2,2,2-Trichloro-N-(2,4-dichloro­phen­yl)acetamide

The conformation of the N-H bond in the structure of the title compound, C₈H₄Cl₅NO, is syn to the ortho-chloro substituent, similar to that observed in N-(2-chloro­phen­yl)acetamide, N-(2,4-dichloro­phen­yl)acetamide, 2,2,2-trichloro-N-(2-chloro­phen­yl)acetamide and N-(2-chloro­phen­yl)-2,2,2-trimethyl­acetamide. The bond parameters are similar to those in other acetanilides. The amide H atom is involved in two intra­molecular hydrogen bonds with the ortho ring Cl atom and one of the Cl atoms of the CCl₃ group.

Key indicators

• Single-crystal X-ray study
• T = 299 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.055
• wR factor = 0.156
• Data-to-parameter ratio = 14.7

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.29
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         C4
PLAT340_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          5

Alert level G
ABSTM02_ALERT_3_G  When printed, the submitted absorption T values will be
            replaced by the scaled T values. Since the ratio of scaled T's
            is identical to the ratio of reported T values, the scaling
            does not imply a change to the absorption corrections used in
            the study.
            Ratio of Tmax expected/reported      0.286
            Tmax scaled      0.057 Tmin scaled      0.026

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   1 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
   2 ALERT type 3 Indicator that the structure quality may be low
   1 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-(2,4-dichlorophenyl)-2,2,2- trichloroacetamide has been determined as part of a study in the direction of systematization of the crystal structures of N-aromatic amides (Gowda et al., 2000; 2007a, b, c, d). The conformation of the N—H bond is syn to the ortho-chloro substituent (Fig. 1), similar to that observed in N-(2-chlorophenyl)-acetamide (Gowda et al., 2007c), N-(2,4-DiChlorophenyl)-acetamide (Gowda et al., 2007d), N-(2-chlorophenyl)-2,2,2- trichloroacetamide (Gowda et al., 2000) and N-(2-chlorophenyl)- 2,2,2-trimethylacetamide (Gowda et al., 2007b). The geometric parameters are similar to those in other acetanilides (Gowda et al., 2000; 2007a, b, c, d). The amide H is involved in two intra-molecular hydrogen bonding with the ortho ring Cl atom and one of the Cl atoms of the CCl₃ group (Fig. 1) (Fig. 2 & Table 1).

Related literature

For related literature, see: Gowda et al. (2000); Gowda, Kozisek et al. (2007); Gowda et al. (2007a,b,c); Pies et al. (1971); Shilpa & Gowda (2007).

S2. Experimental

The title compound was prepared according to the literature method (Shilpa & Gowda, 2007). The purity of the compound was checked by determining its melting point. It was characterized by recording its infrared, NMR (Shilpa & Gowda, 2007) and NQR spectra (Pies et al., 1971). Single crystals of the title compound were obtained from a slow evaporation of its ethanolic solution (2 g in about 30 ml e thanol) and used for X-ray diffraction studies at room temperature.

S3. Refinement

The H atoms were positioned with idealized geometry using a riding model with N—H = 0.86 Å and C—H = 0.93 Å]. U_iso(H) values were set equal to 1.2 U_eq of the parent atom.

Computing details

Data collection: CAD-4-PC (Enraf-Nonius, 1996); cell refinement: CAD-4-PC; 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: ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97.

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. Crystal packing of the title compound. Hydrogen bonds are shown as dashed lines.

