Bis(4-acetylphenyl) selenide

In the title compound, C16H14O2Se, the dihedral angle between the benzene rings is 87.08 (11)°. In the crystal, molecules are linked into layers parallel to the bc plane by intermolecular C—H⋯O hydrogen bonds.

In the title compound, C 16 H 14 O 2 Se, the dihedral angle between the benzene rings is 87.08 (11) . In the crystal, molecules are linked into layers parallel to the bc plane by intermolecular C-HÁ Á ÁO hydrogen bonds.

Comment
Organoselenides and derivatives are of considerable interest in academia as anti-cancer (Clement et al., 1997), anti-oxydant (Anderson et al., 1996, anti-inflammatory and antiallergic agents (Abdel-Hafez, 2008), and in industry because of their wide involvement as key intermediates for the synthesis of pharmaceuticals (Woods et al., 1993), perfumes, fine chemicals and polymers (Hellberg et al., 1997). In the framework of our ongoing program related to the synthesis and pharmaceutical evaluation of new organoselenide derivatives, we report here the synthesis and crystal structure of the title compound.
In the molecule of the title compound ( Fig. 1), the selenium atom is linked to two phenyl acetyl groups. All bond distances and angles are within the ranges of accepted values (CSD; Allen, 2002). The molecule is not planar, as can be seen from the dihedral angle of 87.08 (11)° between the planes of the two benzene rings. In the crystal structure, molecules are linked into chains running parallel to the c axis by intermolecular C2-H2···O2 hydrogen interactions (Fig. 2, Table 1). The chains are further connected by C12-H12···O1 hydrogen bonds to form layers parallel to the bc plane (Fig. 3).

Experimental
The title compound was prepared according to a literature method (Henry, 1943). Methyl acyl chloride (2.4 mmol) and anhydrous aluminium chloride (3.0 mmol) were dissolved in dry methylene chloride (4 ml). The reaction mixture was cooled at 0-5 °C, protected from atmospheric moisture, and stirred continuously from 15 min. A solution of diphenyl selenide (1 mmol) in methylene chloride (0.5 ml) was then added dropwise over a period of 5 min. The reaction mixture was allowed to reach room temperature gradually and stirred at this temperature overnight. The solution was then washed with ice water-HCl and extracted with methylene chloride. The organic layer was separated and dried over Na 2 SO 4 . Removal of the solvent afforded the crude title product which was recrystallized from CH 3 OH. Some crystals suitable for X-ray diffraction analysis were carefully isolated under polarizing microscope.

Refinement
All H atoms were localized in a Fourier difference map and introduced in calculated positions as riding on their parent C atoms, with C aryl -H = 0.93 Å, C methyl -H = 0.96 Å, and with U iso (H) = 1.5U eq (C methyl ) or U iso (H) = 1.2U eq (C aryl ). Fig. 1. The molecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level.