The reactivity of coordinatively unsaturated iridium methylene complex Ir = CH2[N(SiMe2CH2PPh2)(2)]: A quantum chemistry study

摘要

The mechanisms for the reactions of the coordinatively unsaturated iridium methylene complex Ir = CH2[N(SiMe2CH2PPh2)](2) with a variety of small molecules including H-2, PMe3, CO, AI(2)Me(6), and CH3I have been investigated by the density functional theory (DFT) calculations. The calculation results showed that the reaction of methylene complex with Hy generates the trihydride amine IrH3[HN(SiMe2CH2PPh2)(2)] via a series of oxidative addition and reductive elimination steps. The reaction of methylene complex with PMe3 produces the square planar complex Ir(PMe3)[N(SiMe2CH2PPh2)(2)] and CH2 = PMe3, and the latter can further react with methylene complex to give ethene. The reaction of methylene complex with CO results in the formation of Ir(CO)[(CH2PPh2CH2SiMe2NSiMe2CH2PPh2)] by the formation of C-P bond. The reactions of methylene complex with Al2Me6 and methyl iodide were also examined, and the oxidative addition step can afford a metal-carbon bond that undergoes a C-C bond forming migratory insertion to ultimately lead to the formation of ethene. Present study can provide new insights into the reactivity of transition metal methylene complex.