ANSA-METALLOCENE DERIVATIVES .2. SYNTHESE S AND STRUCTURES OF TETRAMETHYLDISILOXANDIYL BIS(1-INDENYL AND TETRAHYDROINDENYL) ZIRCONIUM DICHLORIDES

The ansa-zirconocene derivative tetramethyldisiloxandiyl bis(1-indenyl ) zirconium dichloride (1) has been prepared by the reaction of the di lithium salt of 1,3-bis(l-indenyl) tetramethyldisiloxane with ZrCl4 . 2THF, After catalytic hydrogenation, the corresponding tetrahydroinden yl complex (2) has been formed. Both 1 and 2 have been shown by H-1 NM R spectra to be the mixture of the cis(meso) and trans(rac) isomers, T he pure trans isomers 1(l), 2(l) and cis isomer 2(c) were obtained by recrystallization, The crystal structures of 1(l) and 2(c) were determ ined by X-ray diffraction. Both crystals of 1(l) and 2(c) are monoclin ics, belonging to space groups P2(1)/n(1(l)) and P2(1)/c(2(c)). In the unit cell of 2(c), one of the six-membered rings of the tetrahydroind enyl Ligands has two different conformations which have the same proba bilities.