SYNTHESIS AND CHARACTERIZATION OF NEW ALKOXIDE AND ARYLOXIDE DERIVATIVES OF TITANIUM AND ZIRCONIUM - X-RAY MOLECULAR-STRUCTURE OF [ZRCP(2)(OC6F5)(2)]

Lithium or sodium alkoxides MOR (R = CH2CH=CMe(2); M = Li 1; Na 2; R = C6F5; M = Li 3) were prepared by reaction of the alcohols with n-butyl lithium or sodium metal in hexane. Reaction of a hexane suspension of 3 with SiCIMe(3) afforded SiMe(3)(OC6F5) 4, whereas the reaction of 3 equivalents of C6F5OH with AlMe(3) in hexane led to Al(OC6F5)(3) 5. Compounds 1 or 2 react with one equivalent of [TiCp*Cl(2)Me] (Cp* = C(5)Me(5)) in toluene to give [TiCp*ClMe(OCH2CH=CMe(2))] 6. Complex 6 reacts with AlEtCl(2) to give quantitatively [TiCp*Cl-3]. In the presence of water, the hydrolysis of 6 takes place giving the mu-oxo compound [{(TiCp*Cl)(mu - O)}(3)]. [TiCp*Cl(2)Me] reacted with an excess of the alcohol C6F5OH to give [TiCp*(OC6F5)(3)] 7. [ZrCp(2)Cl(2)] reacted with two equivalents of pentaflurophenol in the presence of aniline to give the dialkoxide [ZrCp(2)(OC6F5)(2)] 8. When the same reaction was carried out in a 1:1 molar ratio, a mixture of 8 and the chloroalkoxide [ZrCp(2)Cl(OC6F5)] 9 was obtained. A clean reaction takes place when the mu-oxo compound [(ZrCp(2)Me)(2)(mu-O)] is treated with two equivalents of pentafluorophenol, leading to the isolation of the alkoxo complex [{ZrCp(2)(OC6F5)}(2)(mu-O)] 10. The methylalkoxo derivative [ZrCp(2)Me(OC6F5)] 11, was obtained by reaction of [ZrCp(2)ClMe] with one equivalent of 3. Alternative methods can also be followed to synthesize 8 and 11. The crystal and molecular structure of 8 has been determined by X-ray diffraction methods. The most interesting feature of this structure is the disposition of the (C6F5) ring planes, which are located practically on the reflection plane defined by O(1), Zr(1) and O(1)'.