COORDINATION PROPERTIES OF KLAUIS TRIPODAL OXYGEN DONOR TOWARD ZIRCONIUM(IV)

The coordination properties of [(eta(5)-C5H5)Co{PR2(O)}(3)](-) (R = OE t (L-OEt(-)), Et (L-Et(-))) toward Zr(IV) have been investigated and c ompared to related cyclopentadienyl complexes. Addition of 2 equiv of L-OEt(-) to [ZrCl4(THF)(2)] yields labile [Zr(L-OEt)(2)Cl-2] (2), whic h undergoes Arbuzov dealkylation to yield a dinuclear, seven-coordinat e complex 1. Reaction of 2 with MeLi yields the metathesis product LiL OEt. Addition of 2 equiv of AgOTos to 2 affords octahedral [Zr(L-OEt)( 2)](OTos)(2) (3). Reaction of [ZrCpCl3] with L-OEt(-) leads to Cp- dis placement to give [ZrLOEtCl3] (4). Addition of 2 equiv of L-Et(-) to [ ZrCl4(THF)(2)] yields octahedral [Zr(L-Et)(2)](Cl)(2) (5). Compounds 1 , 3, 4; and 5 have been characterized by X-ray crystallography.