Diazabutadiene derivatives of ytterbocenes. Syntheses, properties, and crystal structures of the (C 5 Me 5 ) 2 Yb(Bu t NCHCHNBu t ) and [CpYb(μ 2 -OC 13 H 8 —C 13 H 8 O)(THF)] 2 complexes

Abstract

Oxidation of (C5Me5)2Yb(THF)2 with diazabutadiene ButN=CHCH=NBut (DAD) afforded the (C5Me5)2Yb(ButNCHCHNBut) complex (1). The magnetic measurements and X-ray diffraction study confirmed the trivalent state of the ytterbium atom and the radical nature of the DAD ligand in complex 1. The oxidation state of ytterbium in the (C5Me5)2YbDAD—solvent system depends on the coordinating properties of the solvent, whereas the ytterbium atom in the Cp2YbDAD complex (2) remains trivalent regardless of the solvent nature. In complex 2, the redox replacement of DAD·– with 9-fluorenone accompanied by the pinacol dimerization of 9-fluorenone and detachment of one Cp ligand from the ytterbium atom gave rise to the dimeric [CpYb(μ2-OC13H8-C13H8O)(THF)]2 complex (3). The structure of complex 3 was established by X-ray diffraction analysis.