Monocyclopentadienyl-type titanium complexes with the [.eta.5-.eta.5-(C5H4)2SiMe2]2- ligand. X-ray crystal structure of [(TiCl)2(.mu.2-O){.mu.2-.eta.5-.eta.5-(C5H4)2SiMe2}]2(.mu.2-O)2. The first example of a nonplanar titanium oxide ["Ti4O4"] core

Alkylidenverbrückte dissymmetrische zweikernige Metallocenkomplexe als Katalysatoren für die Ethylenpolymerisation

“…Petersen und Royo synthetisierten eine Serie von zweikernigen Metallocenkomplexen wie etwa [Cl 2 (g-C 5 H 5 )Zr{l-C 5 H 4 (SiMe 2 )C 5 H 4 }Zr(g-C 5 H 5 )Cl 2 ] und zeigten Struktureigenschaften dieser Komplexe auf [21][22][23][24]. Spaleck beschrieb dinukleare Metallocenkomplexe f€ ur die Darstellung von isotaktischem Polypropylen [25].…”

“…In Abb. 11 werden die Aktivit€ aten der unsubstituierten, dissymmetrischen Zweikernkomplexe 17 und 18 mit den jeweiligen in 2-Position der unverbr€ uckten Indenylliganden benzyl- (24,25), ethylphenyl- (26,27), propylphenyl-(28, 29) und methylsubstituierten (22,23), dissymmetrischen Zweikernkomplexe verglichen.…”

Synthesis and styrene polymerization properties of dinuclear half-titanocene complexes with xylene linkage

“…Differently from the other metallocene catalysts polymerization properties of the dinuclear complex that holds two half-titanocene fragments through the bridging ligand have not been explored until very recently. The initial attempt to exploit dinuclear half-titanocene was performed by Royo although he did not pay attention to the styrene polymerization study [20,21]. Flores and coworkers described the synthesis of the dinuclear half-titanocenes with indenyl as a Cp derivative and ethylene as a bridge and study of the effects on activity and syndiospecificity resulting from possible cooperative chemical behavior between two active centers [22].…”

Synthesis and reactivity of new mixed dicyclopentadienyl Group 4 metal complexes with the doubly bridged bis(dimethylsilanediyl)-cyclopentadiene-(η5-cyclopentadienyl) ligand

“…Many dinuclear compounds containing bridging h 5 -h 1 cyclopentadienyl rings and h 5 -h 5 -fulvalene systems, resulting from ring C H activation in dicyclopentadienyl derivatives, have been reported [1,11]. However di-h 5 -cyclopentadienyl ligands singly bridged by various alkyl [2 -5] and silyl [6][7][8][9][10][11][12][13][14] groups are among the most frequently used systems to bridge dinuclear metal compounds. We have recently reported the use of the 1,1%-2,2%-(dimethylsilanediyl)dicyclopentadienyl ligand to synthesize ansadicyclopentadienyl and bridged homodinuclear monoand di-cyclopentadienyl complexes of the Group 4 and 6 metals [15][16][17][18][19][20].…”