New eta(2)-formamidiny zirconium complexes: Synthesis, characterization, and catalytic activity

The new h2-formamidinyl Zr complex Zr(NMeCyc)2[C(NAr)NMeCyc]2, (1) (Ar= 2,6-dimethylphenyl, Cyc= cyclohexyl) was prepared upon double insertion of 2,6-dimethyl phenyl isocyanide in the Zr-N bond of Zr(NMeCyc)4. (1) was then converted into Zr(OC6F5)2[C(NAr)NMeCyc]2 (2) and ZrCl2[C(NAr)NMeCyc]2 (3), by reacting it with C6F5OH and [NHMe3]Cl, respectively. The crystal structure of (1) was established by X-ray analysis. All the complexes have been tested as catalysts for the polymerization of ethylene and 1-hexene in the presence of [NHMe2Ph][B(C6F5)4] as co-catalyst.