2-Chloro-4-iodo­aniline

Abstract

The title dihaloaniline, C₆H₅ClIN, shows no significant hydrogen bonds nor the commonly observed I⋯I inter­actions in the crystal structure, although an amino group and an I atom are available for such contacts. The crystal structure is stabilized by weak inter­actions involving the amine functionality as donor group and N or halogen atoms as acceptors.

Related literature

The title compound was first synthesized 90 years ago (Dains et al., 1918 ▶). For structures of halogenated anilines, see: Cox (2001 ▶); Dey et al. (2003 ▶); Dou et al. (1993 ▶); Fukuyo et al. (1982 ▶); Goubitz et al. (2001 ▶); Parkin et al. (2005 ▶); Sakurai et al. (1963 ▶).

Experimental

Crystal data

• C₆H₅ClIN

• M _r = 253.46

• Orthorhombic,

• a = 5.6277 (2) Å

• b = 8.7859 (3) Å

• c = 14.9217 (5) Å

• V = 737.79 (4) ų

• Z = 4

• Mo Kα radiation

• μ = 4.61 mm⁻¹

• T = 90.0 (2) K

• 0.22 × 0.15 × 0.10 mm

Data collection

• Nonius KappaCCD diffractometer

• Absorption correction: multi-scan (SCALEPACK; Otwinowski & Minor, 1997 ▶) T _min = 0.424, T _max = 0.630

• 5635 measured reflections

• 1696 independent reflections

• 1587 reflections with I > 2σ(I)

• R _int = 0.033

Refinement

• R[F ² > 2σ(F ²)] = 0.024

• wR(F ²) = 0.046

• S = 1.14

• 1696 reflections

• 89 parameters

• 1 restraint

• H atoms treated by a mixture of independent and constrained refinement

• Δρ_max = 1.18 e Å⁻³

• Δρ_min = −0.76 e Å⁻³

• Absolute structure: Flack (1983 ▶), 681 Friedel pairs

• Flack parameter: −0.03 (3)

Data collection: COLLECT (Nonius, 2002 ▶); cell refinement: SCALEPACK (Otwinowski & Minor, 1997 ▶); data reduction: DENZO–SMN (Otwinowski & Minor, 1997 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXL97 and local procedures.

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N⋯N1i	0.82 (3)	2.61 (3)	3.359 (4)	153 (4)
N1—H1N⋯Cl1ii	0.82 (3)	2.94 (4)	3.515 (4)	129 (4)
N1—H2N⋯I1iii	0.81 (3)	3.16 (3)	3.807 (4)	139 (4)

Symmetry codes: (i) ; (ii) ; (iii) .

supplementary crystallographic information

Comment

Although structurally simple and readily available, few crystal structures of dihaloanilines have been measured. A total of 10 structures were found in the 2007 CSD; the refcodes are CAJWEQ, CAJWEQ01 (Goubitz et al., 2001), DCHLAN, DCHLAN01 (Sakurai et al., 1963), KUMTER (Cox, 2001), WEMDAT, WEMDEX, WEMDIB, WEMDOH, WEMDUN (Dou et al., 1993). 2-Chloro-4-iodoaniline, (I), an aniline with two different halogen substituents, was first synthesized 90 years ago (Dains et al., 1918), yet its crystal structure is reported here for the first time.

The asymmetric unit contains one molecule (Fig. 1). The N atom is not coplanar with the aromatic ring; H atoms of the amino group are also out of the halogenated benzene ring, but in the opposite direction to that of the N atom. So, the C(Ar)NH₂ group has a pyramidal shape. This is similar to the structure of aniline at 252 K (Fukuyo et al., 1982), 2-iodoaniline at 100 K (Parkin et al., 2005) and 4-iodoaniline at 203 K (Dey et al., 2003).

Despite the presence of amino, chloro and iodo groups, no classic interactions associated with them, such as hydrogen bonds, Cl···Cl, or I···I contacts were observed in the crystal structure of (I). Instead, weak interactions such as N—H···N, N—H···I, and N—H···Cl are found to provide stability to the crystal (Fig. 2).

Experimental

The compound was purchased from TCI America Laboratory Chemicals as colorless block crystals suitable for single-crystal X-ray diffraction measurement.

Refinement

H atoms were found in a difference map and those on the aromatic ring subsequently placed in idealized positions with C—H distances of 0.95 Å and isotropic displacement parameters equal to 1.2U_eq of the carrier C atom. Amine H atoms H1N and H2N were refined freely but were restrained to converge to the same N—H bond lengths, with a standard deviation of 0.02 Å. Isotropic displacement parameters for H1N and H2N were computed as 1.5U_eq(N1)

Figures

Fig. 1.

The molecular structure of (I), with displacement ellipsoids drawn at the 50% probability level (arbitrary spheres for the H atoms).

Fig. 2.

A packing diagram of (I) down the a axis.

Crystal data

C6H5ClIN	F000 = 472
Mr = 253.46	Dx = 2.282 Mg m−3
Orthorhombic, P212121	Mo Kα radiation λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 1019 reflections
a = 5.6277 (2) Å	θ = 1.0–27.5º
b = 8.7859 (3) Å	µ = 4.61 mm−1
c = 14.9217 (5) Å	T = 90.0 (2) K
V = 737.79 (4) Å3	Rounded block, colourless
Z = 4	0.22 × 0.15 × 0.10 mm

Data collection

Nonius KappaCCD diffractometer	1696 independent reflections
Radiation source: fine-focus sealed tube	1587 reflections with I > 2σ(I)
Monochromator: graphite	Rint = 0.033
Detector resolution: 18 pixels mm-1	θmax = 27.5º
T = 90.0(2) K	θmin = 2.7º
ω scans at fixed χ = 55°	h = −7→7
Absorption correction: multi-scan(SCALEPACK; Otwinowski & Minor, 1997)	k = −11→11
Tmin = 0.424, Tmax = 0.630	l = −19→19
5635 measured reflections

