Contribution to Halo‐Chalcogenates Chemistry

Abstract. By direct reactions of selenium with halogen and trimethylphenylammonium halogenide and tetraphenylphosphonium, ethyltriphenylphosphonium, and methyltriphenylphosphonium bromides, the tetrahalogenidoselenates(II) – bis(trimethylphenylammonium)tetrabromidoselenate(II) bromide, [NPhMe 3 ] 2 [SeBr 4 ] · [NPhMe 3 ]Br, a mixed bis(trimethylphenylammonium) tetra(bromido/chlorido)selenate(II), [NPhMe 3 ] 2 [SeBr 4– x Cl x ] · [NPhMe 3 ] 2 SeBr 1– y Cl y ], [NPhMe 3 ] 2 [SeBr 4– x Cl x ],the haxahalogenidodiselenates(II) – bis(trimethylphenylammonium) hexabromidodiselenate(II), [NPhMe 3 ] 2 [Se 2 Br 6 ], bis(trimethylphenylammonium) hexachloridodiselenate(II), [NPhMe 3 ] 2 [Se 2 Cl 6 ], a mixed bis(trimethylphenylammonium) bromido/chlorido‐diselenate(II), [NPhMe 3 ] 2 [Se 2 Br 5 Cl], bis(tetraphenylphosphonium) hexabromidodiselenate(II), [PPh 4 ] 2 [Se 2 Br 6 ], bis(ethyltriphenylphosphonium) hexabromidodiselenate(II), [PEtPh 3 ] 2 [Se 2 Br 6 ], and bis(methyltriphenylphosphonium) hexabromidodiselenate(II), [PMePh 3 ] 2 [Se 2 Br 6 ], were prepared. By the reaction of selenium with bromine in acetonitrile in the presence of trimethylphenylammonium, benzyltrimethylammonium, and tetramethylammonium bromides, the salts of the unique bromidoselenate(I) anions – bis(trimethylphenylammonium) hexabromidotetraselenate(I), [NPhMe 3 ] 2 [Se 4 Br 6 ], bis(benzyltrimethylammonium) hexabromidotetraselenate(I), [NBzMe 3 ] 2 [Se 4 Br 6 ], and bis(tetramethylammonium) octadecabromidohexadecaselenate(I), [NMe 4 ] 2 [Se 16 Br 18 ], were isolated. First mixed‐valence bromidoselenates(II/I) – bis(tetraethylammonium) octabromidotriselenate(II){dibromidodiselenate(I)}, [NEt 4 ] 2 [Se 3 Br 8 (Se 2 Br 2 )], bis(tetraphenylphosphonium) hexabromidodiselenate(II)‐bis{dibromidodiselenate(I)}, [PPh 4 ] 2 [Se 2 Br 6 (Se 2 Br 2 ) 2 ], and tetrakis(tetramethylammonium) bis{decabromidotetraselenate(II)}‐bis{dibromidodiselenate(I)}, [(CH 3 ) 4 N] 4 [(Se 4 Br 10 ) 2 (Se 2 Br 2 ) 2 ] – were synthesized. Mixed bis(trimethylphenylammonium) hexabromidoselenate/tellurate(IV), [NPhMe 3 ] 2 [Se 0.75 Te 0.25 Br 6 ], catena ‐poly[(di‐μ‐bromidobis‐{tetrabromidoselenate/tellurate(IV)})‐ μ‐bromine], [NPhMe 3 ] 2n [Se 1.5 Te 0.5 Br 10 · Br 2 ] n were isolated. First mixed‐valence bromidoselenate(IV/I)‐bis(trimethylphenylammonium) hexabromidoselenate(IV)‐bis{dibromidodiselenate(I)}, [NPhMe 3 ] 2 [SeBr 6 (Se 2 Br 2 ) 2 ], a number of mixed bromidochalcogenates(IV/I) – bis(trimethylphenylammonium), bis(tetraethylphosphonium), bis(ethyltriphenylphosphonium) hexabromidotellurates(IV)‐bis{dibromidodiselenates(I)}, [NPhMe 3 ] 2 [TeBr 6 (Se 2 Br 2 ) 2 ], [PEt 4 ] 2 [TeBr 6 (Se 2 Br 2 ) 2 ], [PEtPh 3 ] 2 [TeBr 6 (Se 2 Br 2 ) 2 ], bis(triethylmethylammonium) hexabromidotellurate(IV)‐tris{dibromidodiselenate(I)}, [NMeEt 3 ] 2n [TeBr 6 (Se 2 Br 2 ) 3 ] n , were synthesized. Mixed‐valence bromidoselenate(IV/II) – bis(methyltriphenylphosphonium) hexabromidoselenate(IV)‐bis{dibromidoselenate(II)},[PMePh 3 ] 2 [SeBr 6 (SeBr 2 ) 2 ], received by direct synthesis and two mixed‐valence bromidochalcogenates(IV/II) – bis(methyltriphenylphosphonium) and bis(tetrapropylammonium) hexabromidotellurates(IV)‐selenates(II), [PMePh 3 ] 2 [TeBr 6 (SeBr 2 ) 2 ] and [N n Pr 4 ] 2 [TeBr 6 (SeBr 2 ) 2 ], were synthesized from elemental selenium, tellurium dioxide, and corresponding onium bromide. The structures of all compounds were determined by X‐ray diffraction.