Ansa·metallocene Derivatives Iii *. Influence of an Interannular Ethylene Bridge on the Reactivity of Titanocene Derivatives
نویسنده
چکیده
Titanocene derivatives with an interannular ethylene bridge, while resem· bling their unbridged counterparts in many transformations involving Ti or TillI oxidation stages, do not follow reaction paths previously observed for unbridged titanocene in a number of reactions, such as formation of a TiII dinitrogen complex, isotope exchange of the cyclopentadienyl riIig ligands with D 2, or formation of a Ti hydride compound. These reactions are considered to be blocked by the unavailability of a «free" titanocene species, [(CH2h(CSH4hTiII]n' as an intermediate in such systems.
منابع مشابه
ansa - Metallocene derivatives XXIII * .
9 Titanocene and zirconocene complexes with a phenyl or I-naphthyl substituent in one ,B-position of each Cs-ring ligand and with an interannular tetramethylethanoor dimethylsilano-bridge have been prepared. Racemic complex isomers, which are formed together with varying amounts of their meso isomers, were separated from the latter and characterised by lH NMR spectroscopy and X-ray crystallogra...
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207 Novel olefin-linked biscylopentadienylligands have been prepared by McMurry coupling reactions of benzoyland acetyl-cyclopentadienyl sodium. Reactions of the disodium salts with TiC1 4 or TiCl 3 • 3THF afford the alkene-bridged ansa-titanocene dichlorides. 13C-NMR shifts of the bridge carbon atoms do not indicate any interaction between the olefin 'IT-system and the metal.
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