Reactivity Studies of Methylzirconocene Phosphide Complexes

The reaction of Cp 2 ZrMe(PHR) with benzophenone, cyclohexanone, acetone, benzaldehyde, and benzophenone results in the insertion of the organic substrate into the Zr−P bond. In this way, the complexes Cp 2 ZrMe(OCPh 2 PH(C 6 H 2 -2,4,6- t -Bu 3 )) ( 3 ), Cp 2 ZrMe(OC 6 H 10 PH(C 6 H 2 -2,4,6- t -Bu 3 )) ( 4 ), Cp 2 ZrMe(OCMe 2 PHR) (R = (C 6 H 2 -2,4,6- t -Bu 3 ) ( 5 ), R = (C 6 H 2 -2,4,6-Me 3 ) ( 8 ), and Cp 2 ZrMe(NC(Ph)PH(C 6 H 2 -2,4,6- t -Bu 3 )) ( 6 ) were prepared. The species Cp 2 ZrMe(PH(C 6 H 2 -2,4,6-Me 3 )) ( 7 ) was also formed in the reaction of Cp 2 ZrMe 2 with H 2 P(C 6 H 2 -2,4,6-Me 3 ); however, 7 reacted further with Cp 2 ZrMe 2 to give the bimetallic species (Cp 2 ZrMe) 2 (μ-P(C 6 H 2 -2,4,6-Me 3 ) ( 9 ). In the analogous reaction of Cp 2 ZrMe 2 with 1 equiv of H 2 P(C 6 H 2 -2,4,6-Me 3 ), the species (Cp 2 Zr)(Cp 2 ZrPH(C 6 H 2 -2,4,6-Me 3 ))(μ-P 6 H 2 -2,4,6-Me 3 ))(μ-η 1 -η 5 -C 5 H 4 ) ( 11 ) was obtained. Compound 11, which results from cyclopentadienyl C−H bond activation, was also formed directly from degradation of the unstable terminal phosphinidene species Cp 2 Zr(P(C 6 H 2 -2,4,6-Me 3 ))(PMe 3 ) ( 12 ). The implications of this chemistry are considered and discussed. Compound 3, 9, and 11 have been characterized crystallographically.