trimethylstannyl chloride in diethyl ether; toluene inert atmosphere; addn. of Me3SnCl to Li-salt in Et2O at -40°C, warming to room temp., evapn., addn. of ZrCl4 suspn. in toluene, stirring(80°C, 4 h); evapn. (80-90°C, 1 torr), recrystn. or washing;

n-butyllithium in tetrahydrofuran; hexane; benzene n-BuLi in hexane was added to a stirred soln. of Cp2SiMe2 in THF at 0°C, stirred at 25°C for 2 h, a suspn. of ZrCl4 in THF-benzene was added dropwise at 0°C, stirred at 25°C for 2 h (Ar atm.);; evapd., extd. with CHCl3, cooled to -20°C; elem. anal.;;

C5H5Na; n-C4H9Li in tetrahydrofuran; ethylene glycol dimethyl ether; hexane Cl2SiMe2 is added to C5H5Na in THF (-60°C), mixt. is stirred for 1 h and then warmed, at -80°C a soln. of n-BuLi in hexane is added, mixt. is stirred (30 min, 25°C), ZrCl4 in DME is added, mixt. is stirred overnight, refluxed for 2h; solvents are removed, residue is washed with pentane, pentane insol. product is dried and extd. with CH2Cl2, recrystn. from CH2Cl2, elem. anal.;

n-butyllithium in diethyl ether; hexane byproducts: butane, LiCl; (Ar); addn. of a soln. of lithium compd. in hexane to a soln. of ligand in Et2O, stirring for 8 h at room temp., cooling to -78°C, addn. of ZrCl4, warming to room temp. within 6 h, stirring for 6 h; evapn., suspn. in CH2Cl2, filtration through Na2SO4, evapn., washing with pentane and Et2O, crystn. (CH2Cl2, -28°C);

in tetrahydrofuran; toluene dry Ar-atmosphere; slow addn. of ligand (in THF) to equimolar amt. of Zr-compd. (in PhMe) at -10°C, stirring at room temp. for 14 h; solvent removal (vac.), washing (cold hexane), extn. into CH2Cl2 (Soxhlet), concn., cooling to 0°C (pptn.), recrystn. (PhMe/hexane);

in not given

in not given (Ar); 80°C;

in not given

methylaluminoxane in benzene-d6 under Ar, standard Schlenk techniques; solid dichloride Zr complex mixedwith 1 equiv. of Cp2ZrClMe; dissolved in benzene-d6; a minute amt. of s olid methylaluminoxane added; equil. reached within several min; not isolated; monitored by (1)H NMR spectra;

in benzene-d6 C6D6, 2-5-fold excess of Al-compound, room temp.; not sepd., detected by NMR spectra;