THE DIRECT SYNTHESIS OF ARYLXENON TRIFLUOROMETHANESULFONATES VIA ELECTROPHILIC SUBSTITUTION

The reaction of xenonbis(trifluoroacetate) and trifluoromethanesulfoni c acid (triflic acid) gave the new, highly reactive unsymmetrical xeno n-ore species CF3COOXeOSO2CF3. Benzene derivates, containing electron withdrawing substituents such as -F, -CF3, -Cl or -NO2 were electrophi lic attacked by this intermediate to yield arylxenon trifluoromethanes ulfonates. Via this one-pot synthesis trifluoromethanesulfonates with the cations [Xe(2,4,6-F3C6H2)](+), [Xe(2-F-5-NO2C6H3)](+), [Xe(2-F-5-C F3C6H3)](+) and [Xe(3,5-(CF3)(2)C6H3)](+) were prepared. All compounds were characterized by their NMR, mass, and vibrational spectra.Additi onally, several new arylxenon trifluoromethanesulfonates were detected by Xe-129-NMR spectroscopy as products of the reaction of 1,3-F2C6H4 and further deactivated benzenes with xenontrifluoroacetate trifluorom ethane sulfonate. Fluoro substituents in ortho position to xenon signi ficantly increase the thermal stability of the arylxenon trifluorometh anesulfonates obtained. The molecular structure of [Xe(2,6-F2C6H3)][OS O2CF3] was determined by single crystal diffraction methods. The arylx enon unit is weakly coordinated by one oxygen atom of the CF3SO3 anion . The salt crystallizes in the triclinic space group <P(1)over bar>, a =880.9(3) pm, b=1093.9(5) pm, c=1209.8(5) pm, alpha=89.04(4)degrees, b eta=74.23(3)degrees, gamma=86.03(3)degrees, Z=4.