Refinement

Refinement on F2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F2 > 2σ(F2)] = 0.024	w = 1/[σ2(Fo2) + (0.P)2 + 0.4678P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.046	(Δ/σ)max = 0.001
S = 1.14	Δρmax = 1.18 e Å−3
1696 reflections	Δρmin = −0.76 e Å−3
89 parameters	Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
1 restraint	Extinction coefficient: 0.0021 (3)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983), 681 Friedel pairs
Secondary atom site location: difference Fourier map	Flack parameter: −0.03 (3)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
I1	0.48590 (4)	0.17882 (2)	0.730162 (15)	0.01928 (9)
Cl1	0.46148 (17)	0.51349 (10)	0.40305 (6)	0.0194 (2)
N1	0.9067 (6)	0.6647 (5)	0.4646 (2)	0.0188 (8)
H1N	1.048 (5)	0.679 (5)	0.474 (3)	0.028*
H2N	0.882 (7)	0.656 (5)	0.411 (2)	0.028*
C1	0.6370 (6)	0.3328 (4)	0.6386 (2)	0.0133 (7)
C2	0.5194 (7)	0.3639 (3)	0.5594 (2)	0.0138 (7)
H2	0.3764	0.3121	0.5448	0.017*
C3	0.6128 (6)	0.4711 (4)	0.5018 (2)	0.0145 (8)
C4	0.8253 (6)	0.5480 (4)	0.5199 (3)	0.0152 (8)
C5	0.9422 (6)	0.5117 (4)	0.5999 (2)	0.0166 (8)
H5	1.0875	0.5611	0.6142	0.020*
C6	0.8494 (7)	0.4049 (4)	0.6588 (3)	0.0163 (8)
H6	0.9312	0.3812	0.7127	0.020*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
I1	0.02354 (13)	0.01764 (13)	0.01666 (14)	−0.00271 (12)	0.00379 (13)	0.00106 (9)
Cl1	0.0189 (5)	0.0231 (4)	0.0163 (4)	0.0003 (4)	−0.0036 (4)	−0.0007 (3)
N1	0.0163 (16)	0.0192 (18)	0.0208 (18)	−0.0046 (15)	0.0035 (15)	0.0025 (15)
C1	0.0136 (16)	0.0101 (17)	0.0161 (19)	0.0001 (15)	0.0027 (15)	−0.0029 (16)
C2	0.0142 (18)	0.0107 (15)	0.0165 (17)	0.0005 (16)	0.003 (2)	−0.0046 (13)
C3	0.0134 (18)	0.0133 (17)	0.0169 (19)	0.0020 (16)	−0.0006 (16)	−0.0017 (16)
C4	0.0121 (18)	0.0129 (18)	0.020 (2)	0.0043 (15)	0.0034 (16)	−0.0031 (17)
C5	0.0096 (18)	0.0154 (17)	0.025 (2)	0.0007 (14)	0.0002 (16)	−0.0053 (15)
C6	0.0172 (19)	0.0182 (19)	0.0133 (18)	0.0019 (16)	−0.0003 (16)	−0.0034 (16)

Geometric parameters (Å, °)

I1—C1	2.103 (4)	C2—C3	1.379 (5)
Cl1—C3	1.742 (4)	C2—H2	0.9500
N1—C4	1.394 (5)	C3—C4	1.400 (5)
N1—H1N	0.82 (3)	C4—C5	1.400 (5)
N1—H2N	0.81 (3)	C5—C6	1.387 (5)
C1—C2	1.382 (5)	C5—H5	0.9500
C1—C6	1.386 (5)	C6—H6	0.9500
C4—N1—H1N	110 (3)	C4—C3—Cl1	118.6 (3)
C4—N1—H2N	117 (3)	N1—C4—C5	121.2 (3)
H1N—N1—H2N	110 (5)	N1—C4—C3	121.4 (3)
C2—C1—C6	120.6 (3)	C5—C4—C3	117.2 (3)
C2—C1—I1	119.3 (3)	C6—C5—C4	121.1 (3)
C6—C1—I1	120.1 (3)	C6—C5—H5	119.4
C3—C2—C1	119.0 (3)	C4—C5—H5	119.4
C3—C2—H2	120.5	C1—C6—C5	119.7 (3)
C1—C2—H2	120.5	C1—C6—H6	120.1
C2—C3—C4	122.3 (3)	C5—C6—H6	120.1
C2—C3—Cl1	119.1 (3)
C6—C1—C2—C3	−1.9 (5)	Cl1—C3—C4—C5	179.8 (3)
I1—C1—C2—C3	176.5 (2)	N1—C4—C5—C6	174.2 (3)
C1—C2—C3—C4	1.2 (5)	C3—C4—C5—C6	−0.5 (5)
C1—C2—C3—Cl1	−178.6 (3)	C2—C1—C6—C5	1.5 (5)
C2—C3—C4—N1	−174.7 (3)	I1—C1—C6—C5	−176.9 (2)
Cl1—C3—C4—N1	5.1 (5)	C4—C5—C6—C1	−0.3 (5)
C2—C3—C4—C5	0.0 (5)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···N1i	0.82 (3)	2.61 (3)	3.359 (4)	153 (4)
N1—H1N···Cl1ii	0.82 (3)	2.94 (4)	3.515 (4)	129 (4)
N1—H2N···I1iii	0.81 (3)	3.16 (3)	3.807 (4)	139 (4)

Symmetry codes: (i) x+1/2, −y+3/2, −z+1; (ii) x+1, y, z; (iii) −x+3/2, −y+1, z−1/2.