3-Bromomethyl-4-methoxy-2-(2-nitrophenyl)-9-phenylsulfonyl-9H-carbazole

In the title compound, C26H19BrN2O5S, the carbazole tricycle is essentially planar, with the largest deviation being 0.126 (3) Å for the C atom connected to the nitrophenyl group. The carbazole moiety is almost orthogonal to the benzene rings of the adjacent phenylsulfonyl and nitrophenyl groups, making dihedral angles of 85.43 (15) and 88.62 (12)°, respectively. The molecular conformation is stabilized by two C—H⋯O hydrogen bonds involving the sulfone group, which form similar six-membered rings. In the crystal, molecules symmetrically related by a glide plane are linked in C(6) chains parallel to [001] by C—H⋯O hydrogen bonds formed with the participation of the nitro group. The chains are reinforced by additional C—H⋯π interactions.

In the title compound, C 26 H 19 BrN 2 O 5 S, the carbazole tricycle is essentially planar, with the largest deviation being 0.126 (3) Å for the C atom connected to the nitrophenyl group. The carbazole moiety is almost orthogonal to the benzene rings of the adjacent phenylsulfonyl and nitrophenyl groups, making dihedral angles of 85.43 (15) and 88.62 (12) , respectively. The molecular conformation is stabilized by two C-HÁ Á ÁO hydrogen bonds involving the sulfone group, which form similar six-membered rings. In the crystal, molecules symmetrically related by a glide plane are linked in C(6) chains parallel to [001] by C-HÁ Á ÁO hydrogen bonds formed with the participation of the nitro group. The chains are reinforced by additional C-HÁ Á Á interactions.

Comment
Carbazole and its derivatives have become quite attractive compounds owing to their applications in pharmacy and molecular electronics. It has been reported that carbazole derivatives exihibit various biological activities such as antitumor and antioxidative (Itoigawa, et al. 2000), and anti-inflammatory and anti-mutagenic (Ramsewak, et al. 1999).
They also exhibit electroactivity and luminenscence and are considered to be potential candidates for electronic applications such as colour displays, organic, semi-conductors, laser and solar cells (Friend, et al. 1999;Zhang et al. 2004).
The title compound, Fig. 1, comprises a carbazole ring system which is attached to a phenylsulfonyl group, a nitrophenyl, a methoxy and a bromomethyl group. The carbazole ring system is essentially planar with maximum deviation of -0.126 (3) Å for the carbon atom C10. The oxygen atom O5 significantly deviates from the carbazole ring by 0.1560 (22) Å. The carbazole ring is almost orthagonal to phenyl ring attached to sulfonyl group and nitrophenyl ring with dihedral angles of 85.43 (15)° and 88.62 (12)°, respectively.
The sum of the bond angles around N1 [353.6°] indicate the sp 2 hybridization. The nitrogen atom N2 is almost in the plane of phenyl ring with the torsional angle of C21-C20-C25-N2 = -179.6 (3)°. The bromine atom forms the torsional The molecular structure is stabilized by C-H···O hydrogen bonds (Table 1 Fig. 1), which generate two S(6) ring motifs. In the crystal packing, molecules are linked via C23-H23···O1 i intermolecular hydrogen bonding, which generate C(6) infinite chains running parallel to the base vector [0 0 1]. The crystal packing is further stabilized by C22-H22···Cg1 ii intermolecular interaction, where the Cg1 is the centre of gravity of the benzene ring(C7-C12) (Bernstein, et al. 1995). The packing view of the title compound shown in the Fig-2 and Fig-3. The symmetry codes are: (i) x, -y + 1/2

Refinement
The positions of the hydrogen atoms were localized from the difference electron density maps and the distances were geometrically constrained. The hydrogen atoms bound to the C atoms are treated as riding atoms, with d(C-H) = 0.93 Å and U iso (H) = 1.2Ueq (c) for aromatic and methoxy group, d(C-H) = 0.96 Å and U iso (H) = 1.5Ueq(c) for the bromomethyl group. The rotation angle for the methyl group was optimized by least squares.

Figure 1
The molecular Structure of the title compound with the atom numbering scheme, displacement ellipsoids are drawn at 30% probability level. H atoms are present as small spheres of arbitrary radius.  Part of the crystal packing of the title compound viewed down b axis. the dashed lines indicate C22-H22···Cg1 ii interactions, where the Cg1 is the centre of the gravity of (C7-C12). Symmetry code: (ii) x, -y + 1/2, +z -3/2 Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.