Investigation of the mechanism of conversion of the bimetallic complex [PNP(H)Ir-μ(CH2)-μ(O)-Re(O)2][PF6] (1) to its structural isomer [PNP(Me)(CH3CN)Ir-ReO3][PF6] (2) by detailed kinetics and DFT computational studies is reported. The reaction proceeds by intramolecular rearrangement of 1 to [PNP(Me)Ir-ReO3][PF6] (S) via a methyl-bridged [PNP(H)Ir-μ(CH3)-Re(O)3][PF6] (P) intermediate followed by CH3CN coordination. The rate-determining step is the transformation of 1 to P displaying ΔG‡ of 21.8 kcal/mol. Experimental kinetic results include zero-order dependence on acetonitrile, positive ΔS‡, and deuteration of the bridging methylidene group in the reaction of 1 with CD3OD. All of these results support the proposed mechanism.
ASJC Scopus subject areas
- Organic Chemistry
- Physical and Theoretical Chemistry
- Inorganic Chemistry