Bis(cyclopentadienyl)titanium(IV)zirconium(IV) derivatives with jäger-type ligands

Bis(cyclopentadienyl)titanium(IV)/zirconium(IV) complexes, [Cp₂M(J-R)] [where M = Ti or Zr and H₂J-R is a Jäger type ligand with bridging group R (ethylene, o-phenylene or 4-methyl-o-phenylene], have been synthesized. The subsequent condensations of the complexes (R = o-phenylene) with o-phenylenediamine have also been studied, which cause ring closure and the formation of cyclic complexes. All these derivatives were characterized by elemental analyses, electrical conductance, magnetic moment and spectral (electronic, IR, ¹H NMR) data. ¹H NMR spectra of these complexes indicate that there is rapid rotation of the cyclopentadienyl ring about the metal ring axis. The probable structures of the complexes are proposed.