Cyclopentadienyl bridge

Novel Types of Metal-Metal Bonded Complexes Containing Allyl and Cyclopentadienyl Bridging Ligands, 19, 155... 

Neither of the MCp3 structures is monomeric, but they consist of infinite chains, in which two pentahapto Cp ligands are bound to a single metal center and the other Cp bridges two metals [11]. Although the cyclopentadienyl bridge occur in a (or... 

The binuclear samarium and ytterbium complexes with mixed valence of Ln(II, IQ) (Me5C5)2Sm( i-Cp)Sm(C5Me5)2 [37] and (Me5C5)2Yb(ji-F)Yb(C5Me5)2 [46], are close to the being considered class of compounds in their nature. The complex with cyclopentadienyl bridge can be isolated from the mixture containing cyclopentadiene and... 

The photochemical disproportionation of [Mo2(C0)gCp2l with PPh3 and the back reaction have been studied.Complexes [M2(n-h in -C5H4SlMe2C5H4)(C0)g] (M = Mo,W) with a linked cyclopentadienyl bridge and their reactions with P2Me4 are described,The structure and reactivity of fulvalene bridged... 

Zirconocene complexes containing two indenyl or tetrahydroindenyl groups bridged with short links such as —CH2—CH2— or —Si(CH3)— can produce isotactic polymers of higher a-olefins (32). To synthesize syndiotactic PO, bridged zirconocene complexes with rings of two different types are required, one example of which is isopropyl(cyclopentadienyl)(l-fluorenyl)zirconocene. These complexes are used for the synthesis of syndiotactic PB... 

Metallocene Catalysts. Polymerization of cycloolefins with Kaminsky catalysts (combinations of metallocenes and methylaluminoxane) produces polymers with a completely different stmcture. The reactions proceeds via the double-bond opening in cycloolefins and the formation of C—C bonds between adjacent rings (31,32). If the metallocene complexes contain bridged and substituted cyclopentadienyl rings, such as ethylene(hisindenyl)zirconium dichloride, the polymers are stereoregular and have the i j -diisotactic stmcture. 

Cp derivatives (Scheme 185) to form -oxo-bridged dimeric complexes. The stabilities of the Af,0-bound carbamate intermediates depend mainly on the cyclopentadienyl ring substituents, but there is also a small dependence on the nature of the length of the (dimethylamino)alkyl chain for the C5H4Me systems. ... 

The crystal and molecular structure of the 44, 45, and C5-vinylferro-cenyl-thymidine show that the substituted cyclopentadienyl ring is essentially co-planar with the nucleobase (164). DFT calculations indicate that, irrespective of the extent of saturation in the bridging C2-unit in ethynyl-, vinyl- or ethyl-ferrocenyl-C5-thymidine, a similar amount of spin density is transferred to the nucleobase (Fig. 48). The reduction potentials for these compounds are shifted little compared to the parent ferrocenyl derivatives. 

---