New η2-Formamidinyl Zirconium Complexes: Synthesis, Characterization, and Catalytic Activity

The new η 2 -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 wasthen converted into Zr(OC 6 F 5 ) 2 [C(NAr)N-MeCyc] 2 (2) and ZrCl 2 [C(NAr)NMeCyc] 2 (3) by reacting it with C 6 F 5 OH and [NHMe 3 ]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 [NHMe 2 Ph][B(C 6 F 5 ) 4 ] as cocatalyst.