Strategy. Our strategy is to use substituted cyclopentadienyl ligands that are more heavily substituted than the 1,3-(Me 3 E) 2 C 5 H 3 (E = C, Si) ligands, since these less substituted cyclopentadienyl ligands yield oxo-dimers of the type (η 5 -1,3-R 2 C 5 H 3 ) 4 U 2 (μ-O) 2 (R = SiMe 3 , CMe 3 ), which have been prepared by two synthetic routes: the reaction of the corresponding dimethyl derivatives with water or the thermal oxidative elimination of dihydrogen from the ...