2,2,2-Trichloro-N-(2,4-dichlorophenyl)acetamide

Crystal data

C8H4Cl5NO	F(000) = 1216
Mr = 307.37	Dx = 1.807 Mg m^−3
Orthorhombic, Pbca	Cu Kα radiation, λ = 1.54180 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 25 reflections
a = 14.306 (2) Å	θ = 5.7–19.1°
b = 8.625 (2) Å	µ = 11.47 mm^−1
c = 18.317 (4) Å	T = 299 K
V = 2260.1 (8) Å^3	Rod, colourless
Z = 8	0.40 × 0.25 × 0.25 mm

Data collection

Enraf-Nonius CAD-4 diffractometer	1780 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.034
Graphite monochromator	θmax = 67.0°, θmin = 4.8°
ω/2θ scans	h = −17→0
Absorption correction: psi-scan (North et al., 1968)	k = −10→0
Tmin = 0.091, Tmax = 0.199	l = −21→21
3958 measured reflections	3 standard reflections every 120 min
2017 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)] = 0.055	H-atom parameters constrained
wR(F^2) = 0.156	w = 1/[σ^2(Fo^2) + (0.1016P)^2 + 1.9543P] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max = 0.001
2017 reflections	Δρmax = 0.61 e Å^−3
137 parameters	Δρmin = −0.57 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0026 (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
C4	0.8787 (2)	0.4639 (4)	0.21953 (18)	0.0379 (7)
C5	0.7991 (2)	0.4206 (4)	0.27435 (17)	0.0363 (7)
C8	0.7702 (2)	0.2521 (4)	0.38080 (17)	0.0376 (7)
C9	0.8146 (2)	0.1638 (4)	0.43387 (17)	0.0411 (7)
C10	0.7655 (3)	0.0913 (4)	0.48874 (18)	0.0455 (8)
H10	0.7961	0.0307	0.5233	0.055*
C11	0.6702 (3)	0.1103 (4)	0.49132 (17)	0.0441 (8)
C12	0.6239 (2)	0.1961 (5)	0.4390 (2)	0.0473 (8)
H12	0.5592	0.2064	0.4410	0.057*
C13	0.6742 (2)	0.2669 (4)	0.38368 (18)	0.0444 (8)
H13	0.6431	0.3245	0.3483	0.053*
N7	0.8264 (2)	0.3205 (4)	0.32653 (15)	0.0432 (7)
H7N	0.8846	0.2955	0.3267	0.052*
O6	0.72271 (18)	0.4723 (3)	0.26554 (15)	0.0549 (7)
Cl1	0.85165 (7)	0.63777 (11)	0.17582 (6)	0.0615 (4)
Cl2	0.88387 (7)	0.31299 (12)	0.15463 (5)	0.0555 (3)
Cl3	0.98924 (6)	0.48027 (15)	0.26205 (5)	0.0634 (4)
Cl14	0.93496 (6)	0.13974 (14)	0.43103 (6)	0.0628 (4)
Cl15	0.60865 (8)	0.02480 (14)	0.56195 (5)	0.0654 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C4	0.0413 (16)	0.0405 (17)	0.0317 (15)	0.0016 (13)	0.0019 (12)	0.0003 (14)
C5	0.0360 (15)	0.0407 (15)	0.0323 (15)	−0.0028 (13)	0.0027 (12)	−0.0064 (13)
C8	0.0427 (16)	0.0431 (16)	0.0269 (14)	−0.0022 (13)	0.0021 (12)	−0.0029 (13)
C9	0.0388 (16)	0.0503 (18)	0.0343 (16)	−0.0006 (14)	−0.0053 (12)	−0.0033 (14)
C10	0.056 (2)	0.0504 (18)	0.0299 (16)	−0.0004 (16)	−0.0030 (14)	0.0018 (14)
C11	0.0546 (19)	0.0504 (18)	0.0273 (15)	−0.0053 (15)	0.0073 (13)	−0.0009 (14)
C12	0.0396 (16)	0.055 (2)	0.047 (2)	−0.0009 (15)	0.0063 (14)	0.0037 (17)
C13	0.0449 (16)	0.0541 (19)	0.0341 (15)	0.0038 (15)	0.0027 (13)	0.0058 (15)
N7	0.0348 (13)	0.0548 (17)	0.0400 (15)	0.0028 (12)	0.0055 (11)	0.0101 (13)
O6	0.0440 (14)	0.0669 (17)	0.0539 (16)	0.0076 (12)	0.0069 (11)	0.0172 (13)
Cl1	0.0623 (6)	0.0503 (6)	0.0718 (7)	0.0066 (4)	0.0147 (5)	0.0210 (5)
Cl2	0.0710 (6)	0.0582 (6)	0.0373 (5)	0.0051 (4)	0.0075 (4)	−0.0117 (4)
Cl3	0.0425 (5)	0.0980 (8)	0.0499 (6)	−0.0173 (5)	−0.0058 (4)	0.0079 (5)
Cl14	0.0406 (5)	0.0869 (8)	0.0610 (6)	0.0034 (4)	−0.0072 (4)	0.0154 (5)
Cl15	0.0772 (7)	0.0718 (7)	0.0473 (6)	−0.0046 (5)	0.0198 (4)	0.0156 (5)

