Reaction of [Yb(OAr)2(THF)3] (OAr = OC6H2-2,6-tBu2-4-R; R = H, Me, tBu) with perfluorodecalin in THF at room temperature results in C-F activation and formation of the first heteroleptic aryloxofluorolanthanoid complexes, [Yb(OAr)2F(THF)]2. Oxidation of bis(cyclopentadienyl)ytterbium(II) with perfluoro(methylcyclohexane) or perfluorodecalin in DME surprisingly gives unsolvated [YbCp2F]3: The analogous reaction of bis(methylcyclopentadienyl)ytterbium(II) yields unsolvated [Yb(MeCp)2F]4, whilst in THF; the oxidation provides [Yb(MeCp)2F(THF)]2. Treatment of [YbCp2F(THF)]2 with triphenylphosphane oxide gives [YbCp2F(OPPh3)]2. X-ray structure determinations revealed [Yb(OAr)2F(THF)]2 (R = H or tBu) to be centrosymmetric fluoride-bridged dimers with five-coordination for ytterbium. Examination of the structures of the cyclopentadienyl complexes showed that [YbCp2F]3 is trimeric with formal eight-coordination for ytterbium and a planar (YbF)3 ring, whereas [Yb(MeCp)2F]4 is an eight-coordinate tetramer having a puckered (YbF)4 ring with F-Yb-F angles of ca. 90°and Yb-F-Yb angles close to 180°[178.9(4), 168.4(3)°]. Both [Yb(-MeCp)2F(THF]2 and [YbCp2F(OPPh3)]2 are nine-coordinate fluoride-bridged dimers.
|Number of pages||11|
|Journal||European Journal of Inorganic Chemistry|
|Publication status||Published - 1 Jan 2000|
- C-F activation