Synthesis and structure of the edge-bridged open zirconocene, Zr(6,6-dmch)2(PMe3)2 (dmch=dimethylcyclohexadienyl), and its imine coupling product

The reaction of ZrCl4 with four equivalents of the 6,6-dimethylcyclohexadienyl anion (6,6-dmch−) in the presence of PMe3 leads to the 18 electron Zr(6,6-dmch)2(PMe3)2. This complex was found to undergo a coupling reaction with two equivalents of PhCHNPh, such that the couplings involved the two termini of the same dienyl ligand, yielding a formal Zr(η5-dienyl)(η3-allyl)(π-amide)2 complex. Both metal complexes have been structurally characterized.