0000000000563597
AUTHOR
Shaen G. Mkoyan
Group 4 and Group 8 unbridged metallocene derivatives with a pendant fluorenyl group. X-ray structure of 1,1â²-bis[2-(2-fluorenyl)propyl]ferrocene
Abstract The action of one equivalent of BuLi on 2-cyclopentadienyl-2-fluorenylpropane (C5H5CMe2C13H9) led to the monoanionic salt LiC5H4CMe2C13H9. This anion was reacted with Fe2Cl4(THF)3, TiCl3(THF)3, ZrCl4, HfCl4 or CpZrCl3, DME and, in a mixture with CpLi, with Fe2Cl4(THF)3 affording the corresponding metallocenes and metallocene dichlorides. The X-ray structure of Fe(η5-C5H4CMe2C13H9)2 is described. The first results about the reactivity of the fluorenyl group are reported together with the synthesis of Zr(η5-C5H5)[η5-C5H4CMe2-η5-C13H8Rh(cod)]Cl2, which has been tested using hydroformylation and cyclotrimerisation catalysis.
Novel group 4b ansa-metallocene complexes with the shortest bridge: [1,1′-isopropylydene-3,3′-di-t.Bu-bis(η5-cyclopentadienyl)] Ti and Zr dichlorides
Abstract Reaction of [1,1′-isopropylidene-3,3′-di-tert.butyl-bis(η5-cyclopentadienide)] dilithium with TiCl3, followed by treatment with HCl, and ZrCl4 in various solvent mixtures in the temperature range 0–50°C gives corresponding ansa-metallocene dichlorides as mixtures of the anti/syn-isomers, 1:1. The crystal and molecular structures of three of the four isomers were determined, i.e. rac(anti)-[1,1′-isopropylidene-3,3′-di-tert.butyl-bis(η5-cyclopentadienyl)]TiCl2, space group B2/b, rac(anti)-[1,1′-isopropylidene-3,3′-di-tert.butyl-bis(η5-cyclopentadienyl)]ZrCl2, space group P212121, and meso(syn)-1,1′-[isopropylidene-3,3′-di-tert.butyl-bis(η5-cyclopentadienyl)]ZrCl2, space group P21/n.