COORDINATIVE BEHAVIOR OF THE PENTAFLUOROP HENYLXENONIUM SALT [C6F5XE](-) TO PYRIDINES OF DIFFERENT BASICITY()[ASF6]()

The arylxenonium cation in the salt [C6F5Xe](+) [AsF6](-) is isoelectr onic to C6F5I, but coordinatively unsaturated with respect to N-bases like MeCN and pyridines. Go-ordination of strongly basic pyridines cau ses weakening of the Xe-C bond and C,FS radical formation. The thermal decomposition of pyridine co-ordinated arylxenonium cations gives thr ee groups of products: C-pentafluorophenylated pyridines, N-pentafluor ophenylated pyridinium and N-protonated pyridinium salts. The co-ordin ation ability of the different pyridines shows a good correlation (C6F 5 group) with the F-19 NMR shift values of the p-F atom and the coupli ng constants (3)J(F-19-Xe-129). An X-ray structure analysis was perfor med for the co-ordination product [C6F5Xe . 2,6-C5H3F2N](+) [AsF6](-) and for [C6F5-C5H5N](+) [(C6F5)(2)BF2](.), which was obtained by therm olysis of the corresponding adduct.