On the attempted synthesis of salts with the trimethyl[bis(pentafluorophenyl)]silicate ion, [Me3Si(C6F5)2]−—A polyphenyl problem

Reactions of Me3SiC6F5 and MF (M = Cs, [NMe4]) in molar ratios varying from 1:1 to 2:1 in a temperature range between −70 °C and ambient proceed more or less selectively to form 1-H-perfluoro-4,4′-polyphenyls, 1-H(C6F4)nF, independent of the solvent used (DME, THF). The silicates expected, M[Me3Si(C6F5)F] and M[Me3Si(C6F5)2], were not detected even in low temperature NMR experiments. lymeric material formed was identified after aqueous working up as a mixture of 1-H(C6F4)nF (n = 4–13) by elemental analyses and EI mass spectrometric studies.