π-H3C5(Me2Si) (Me2SiSiMe2)-π-C5H3: Ein neuartiger, zweifach verbrückter Dicyclopentadienyl-Ligand: Synthese und beispielhafter Einsatz in der Komplexchemie

Abstract Deprotonation of dicyclopentadienyldimethylsilane with two equivalents of n -butyllithium and subsequent reaction with 1,2-dichlorotetramethyldisilane yields the double-bridged dicyclopentadiene H 4 C 5 (SiMe 2 XSi 2 Me 4 )C 5 H 4 (1 = H 2 L). Reaction of 1 with two equivalents of n -butyllithium leads to the dilithio compound Li 2 [H 3 C 5 (SiMe 2 )(Si 2 Me 4 )C 5 H 3 ] ( 2 = Li 2 L) with the bridging dimethylsilyl and tetramethyldisilanyl group in 1,2 position (ortho-position) at each cyclopentadienyl unit. 2 is used as starting material for the exemplary synthesis of the following metal complexes: Cp″Cl 2 ZrLZrCl 2 Cp″ ( 3 ; Cp″ = 1,3-(t-Bu) 2 C 5 H 3 ), Cp″Cl 2 ZrLH ( 4 ); Me 5 C 5 RuLRuC 5 Me 5 (syn: 5a ; anti: 5b ); syn -(CO) 2 CoLCo(CO) 2 ( 6 ). All compounds are characterized by spectroscopic and analytical data. X-ray crystal structures are presented for 1 and for 3 . Stereochemical effects in metal complexes with the new unsymmetrically bridged dicydopentadienyl ligand L are discussed.