NEW 1,1'-RING-SUBSTITUTED VANADOCENE DICHLORIDES - CRYSTAL-STRUCTURESOF [V(ETA(5)-C(5)H(4)SIME(3))(2)CL-2] AND [V(ETA(5)-C5H5)(2)CL-2]

The 1,1'-ring-substituted vanadocene dichlorides [V(eta(5)-C(5)H(4)R)( 2)Cl-2] (R = CMe(3), SiMe(3), SiEt(3)) have been prepared from VCl4 an d the appropriate lithiated cyclopentadiene, C(5)H(4)RLi, in 1:2 ratio s. All complexes were characterized by elemental microanalysis and IR spectroscopy. The crystal structures of [V(eta(5)-C(5)H(4)SiMe(3))(2)C l-2] 3 and the parent compound [V(eta(5)-C5H5)(2)Cl-2] have been deter mined by X-ray diffraction and are in accordance with expectations. Co mpound 1 crystallizes with two crystallographically independent molecu les in its monoclinic unit cell. These two molecules are quite similar in their essential structural features. Compound 3 crystallizes in th e triclinic space group <P(1)over bar>. The trimethylsilylcyclopentadi enyl rings are bound in a staggered relative orientation.