Synthesis and Structural and Computational Studies of a Conformationally Locked (η1-Perfluoroalkylidene)(η2-alkene) Transition Metal Complex: Ir(Cp*)(CFCF3)(C2H4)

Reaction of Cp*Ir(CO)(C2F5)I with N-methylmorpholine-N-oxide (NMO) afforded the iodide-bridged dimer complex [Cp*Ir(C2F5)I](2). The dimer reacted reversibly with ethylene to give Cp*Ir(CH2=CH2)(C2F5)I, which dissociated ethylene under reduced pressure. Treatment of Cp*Ir(CH2=CH2)(C2F5)I with AgOTf gave isolable Cp*Ir(CH2=CH2)(C2F5)(OTf). Reduction of this compound with potassium graphite gave the first example of an (ethylene)(perfluoroethylidene) complex, Cp*Ir(CH2=CH2)(CFCF3), which has been characterized crystallographically, spectroscopically, and computationally. Comparisons of a variety of hybrid and gradient-corrected density functionals in predicting geometric parameters, energies, barriers to ligand rotation, and possible alkene metathesis in Cp*Ir(CH2=CH2)(CFCF3) are presented.