in toluene Zr-complex was placed in flask, toluene and SiMe3Cl were added, heated at 65°C overnight; solvent was removed, washed with pentane; elem. anal.;

NEt3 in toluene Ar-atmosphere; stirring (room temp., 12 h); filtering, evapn. (reduced pressure), recrystn. (toluene, -40°C);

in hexane soln. of Li amide in hexane quickly added at -60.degreeC under Ar to a susp. of equimolar amt. Zr complex in hexane; warmed slowly to room temp.and stirred for 8 h; filtered, concnd., cooled to -40°C; crystalline ppt. collected; recrystn. from toluene at -40°C;

C5H5Si(CH3)2NHC(CH3)3 in toluene byproducts: Et2NH; Ar-atmosphere; dropwise addn. of equimolar amt. of ligand (mixt. of isomers) to Zr-compd. at -78°C, stirring for 5 h at room temp., refluxing for 5 h, distn. off of Et2NH (vac., then Ar-stream), addn. of 2 equiv. Me3SiCl, refluxing for 5 h; filtration over Na2SO4, concn. (vac.), crystn. (-30°C);