473435-87-9Relevant academic research and scientific papers
Structural features of Me2Si-bridged Cp/phosphido group 4 metal complexes, CpSiP constrained-geometry Ziegler-Natta catalyst precursors
Altenhoff, Gereon,Bredeau, Stephane,Erker, Gerhard,Kehr, Gerald,Kataeva, Olga,Fr?hlich, Roland
, p. 4084 - 4089 (2002)
Double deprotonation of [(C5Me4H)-SiMe2-PH(cyclohexyl)] (4) was achieved by treatment with n-butyllithium in THF/pentane to afford the dianionic ligand [(C5Me4)-SiMe2-P(cyclohexyl)]2- as its dilithio salt (5). The reagent 5 was transmetalated by subsequent treatment with [Cl2Ti(NMe2)2] (6a) to yield the dimethylsilanediyl-bridged Cp*/phosphido titanium complex [(C5Me4)-SiMe2-PCy]Ti(NMe2)2 (7a; 67% isolated yield). The analogous reaction of 5 with [Cl2Zr(NEt2)2(THF)2] (6b) gave [(C5Me4)-SiMe2-PCy]Zr(NEt2)2 (7b; isolated in 59% yield). Single crystals of the complexes 7a,b were obtained from pentane. The X-ray crystal structure analyses revealed distorted constrained geometry group 4 metal complex structures due to the presence of a chiral, nonplanar coordination geometry at the phosphorus atom. Complexes 7a,b both give active homogeneous Ziegler-Natta catalysts for ethene/1-octene copolymerization upon activation with excess methylalumoxane.
