in benzene treatment of the Zr compd. in benzene suspn. with SbCl2Br (1 equiv) (25°C), removal of solvent (vac.); extn. (hexane/ether (10:1)), chromy. (anhyd. MgSO4);

in benzene treatment of the Zr compd. in benzene suspn. with SbCl2Br (1 equiv) (25°C), removal of solvent (vac.); extn. (hexane/ether (10:1)), chromy. (anhyd. MgSO4);