supplementary materials

In continuation of our studies of carbazole derivatives, which are found to possess various biological activities, such as antitumor (Itoigawa et al., 2000), antioxidative (Tachibana et al., 2001), anti-inflammatory and antimutagenic (Ramsewak et al., 1999), the crystal structure of the title compound has been determined. These compounds are thermally and photochemically stable, which makes them useful materials for technological applications. For instance, the carbazole ring is easily functionalized and covalently linked to other molecules (Diaz et al., 2002). This enables its use as a convenient building block for the design and synthesis of molecular glasses, which are widely studied as components of electroactive and photoactive materials (Zhang et al., 2004).

The geometric parameters of the title molecule (Fig. 1) agree well with reported similar structures (Chakkaravarthi et al., 2008a,b; Hökelek et al., 1998). The mean planes of thieno[2,3-b]carbazole and phenyl rings are inclined at an angle of 63.6 (1)°. Thiophene ring C21/C22/C23/C24/S3 forms a dihedral angle of 49.2 (1)° with phenyl ring. The methoxy group is slightly twisted [torsion angle C16—C17—O3—C25 is 13.9 (5)°] out of the plane of the benzene ring C15–C20.

The N—C bond lengths, namely N1—C7 and N1—C20 [1.434 (4) and 1.450 (4) Å] deviate slightly from the normal mean value reported in the literature (Allen et al., 1987). This indicates that the substitution of the phenylsulfonyl group at atom N1 results the lengthening of C—N bond lengths. This may be due to the electron-withdrawing character of the phenylsulfonyl group (Govindasamy et al., 1998).

A distorted tetrahedral geometry around S1 is observed. The deviations being seen for the O—S—O [O1—S1—O2 119.3 (1)°] and O—S—N [O1—S1—N1 106.8 (1)°] angles. The widening of the angles may be due to repulsive interactions between the two short S═O bonds, similar to what is observed in similar structures (Chakkaravarthi et al., 2008a,b). The sum of the bond angles around N1 [343.3 (2)°] indicate the sp² hybridized state of the atom N1 in the molecule.

The torsion angles O1—S1—N1—C7 and O1—S1—C1—C6 [50.2 (2)° and -22.3 (3)°, respectively] describe the syn conformation of the phenylsulfonyl group with respect to carbazole ring system. This conformation is influenced by the intramolecular C—H··· O hydrogen bonds (Table 1); C6—H6··· O1, C8—H8··· O1 and C19—H19···O2, involving sulfonyl atoms O1 and O2. In addition, intramolecular C8—H8···O1 and C19—H19···O2 hydrogen bonds form six-membered rings, both with a graph-set motif of S(6) and C19—H19···O2 forms five-membered ring, with graph-set motif of S(5). The intermolecular C22—H22—S2 interaction generates a ten-membered ring, with graph-set motif of R₂²(10) (Etter et al., 1990).

The crystal structure of the title compound is stabilized by weak intermolecular C—H···S (Fig. 2 and Table 1) and π–π [Cg1···Cg3(2 - x, -y, -z) distance of 3.781 (2) Å; Cg1···Cg5(2 - x, -y, -z) distance of 3.734 (2) Å; Cg2···Cg6(2 - x, -y, -z) distance of 3.888 (2) Å, Cg3···Cg1(2 - x, -y, -z) distance of 3.781 (2) Å, Cg5···Cg5(2 - x, -y, -z) distance of 3.770 (2) Å and Cg6···Cg2(1 - x, 1 - y, -z) distance of 3.888 (2) Å (Cg1, Cg2, Cg3, Cg5 and Cg6 are the centroid of the rings defined by the atoms S2/C9/C12/C11/C10, S3/C21/C22/C23/C24, N1/C7/C14/C15/C20, C7/C8/C9/C12/C13/C14 and C15–C20, respectively)] interactions.