COOPERATIVE ACTIVATION OF CO BY EARLY LATE HETEROBIMETALLICS - REACTIONS OF [CP2TI(ETA-PR2)]2, [CP2ZR(ETA-PR2)]2 WITH [CPMO(CO)3]2

The reactions of the Ti(III) and Zr(III) species [Cp2M(í¿-PEt2)]2 with [CpMo(CO)3]2 have been studied. In the Zr case, the reaction proceeds with reduction of the Mo-Mo bond and concurrent oxidation of the Zr(III) center to Zr(IV). The product is formulated as Cp2Zr(M-PEt2)(M-»1,j2-OC)Mo(CO)Cp (1). Compound 1 crystallizes in the monoclone space group P2Jc with α = 14.644 (2) A, b = 9.795 (2) Â, c = 14.667 (3) Â,β = 104.27 (1)°, Z = 4, and V = 2039 (1) A3. The reaction of the Ti(III) phosphide species with [CpMo(CO)3]2 proceeds via an alternate pathway. Reduction of the Mo-Mo bond occurs with oxidation of the phosphide ligand on Ti, affording the complex Cp2Ti(THF)(M-jj1,y-OC)Mo(CO)2Cp (2) and P2Et4. The Ti(III)/Mo(0) complex 2 crystallizes in the triclinic space group PI with α = 16.320 (4) Â, b = 7.907 (2) Â, c = 10.882 (3) Â, α = 115.39 (1)°, β = 82.99 (2)°, y = 124.66 (2)°, Z = 2, and V = 1029 (1) Â3. The spectral and structural characterizations of complexes 1 and 2 are presented. The differing modes of CO activation in species 1 and 2 are described, and the implications regarding heterobimetallic activation of CO are discussed. © 1990, American Chemical Society. All rights reserved.