Structural aspects of some organoselenium compounds

The crystal structures of four organoselenium compounds, viz. bis(2-formylphenyl)diselenide (5), bis(2-methylnaphthyl)diselenide (6), organoselenenyl sulfide (7), and spiroselenurane (8) are described. Crystal data for 5: space group Pca21, crystal system orthorhombic, a=7.9969(4) Å, b=20.8794(12) Å, c=15.8307(13) Å, Z=8, R=0.0292. Owing to the presence of a strong Se···O interaction in compound 5 the geometry around the selenium atom may be considered as T-shaped. Crystal data for 6: space group Pna21, crystal system orthorhombic, a=18.2253(12) Å, b=13.0714(8) Å, c=7.7355(5) Å, Z=4, R=0.0570. The molecule has a cisoid conformation. Crystal data for 7: space group Pbcn, crystal system orthorhombic, a=22.2144(13) Å, b=8.0255(4) Å, c=15.4496(9) Å, Z=8, R=0.0292. Due to intramolecular Se···N interaction in 7 the geometry around selenium is T- shaped. Crystal data for 8: space group P21/c, crystal system monoclinic, a=7.4585(5) Å, b=19.5634(13) Å, c=8.0428(5) Å, β=97.1320(10)°, Z=4, R=0.0254. The O-Se-O angle is 172.86(6)°