Reactivity of the dinuclear fulvalene cyclopentadienyl zirconium cationic species [{Zr(η5-C5H5)}2(μ-CH2)(μ-Cl)(μ-η5-C5H4-η5-C5H4)]+ with isocyanides and carbon monoxide: insertion reactions, spectroscopic characterization and synthetic aspects

The dinuclear cationic zirconium compound [{Zr(η5-C5H5)}2(μ-CH2)(μ-Cl)(μ-η5-C5H4-η5-C5H4)][BMe(C6F5)3] 1 reacts in dichloromethane at −78 °C with three equivalents of RNC (R=tBu, 2,6-Me2C6H3) via insertion into the Zr-μ-methylene bond to give the new zirconium cationic species [{Zr(η5-C5H5)}2(Cl)(CNtBu){μ-[η2-CN(tBu)-CH2-η2-CN(tBu)}(μ-η5-C5H4-η5-C5H4)][BMe(C6F5)3] 2 and [{Zr(η5-C5H5)}2(Cl){CN(2,6-Me2C6H3)}[μ-η2-{CN(2,6-Me2C6H3)}-CH2-η2-{CN(2,6-Me2C6H3)}](μ-η5-C5H4-η5-C5H4)][BMe(C6F5)3] 3, whereas reaction with CO affords the ketene compound [{Zr(η5-C5H5)}2(μ-Cl){μ-OC(CH2)}(μ-η5-C5H4-η5-C5H4)][BMe(C6F5)3] 4. The new complexes reported herein were characterized by elemental analysis and IR and NMR spectroscopy.Financial support by DGICYT (Project PB97-0776) is gratefully acknowledged. E.R. acknowledges MECFPI for the award of Fellowshi