Contribution to Halo‐Chalcogenates Chemistry
Authors: Janickis Vitalijus 
Published: November 2011

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, [NPhMe3]2[SeBr4]·[NPhMe3]Br, a mixed bis(trimethylphenylammonium) tetra(bromido/chlorido)selenate(II), [NPhMe3]2[SeBr4–xClx]·[NPhMe3]2SeBr1–yCly], [NPhMe3]2[SeBr4–xClx],the haxahalogenidodiselenates(II) – bis(trimethylphenylammonium) hexabromidodiselenate(II), [NPhMe3]2[Se2Br6], bis(trimethylphenylammonium) hexachloridodiselenate(II), [NPhMe3]2[Se2Cl6], a mixed bis(trimethylphenylammonium) bromido/chlorido‐diselenate(II), [NPhMe3]2[Se2Br5Cl], bis(tetraphenylphosphonium) hexabromidodiselenate(II), [PPh4]2[Se2Br6], bis(ethyltriphenylphosphonium) hexabromidodiselenate(II), [PEtPh3]2[Se2Br6], and bis(methyltriphenylphosphonium) hexabromidodiselenate(II), [PMePh3]2[Se2Br6], 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), [NPhMe3]2[Se4Br6], bis(benzyltrimethylammonium) hexabromidotetraselenate(I), [NBzMe3]2[Se4Br6], and bis(tetramethylammonium) octadecabromidohexadecaselenate(I), [NMe4]2[Se16Br18], were isolated. First mixed‐valence bromidoselenates(II/I) – bis(tetraethylammonium) octabromidotriselenate(II){dibromidodiselenate(I)}, [NEt4]2[Se3Br8(Se2Br2)], bis(tetraphenylphosphonium) hexabromidodiselenate(II)‐bis{dibromidodiselenate(I)}, [PPh4]2[Se2Br6(Se2Br2)2], and tetrakis(tetramethylammonium) bis{decabromidotetraselenate(II)}‐bis{dibromidodiselenate(I)}, [(CH3)4N]4[(Se4Br10)2(Se2Br2)2] – were synthesized. Mixed bis(trimethylphenylammonium) hexabromidoselenate/tellurate(IV), [NPhMe3]2[Se0.75Te0.25Br6], catena‐poly[(di‐μ‐bromidobis‐{tetrabromidoselenate/tellurate(IV)})‐ μ‐bromine], [NPhMe3]2n[Se1.5Te0.5Br10·Br2]n were isolated. First mixed‐valence bromidoselenate(IV/I)‐bis(trimethylphenylammonium) hexabromidoselenate(IV)‐bis{dibromidodiselenate(I)}, [NPhMe3]2[SeBr6(Se2Br2)2], a number of mixed bromidochalcogenates(IV/I) – bis(trimethylphenylammonium), bis(tetraethylphosphonium), bis(ethyltriphenylphosphonium) hexabromidotellurates(IV)‐bis{dibromidodiselenates(I)}, [NPhMe3]2[TeBr6(Se2Br2)2], [PEt4]2[TeBr6(Se2Br2)2], [PEtPh3]2[TeBr6(Se2Br2)2], bis(triethylmethylammonium) hexabromidotellurate(IV)‐tris{dibromidodiselenate(I)}, [NMeEt3]2n[TeBr6(Se2Br2)3]n, were synthesized. Mixed‐valence bromidoselenate(IV/II) – bis(methyltriphenylphosphonium) hexabromidoselenate(IV)‐bis{dibromidoselenate(II)},[PMePh3]2[SeBr6(SeBr2)2], received by direct synthesis and two mixed‐valence bromidochalcogenates(IV/II) – bis(methyltriphenylphosphonium) and bis(tetrapropylammonium) hexabromidotellurates(IV)‐selenates(II), [PMePh3]2[TeBr6(SeBr2)2] and [NnPr4]2[TeBr6(SeBr2)2], were synthesized from elemental selenium, tellurium dioxide, and corresponding onium bromide. The structures of all compounds were determined by X‐ray diffraction.