Geometric parameters (Å, º)

C4—C5	1.564 (4)	C9—Cl14	1.735 (3)
C4—Cl1	1.744 (3)	C10—C11	1.374 (5)
C4—Cl2	1.764 (3)	C10—H10	0.9300
C4—Cl3	1.769 (3)	C11—C12	1.379 (5)
C5—O6	1.190 (4)	C11—Cl15	1.730 (3)
C5—N7	1.347 (4)	C12—C13	1.385 (5)
C8—C13	1.381 (5)	C12—H12	0.9300
C8—C9	1.389 (5)	C13—H13	0.9300
C8—N7	1.408 (4)	N7—H7N	0.8600
C9—C10	1.377 (5)
C5—C4—Cl1	109.8 (2)	C11—C10—C9	118.5 (3)
C5—C4—Cl2	106.7 (2)	C11—C10—H10	120.7
Cl1—C4—Cl2	109.54 (18)	C9—C10—H10	120.7
C5—C4—Cl3	112.8 (2)	C10—C11—C12	121.1 (3)
Cl1—C4—Cl3	109.38 (18)	C10—C11—Cl15	118.7 (3)
Cl2—C4—Cl3	108.55 (18)	C12—C11—Cl15	120.2 (3)
O6—C5—N7	127.1 (3)	C11—C12—C13	119.7 (3)
O6—C5—C4	119.5 (3)	C11—C12—H12	120.1
N7—C5—C4	113.4 (3)	C13—C12—H12	120.1
C13—C8—C9	118.6 (3)	C8—C13—C12	120.3 (3)
C13—C8—N7	123.8 (3)	C8—C13—H13	119.9
C9—C8—N7	117.6 (3)	C12—C13—H13	119.9
C10—C9—C8	121.8 (3)	C5—N7—C8	127.1 (3)
C10—C9—Cl14	118.3 (3)	C5—N7—H7N	116.4
C8—C9—Cl14	119.9 (3)	C8—N7—H7N	116.4
Cl1—C4—C5—O6	23.0 (4)	C9—C10—C11—C12	2.0 (6)
Cl2—C4—C5—O6	−95.6 (3)	C9—C10—C11—Cl15	−177.8 (3)
Cl3—C4—C5—O6	145.3 (3)	C10—C11—C12—C13	−1.2 (6)
Cl1—C4—C5—N7	−159.3 (2)	Cl15—C11—C12—C13	178.6 (3)
Cl2—C4—C5—N7	82.1 (3)	C9—C8—C13—C12	0.7 (5)
Cl3—C4—C5—N7	−37.0 (3)	N7—C8—C13—C12	−179.9 (3)
C13—C8—C9—C10	0.0 (5)	C11—C12—C13—C8	−0.2 (6)
N7—C8—C9—C10	−179.4 (3)	O6—C5—N7—C8	1.7 (6)
C13—C8—C9—Cl14	178.8 (3)	C4—C5—N7—C8	−175.7 (3)
N7—C8—C9—Cl14	−0.6 (4)	C13—C8—N7—C5	7.0 (5)
C8—C9—C10—C11	−1.4 (5)	C9—C8—N7—C5	−173.7 (3)
Cl14—C9—C10—C11	179.8 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N7—H7N···Cl3	0.86	2.49	2.953 (3)	115
N7—H7N···Cl14	0.86	2.44	2.916 (3)	115