2,4-Dichloro­benzaldehyde

Ricardo Cabello; Maksymilian Chruszcz; Wladek Minor

doi:10.1107/S160053680905435X

. 2009 Dec 24;66(Pt 1):o243. doi: 10.1107/S160053680905435X

2,4-Dichlorobenzaldehyde

Ricardo Cabello ^a, Maksymilian Chruszcz ^a, Wladek Minor ^a,^*

PMCID: PMC2980260 PMID: 21580124

Abstract

In the crystal structure of the title compound, C₇H₄Cl₂O, the molecules form a network of weak C—H⋯O interactions involving the aldehyde O atom and the ortho-H atom on the benzene ring together with C—H⋯O interactions between the formyl groups. Together, these connect the molecules into (10 Inline graphic ) layers, which are stabilized additionally by π–π stacking interactions of the benzene rings [centroid–centroid distance = 3.772 (1) Å]. The aldehyde group is twisted relative to the benzene ring by 7.94 (13)°.

Related literature

For applications of the title compound, see: Katagi (1988 ▶); Wang et al. (2004 ▶). For a related structure, see: Gawlicka-Chruszcz et al. (2006 ▶).

Experimental

Crystal data

C₇H₄Cl₂O
M _r = 175.01
Monoclinic,
a = 13.100 (1) Å
b = 3.772 (1) Å
c = 15.332 (1) Å
β = 113.797 (2)°
V = 693.2 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.85 mm⁻¹
T = 100 K
0.40 × 0.10 × 0.10 mm

Data collection

Rigaku R-AXIS RAPID diffractometer
Absorption correction: multi-scan (Otwinowski et al., 2003 ▶) T _min = 0.90, T _max = 0.92
6924 measured reflections
3737 independent reflections
3221 reflections with I > 2σ(I)
R _int = 0.063

Refinement

R[F ² > 2σ(F ²)] = 0.036
wR(F ²) = 0.114
S = 1.10
3737 reflections
107 parameters
All H-atom parameters refined
Δρ_max = 0.67 e Å⁻³
Δρ_min = −0.41 e Å⁻³

Data collection: HKL-2000 (Otwinowski & Minor, 1997 ▶); cell refinement: HKL-2000; data reduction: HKL-2000; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶) and HKL-3000SM (Minor et al., 2006 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶) and HKL-3000SM; molecular graphics: HKL-3000SM, ORTEPIII (Burnett & Johnson, 1996 ▶), ORTEP-3 (Farrugia, 1997 ▶), Mercury (Macrae et al., 2006 ▶) and POV-RAY (The POV-RAY Team, 2004 ▶); software used to prepare material for publication: HKL-3000SM.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053680905435X/gk2246sup1.cif

e-66-0o243-sup1.cif^{(14.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680905435X/gk2246Isup2.hkl

e-66-0o243-Isup2.hkl^{(183.2KB, hkl)}

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
C7—H7⋯O1ⁱ	0.946 (17)	2.533 (17)	3.4289 (11)	158.0 (14)
C6—H6⋯O1ⁱⁱ	0.950 (19)	2.512 (17)	3.2774 (11)	137.8 (12)

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

This work was supported by contract GI11496 from HKL Research, Inc.

supplementary crystallographic information

Comment

2,4-Dichlorobenzaldehyde is primarily used in the preparation of dyes, insecticides, herbicides, antiseptics and disinfectants (Wang et al., 2004). It is also used as an intermediate of organic synthesis of fungicide diniconazole (Katagi, 1988).

In the crystal structure of 2,4-dichlorobenzaldehyde (Fig. 1), the aldehyde group is twisted relative to the benzene ring with torsion angles C6—C1—C7—O1 and C2—C1—C7—O1 being -7.94 (13)° and 170.86 (9)°. These torsion angles are significantly smaller in comparison to the corresponding angles in 2,6-dichlorobenzaldehyde (Gawlicka-Chruszcz et al., 2006) which are -27.3° and 152.6° respectively. Significantly bigger twist of the aldehyde group in the case of 2,6-dichlorobenzaldehyde is caused by presence of the chlorine atoms in ortho positions.

The change of the position of chlorine atom causes that interactions in which chlorine atoms are involved in 2,4-dichlorobenzaldehyde and 2,6-dichlorobenzaldehyde differ significantly. In the case of 2,6-dichlorobenzaldehyde Cl2 was involved in weak interaction with hydrogen atom from neighboring benzene ring, while in 2,4-dichlorobenzaldehyde structure such interactions are not observed for any of the chlorine atoms. However, in the case of 2,4-dichlorobenzaldehyde, the chlorine atoms from neighboring molecules form short contacts with Cl1···Cl2 (1/2 + x,1/2 - y,1/2 + z) distance being 3.442Å (Fig. 2).

The weak O···H—C interactions (Table 1) between the aldehyde oxygen and the benzene hydrogen atoms connect molecules to form layers, which are additionally stabilized by stacking of benzene rings (Fig. 2). The oxygen atom from the aldehyde group plays a central role in the formation of weak interactions, and O1···H6—C6 (1 - x,-1 - y,1 - z) and O1···H7—C7 (1,5 - x,-1/2 + y,1.5 - z) distances are 2.51Å and 2.53Å respectively.

Experimental

2,4-dichlorobenzaldehyde was purchased from ALDRICH (99% purity, lot 08722CD). The compound was provided in crystalline form.