New polyfluorinated aromatic and aza-aromatic diselenides, selenyl chlorides, non-symmetric selenides and selenoxides

New polyfluorinated ArSeSeAr, ArSeCl (Ar = 4-RC6F4-1-yl, 5-HC5F3N-3-yl), non-symmetric ArSeAr′ (Ar = 4-RC6F4-1-yl, Ar′ = 4-NC5F4-1-yl) and non-symmetric, i.e. chiral, ArSe(O)Ar′ (Ar = Ar = 4-RC6F4-1-yl, Ar′ = 4-NC5F4-1-yl) derivatives, as well as (4-NC5F4-1-yl)SeNa, were prepared and characterized by single-crystal X-ray diffraction and multinuclear NMR (1H, 13C, 14N, 19F, 77Se).