Back to Search
Start Over
Structural Features of Me<INF>2</INF>Si-Bridged Cp/Phosphido Group 4 Metal Complexes, CpSiP Constrained-Geometry Ziegler−Natta Catalyst Precursors
- Source :
- Organometallics; September 2002, Vol. 21 Issue: 20 p4084-4089, 6p
- Publication Year :
- 2002
-
Abstract
- Double deprotonation of [(C<INF>5</INF>Me<INF>4</INF>H)−SiMe<INF>2</INF>−PH(cyclohexyl)] (<BO>4</BO>) was achieved by treatment with n-butyllithium in THF/pentane to afford the dianionic ligand [(C<INF>5</INF>Me<INF>4</INF>)-SiMe<INF>2</INF>−P(cyclohexyl)]<SUP>2</SUP><SUP>-</SUP> as its dilithio salt (<BO>5</BO>). The reagent <BO>5</BO> was transmetalated by subsequent treatment with [Cl<INF>2</INF>Ti(NMe<INF>2</INF>)<INF>2</INF>] (<BO>6a</BO>) to yield the dimethylsilanediyl-bridged Cp*/phosphido titanium complex [(C<INF>5</INF>Me<INF>4</INF>)−SiMe<INF>2</INF>−PCy]Ti(NMe<INF>2</INF>)<INF>2</INF> (<BO>7a</BO>; 67% isolated yield). The analogous reaction of <BO>5</BO> with [Cl<INF>2</INF>Zr(NEt<INF>2</INF>)<INF>2</INF>(THF)<INF>2</INF>] (<BO>6b</BO>) gave [(C<INF>5</INF>Me<INF>4</INF>)−SiMe<INF>2</INF>−PCy]Zr(NEt<INF>2</INF>)<INF>2</INF> (<BO>7b</BO>; isolated in 59% yield). Single crystals of the complexes <BO>7a</BO>,<BO>b</BO> 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 <BO>7a</BO>,<BO>b</BO> both give active homogeneous Ziegler−Natta catalysts for ethene/1-octene copolymerization upon activation with excess methylalumoxane.
Details
- Language :
- English
- ISSN :
- 02767333 and 15206041
- Volume :
- 21
- Issue :
- 20
- Database :
- Supplemental Index
- Journal :
- Organometallics
- Publication Type :
- Periodical
- Accession number :
- ejs3792485
- Full Text :
- https://doi.org/10.1021/om0200959