ANSA-METALLOCENE DERIVATIVES .30. SYNTHESES AND STRUCTURES OF TITANOCENE, ZIRCONOCENE, AND VANADOCENE DICHLORIDE COMPLEXES WITH 2 ETHANEDIYL BRIDGES

A bis(cyclopentadienyl) ligand containing two ethanediyl bridges is obtained by Skattebol rearrangement of the bis(dibromocarbene) adduct of 1,2,5,6-tetramethylenecyclooctane. Reactions of its dilithium salt with TiCl3(THF)3, ZrCl4, and VCl3(THF)3 afford, after appropriate workup, the corresponding doubly bridged metallocene dichlorides. X-ray diffraction studies give space group P2(1)/n for all three of the complexes (C2H4)2(C5H3)2TiCl2, (C2H4)2(C5H3)2ZrCl2, and (C2H4)2(C5H3)2VCl2.