ISSN:
1434-1948
Schlagwort(e):
Lanthanide(III)
;
Ytterbium
;
Aryloxides
;
Fluorine
;
C-F Activation
;
Chemistry
;
General Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
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.
Zusätzliches Material:
6 Ill.
Materialart:
Digitale Medien
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