(Z)-2-[(4-Methylphenyl)sulfonyl]-1,2-diphenyletheneselenol

In the title compound, C21H18O2SSe, the dihedral angle between the cis phenyl rings is 64.3 (1)° and those between the toluene and the phenyl rings are 21.1 (2) and 72.0 (1)°, respectively. An intramolecular Se—H⋯O hydrogen bond occurs. In the crystal, molecules are connected by C—H⋯O hydrogen bonds and weak C—H⋯π interactions help to consolidate the crystal packing.

In the title compound, C 21 H 18 O 2 SSe, the dihedral angle between the cis phenyl rings is 64.3 (1) and those between the toluene and the phenyl rings are 21.1 (2) and 72.0 (1) , respectively. An intramolecular Se-HÁ Á ÁO hydrogen bond occurs. In the crystal, molecules are connected by C-HÁ Á ÁO hydrogen bonds and weak C-HÁ Á Á interactions help to consolidate the crystal packing.

Comment
Selenium is chemically related to sulfur and oxygen and has a wide range of applications in the inorganic field, including uses in semiconductors, photovoltaic and photocell devices, and photographic toner applications. It is used industrially to produce deep red color in glasses and ceramics (Stevenson, 2011). Vinylic selenides are organoselenium compounds that play a role in organic synthesis, especially in the development of convenient stereoselective routes to functionalized alkenes (Comasseto et al., 1997). Selenols have important roles in certain biological processes. Three enzymes namely iodothyronine deiodinase, glutathione peroxidase (Epp et al., 1983) and thioredoxin reductase (Gladyshev et al., 1996) found in mammals contain selenols at their active sites. The selenols in these proteins are part of the essential amino acid selenocysteine (Wessjohann et al., 2007).
The title molecule is an organoselenium compound ( Fig. 1) containing three phenyl rings with vinylic selenol group. The dihedral angle between the cis substituted phenyl rings is 64.3 (1)°. The dihedral angles between the toluene sufonyl and the phenyl rings substituted on C1 and C8 atoms are 21.1 (2)° and 72.0 (1)°, respectively. The molecules are not showing any classical hydrogen bonds, still the molecules accept a Se-H···O type intra (Fig.2) and two C-H···O type intermolecular interactions. In addition, two C-H···π interactions also help to consolidate the molecules in the unit cell crystal packing.
The complete details of the molecular interactions are shown in Table 1.

Experimental
The compound 2-phenylacetophenone (0.1M) was heated with Woollins' reagent (1 equiv.) in toluene to produce 2phenylselenoacetophenone. Then 1 equiv. of this compound was stirred with p-toluenesulfonylchloride (1 equiv.) in the presence of triethylamine (2 equiv.) in dry THF resulted the title compound and was recrystallized using methanol.

Refinement
H atoms were positioned geometrically and refined using a riding model with Se-H = 0.82Å for selenol H, C-H = 0.93 Å for aromatic H and 0.96 Å for methyl H atoms. The U iso values were constrained to be 1.5Ueq of the carrier atom for the methyl and selenol H atoms and 1.2Ueq for the remaining H atoms.