PHENYLETHYNYL COMPLEXES OF TITANOCENE AND VANADOCENE

The syntheses and properties of (C5H5)2VIV(CCC6H5)2, (C5H5)2VIII(CCC6H5), (C5H5)2TiIV(CCC6H5)2 and of a diamagnetic complex of composition [(C5)2TiIII(CCC6H5)]2 are reported. In the first three compounds the CCC6H5 groups are σ-bonded to the metal atoms, while in [(C5H5)2TiIII(CCC6H5)]2 the CCC6H5 groups are probably bridging ligands. The isolation of (C5H5)2VIV(CCC6H5)2 strongly supports our hypothesis1.2 that the failure to obtain other complexes (C5H5)2VIVR2(R = alkyl, aryl) is due to steric reasons. The stability of the compound [(C5H5)2TiIII(CCC6H5)]2, which is in marked contrast with the instability of other complexes (C5H5)2TiIIIR, supports our hypothesis that in stable complexes containing the (C5H5)2Ti group the metal atom is coordinated by two ligands (or one bidentate ligand) in addition to the two C5H5 groups1,2. © 1969.