Reactions of tetraalkynylsilanes (RC C)(4)Si (R = Ph, Bu-t, SiMe3) with titanocene and zirconocene complexes

Reactions of the branched tetraalkynylsilanes (RC=C)(4)Si (1a: R = Ph, 1b: (BU)-B-t, 1c: SiMe3) with the metallocene source Cp2Ti(eta(2)-Me3SiC=CSiM3) (2) led to complexes 4-6, and those of 1a with Cp2Zr(THF)(eta(2)-Me3SiC=CS iMe3) (3) to complex 7. These, via 2-fold migration and C-C coupling of the alkynyl groups, gave a; novel type of dinuclear carbon-rich spiro complexe s, The conversions proved to be independent of the metals, the substituents R, and the stoichiometries employed All new complexes have been characteri zed spectroscopically. Additionally, an X-ray crystal structure analysis wa s performed for 7.