Ruthenocene mit sterisch anspruchsvollen cyclopentadienylliganden: Ruthenocene complexes containing sterically demanding cyclopentadienyl ligands

1-tert-Butyl-2,4-cyclopentadiene (1), 1,3-di(tert-butyl)-2,4-cyclopentadiene (2), 1-ethyl-2,3,4,5-tetramethyl-2,4-cyclopentadiene (3), 1-iso-propyl-2,3,4,5-tetramethyl-2,4-cyclopentadiene (4), 1-tert-butyl-2,3,4,5-tetramethyl-2,4-cyclopentadiene (5), and l-phenyl-2,3,4,5-tetramethyl-2,4-cyclopentadiene (6) react with n-butyl lithium followed by tributyltin chloride to give the corresponding tributyl(cyclopentadienyl)stannanes Bu 3 SnCp # la to 6a. The reactions of la to 6a with Ru(COD)Cl 2 result in the formation of the corresponding ruthenocenes RuCp # 2 1b to 6b. Ru(C 5 H 3 Ph 2 ) 2 (7b) is prepared from [Ru(p-cymol)Cl 2 ] 2 and Na[C 5 H 3 Ph 2 ]. The 1 H and 1 3 C NMR spectra of the new stannanes la to 6a and the ruthenocenes 1b to 7b as well as the single crystal X-ray structure of 4b are reported and discussed.