (2)	C2—C1—N1—C7	−148.3 (3)
C4—C5—C6—C1	0.0 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1^i	0.78 (3)	2.08 (3)	2.852 (3)	171 (3)

Symmetry code: (i) x, −y+3/2, z−1/2.