The preparation of S7BrMF6 (M = As, Sb), and the preparation and crystal structure of (S7Br)4S4(AsF6)6 containing the bromo-cycloheptasulphur (1+) cation

• Published in: Canadian journal of chemistry 1985-06, Vol.63 (6), p.1209-1214
• Main Authors: Passmore, Jack, Sutherland, George, Whidden, Tom K, White, Peter S, Wong, Chi-Ming
• Format: Article
• Language: English
• Subjects: Chemistry; Condensed matter: structure, mechanical and thermal properties; Elements and non-metal compounds (oxides, hydroxides, hydrides, sulfides, carbides, ...); Exact sciences and technology; Hydrides, borides, nitrides, etc., and metalloidal compounds; Inorganic chemistry and origins of life; Inorganic compounds; Physics; Preparations and properties; Structure of solids and liquids; crystallography; Structure of specific crystalline solids
• ISSN: 0008-4042; 1480-3291
• DOI: 10.1139/v85-206

S 7 BrMF 6 (M = As, Sb) were prepared essentially quantitatively by a variety of similar routes to those that led to S 7 IMF 6 ; and in addition, by the reaction of bromine and S 7 IAsF 6 . (S 7 Br) 4 S 4 (AsF 6 ) 6 was prepared essentially quantitatively directly from sulphur, bromine, and arsenic pentafluoride in the appropriate ratios. Crystals of (S 7 Br) 4 S 4 (AsF 6 ) 6 are isostructural with (S 7 I) 4 S 4 (AsF 6 ) 6 space group P 4 /n, a = 19.19(3), c = 8.01(1) Å. The structure was refined from a low temperature set of data to a final R = 0.12. The salt contains a discrete planar S 4 2+ and bromo-cycloheptasulphur (1+) cations, the latter having a similar geometry, sulphur-sulphur bond distances and an intra-cationic halogen-sulphur contact to that observed in S 7 I + .