N-(3-Chlorophenyl)maleimide

The title compound, C10H6ClNO2, has a dihedral angle of 46.46 (5)° between the benzene and maleimide rings. A short intermolecular halogen–oxygen contact is observed, with a Cl⋯O distance of 3.0966 (13) Å. Both CO groups are involved in two C—H⋯O interactions, which gives rise to sheets parallel to (100). In addition, these sheets exhibit a π–π stacking interaction between the benzene and maleimide rings [mean interplanar distance of 3.337 (3) Å].

The title compound, C 10 H 6 ClNO 2 , has a dihedral angle of 46.46 (5) between the benzene and maleimide rings. A short intermolecular halogen-oxygen contact is observed, with a ClÁ Á ÁO distance of 3.0966 (13) Å . Both CO groups are involved in two C-HÁ Á ÁO interactions, which gives rise to sheets parallel to (100). In addition, these sheets exhibit astacking interaction between the benzene and maleimide rings [mean interplanar distance of 3.337 (3) Å ].
RMF is grateful to the Instituto de Química Física Rocasolano, CSIC, Spain, for the use of the license for the Cambridge Structural Database System (Allen, 2002). RMF and ZPB acknowledge the Universidad del Valle, Colombia for partial financial support.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: FJ2114).

Comment
Due to the interest created by the N-substituted maleimides in free radical polymerization process upon exposure to light (Howell & Zhang, 2006), the synthesis and study of the crystal structure of N-(m-chlorophenylmaleimide) (I) was under- -Fuquen et al., 2006) and N-(o-chlorophenyl) maleimide (2ClPMI) (Miller et al., 2001) systems can be taken as a reference systems to compare with the structural characteristics of (I). Perspective view of (I), showing the atomic numbering scheme, is given in Fig. 1. Photochemical properties of arylmaleimide systems have shown that they depend on the value of the dihedral angle between the benzene and imidic rings (Miller et al., 2000). This angle is 56.2 (1)° and 52.9 (1)° for 3NPMI, 66.10 (4) ° for 2ClPMI, and 46.46 (5)° for (I). The molecules of (I) are linked into sheets by a combination of C-H···O hydrogen bonds (Nardelli, 1995) (Table 1). Indeed, the atoms C3 i in the molecule at (3/2 -x, 1/2 + y, 1/2 -z) and C8 ii in the molecule at (-1/2 + x, 1/2 -y, -1/2 + z) act as hydrogen-bond donors to maleimidic O2 atom in the molecule at (x, y, z), so generating by 2 1 screw axis a C(6) chain (Etter, 1990), which is running parallel to [010] direction (Fig. 2, supp. material). Within the asymmetric unit the atom C2 at (x, y, z) acts as hydrogen bond donor to maleimidic O1 iii in the molecule at (2 -x, -y, -z), so forming by translation a R 2 2 (14) centrosymmetric rings (Etter, 1990); in addition, atom C8 at (x, y, z) acts as a hydrogen bond donor to maleimidic O1 ii in the molecule at (2 -x, -y, 1 -z), so generating by translation a R 2 2 (8) centrosymmetric rings. Both rings are running along [001] direction (Fig.3, supp. material). In addition, (I) exhibits an aromatic π···π stacking interactions between benzene and maleimide rings with a mean interplanar distance of 3.337 (3) Å. The halogen-oxygen interaction is recognized as a strong driving force in formation of molecular crystals (Sureshan et al., 2001). (I) shows a short Cl···O intermolecular contact, disposed about an inversion centre. The Cl1···O2, shows a distance of 3.0966 (13) Å, [O2 with symmetry 2 -x, 1 -y, -z] and this contact is shorter than the sum of their van der Waalś radii (3.27 Å, Metrangolo & Resnati, 2001). In (I), the angle of the oxygen O2 relative to the C6-Cl bond shows a slight deviation from linearity with a value of 174.31 (6)° and the angle of the chlorine atom relative to the C10-O2 bond shows a value of 136.96 (11)°, suggesting strong halogen bonding. This could also prevent a larger rotation between the planes of (I). The title system does not have enough influence on the processes of polymerization because the dihedral angle between their rings possess a low value with respect to other systems with substituents in the position ortho (Miller et al., 2000).

Experimental
Reagents and solvents for the synthesis were from Aldrich Chemical Co. and they were used without additional purification.
Column chromatography was performed using silica gel H60 to purify the intermediates and final products. Thin layer chromatography (TLC) was used to confirm the structure of the individual compounds.